New Zealand Coding Authority coding queries

Created June 2016
Reviewed June 2023

Query

What procedure code should be assigned for a patient who previously had a right below knee amputation (BKA) and is admitted to have right above knee amputation (AKA) (redo of previous BKA) due to ischaemic non-healing and infected right BKA stump?

Suggestions:

44367-00 [1484] Amputation above knee
Or
44376-00 [1566] Reamputation of amputation stump

Response

The NZCA was provided with the operation note for this case. The operation title was ‘Reamputation of previous right BKA stump, AKA’. What was described in the operation note was an above knee amputation (AKA). This procedure (previous BKA proceeding to AKA) has been confirmed by a vascular surgeon as a new amputation, as the amputation (AKA) is at a new level.

A reamputation of an amputation stump involves cutting away small amounts of bone and soft tissue to tidy up the amputation stump at the same level.

Created August 2019
Reviewed June 2023

Query

A patient is admitted with delirium secondary to urinary tract infection (UTI) and has a background of dementia. If the dementia does not meet ACS 0002 Additional diagnoses, can the supplementary code U79.1 Dementia (including in Alzheimer's disease) be assigned rather than a code from the range F00-F03 (or F1-.5)? Or does the Coding Rule Q2649 Confusion or delirium with dementia override this and we continue to assign the appropriate dementia code?

Response

The IHACPA Coding Rule Q2649 Confusion or delirium with dementia was updated June 2022 as part of Twelfth Edition. 

The Coding Rule states: 'where acute confusional state/delirium is specifically documented: 

• in a patient who also has dementia and documentation states that the acute confusional state/delirium is due to a general medical condition, assign F05.8 Other delirium in addition to the general medical condition (other than dementia).'

Therefore, a current dementia code from range F00-F03 is to be assigned as an additional diagnosis with code F05.8 and a code/s for the general medical condition.

Created August 2019
Updated June 2023

Query

If a chronic condition is documented on a referral letter/form from an external provider (GP, another facility, White Cross, etc) but nowhere else in the documentation for the episode of care, is this sufficient to assign the appropriate supplementary condition code from U78–U88?

Response

Documentation of a chronic condition on a referral letter/form alone is insufficient for a code assignment. The condition must be documented within the current episode of admitted patient care.

Refer to ACS 0003 Supplementary codes for chronic conditions, ACS 0010 Clinical documentation and general abstraction guidelines and the IHACPA Coding Rules:

• Q3008 Assignment of U codes from patient documentation
• TN1601 Twelfth Edition FAQ: Referrals requesting admission

Created August 2019
Reviewed June 2023

Query

In the section ‘nonobstetric conditions complicating pregnancy’ of ACS 1521 Conditions and injuries in pregnancy it states: in the absence of specific documentation, a nonobstetric condition is classified as complicating the pregnancy as indicated by two or more of the four listed criteria.
If the second criterion is met by an obstetrician evaluating the patient and the evaluation includes listening to the fetal heart rate (eg, via stethoscope) is the third criterion then met as well? Or is fetal evaluation more than that?

Response

Clinical advice received was that stethoscopes are very rarely used, if at all, to listen to a fetal heart rate. The most common device used to listen to a fetal heart rate is a sonicaid/doppler. However, the obstetricians consulted considered listening to a fetal heart rate with a stethoscope as a form of monitoring/evaluation, therefore would meet the third criterion.

Created December 2012
Updated June 2023

Query

Can we assign Z72.1 Alcohol use when alcohol was involved with an injury?

Response

No. Z72.1 Alcohol use should not be routinely assigned for cases where there is documentation of alcohol involvement with an injury.  

The Note at category Z72 Problems related to lifestyle states:

'Hazardous use is a pattern of substance use that increases the risk of harmful consequences for the user. In contrast to harmful use, hazardous use refers to patterns of use that are of public health significance despite the absence of any current disorder in the individual user'.

Therefore, assign Z72.1 Alcohol use where there is documentation indicating hazardous use of alcohol and it is relevant to the current episode of care. The code for alcohol use cannot be routinely assigned, as is done for tobacco use because of the subjective nature of its usage (ie, when looking at age, sex, weight issues etc), and that code assignment is dependent on the condition meeting the criteria in ACS 0002 Additional diagnoses.

Where there is no documentation within the clinical record to support code assignment from category F10 Mental and behavioural disorders due to use of alcohol, coders may record alcohol involvement in the NMDS event supplementary field.

See also ACS 0503 Drug, alcohol and tobacco use disorders.

Created December 2012
Reviewed June 2023

Query

We often have documentation of a drug overdose taken in the context of alcohol intoxication, in which the alcohol consumption is documented to be a distinct event from the drug consumption. 

An example is a patient who was out drinking with his partner and flat mates. The conversation turned sour and some hours later the patient returned home and took an overdose of Zopiclone. At no point in the clinical record was the alcohol documented as anything other than intoxication. 

In these limited circumstances can we code the Zopiclone overdose with alcohol intoxication (F10.0 Mental and behavioural disorders due to use of alcohol, acute intoxication)? Or must we include the alcohol in the list of drugs in the overdose?

Response

In the limited circumstances detailed in the query (ie, the alcohol consumption is clearly documented to be a distinct event from the drug consumption) it is appropriate to code the alcohol as intoxication (F10.0) and not as poisoning.

The more common scenario is that alcohol is consumed as a part of the overdose and in these cases it is appropriate to assign the poisoning code T51.0 Toxic effect of ethanol.

Note: alcohol poisoning and intoxication should not be assigned together on the same event record.

Where the clinical notes include documentation of a blood alcohol level, a code from Y90.- Evidence of alcohol involvement determined by blood alcohol level may be assigned in addition to the F10.0 Mental and behavioural disorders due to use of alcohol, acute intoxication or T51.0 Toxic effect of ethanol. 

Refer to ACS 0503 Drug, Alcohol and Tobacco Use Disorders

Created December 2012
Reviewed June 2023

Query

Is anaemia considered an inherent part of multiple myeloma as it is in conditions such as myelodysplastic syndromes (MDS) (D46.-) and myeloproliferative disorders (D47.1)?

Response

Not all patients with multiple myeloma have anaemia. Therefore, admissions for blood transfusion should be coded as per the clinical documentation and conventions of the classification.

Created December 2019
Reviewed June 2023

Query

When procedures are performed on the ward and only documented in the progress notes, such as dressing of burn in a burns bathroom, if IV midazolam is given before the procedure can we interpret this as ‘IV sedation’, hence we need to code ‘dressing of burn’ as per ACS 1911 Burns?

Response

Yes. Ideally the clinical documentation should state that the IV midazolam was administered for sedation. However, based on Clinical Coders’ Creed, if IV midazolam was given directly before the procedure and no other reason is documented as to why it was given, then the IV midazolam can be interpreted as IV sedation administered for the procedure performed and the dressing of burn will be coded as per ACS 1911 Burns. 

Created December 2019
Updated June 2023

Query

If a patient is given a nerve block documented only on the operation record by a surgeon at the beginning of the procedure, are we able to code the block as anaesthesia?

Response

Firstly, check the anaesthetic form for documentation of the block. If there is no documentation about the block on the anaesthetic form consult with clinician. 

In cases where no further information is available and the documentation within the operation note indicates the block was administered at the beginning of the procedure and/or there is no documentation indicating the block was administered at the end of the procedure, the nerve block can be coded as a form of anaesthesia.

See also IHACPA Coding Rule Q3222 Pain buster infusion devices

Created February 2002
Updated June 2023

Query

ACS 1500 Diagnosis sequencing in obstetric episodes of care states that Anti-D should be coded if an obstetric patient has this administered during an admission with the diagnosis Z29.1 Prophylactic immunotherapy.

When should the code O36.0 Maternal care for rhesus isoimmunisation be assigned?

We have obstetric patients come in for antenatal visits and have Anti-D administered. Less than a week later the patient presents to hospital to deliver and at that time has another administration of Anti-D.

In the second admission we have assigned O36.0 as at this stage it is known the patient will require this.

Is assigning O36.0 Maternal care for rhesus isoimmunisation correct in these cases?

Response

Based on clinical advice Anti-D is given prophylactically. Therefore, in the case cited assign diagnosis code Z29.1 Prophylactic immunotherapy for the second episode of care.

The diagnosis code O36.0 Maternal care for rhesus isoimmunisation should be assigned when it is the reason for maternal care.

See Includes  note in ICD-10-AM Tabular List at category O36 Maternal care for other known or suspected fetal problems – Includes: the listed conditions in the fetus as a reason for observation, hospitalisation or other obstetric care, or for caesarean section or for termination of pregnancy.

Created December 2019
Reviewed June 2023

Query

Are blisters due to adhesive plasters/dressing coded as a superficial Injury to site with X58 Exposure to other specified factors? Or L23.1 Allergic contact dermatitis due to adhesives?

Response

Consult the clinician to obtain a more specific diagnosis eg, allergic dermatitis. 
If no further information can be obtained or is available and the condition meets the criteria in ACS 0002 Additional diagnoses assign R23.8 Other and unspecified skin changes (as per the Alphabetic index, Blisters/multiple, skin, nontraumatic) and Y56.3 Emollients, demulcents and protectants causing adverse effects in therapeutic use.

Created March 2011
Reviewed June 2023

Query

Following a road traffic accident patient is initially assessed at Hospital A and is noted to have a Blood Alcohol Level 54 mmol/l.  After transfer to Hospital B the Blood Alcohol Level is now 20 mmol/l.

Under the criteria of ACS 0503 Drug, Alcohol and Tobacco Use Disorders – Evidence of Alcohol Involvement Determined by Blood Alcohol Level and Intoxication and ACS 0002 Additional Diagnoses, the Blood Alcohol Level needs to be coded.

Which level should be used to assign the Blood Alcohol Level code?

Should the clinical notes/results from Hospital A be used to code from when coding Hospital B?

Response

Firstly, before the Blood Alcohol Level code (Y90.-) can be assigned the documentation in the clinical record needs to support the code assignment for alcohol intoxication (F10.0), harmful use (F10.1) or dependence syndrome (F10.2) or alcohol poisoning (T51.0) as per ACS 0503 Drug, Alcohol and Tobacco Use Disorders – Evidence of Alcohol Involvement Determined by Blood Alcohol Level and Intoxication.

Once the appropriate alcohol code (F10.- or T51.0) has been determined the clinical coder would then look for documentation of the Blood Alcohol Level.

If the Blood Alcohol Level is documented in the current episode of care and is confirmed by the laboratory result, then the appropriate Blood Alcohol Level code (Y90.-) is to be assigned.

In this case the Blood Alcohol Level at Hospital B was 20mmol/l, therefore, the code Y90.4 Blood alcohol level of 80–99 mg/100 ml is to be assigned.

Clinical coders should only use the documentation/results pertinent to the current episode of care. It would not be acceptable to use the results of the Blood Alcohol Level from Hospital A.

The Blood Alcohol Level will be captured in the coding (as per the criteria of ACS 0503 Drug, Alcohol and Tobacco Use Disorders) at Hospital A if the event meets the NMDS three hour admission rule.

Created November 2010
Reviewed June 2023

Query

What code should we assign for a bovine pericardium patch graft performed during carotid endarterectomy? 

Response

Options for patch graft of an artery are:

33548-00 [707] Patch graft of artery using autologous material
33548-01 [707] Patch graft of artery using synthetic material

Assign code 33548-00 [707] Patch graft of artery using autologous material as ‘using autologous material’ is a non-essential modifier in the ACHI Index. 

Free text should be used to specify the procedure performed eg, Bovine pericardium patch graft R carotid artery.

Created March 2018
Reviewed June 2023

Query

What ACHI codes are assigned for reconstruction of left breast using insertion of tissue expander and acellular dermal matrix (ADM) (eg, Veritas) when performed in the same operative episode as a left subcutaneous mastectomy?

Response

As the procedures are performed in the same operative episode, assign ACHI codes:
          31524-00 [1747] Subcutaneous mastectomy, unilateral
          45539-00 [1756] Reconstruction of breast with insertion of tissue expander
          45527-00 [1753] Augmentation mammoplasty following mastectomy, unilateral 

Use free text to specify the type/brand of ADM used eg, Veritas.

The acellular dermal matrix (ADM) product Veritas is a type of biological mesh, it is derived from bovine pericardium. Other types of acellular dermal matrix (ADM) products may be used. 

For further information about breast reconstruction using acellular dermal matrix refer to the website provided.
http://www.melbournebreastcancersurgery.com.au/types-of-breast-reconstruction-including-acellular-dermal-matrix-adm.html

Created August 2019
Updated June 2023

Query

We are coming across many cases of children/young people receiving social work support and/or needing input from child and youth services because of bullying and we are not sure what diagnosis code best covers this.

Response

Where bullying is documented and meets the ACS 0002 Additional diagnoses criteria try to obtain further information as to the type of bullying. In the cases where further information is unable to be obtained assign Z60.4 Social exclusion and rejection following the lead term Social/exclusion in ICD-10-AM Alphabetic Index and add free text to specify bullying.
Where there is specific documentation of the type of bullying (eg, ethnic origin or there is a personal history), assign another code from Chapter 21 Factors influencing health status and contact with health services (Z00-Z99). 

 See also ACS 2119 Socioeconomic and psychosocial circumstances.

Created November 2007
Reviewed June 2023

Query

How do you code the following scenario?

A patient is booked for surgery with a specific condition. After admission, and before surgery, it is found that the condition is no longer present, therefore the patient does not require the booked procedure.

Response

The principal diagnosis is the condition for which the patient was to have surgery for. Use an additional diagnosis Z53.8 Procedure not carried out for other reasons and use free text to specify the reason for the cancelled procedure.

Created June 2010
Reviewed June 2023

Query

Patient has documentation of posterior subcapsular and nuclear sclerosis cataract in the same eye. This has been coded to H25.1 Senile nuclear cataract as a progression of disease.

However, one of our ophthalmologists said that H25.8 Other senile cataract is more appropriate because of the inclusion term ‘combined forms of senile cataract’. What is the intention of H25.8? Does it really include incipient cataracts along with mature?

Response

Refer to ACS 0701 Cataract for the definition and classification of cataract.

Cataract definition:
Cataracts are the opacity or loss of clarity of the crystalline lens. They are classified according to a number of criteria including aetiology, morphology, age of onset, maturity, etc.

Classification of cataract can be:

1. Aetiological: Senile, traumatic, metabolic, toxic, secondary (complicated), maternal infection, maternal drug ingestion, hereditary, associated with syndromes (eg, Down's syndrome)
2. Morphological: Capsular (congenital or acquired), subcapsular (posterior or anterior), nuclear (congenital or senile), cortical (congenital or senile), lamellar, sutural
3. According to maturity: Immature, mature, intumescent, hyper mature or morgagnian
4. According to age of onset: Congenital, infantile, juvenile, presenile, and senile.

Cataract classification:
Unless the cataract is specified as senile, traumatic, drug-induced, etc assign H26.9 Cataract, unspecified. Attempt to obtain further specificity if possible.

The morphological classification of a senile cataract comprises three main types: subcapsular, nuclear or cortical, which describe where in the lens the opacity occurs. ‘Combined forms of senile cataract’ refers to any combination of these main types.

Classification of cataracts can also be based on maturity; and senile cataract ranges from incipient through to hypermature. Note that a senile incipient cataract is not the same as an unspecified incipient cataract (‘incipient’ means ‘beginning to exist or appear’) – so the diagnosis codes for these are H25.0 Senile incipient cataract and H26.9 Cataract, unspecified respectively.

This query is about a senile cataract with combined subcapsular and nuclear lens opacity, therefore the correct code to assign is H25.8 Other senile cataract. The intention of the code H25.8 Other senile cataract is to classify the cataract in terms of its morphology, and not according to its maturity.

Created September 2022
Updated June 2023

Query

What ICD-10-AM code is assigned for ‘flare of central sensitisation syndrome”?

Case summary: 

A patient was admitted to hospital for a flare-up of widespread chronic pain, especially in both lower legs and abdomen. In 2021 the patient had multiple admissions to hospital due to central sensitisation syndrome with severe pain.

A web search states: 

“Central sensitisation syndromes (CSS) are a collection of disorders where the central nervous system misfires and amplifies sensory input resulting in pain, fatigue, brain fog, and sleep problems. Fibromyalgia (FMS), chronic fatigue syndrome (ME/CFS), and other chronic pain conditions fall under the CSS umbrella.” – Central Pain Syndrome – NORD Rare Disease Database

Response

Based on research ‘central sensitisation syndrome’ is also known as ‘central pain syndrome’. The disorder develops following damage to the central nervous system – the brain, brainstem or spinal cord. Such damage is most often associated with a stroke, multiple sclerosis, spinal cord (but also brain) injury or brain tumours. Central pain syndrome can also develop after neurosurgical procedures involving the brain or spine. Reference: Central Pain Syndrome – NORD Rare Disease Database

For clinical documentation of ‘central sensitisation syndrome’ assign G96.8 Other specified disorders of central nervous system following the ICD-10-AM Alphabetic Index Disorder/nervous system/central/specified NEC G96.8 and assign R52.2 Chronic pain  where there is also clinical documentation of chronic pain. Please use free text on code G96.8 to specify ‘central sensitisation syndrome’.

The code U91 Syndrome not elsewhere classified is not assigned as ACS 0005 Syndromes states where a syndrome is classified to a single ICD-10-AM code U91 Syndrome not elsewhere classified is not assigned.

A coding query has been raised with the Independent Health and Aged Care Pricing Authority (IHACPA) to confirm code assignment.

Created October 2012
Reviewed June 2023

Query

A patient who suffers from Type 2 diabetes mellitus on insulin with a variety of other comorbidities has Charcot-Marie-Tooth (CMT) type I disease. There is no ‘diabetes with’ look up under Charcot-Marie-Tooth specifically, however as this is a neuropathic condition, we wondered if it should be coded out as:

E11.42  Type 2 diabetes mellitus with diabetic polyneuropathy
G60.0   Hereditary motor and sensory neuropathy

The Charcot-Marie-Tooth Disease article on the Medscape website was used as a first line investigation and this might be helpful.

Response

Charcot-Marie-Tooth (CMT) disease is a hereditary neurological disorder which affects both motor and sensory nerves. CMT is divided into types I-IV. Type I affects the myelin sheath (the protective covering of the nerve) and type II affects the nerve fibers (axons).

Following the classification principles in ACS 0401 Diabetes mellitus and intermediate hyperglycaemia and the ICD-10-AM Alphabetic Index for ‘Diabetes, diabetic’ assign E11.42 Type 2 diabetes mellitus with diabetic polyneuropathy. Refer to ACS 0401 Rule 4b to determine if the additional diagnosis of G60.0 Hereditary motor and sensory neuropathy is assigned.

Diabetes, diabetic (controlled) (mellitus)
- with
- - neuropathy
- - - polyneuropathy E1-.42
- - - - sensorimotor E1-.42

Created December 2015
Updated June 2023

Query

Our trainees have discovered that there are two different ICD-10-AM Alphabetic Index pathways for chronic tonsillitis with hypertrophy:

Tonsillitis (acute) (follicular) (gangrenous) (infective) (lingual) (septic) (subacute) (ulcerative) J03.9
- hypertrophic J35.0

Hypertrophy, hypertrophic
- tonsils (faucial) (greater than grade 3) (infective) (lingual) (lymphoid) J35.1

Should both codes (J35.0 and J35.1) for this disease concept be assigned or should a combined code be used?

Response

Hypertrophy of the tonsils is a symptom of tonsillitis. Therefore, assign J35.0 Chronic tonsillitis only according to the lead term ‘Tonsillitis’ in the ICD-10-AM Alphabetic Index.

Created August 2012
Updated June 2023

Query

What diagnosis code should be assigned for the condition Chronotropic incompetence?

On researching this condition it is defined as “Chronotropic incompetence refers to the inability of the heart to increase its rate commensurate with increased activity or demand of the patient.”

As there is no ICD-10-AM Alphabetic Index entry we’ve chosen I49.8 Other specified cardiac arrhythmias in the meantime, but would like confirmation.

Response

Based on clinical advice chronotropic incompetence is usually due to sinus node dysfunction and the clinicians consulted have advised the most appropriate diagnosis code to assign is I49.50 Sinus node dysfunction, unspecified. Free text should be used to specify the condition.

Created April 2017
Reviewed June 2023

Query

Patient admitted with keratitis with ulceration due to contact lenses and found with bacteria growing. What diagnoses codes should be assigned?

Response

As a contact lens is not an intraocular device, assign the diagnosis codes:
H16.0 Corneal ulcer
B96.- Other bacterial agents as the cause of diseases classified to other chapters
Z97.3 Presence of spectacles and contact lenses

Free text should be used to add specificity.

Created December 2015
Reviewed June 2023

Query

Should a code to indicate the site of the infection (eg, bronchiolitis) be assigned in addition to B25.- Cytomegaloviral disease when there is no subterm for the site of the infection listed under CMV infection in the ICD-10-AM Alphabetic Index?

Response

Yes. In the ICD-10-AM Alphabetic Index follow the lead term for the site of the infection where the site is documented (eg, bronchiolitis). Under the lead term look for a subterm (essential modifier) for CMV, if one is not present add an appropriate code from category B25.- Cytomegaloviral disease.

Bronchiolitis (acute) (infective) (subacute) J21.9
- due to
- - chemicals (chronic) (gases, fumes or vapours) J68.4
- - external agent NEC J70.8
- - human metapneumovirus J21.1
- - radiation J70.0
- - respiratory syncytial virus J21.0
- - specified organism NEC J21.8

Infection, infected (opportunistic) (see also Infestation)
- cytomegalovirus, cytomegaloviral B25.9
- - congenital P35.1
- - maternal care for damage to fetus (suspected) O35.3
- - mononucleosis B27.1
- - resulting from HIV disease B20
- - specified NEC B25.8

Created June 2012
Reviewed June 2023

Query

What ACHI codes should be assigned for decompression of colonic pseudo-obstruction and gastric pseudo-obstruction?

Response

Refer to the clinical documentation to obtain information as to how the decompression was performed eg, was it via an endoscope or insertion of tube, or was it done at time of an open procedure?

This will then determine if the decompression is coded or not, see ACS 0042 Procedures normally not coded, point 13 Nasogastric intubation, aspiration and feeding.

For this query the operation reports were reviewed for the two cases. In both cases a flexible sigmoidoscopy was performed to decompress the colon.

Therefore, assign the procedure code 32084-00 [905] Fibreoptic colonoscopy to hepatic flexure for the flexible sigmoidoscopy only and use free text to specify the decompression eg, Flexible sigmoidoscopy with decompression of pseudo-obstruction.

Created October 2016
Reviewed June 2023

Query

During dental admissions the dentists use the term ‘discing’ or ‘disking’.

We couldn’t identify an appropriate ACHI code so have been assigning 97982-00 [490] Enamel stripping of tooth. Another suggested code is 97171-00 [455] Ondontoplasty, per tooth.

An extract from an op note might read as follows: “The labial surfaces of teeth 71, 72 and 82 were disked and fluoride applied”

Please advise what ACHI code should be assigned for dental discing/disking?

Response

Dental discing/disking is a procedure generally performed for children who have tight teeth that are prone to decay. The procedure involves removal of enamel by sanding the tooth surface to reshape or reduce the tooth size to allow for adjacent permanent teeth to erupt. 

When discing/disking is performed assign ACHI code 97982-00 [490] Enamel stripping of tooth per tooth and use free text to specify the procedure and the tooth involved, for example, Disking labial surface of tooth 71.

The code assignment has been confirmed following consultation with several public hospital dental clinicians.  

Created June 2016
Reviewed June 2023

Query

What procedure code should be assigned for division of lung adhesions via thoracotomy?
Patient was admitted for coronary artery bypass graft (CABG) and intraoperatively was found to have adhesions of the lung which, were divided. 

Suggestions are:
90166-00 [549] Division of pleural adhesions
or
38456-02 [558] Other open procedures on lung or pleura

Response

Assign ACHI code 90166-00 [549] Division of pleural adhesions for division of lung adhesions following ACHI Alphabetic Index: Division/adhesions/pleura/open.

Created February 2006
Reviewed June 2023

Query

Patient has a diagnosis of ductal carcinoma in situ (DCIS) from biopsy, but has positive axilla lymph nodes.
If DCIS is not metastatic, how is this situation appropriately coded?

Response

Based on advice from the New Zealand Cancer Registry, DCIS is indeed not metastatic. The lymph node cancer would have to be coded out separately. This is a situation where it could be a secondary from another site, or it could be another cancer from the breast that was not picked up on pathology.

Where there is appropriate documentation within the episode of care, codes assigned in this case would be:
D05.1   Intraductal carcinoma in situ of breast
C80.9   Malignant neoplasm, primary site unspecified
C77.3   Secondary and unspecified malignant neoplasm of axillary and upper limb lymph nodes.

Created April 2016
Updated June 2023

Query

Obstetric patient was admitted for an elective caesarean section. Indication was previous C-section delivery. 
At the operation it was planned to excise a keloid scar that formed at the incision site first and then perform the C-section.

Are additional diagnosis and procedure codes required in addition to the instructions of ACS 1506 Fetal presentation, disproportion and abnormality of maternal pelvic organs?

If additional diagnosis and procedure codes are to be used, what should they be?

Our suggestion after reviewing the documentation and seeking clinical clarification is to assign the additional codes:
O99.7   Diseases of the skin and subcutaneous tissue in pregnancy, childbirth and the puerperium
L91.09  Hypertrophic scar due to other specified cause
45518-00 [1657] Revision of scar of other site more than 7 cm in length

Response

Where there is clinical documentation specifying a problem with the previous caesarean scar (eg, keloid scar, painful scar) and it meets ACS 0002 Additional diagnoses (eg, scar excision prior to caesarean) the appropriate codes to assign in addition to other obstetric conditions (eg, O34.2 Maternal care due to uterine scar from previous surgery) are:

O99.7   Diseases of the skin and subcutaneous tissue in pregnancy, childbirth and the puerperium
L91.09  Hypertrophic scar due to other specified cause

Excision of scar procedure. Where there is no documentation of the scar length 45515-00 [1657] Revision of scar of other site <= 7 cm in length should be assigned as per the ACHI Index and ACS 0038 Procedures distinguished on the basis of size, time, number of lesions or sites.

Created February 2012
Reviewed June 2023

Query

What ICD-10-AM diagnosis code should be assigned for emphysematous cystitis?

Research indicates this is a ‘rare disease entity caused by gas fermenting bacterial and fungal pathogens. Clinical symptoms are nonspecific and diagnostic clues often arise from the unanticipated imaging findings’. (Emphysematous cystitis: An unusual disease of the Genito-Urinary system suspected on imaging)

Response

Based on research and clinical advice assign ICD-10-AM diagnosis code N30.8 Other cystitis for emphysematous cystitis and use free text to specify the type of cystitis.

ICD-10-AM Alphabetic Index

Cystitis (exudative) (haemorrhagic) (septic) (suppurative) N30.9
- specified NEC N30.8

Created August 2018
Reviewed June 2023

Query

What ACHI codes are assigned for ‘Excision of right parapharyngeal tumour via lip split/mandibulotomy’?
Provided below is the relevant section for the operation note.

Procedure:
Lower lip splitting incision curving around the right side of the chin and into the upper neck incision. The mandibular parasymphyseal region was exposed subperiosteally and the mental nerve identified.

The site for an osteotomy between the 43/44 tooth roots was marked. A striker 2.3mm recon plate was then applied and pre-contoured, and pre-plated with titanium screws. The plate was then removed and the osteotomy performed.

Mandibular swing then carried out with incision along the mucosal of the floor of the mouth to the retromolar trigone region. The lingual nerve was protected throughout. The tumour in the parapharyngeal space was easily identified and was well encapsulated. It was shelled out in entirety with no breach to the capsule.

Mandible fixated using pre-drilled plate.

Response

In the absence of a specific code or ACHI Index entry for excision of parapharyngeal tumour via transmandibular approach, assign codes 31409-00 [421] Excision of parapharyngeal lesion by cervical approach with free text to specify the transmandibular approach and 45723-00 [1706] Osteotomy of mandible with internal fixation, unilateral.

Created February 2012
Reviewed June 2023

Query

What ACHI code would be assigned for excision of radioulnar synostosis?

Patient had previously sustained a complex elbow fracture dislocation, which was treated with reconstruction (ligament repair and radial head fixation). Patient presents with the diagnosis of ‘post traumatic radioulnar synostosis elbow’. The synostosis was excised.

Response

The procedure was described as ‘excision of accessory ossification from the radius and ulna’, and so the codes to assign are 48406-03 [1426] Ostectomy of radius and 48406-05 [1426] Ostectomy of ulna.

Note that the documented accessory ossification is not the same thing as an accessory bone.

Created December 2019
Reviewed June 2023

Query

What would the best activity code be for the sport ‘Kabaddi’?
The Rules of the Sport – Kabaddi Rules gives a good summary https://www.rulesofsport.com/sports/kabaddi.html

Suggested code is U61.8 Activity, Other specified combative sport

Response

Kabaddi is a contact team sport and does not involve a ball, bat or stick etc. Therefore, U61.8 Activity, Other specified combative sport is the most appropriate activity code to assign. Use free text to specify the type of sport.

Created February 2015
Reviewed June 2023

Query

In the case of coding a complication following a hemicolectomy with stoma formation which Y83.- external code should be assigned?
Y83.6 Removal of other organ (partial)(total) or Y83.3- Surgical operation with formation of external stoma or both?

I have been told to use the code higher in the ICD-10-AM Tabular List but I cannot find any written guideline on this.

Response

Code assignment should be determined on a case by case basis. There are no guidelines in the ICD-10-AM classification for categories Y83–Y84 Surgical and other medical procedures as the cause of abnormal reaction, or of later complication, without mention of unintentional events at the time of the procedure that instruct coders to assign a code which is higher in the Tabular List of codes.

Clinical coders need to determine the nature of the complication for example, if the complication is because of (or related to) the stoma, then Y83.3- Surgical operation with formation of external stoma is the appropriate code to assign. However, if the complication is because of the hemicolectomy, then Y83.6 Removal of other organ (partial)(total) is the appropriate code to assign.

Created June 2013
Reviewed June 2023

Query

1. We come across a lot of cases where the place of occurrence is on a course/track across privately owned land (farm), national park, or public reserves. In these cases should we assign the place of occurrence code for farm, national park, or public reserve? 
2. We also have the Burt Munro motorcycle event where the beach and street are closed off. Currently we are coding these events to Y92.33 Place of occurrence, racetrack and racecourseas the primary use at the time is a racecourse. Is this correct? 
3. In other instances there are sporting events such as the cycling Tour of Southland which occurs on an open road where the road is not barricaded off and cars can still travel on it. Should this be coded to Y92.49 Place of occurrence, unspecified public highway, street or road?

Response

The definition of racetrack is ‘a purpose built facility or building’ and racecourse is ‘a term for non-permanent (temporary) tracks for sports.

In the ICD-10-AM Tabular List the definition of a public highway is:

(b) A public highway [trafficway] or street is the entire width between property lines (or other boundary lines) of land open to the public as a matter of right or custom for purposes of moving persons or property from one place to another. A roadway is that part of the public highway designed, improved and customarily used for vehicular traffic.

From an injury prevention perspective it is important to describe the situation at the time of the incident rather than the usual situation at the location e.g. incident occurred while rallying on a blocked off road. The patch of ground at the time of rallying is used as a racecourse (Y92.33), however the day before or day after will be used as a public road (Y92.49). Based on the information received it is important to determine where the incident occurred, if it is on an open or closed road, also if it is part of an organised event or not.

1. Where the incident has occurred on a course/track on privately owned land (farm), national park, or public reserve and is not part of an organised event, assign the specific place of occurrence code for the farm (Y92.7 Place of occurrence, farm), national park (Y92.84 Place of occurrence, forest) or public reserve (Y92.88 Other specified place of occurrence).
   In the cases where the incident has occurred on a course/track on privately owned land (farm), national park, or public reserve and is part of an organised event the place of occurrence code assigned should be Y92.33 Place of occurrence, racetrack and racecourse.  
2. Where the road is closed off for the purpose of creating a temporary racecourse as part of an organised event, assign the place of occurrence code Y92.33 Place of occurrence, racetrack and racecourse. 
3. As the road is still open for public use the code assigned should be Y92.49 Place of occurrence, unspecified public highway, street or road.

Note: Free text should be used to specify the actual place and/or event.

Correspondence from: Injury Prevention Research Unit and Professor James Harrison

Created October 2011
Reviewed June 2023

Query

What place of occurrence code should be assigned for ‘refuse transfer station’, ‘recycling centre’, ‘tip’ or ‘dump’?

Response

As there is variability across the country as to the how these places are defined and operate, the external cause code is to be assigned on a case by case basis according to the information of the place of occurrence, and the reason why the person was there may also be a factor.

The place of occurrence external cause code that would generally be assigned in the majority of cases is Y92.58 Place of occurrence, other specified trade and service area. For example, a person injured while purchasing or selling items at a recycle centre, or a person at the refuse transfer station dumping a trailer load of rubbish tripped over the tail gate and fell into the pit.

Y92.68 Place of occurrence, other specified industrial and construction area may be assigned depending on the documentation. For example, if there was documentation that the person was injured while at work operating a compactor roller/digger at the dump (landfill area) or transfer station, then Y92.68 would be the appropriate place of occurrence code to assign.

Created December 2017
Reviewed June 2023

Query

What external cause code is assigned for taser administered by police?

Response

Y35.09 Legal intervention involving discharge from other and unspecified firearms is the most appropriate external cause code to assign. Please use free text to specify the taser device.

Created July 2017
Reviewed June 2023

Query

What is the most appropriate external cause code to assign for ‘fall (thrown) from biscuit being towed by boat’?

Accident was described as ‘was biscuiting on Lake Wanaka when hit a wave and was thrown off, landing heavily on the water’, causing a spleen injury. Further information from the medical centre in Wanaka states, ‘the biscuit was swinging around behind the boat and hit the boats wake’.

Response

A review of external cause data reported to the National Minimum Dataset (NMDS) revealed that clinical coders are consistently assigning W02.2 Fall involving water ski for accidents involving inflatable biscuit/water ring, water skis and wakeboards. Therefore, assign W02.2 Fall involving water ski for ‘fall involving biscuit causing injury’, and use free text to add specificity (e.g. thrown from inflatable biscuit being towed by boat).

Refer to published Coding Rule TN200 June 2009 ‘Fall while water skiing’.

Fall from jet ski – assign V92.3 Water-transport-related drowning and submersion without accident to watercraft, other powered watercraft.

Fall from raft – assign V92.6 Water-transport-related drowning and submersion without accident to watercraft, inflatable craft (nonpowered).

Created December 2016
Reviewed June 2023

Query

What external cause code should be assigned for an ambulance that slid on hail hitting a barrier on the side of the road and injuring an unrestrained medic in the back of the ambulance?

Suggestions are:

V83.1 Passenger of special industrial vehicle injured in traffic accident
V57.6 Occupant of a pick-up truck or van injured in collision with fixed or stationary object, passenger injured in traffic accident

Response

After consultation with the Injury Prevention Research Unit (IPRU) the appropriate code to assign for this scenario is V57.6 Occupant of a pick-up truck or van injured in collision with fixed or stationary object, passenger injured in traffic accident.

Created Aug 2023

Effective from 1 Jul 2023

Updated Jan 2024

Query

What is the principal diagnosis for an individual admitted for gender reaffirming surgery when the documented diagnosis is gender dysphoria?

Response

Gender reaffirming surgery aims to transition individuals who experience gender dysphoria to the gender they identify with.

In the ICD-10-AM Twelfth Edition classification gender dysphoria is classified to diagnosis code F64 Gender incongruence. When an individual is admitted for gender reaffirming surgery and the diagnosis documented is gender dysphoria (or an equivalent term) assign F64 Gender incongruence as the principal diagnosis.

It is important that the event records are consistently coded and group to the same DRGs, as each year the costs and number of event records reported to NMDS are reviewed as part of the casemix work programme to ensure the case weight and co-payment allocation are appropriate for the DRGs. See the New Zealand Casemix Framework for Publicly Funded Hospitals WIESNZ23, section 4.4.10 Co-payment for Gender Reaffirming Surgery (GR) https://www.tewhatuora.govt.nz/our-health-system/data-and-statistics/nz-health-statistics/data-references/#weighted-inlier-equivalent-separations-wies

The IHACPA coding rules Q3527 Chest masculinisation surgery for gender dysphoria and Q3841 Genital reconfiguration surgery are not applicable to New Zealand coding practice.

New Zealand coding teams are advised to add a note in electronic coding tools to ensure consistent principal diagnosis code assignment.

Created February 2012
Reviewed June 2023

Query

What ICD-10-AM diagnosis code should be assigned for ‘grey (gray) zone lymphoma’?
Grey zone lymphoma has features of Hodgkin lymphoma as well as diffuse B-cell.

Response

Advice was sought from the New Zealand Cancer Registry (NZCR). In the World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues, 4th Edition 2008 manual, Grey Zone Lymphoma is referenced as ‘B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma.’

Definition is: ‘A B lineage lymphoma that demonstrates overlapping clinical, morphological and/or immunophenotypic features, between classical Hodgkin lymphoma (CHL) and diffuse large B-cell lymphoma (DLBCL), especially primary mediastinal large B-cell lymphoma (PMBL).’

Synonyms include ‘Grey zone lymphoma, large B-cell lymphoma with Hodgkin features, and Hodgkin-like anaplastic large cell lymphoma.’

NZCR ICD-O code is M9596/3 Composite Hodgkin and non-Hodgkin lymphoma.

Therefore, following the ICD-10-AM Alphabetic Index the most appropriate diagnosis code to assign is C85.7 Other specified types of non-Hodgkin lymphoma.

Lymphoma (malignant) (M9590/3) C85.9
- Hodgkin (M9650/3) C81.9
- - and non-Hodgkin, composite (M9596/3) C85.7

- non-Hodgkin type NEC (M9591/3) C85.9
- - and Hodgkin, composite (M9596/3) C85.7

Reference: https://seer.cancer.gov/seertools/hemelymph/51f6cf57e3e27c3994bd5333/

Created December 2015
Updated June 2023

Query

When healthy neonates are transferred from one facility to another, the principal diagnosis is Z76.22 Health supervision and care of other infant or child, NEC with a condition onset flag of 2.

What is the principal diagnosis and condition onset flag when a healthy neonate develops a condition that meets ACS 0002 Additional diagnoses after admission?

Response

If a condition arises during the transferred episode of care (non birth event), this will become the principal diagnosis in place of Z76.22 Health supervision and care of other infant or child, NEC and the COF will be 2 as per the ACS 0048 Condition onset flag – Guide for use point 3.

Refer to the note at the beginning of Chapter 21 in the ICD-10-AM Tabular List.

Note: Categories Z00–Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00–Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:

(a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination or to discuss a problem which is in itself not a disease or injury.

(b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury. Such factors may be elicited during population surveys, when the person may or may not be currently sick, or be recorded as an additional factor to be borne in mind when the person is receiving care for some illness or injury.

Created October 2012
Updated June 2023

Query

1. If the patient has heart valve disease of more than one valve eg, aortic stenosis and mitral regurgitation and only one valve (aortic) is being repaired eg, TAVI, do you assign the specific code for the one valve (aortic) or the multiple valve disease (aortic and mitral) code?
2. In the cases of multiple disorders of one heart valve eg, severe aortic stenosis and mild aortic regurgitation do you assign the specific codes for each of the disorders or the combination code?

Response

1. In the case where multiple valve disorders are documented it is clinically important to capture all the valve disorders. Where the documentation does not specify a cause eg, congenital, non-rheumatic, rheumatic, follow the ICD-10-AM Alphabetic Index and the Excludes note in the Tabular List. In the scenario where aortic stenosis and mitral regurgitation is documented the diagnosis code I08.0 Disorders of both mitral and aortic valves should be assigned and use free text on the code description to further specify the specific disorders.

Please note:
The codes in I08 Multiple valve diseases sit within the category (I05-I09) Chronic rheumatic heart diseases. As there is a high level of interest in rates of rheumatic heart disease in New Zealand, from a public health perspective it is important to identify where possible if the heart valve disease, and in particular multiple valve disease, is rheumatic or non-rheumatic. Disorders of multiple heart valves that are specific as non-rheumatic are not coded to I08.

2. Where a combination code is available in the classification and multiple disorders of a heart valve are documented assign the combination code. For example, assign the diagnosis code I35.2 Aortic (valve) stenosis with insufficiency for documentation of ‘severe aortic stenosis with regurgitation’.

Heart valve disorders with a severity of mild, moderate and severe should be coded when documented.

See also IHACPA Coding Rule Q3438 Multiple heart valve diseases published March 2020.

Created October 2013
Reviewed June 2023

Query

Patient presented to the Respiratory service with ‘iatrogenic pneumothorax due to acupuncture needle’. Patient had acupuncture for tennis elbow the day before. Should the external cause code be W27 Contact with non-powered hand tool (due to needle) or Y60.8 Unintentional cut, puncture, perforation or haemorrhage during other surgical and medical care (medical misadventure)?

Y60.8 is suggested because of the wide acceptance of acupuncture as a legitimate therapy. For example, ACC funds this treatment in certain circumstances.

Response

Acupuncture is part of Traditional Chinese Medicine. It is used worldwide as an alternative medical therapy. In New Zealand to be a qualified ACC treatment provider an acupuncturist has to pass a serial assessment or completed years of training to register with an ACC approved organisation for example, New Zealand Register of Acupuncturists (NZRA) or New Zealand Acupuncture Standards Authority (NZASA) Inc.

Therefore, as acupuncture is an approved alternative medical therapy in New Zealand, ‘iatrogenic pneumothorax due to acupuncture needle’ should have the external cause code Y60.8 Unintentional cut, puncture, perforation or haemorrhage during other surgical and medical care assigned with free text to further specify circumstances.

Created February 2020
Updated June 2023

Query

What postprocedural complication code is to be assigned for ‘infection of muscle or myocutaneous flap’?

Response

As per the ICD-10-AM Alphabetic Index code T84.7 Infection and inflammatory reaction due to other internal orthopaedic prosthetic devices, implants and grafts is to be assigned for infection of muscle or myocutaneous flap.

Complication
- graft (bypass) (patch) (see also Complication(s)/by site and type)
- - muscle
- - - infection T84.7

The term ‘internal orthopaedic’ appearing in the code title does not preclude clinical coders from assigning the code T84.7. It should be understood that within the classification there are defaults and therefore some of the terms appearing in code titles will not appear as subterms in the index.

Created March 2018
Reviewed June 2023

Query

Patient is admitted for PIPJ release and insertion of K-wire into joint for treatment of little finger camptodactyly.
What ACHI code is assigned for insertion of the K-wire into PIP joint?

Response

As per the ACHI Index assign code 47921-00 [1554] Insertion of internal fixation device, NEC and use free text to specify the procedure performed.

ACHI Alphabetic Index

Insertion
- device — see also Insertion/by type of device
- - fixation, internal
- - - bone — see also Fixation/bone
- - - - orthopaedic (pin) (plate) (wire) 47921-00 [1554]
…
- pin or wire
- - orthopaedic 47921-00 [1554]
…
- wire or pin (orthopaedic) 47921-00 [1554]

Created June 2012
Updated June 2023

Query

Should a gastroscopy procedure code be assigned in addition to 30481-00 [870] Initial insertion of percutaneous endoscopic gastrostomy [PEG] tube?

We thought the code 30481-00 [870] included the endoscope. However our Paediatric surgeon advised that the PEG can be inserted with or without an endoscope, so it should be coded separately if done. Our Paediatric coder has been coding both, does NZCA agree?

Response

Techniques for inserting a percutaneous gastrostomy tube have changed over time, and can be performed via laparoscopy or fluoroscopy instead of endoscopically.

As ACHI only contains procedure codes for initial and repeat insertion of percutaneous endoscopic gastrostomy [PEG] tube it is advised that an additional procedure may be assigned to further specify the approach. Free text should be used on the code description to add specificity. For example:

Percutaneous gastrostomy tube inserted via OGD
30481-00 [870] Initial insertion of percutaneous endoscopic (OGD) gastrostomy [PEG] tube 

Percutaneous gastrostomy tube inserted via fluoroscopy
30481-00 [870] Initial insertion of percutaneous gastrostomy [PEG] tube using fluoroscopy

Percutaneous gastrostomy tube inserted via laparoscopy
30722-00 [881] Laparoscopic gastrostomy 

References:
Medscape reference: Percutaneous Gastrostomy and Jejunostomy

Applied Medical Technology, Inc: Mini ONER Buttons and Other Gastrostomy Products 

Created December 2021
Reviewed June 2023

Query

What ICD-10-AM code is assigned for internet gaming disorder?

ICD-11-MMS has created new categories at 6C5 for Disorders due to addictive behaviours. [This is alongside 6C4 Disorders due to substance use]. The categories at 6C5 are 6C50 Gambling disorder and 6C51 Gaming disorder.

As gambling disorder is classified to F63.0 Pathological gambling in ICD-10-AM, would code F63.8 Other habit and impulse disorders be appropriate for internet gaming disorder?  

The other ICD-10-AM code considered was Z72.8 Other problems related to lifestyle, but the Note at the top of category Z72 Problems related to lifestyle category says that these codes are used when there is no disorder in the individual, while the documentation in question uses the word ‘disorder’.

Response

Where the clinical documentation is ‘internet/gaming disorder’ and the disorder meets ACS 0001 Principal diagnosis or ACS 0002 Additional diagnoses assign diagnosis code F63.8 Other habit and impulse disorders by following the ICD-10-AM Alphabetic Index:

Disorder
- habit (and impulse)
- - specified NEC F63.8

If the clinical documentation does not mention ‘disorder’ but states internet/gaming use is a problem and it meets ACS 0001 Principal diagnosis or ACS 0002 Additional diagnoses assign code assign Z72.8 Other problems related to lifestyle by following the ICD-10-AM Alphabetic Index:

Problem (related to) (with)
- lifestyle
- - specified NEC Z72.8

Free text should be used on both codes (F63.8 and Z72.8) to specify the condition.

Created August 2017
Reviewed June 2023

Query

How do we code the documentation of life threatening asthma?

It is not common to see doctors documenting ‘acute severe asthma’. Can we code life threatening asthma to J46 Status asthmaticus?

Response

J46 Status asthmaticus should be assigned only if the asthma is documented as ‘acute severe’ or ‘refractory’. Therefore, the coder should consult with the clinician to confirm the diagnosis of life threatening asthma. However, where it is not possible to obtain further clarification from the clinician assign J45.9 Asthma, unspecified.

Created October 2012
Reviewed June 2023

Query

How should ‘long latent phase of labour’ be coded when it meets the ACS 0002 Additional diagnoses criteria?

Some regard the ‘latent phase’ as a part of stage 1 of labour and as a result would code it to O63.0 Prolonged first stage (of labour). Others regard the beginning of stage 1 of labour as ‘established labour’ and only include the active phase. This would leave us with O62.9 Abnormality of forces of labour, unspecified.

Response

The first stage of labour is divided into two phases: latent and active.  

The latent phase is when the cervix thins and dilates from 0–4 cm, contractions may start and stop. The latent phase can last hours, several days or weeks before active labour starts.

The active phase ‘established labour’ is when contractions are regular and the cervix dilates from 4–10 cm.

Clinical advice is that ‘long latent phase of labour’ could be a statement or a diagnosis. Causes for a long latent phase can include diagnoses such as, failure of cervical dilation, atonic uterus and incoordinate uterine action. In the cases where a specific cause is documented assign the appropriate code. Where ‘long latent phase’ is documented without a cause and it meets the ACS 0002 Additional diagnoses criteria assign the diagnosis code O62.9 Abnormality of forces of labour, unspecified and use free text on the code description to specify long latent phase.

Created August 2020
Reviewed June 2023

Query

A 21-month-old child was admitted same day for a MAG-3 nuclear medicine renal study under sedation for a follow up investigation of their congenital left calyceal dilation (previously cancelled pyeloplasty as repeat ultrasound at the time showed improvement).

The study was performed using Technetium labelled MAG3. 200MBq of activity was injected intravenously with administration of 8mg of Lasix (diuretic) intravenously at the beginning of the study.

What ACHI code is assigned for this procedure?

Response

As per ACS 0042 Procedures normally not coded point 11 Imaging services, this nuclear medicine study would normally not be coded. However, as a cerebral anaesthesia was required for the imaging procedure to be performed and the event met the NMDS three-hour admission rule for reporting, the most appropriate ACHI code assigned for the MAG-3 renal scan is 61389-00 [2008] Renal study with preprocedural administration of diuretic or angiotensin converting enzyme [ACE] inhibitor. Free text should be used to specify the procedure.

Created December 2017
Reviewed June 2023

Query

Meibomian gland dysfunction (MGD) has no index entry in ICD-10-AM, but it is a common diagnosis in our Ophthalmology service. Dysfunction implies that the gland(s) is unable to discharge its secretions. This then results in inflammation. Mechanical assistance to discharge results in small amounts of pus coming out. We have various opinions on the best code to use for MGD, ranging across categories H00 Hordeolum and chalazion to H02 Other disorders of eyelid.

Which code should be assigned to indicate MGD?

Response

Assign H00.0 Hordeolum and other deep inflammation of eyelid following the ICD-10-AM Alphabetic Index: Meibomitis H00.0.

Created October 2014
Updated June 2023

Query

Minimally invasive retroperitoneal pancreatic necrosectomy is performed for necrotising pancreatitis.

A skunk wire is first inserted into the necrosis in interventional radiology and then the patient is transferred to theatre for the necrosectomy. The procedure is usually repeated a few times during the episode of care.

The ACHI code we assigned is 30577-00 [979] Major pancreatic or retroperitoneal dissection. 

Response

Minimally invasive necrosectomy involves the removal of dead pancreatic tissue using keyhole surgery. 

30577-00 [979] Major pancreatic or retroperitoneal dissection should be assigned by following the below ACHI Index. This code will be used for open procedures, therefore, free text should be used to specify the procedure performed.

Dissection
- pancreas (major) (retropancreas)
- - for
- - - pancreatic necrosis 30577-00 [979]

If there is documentation of the use of either a laparoscopic or endoscopic approach, then refer to ACS 0023 Minimally invasive interventions. 

Created September 2022 – effective from 1 Jul 2022
Reviewed June 2023

Query

We would like clarification on what diagnosis code to assign for neonatal metabolic bone disease or metabolic bone disease of prematurity.

The Starship metabolic bone disease guidelines state:

“Neonatal metabolic bone disease (MBD), osteopenia of prematurity, neonatal rickets or rickets of prematurity, are terms used to describe a reduction in bone mineral content which may occur 4-6 weeks after preterm birth.

MBD presents between 6 and 12 weeks after birth but may be asymptomatic for weeks until severe demineralisation occurs, presenting as overt rickets or fractures. Symptoms may include poor weight gain, faltering growth, and respiratory difficulties or failure to wean off ventilatory support due to excessive chest wall compliance. Fractures may manifest as pain on handling. Early recognition of MBD is important for nutritional management in preterm infants.

The diagnosis of MBD remains largely subjective because most babies do not manifest overt signs or symptoms. Diagnosis has been based on criteria that include clinical signs, biochemical markers, and measurement of bone mineral content and radiologic findings (a late sign).” – Metabolic bone disease – Starship

Response

For clinical documentation of neonatal metabolic bone disease or metabolic bone disease of prematurity assign code P74.8 Other transitory metabolic disturbances of newborn following the ICD-10-AM Alphabetic Index: Disturbance/metabolism/neonatal, transitory/specified NEC P74.8. Please use free text to specify ‘neonatal metabolic bone disease’ or ‘metabolic bone disease of prematurity’.

Clinical consultation with a neonatologist confirmed code P74.8 was the most appropriate code available in ICD-10-AM and it is also consistent with how the condition is classified in ICD-11.

A coding query has been raised with the Independent Health and Aged Care Pricing Authority (IHACPA) to confirm code assignment.

Created July 2018
Updated June 2023

Query

A patient was admitted for open reduction and internal fixation (ORIF) of fracture of distal tibia (documented not involving ankle). What is the appropriate code for this procedure as there is no specific index entry?
Should we assign 47566-01 [1510] Open reduction of fracture of shaft of tibia with internal fixation or 47600-01 [1539] Open reduction of fracture of ankle with internal fixation of diastasis, fibula or malleolus?

Response

As the fracture does not involve the ankle assign code 47566-01 [1510] Open reduction of fracture of shaft of tibia with internal fixation by following the ACHI Index: Reduction/fracture/tibia/shaft/open/with internal fixation.

The specific site (distal) of fracture is captured in the disease code and can be captured by adding free text on the procedure code descriptor.

Created April 2011
Updated June 2023

Query

A patient is admitted for a total hip joint replacement of the left hip after having had the right hip replaced two years earlier. What osteoarthritis code should be assigned, unilateral or bilateral?

Response

Assign the diagnosis code for unilateral osteoarthritis M16.1 Other primary coxarthrosis with an additional diagnosis for the hip replacement status Z96.64 Presence of right hip implant as the osteoarthritis of the right hip has been eradicated.

Documentation of ‘arthrosis’, ‘osteoarthrosis’ or ‘osteoarthritis’ with no underlying condition identified as the cause, should be assigned the relevant code for ‘primary’.

See also ACS 0049 Disease codes that must never be assigned.

Created May 2024

Query

During a joint replacement (eg, THJR, TKJR) osteophytes are noted and excised. Is it necessary to add a diagnosis code for the osteophytes and a procedure code for the removal of the osteophytes?

Response

Osteophytes or bone spurs are smooth bone growths that develop over time in damaged joints. Osteoarthritis is the most common cause of osteophytes.

Osteoarthritis is a progressive joint disease caused by cartilage breakdown, which results in bone rubbing on bone. As the body attempts to repair the damaged cartilage new bone formation in the form of osteophytes or bone spurs develop. Therefore, as osteophytes are part of osteoarthritis disease progression it is not necessary to assign an additional diagnosis code for osteophytes.

Excision of osteophytes during a joint replacement is a routine component of a joint replacement and therefore an additional procedure code for osteophyte excision should not be assigned when performed in a joint replacement procedure.

Created August 2017
Updated June 2023

Query

Patient is admitted with ear pain for one day, diagnosed as otitis externa, swabs were done which grew Pseudomonas aeruginosa, patient was given oral antibiotics. Otitis externa was not mentioned as being invasive, or complicated. The Pseudomonas was not mentioned in the clinical record, only on the laboratory result.
In the pathway, otitis externa has an entry for Pseudomonas aeruginosa, which goes to H60.2 Malignant otitis externa. Research indicates malignant otitis externa is a relatively rare invasive form of otitis externa. Therefore, the question is, would the correct code assignment be H60.2 Malignant otitis externa or H60.3 Other infective otitis externa with B96.5 Pseudomonas (aeruginosa) as the cause of diseases classified to other chapters or something else?

Response

As per the ICD-10-AM Alphabetic Index ‘Pseudomonas aeruginosa’ and ‘infective’ are essential modifiers. Therefore, as per the classification principles these essential modifiers must be documented in the clinical record. 

In this case, the clinician should be consulted to confirm the diagnosis. However, where it is not possible to obtain further clarification from the clinician assign codes H60.9 Otitis externa, unspecified and B96.5 Pseudomonas (aeruginosa) as the cause of diseases classified to other chapters.

Created November 2023

Query

When should pain management procedures such as femoral nerve block to manage fracture NOF pain, or erector spinae plane block for metastatic rib pain be coded?

Response

If the block procedure meets the criteria of ACS 0031 Anaesthesia either as conductive anaesthesia or as postprocedural analgesia, then it should be coded. Otherwise, as the block procedure is a drug treatment, it should only be coded if the criteria of ACS 0042 Procedures normally not coded are met or there is a specialty standard, classification convention or coding rule instruction.

Created October 2021
Reviewed June 2023

Query

We would like clarification on what diagnosis code to assign for painful bladder syndrome. 

With the nomenclature of painful bladder syndrome (PBS) and interstitial cystitis (IC) being the same or similar we have historically been assigning N30.1 Interstitial cystitis (chronic) and adding the free text of painful bladder syndrome (in the absence of IC as the specified cause). However, we wonder if we should be coding PBS to R39.8 Other and unspecified symptoms and signs involving the urinary system and U91 Syndrome not elsewhere classified in cases where interstitial cystitis is not specified as the cause.

Response

Without further documentation or clarification from a clinician stating interstitial cystitis as the cause for the painful bladder syndrome, cases should be coded as per ACS 0005 Syndromes.

Therefore, the diagnosis codes assigned for documentation of painful bladder syndrome will be R39.8 Other and unspecified symptoms and signs involving the urinary system and U91 Syndrome not elsewhere classified. 

Free text should be used to specify ‘painful bladder syndrome’.

Created August 2012
Reviewed June 2023

Query

We have ‘parenchymal remodelling of breast tissue’ documented recently, which is also documented as ‘glanduloplasty’. Initially we thought it was just the way they close up but the clinician says there is more time involved. The only code we can come up with is 90720-00 [1759] Other procedures on breast. 

Below are two examples.

OPERATION 1: Right breast total duct excision plus excision of mammary duct fistulas at 10 o’clock and 2 o’clock

Procedure:  
General anaesthetic, routine prep and drape, IV Augmentin and Cefazolin.
Periareolar incision used and an elliptical sliver of skin taken with 10 o’clock fistula. Separate elliptical incision utilised to excise mid areolar 2 o’clock fistula as well. Superior and inferior flaps raised. Total duct excised. Ducts excised from subcutaneous aspect of nipple down to approximately 2cm deep into breast tissue. Tissue excised in continuity with 10 o’clock and 2 o’clock fistulas. Haemostasis achieved. Parenchymal remodelling to reconstitute previous nipple/areolar complex mound using 2/0 Vicryl. 4/0 Monocryl to close skin. Steristrips and Opsite.

OPERATION 2: Left breast hookwire localised wide local excision with Level 2 oncoplastic remodelling, left sentinel node biopsy, left axillary node dissection, and right breast reduction

Procedure:
General anaesthetic, prophylactic antibiotics, sequential compression devices, patient prepped and draped in sterile manner. Keyhole skin incisions marked out which included lateral extension. Surgery started on the left side with de-epithelialisation of the skin around the areola and down the central part of the inferior breast. The wide local excision was completed by excising essentially all the upper outer quadrant of parenchyma. Any bleeding was controlled with bipolar diathermy. The dissection was from the subcutaneous tissues down to pectoralis fascia. The specimen was marked with three stitches and three clips at 3 o’clock, two at 6 o’clock and one at 9 o’clock position. Additional upper lateral and lower lateral shaves were then taken. These included all of the lateral breast tissue so that no further breast parenchyma was left laterally. This also incorporated the axillary tail in the upper lateral shave. An additional shave of subcutaneous tissue was taken around the hookwire entry site through the skin. An inferior medial shave was taken. Two shaves were taken deep to the nipple; these were labelled (1) which was deep and (2) which was superficial. Once these shaves were taken the oncoplastic remodelling continued with excision of the lateral tissue inferiorly. An inferior medial pedicle was raised and rotated as much as possible up into the area of parenchyma loss; this was secured in position with 2/0 Vicryl. A 15 French Blake drain was placed.

Response

Following the submission of this query NZCA members were asked to consult with their breast surgeons in order to obtain further information about ‘parenchymal breast remodelling’. 
The breast surgeons consulted agreed that 'parenchymal breast remodelling has become standard component of most, more extensive breast excisions (typically cancer surgery and a few extensive excision biopsies – eg, for radial scar) and has extended surgical time, increased post-op pain, can result in an overnight stay that might not have been required and the use of a drain.  In addition there is a higher risk of post-op haemorrhage and possible return to theatre.'

The breast surgeons also stated that there are varying complexity levels of parenchymal breast remodelling. Therefore, in order for clinical coders to clearly identify the levels of complexity and determine if an additional procedure code should be assigned or not, the levels of complexity have been defined below.

These definitions are based on information provided as part of a clinical response to a request for information on parenchymal breast remodelling.

Onco-plastic level 1
Generally the procedure performed would be a wide local excision with moderate tissue mobilisation or direct wound closure.  An additional procedure code is not required where the documentation indicates onco-plastic level 1.

Onco-plastic level 2
Procedures performed for this level are defined by significant breast remodelling, typical examples include:

• Wide local excision in the form of quadrantectomy
• Central breast excision with Grisotti flap remodelling

An additional procedure code should be assigned when onco-plastic level 2 is documented. Clinical coders would need to refer to the operation note to determine the appropriate procedure code to assign. The procedure for onco-plastic level 2 could include reduction mammoplasty, local flap, or a more specific flap eg, Grisotti or pedicle flap (reconstruction).

Note: The procedure code for onco-plastic level 2 would be assigned in addition to the appropriate excision/resection procedure code(s).

Onco-plastic level 3
Procedures performed for this level maintain breast shape and symmetry with reconstruction techniques rather than glandular flaps. Example:

• Wide local excision - partial mastectomy lateral breast with latissimus dorsi min-flap reconstruction         

Clinical coders should refer to the operation note to confirm procedure code assignment for onco-plastic level 3. Generally this will involve a flap reconstruction, therefore, refer to the ACHI Index.

Reconstruction
- breast
- - with 
- - - flap 45530-02 [1756]

Note: The procedure code for onco-plastic level 3 would be assigned in addition to the appropriate excision/resection procedure code(s).

It is recommended that clinical coders consult with their breast surgeons and ask if they could document in the operation note the appropriate levels.

Response to the above queries

Operation 1
In this operation the parenchyma remodelling would be considered onco-plastic level 1, as it is nothing more than tissue mobilisation with direct wound closure. Therefore, an additional procedure code is not required to be assigned.

Operation 2
In the operation code title there is documentation of 'Level 2 onco-plastic remodelling'. When referring to the detailed procedure information, the documentation states:

'Once these shaves were taken the onco-plastic remodelling continued with excision of the lateral tissue inferiorly.  An inferior medial pedicle was raised and rotated as much as possible up into the area of parenchyma loss; this was secured in position with 2/0 Vicryl. A 15 French Blake drain was placed.'

The procedure code assigned for this onco-plastic level 2 procedure is 455300-02 [1756] Reconstruction of breast using flap following the ACHI index:

Flap
- for
- - reconstruction of breast 45530-02 [1756]

Free text should be used to specify onco-plastic level 2.

Clinical reference:
Mr Michael Landmann MD (Heidelberg, Germany) 1985, German Surgical Board Certification 1994, FRACS 1998, PDiplHealInf (Otago Distinction) 2001.

Created February 2002
Reviewed June 2023

Query

Patient has bilateral hydroceles and a patent right processus vaginalis. They went to OT to have a bilateral exploration of groins, ligation of the right patent processus vaginalis and a bilateral vasectomy.  
What code would be assigned to show the ligation of the patent processus vaginalis?  
What diagnosis code would you use for this condition?

Response

Assign diagnosis code N43.3 Hydrocele, unspecified as patent processus vaginalis is inherent within this code.

No additional procedure code is required for ligation of the right patent processus vaginalis, as the procedure code for the repair of the hydrocele is adequate.

Created July 2015
Updated June 2023

Query

If a patient is admitted to hospital as a same day inpatient for IV pre-hydration prior to a CT scan with contrast, do we code the pre-hydration (IV fluids)?

Response

IV pre-hydration in these situations is not coded as this is standard protocol before receiving IV contrast for the CT scan.

The decision to give IV contrast depends on clinical indication for the study, findings of the study and patient risk factors. The risk factors are: asthma, allergies, renal impairment, hyperthyroidism and metformin use. Patients who are at higher risk will be given IV pre-hydration to minimise the risk of bronchospasm, allergic reaction and contrast induced nephropathy. Low risk patients would be advised to take oral fluids prior to the scan.

Created December 2015
Updated June 2023

Query

1. Patient had a pressure ulcer on his BKA stump. Should this be coded to L89.-Pressure injury, T87.- Complications peculiar to reattachment and amputation, or L97 Ulcer of lower limb, not elsewhere classified?
2. Patient presents for spinal surgery and has a history of BKA. A pressure area is noted on the lower thigh and attributed to the straps from the prosthesis. During the admission he only used his prosthesis when mobilising and this cleared up the pressure area. Do we need to assign external cause codes?  If so, which ones?

Response

In both cases the pressure injury code L89.- is sufficient. The assignment of additional codes will capture information on the relevant comorbidities associated with the development of the pressure injury.

Created October 2019
Reviewed June 2023

Query

What is the appropriate code for ‘reactive gastropathy’?

Histopathology result states ‘there is no increase in chronic inflammatory cells. No acute or granulomatous inflammation is seen. The findings are consistent with reactive gastropathy.’

Response

Reactive gastropathy is usually caused by long-term exposure of the gastric mucosa to substances capable of injuring the gastric mucosa (eg, medications, ethanol, bile reflux) and is characterised by minimal inflammation. Therefore, assign ICD-10-AM code K31.88 Other specified diseases of stomach and duodenum by following the ICD-10-AM Alphabetic Index: Disease/stomach/specified NEC K31.88, and use free text to specify ‘reactive gastropathy’.

Refer to ACS 0002 Additional diagnoses – problems and underlying conditions if the underlying cause if known and documented in the clinical record.

Reference: UpToDate

Created June 2016
Reviewed June 2023

Query

A NUSS bar is inserted to treat pectus excavatum and 38458-00 [564] Repair of pectus excavatum with implantation of subcutaneous prosthesis covers the insertion. Customarily the bar is removed at the end of adolescence, once growth has completed and the chest is well-shaped and there is good lung function. There is no code indexed for the removal of the bar. Suggestions for the removal of the bar include: 

38418-00 [561] Exploratory thoracotomy
90175-04 [567] Other closed procedures on chest wall, mediastinum or diaphragm
47930-00 [1554] Removal of plate, rod or nail, not elsewhere classified

Which would be the best code to assign?

Response

For NUSS bar removal assign 47930-00 [1554] Removal of plate, rod or nail, NEC following the ACHI Index: Removal/fixation device/internal/plate. Free text should be used to specify the device being removed.

Created December 2017
Reviewed June 2023

Query

We have several patients who are admitted for ‘review of their long term mechanical ventilation’ who do not have a tracheostomy in situ.

The Coding Rule Q2719 Management of tracheostomy published June 2013, updated 15 June 2022 indicates that Z43.0 Attention to tracheostomy would be appropriate for patients who have a tracheostomy in situ. But we are not sure which code to use for the patients who do not have a tracheostomy.

Response

Assign Z51.88 Other specified medical care following the ICD-10-AM Alphabetic Index:

Aftercare
- specified type NEC Z51.88

Created April 2011
Reviewed June 2023

Query

What code should be assigned for the procedure ‘Sialoendoscopy’?
This procedure is either performed as a diagnostic procedure (on its own) or in conjunction with a dilatation of the salivary gland.

Response

As there is no specific ACHI code available for this procedure assign 90140-00 [399] Other procedures on salivary gland or duct.

If Sialoendoscopy is performed in conjunction with a dilatation and/or extraction of calculi assign the code for dilatation 30262-00 [398] Dilation of salivary gland or duct or 30266-02 [395] Removal of calculus from salivary gland or duct only and use free text to add specificity.

Created February 2002
Reviewed June 2023

Query

I wish to code the presence of a ‘spinal cord stimulator’ used for the management of angina. I am not sure whether Z97.8 Presence of other specified devices or possibly Z96.8 Presence of other specified functional implants would be the appropriate code to use.

Response

Follow the ICD-10-AM Alphabetic Index: Presence/implanted device (artificial) (functional) (prosthetic)/specified NEC and assign code Z96.8 Presence of other specified functional implants if it meets ACS 0002 Additional diagnoses.

Created December 2013
Reviewed June 2023

Query

A patient had a procedure called a subtalar arthroereisis, according to an internet research it is a procedure in which a spacer or implant is inserted into the joint space (usually the sinus tarsi of the subtalar joint) to reduce the movement of the joint. This joint does not become fixed as in an arthrodesis procedure.

We took the procedure to 90599-00 [1544] Other repair of ankle which is in the same group of blocks (repair) as the similar, but more invasive, subtalar arthrodesis procedure, it was generally agreed that this was probably the best choice but there was also the possibility of 50106-00 [1571] Joint stabilisation, not elsewhere classified.

Included is the specific part of the operation note:

‘Under II control a stab incision was made over the sinus tarsi. Under II control the trial arthroereisis plug was inserted into satisfactory position. The size 9 gave satisfactory block of excessive eversion, satisfactory overall position and reasonable inversion. Definitive implant was inserted under II control.  This wound was washed out and closed with Nylon.’

Response

Assign procedure code is 49709-00 [1542] Stabilisation of ankle and use free text to specify the procedure performed.

Created June 2010
Reviewed June 2023

Query

Patient has ‘superficial siderosis of cerebral hemisphere’. The only codes for siderosis in the classification are that for lung or eye. The Neurologists I consulted said none of the possible codes (G31.-, G37.-, G93.8, G93.9, R29.88, R90.0, R90.8) are really appropriate.

However, in the absence of a better code he suggested that we use G93.8 Other specified disorders of brain and free text the code description.  

Response

Agree, assign code G93.8 Other specified disorders of brain and use free text to specify condition.

Created April 2011 (Herbal highs) 
Reviewed June 2023

Query

We have a patient who presented with poisoning/toxic effect from synthetics/synthetic cannabis.

Clinical notes indicate that Emergency Department as well as Mental Health services have seen and treated a number of users of synthetic drugs.

Please advise the appropriate codes to assign for poisoning/toxic effect of synthetics/synthetic cannabis and how synthetic drugs are to be coded for inpatient episodes of care in general.

Response

The Institute of Environmental Science and Research (ESR) and the Ministry’s National Drug Policy Team advised that T43.8 Other psychotropic drug, NEC is the most appropriate code to assign for synthetic drugs.

For cases of poisoning due to synthetic cannabis assign diagnosis code T43.8 Other psychotropic drug, NEC and add free text to capture condition for example, ‘Poisoning from synthetic cannabis’ with the appropriate external cause codes. Synthetic drug products may be known by various names. 

Psychotropic drug NEC
- specified NEC..........T43.8 - X41 - X61 - Y11

For cases where the documentation is acute intoxication, harmful use etc the diagnosis code to assign is F19 Mental and behavioural disorders due to multiple drug use and use of other psychoactive substances and add free text to capture the condition and include the wording ‘synthetic' and/or specify the synthetic drug name if documented.

Background Synthetic Cannabinoids
Synthetic cannabis is smokeable plant material that has been adulterated with one or more chemical compounds that are referred to as synthetic cannabinoids. The synthetic cannabinoids are added to the dried plant material so that it can be smoked in the same way as cannabis. As there currently are no approved products in New Zealand it is illegal to import or sell these synthetic cannabinoids or products that contain them. Synthetic cannabinoid products are also known as herbal highs, cannabinoids, synnies, synthetics, and party pills.

Reference: ESR – Synthetic Cannabis (PDF, 302 KB)

Created August 2020
Reviewed June 2023

Query

A 56-year-old male was admitted with decompensated heart failure, started on fluid restriction and IV diuresis with frusemide infusion. Patient developed acute kidney failure secondary to IV diuretic therapy, then developed uraemic pericarditis secondary to the acute kidney failure. Patient does not have a history of chronic kidney failure. 

Following the ICD-10-AM Alphabetic Index, uraemic pericarditis leads to a dagger and asterisk code combination of N18.5 Chronic kidney disease, stage 5 and I32.8 Pericarditis in other disease classified elsewhere. 

As the ICD-10-AM Alphabetic Index is a dagger and asterisk code combination should the Index be followed even though the patient has no history of chronic kidney failure?   

Pericarditis
- uraemic N18.5†, I32.8*

Response

Uraemic pericarditis typically occurs in patients with chronic kidney failure, which is supported by the ICD-10-AM Alphabetic Index with the dagger and asterisk code combination.

As there is no history or documentation of chronic kidney failure, clinical coders should seek clarification of the diagnosis ‘uraemic pericarditis’ from the clinician. Where it is not possible to clarify with the clinician, clinical coders must adhere to the classification convention ‘The Dagger and Asterisk System’ from the ICD-10-AM Alphabetic Index and Tabular List, and ACS 0001 Principal Diagnosis and assign the dagger and asterisk code combination of N18.5 Chronic kidney disease, stage 5 and I32.8 Pericarditis in other disease classified elsewhere. Free text should be used to add specificity.

Created Aug 2024

Query

Patient was admitted for abscess of shoulder. During the admission the clinical team persuaded the parents to allow vaccination with Infranrix-IPV (DTaP-IPV). Should vaccination/immunisation diagnosis and procedure codes be assigned?

Response

Vaccination/immunisation administered during an inpatient episode of care is not coded as per point 8. Drug treatment/pharmacotherapy/prescription of drugs from ACS 0042 Procedures normally not coded. However, if any of the three criteria are meet from ACS 0042, that is, a cerebral anaesthesia is required, it is the principal reason for a same day episode of care, a specialty standard provides instruction (eg, ACS 1500 Diagnosis sequencing in obstetric episodes of care, ACS 0113 Coronavirus disease 2019 (COVID-19)), diagnosis and procedure codes may be assigned. Vaccination/immunisation may also be coded where there is a specific coding rule providing instruction.

Vaccination/immunisation information is reported to the Aotearoa Immunisation Register (AIR). Therefore, all vaccination/immunisation activity is captured in the register. 

Created May 2024

Query

Clinical documentation states valgus osteoarthritis of the knee. Is it necessary to assign a diagnosis code for valgus (or varus) deformity in addition to a code for the osteoarthritis?

Response

Osteoarthritis of the knee can occur on the inner side or outer side of the knee joint, which can lead to a knee deformity (eg, genu varus, genu valgus).

Osteoarthritis is a synonym for arthrosis or osteoarthrosis and is classified to subchapter ‘Arthrosis (M15-M19)’. The lead term ‘Arthrosis’ in ICD-10-AM Alphabetic Index includes the non-essential modifier (deformans). Therefore, it is not necessary to assign an additional diagnosis code for clinical documentation of valgus or varus osteoarthritis.

Where clinical documentation indicates a valgus or varus deformity that is not relating to osteoarthritis and meets ACS 0001 Principal diagnosis or ACS 0002 Additional diagnoses the deformity may be coded.

Created October 2015
Reviewed June 2023

Query

Should petechial rash be coded as an additional diagnosis when documented with viral illness or can it be treated as a typical symptom of the viral illness? If it should be coded, is R21 Rash and other nonspecific skin eruption or R23.3 Spontaneous ecchymoses the most appropriate code?

Response

The presence of a petechial rash with a viral illness/infection is a common symptom. However, in some cases a petechial rash may be an indication of a more serious condition and requires further investigations. Therefore, where the petechial rash meets ACS 0002 Additional diagnoses criteria it should be coded in addition to the viral illness.

Assign R23.3 Spontaneous ecchymoses for documentation of petechial rash and use free text to specify the condition.

Where the petechial rash does not meet ACS 0002 Additional diagnoses criteria use free text on the viral illness code descriptor to specify the rash for example, B34.9 Viral illness with petechial rash on both hands.