Part 2: Specificity Coding of Acute Kidney Injury (AKI) and Sequencing | AKI Series
Kim Carrier RHIT, CDIP, CCS, CCS-P
Director of Coding Quality Assurance
AHIMA Approved ICD-10-CM/PCS Trainer
As discussed in Part 1 of this series, AKI/ARF is a common diagnosis that coders see daily. In Part 2, we are going to focus on the different types/specificity of AKI/ARF. We’ll learn what they mean, as well as how to code the diagnosis.
Coding AKI/ARF
There are several different codes that can be used to report the diagnosis of acute kidney injury and/or acute renal failure. This is one example of why diagnoses should not be coded by the use of only the Alphabetic Index within ICD-10-CM. It is imperative that coders also use the tabular before final determination of the code is made. If the coder only looks in the Alphabetic Index under injury | kidney | acute, the index goes to N17.9 (acute renal kidney failure, unspecified). If the type or cause of the AKI/ARF is further specified then N17.9 would not be appropriate. However, if the coder begins the search with the term “failure” there will be several selections for further specificity under failure | renal | acute.
When coding AKI/ARF, there are instructional notes within the ICD-10-CM Index for coders to follow as well as Exclude1 and Excludes2 notes. When a cause for the AKI/ARF has been identified the underlying condition/cause should be reported also. Traumatic kidney injuries are reported with codes from S37.0-.
- N17.0—Acute kidney failure with tubular necrosis. Coders see ATN (acute tubular necrosis) documented in patient records often. This is a common diagnosis that a query is necessary for clarification. If the AKI has progressed to ATN then the code N17.0 is reported and not the code default in the Alphabetic Index for AKI. Other terms that may be used to describe ATN could be renal tubular necrosis or tubular necrosis. These are terms that should be searched for when AKI is documented to see if there could be further specificity in code assignment. ATN occurs when there is damage to the kidney tubule cells. These are the cells that reabsorb fluid and minerals in the kidney from urine as it is forming. When this occurs, there is a lack of oxygen reaching the cells of your kidneys.
- N17.1—Acute kidney failure with acute cortical necrosis. This isn’t as commonly documented as ATN but coders will see this. If the AKI has progressed to acute cortical necrosis then N17.1 is reported and not the code default in the Alphabetic Index for AKI. Other terms that may be used to describe acute cortical necrosis can be cortical necrosis and renal cortical necrosis. This is a rare cause of AKI and is due to ischemic necrosis of the renal cortex. This is typically caused by diminished/reduced renal arterial perfusion. Intravascular coagulation, vascular spasm and microvascular injury are the main causes of this type of AKI.
- N17.2—Acute kidney failure with medullary necrosis This isn’t as commonly documented as ATN but coders will see this. if the AKI has progressed to with medullary necrosis then N17.2 is reported and not the code default in the Alphabetic Index for AKI. Other terms that may be used to describe acute medullary necrosis can be acute medullary [papillary] necrosis or renal medullary necrosis. This is caused by infarction involving the medulla and referred to as necrotizing papillitis.
- N17.8—Other acute kidney failure. This code is reported when there is a specificity to the diagnosis of AKI (non-traumatic) but is not one of the ones above.
- N17.9—Acute kidney failure, unspecified. This code is reported when only AKI/ARF is documented without any further specificity documented.
Sequencing of AKI/ARF
There are many different scenarios that would dictate the sequencing of AKI/ARF. The definition of PDX should always be used when determining the PDX. Remember that just because the condition may be present on admission does not necessarily mean that it is appropriate as PDX. Chapter specific guideline must be followed as well as other coding guidance that your record may require. Some of the most common specific guidelines that come to mind are sepsis, OB/delivery records and transplant complications. Let’s look at an example of each of these:
- Just in my experience, I think sepsis is one of the most common conditions that are associated with a diagnosis of AKI. If a patient presents with high fever, elevated WBC of 20,000, altered mental status. Labs show that the patient has AKI based on elevated creatinine of 4.3 that is way above the baseline for this patient and they are admitted for workup and treatment. This was a complicated stay with several physicians documenting daily. The fever and elevated WBC count is documented to be caused by sepsis. The AKI is further documented as ATN due to sepsis and there is no contradictory documentation that requires a query. The creatinine on discharge had improved to 1.1 which is the patient’s baseline. In this case, ATN would NOT be appropriate as the PDX since it is related to sepsis. There are specific guidelines that state to code the systemic infection first and then any organ dysfunction associated with the diagnosis. Sepsis would be the PDX in this case followed by severe sepsis without shock and ATN as additional SDX codes.
- Patient presents for emergency cesarean section due to heavy bleeding and suspicion of placenta abruption. She is 38 weeks pregnant. Patient does undergo the cesarean without complication other than blood loss. The abruption of the placenta is confirmed. Due to blood loss, the patient is watched closely and is noted to develop AKI/ARF on day two post discharge. This is addressed quickly with IV fluids and the patient does improve over the next few days. Her labs are better each day and the decision of discharge was made. In this case, the AKI/ARF would not be the PDX for two reasons: 1) It occurred after surgery/cesarean, and 2) OB guidelines would be followed and a code from Chapter 15 would be reported as codes from this chapter always take sequencing priority. A code from Chapter 15 for the AKI/ARF would be reported. No additional code for the AKI/ARF would be necessary since this is not further specified and the unspecified code does not provide any further specificity. Other codes for the weeks of gestation and single live birth would be reported as well as ICD-10-PCS for the cesarean.
- Patient presents with generally feeling unwell. They are four months s/p renal transplant that has been doing well during follow up visits. The patient states that she developed a virus a few days ago and has not been able to keep anything on her stomach for three days now. Patient is admitted due to symptoms and to monitor the kidney transplant status. The labs do show that the patient has AKI/ARF with creatinine extremely high at 6.1. The baseline creatinine for this patient since transplant has been 1.1-1.4. Aggressive treatment is begun and the labs show complete improvement in only 2 days of aggressive fluids. The diagnosis from the physician is AKI/ARF in a kidney transplant patient with recovery of full function by discharge. In this case, the AKI/ARF would not be appropriate as the PDX since the function of the transplanted kidney was impaired. Per recent coding guidance, this is coded as T86.19—other complication of kidney transplant and not T86.12—Kidney transplant failure since only the function of the organ was affected but the transplant has not truly failed.
Note: The old sequencing guidance from ICD-9-CM regarding AKI/ARF and dehydration has been clarified in 2019. The sequencing is based on the circumstances of admission and will be a case by case decision. There is no rule that states that the AKI/ARF must be sequenced first over dehydration.
References
cdc.gov/mmwr/volumes/67/wr/mm6710a2.htm
emedicine.medscape.com/article/1925597
americannursetoday.com/acute-kidney-injury
academic.oup.com/ck/article/6/1/8/468698
kidney.org/atoz/content/AcuteKidneyInjury#
mayoclinic.org/diseases-conditions/kidney-failure/symptoms-causes/syc-20369048
uofmhealth.org/health-library/aa115361
ICD-10-CM Alphabetic and Tabular Indexes
ICD-10-CM/PCS Coding Clinic, First Quarter 2019 Page: 12
ICD-10-CM/PCS Coding Clinic, Second Quarter 2019 Page: 7
ICD-10-CM Official Guidelines for Coding and Reporting FY 2020
Happy Coding!
The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.
Part 1: New 2021 CPT Codes | Integumentary System
This is Part 1 of a five part series on the new 2021 CPT codes. In this series we will explore the CPT changes for FY2021 and include examples to help the coder understand the new codes. For 2021 in general, there were 199 new CPT codes added, 54 deleted and 69 revised.
2020: Year in Review | Coding Education
In January, new CPT codes were released. There were 248 new CPT codes added, 71 deleted and 75 revised. Most of the surgery section changes were in the musculoskeletal and cardiovascular subsections. These included procedures such as skin grafting, breast biopsies, deep drug delivery systems, tricuspid valve repairs, aortic grafts and repair of iliac artery.
Coding Tip: New COVID-19 Codes Effective January 1, 2021
We have seen many updates and changes to COVID-19 (SARS-CoV-2) since the pandemic started. On January 1, 2021 we will see even more changes as outlined in this post. Also the CMS MS-DRG grouper will be updated to version 38.1 to accommodate the changes.
New Technology Add-On Payments (NTAP) For FY2021 – Part 4
In the previous three parts of this four-part series, we discussed the new ICD-10-CM diagnosis code changes, ICD-10-PCS procedure code changes and FY2021 IPPS changes. In this last Part 4 of the series, we will review the NTAP procedure codes and reimbursement add-on payments for FY2021.
New ICD Codes and IPPS Changes for FY2021 (ICD-10-CM Diagnoses changes) – Part 3
In the previous two parts of this four part series, we discussed the new ICD-10-CM diagnosis code changes and ICD-10-PC procedure code changes. In this session we will review the major IPPS changes for FY2021.
Subscribe to our weekly newsletter
Part 1: New 2021 CPT Codes | Integumentary System
This is Part 1 of a five part series on the new 2021 CPT codes. In this series we will explore the CPT changes for FY2021 and include examples to help the coder understand the new codes. For 2021 in general, there were 199 new CPT codes added, 54 deleted and 69 revised.
2020: Year in Review | Coding Education
In January, new CPT codes were released. There were 248 new CPT codes added, 71 deleted and 75 revised. Most of the surgery section changes were in the musculoskeletal and cardiovascular subsections. These included procedures such as skin grafting, breast biopsies, deep drug delivery systems, tricuspid valve repairs, aortic grafts and repair of iliac artery.
Coding Tip: New COVID-19 Codes Effective January 1, 2021
We have seen many updates and changes to COVID-19 (SARS-CoV-2) since the pandemic started. On January 1, 2021 we will see even more changes as outlined in this post. Also the CMS MS-DRG grouper will be updated to version 38.1 to accommodate the changes.
New Technology Add-On Payments (NTAP) For FY2021 – Part 4
In the previous three parts of this four-part series, we discussed the new ICD-10-CM diagnosis code changes, ICD-10-PCS procedure code changes and FY2021 IPPS changes. In this last Part 4 of the series, we will review the NTAP procedure codes and reimbursement add-on payments for FY2021.
New ICD Codes and IPPS Changes for FY2021 (ICD-10-CM Diagnoses changes) – Part 3
In the previous two parts of this four part series, we discussed the new ICD-10-CM diagnosis code changes and ICD-10-PC procedure code changes. In this session we will review the major IPPS changes for FY2021.
New ICD Codes and IPPS Changes for FY2021 (ICD-10-CM Diagnoses changes) – Part 2
This is Part 2 of a 4 part series on the FY2021 ICD-10 Code and IPPS changes. In this part, the ICD-10-PCS procedure codes are presented. For FY2021 ICD-10-PCS there are 78,115 total codes (FY2020 total was 77,571); 556 new codes (734 new last year in FY2020)…
New ICD Codes and IPPS Changes for FY2021 (ICD-10-CM Diagnoses changes) – Part 1
This is Part 1 of a 4 part series on the FY2021 changes to ICD-10 and the IPPS. In this part, we discuss some of the new ICD-10-CM diagnosis changes. Here is the breakdown: 72,616 total ICD-10-CM codes for FY2021; 490 new codes (2020 had 273 new codes); 58 deleted codes (2020 had 21 deleted codes); 47 revised codes (2020 had 30 revised codes)
Coding Tip: Reporting “Flash” Pulmonary Edema
Acute pulmonary edema is the rapid accumulation of fluid within the tissue and space around the air sacs of the lung (lung interstitium). When this fluid collects in the air sacs in the lungs it is difficult to breathe. Acute pulmonary edema occurs suddenly and is life threatening.
Client S: $556 increase/record reviewed
“Client S” is a small, not-for-profit, 40 bed micro-hospital in the Southeast. HIA performed a 65-record review this year for Client S and found an opportunity with 15 of them. 9 had an increased reimbursement with a total of $43,228 found.
Coding Tip: Glasgow Coma Scale Coding OCG Update for FY2021
The coma scale codes (R40.2-) can be used in conjunction with traumatic brain injury codes, acute cerebrovascular disease or sequelae of cerebrovascular disease codes. These codes are primarily for use by trauma registries, but they may be used in any setting where this information is collected. The coma scale may also be used to assess the status of the central nervous system for other non-trauma conditions, such as monitoring patients in the intensive care unit regardless of medical condition.
Coding Tip: Cardiac Arrest and Cardiac Shock
In the past, there had been an Excludes1 note at I46.- Cardiac arrest that excluded R57.0, Cardiac shock. HIA had also received a letter from AHA on a case in the past that had stated that only I46.- Cardiac arrest would be coded if both were documented. In addition, the Third Quarter Coding Clinic page 26 had a similar case that asked if both could be coded, and AHA had instructed that only I46.9, cardiac arrest, cause unspecified would be coded if both were documented and that the CDC would be looking at possible revision to the Excludes1 note.
Client X: Let’s Talk Numbers
A higher CMI corresponds to increased consumption of resources and increased cost of patient care, resulting in increased reimbursement to the facility from government and private payers, like CMS. We know that documentation directly impacts coding.
Coding Tip: Endarterectomy During Coronary Artery Bypass
Lately we have seen several cases where the endarterectomy was assigned along with the coronary artery bypass (CABG) procedure when being performed on the same vessel to facilitate the CABG. A coronary artery endarterectomy is not always performed during a CABG procedure, so when it is performed it becomes confusing as to whether to code it separately or not.
Coding Tip: Update – Coding COVID-19 When the Test is Negative
Assign code Z20.828, “Contact with and (suspected) exposure to other viral communicable diseases” for all patients who are tested for COVID-19 and the results are negative, regardless of symptoms, no symptoms, exposure or not as we are in a pandemic.
New ICD-10-PCS Procedure Codes for COVID-19
The Centers for Medicare & Medicaid Services (CMS) announced new procedure codes for treatments of COVID-19 – effective as of August 1, 2020. Among the new codes are Section X New Technology codes for the introduction or infusion of therapeutics including Remdesivir, Sarilumab, Tocilizumab, transfusion of convalescent plasma, as well as introduction of any other or new therapeutic substances for the treatment of COVID-19.
New Rule Helps Medicare ACOs During COVID-19 Pandemic
One common element in many value-based programs is risk adjustment using Hierarchical Condition Categories (HCCs) to create a Risk Adjustment Factor (RAF) score. This method ranks diagnoses into categories that represent conditions with similar cost patterns.
Part 5: Reasons for AKI Denials and Prevention | AKI Series
Why are so many AKI records being denied? It’s hard to give one answer for why so many AKI records are being denied lately, but most appear to be due to the multiple sets of criteria available for use in determining if a patient has AKI, as well as physician documentation. As stated in Part 3 of this series, there are three main criteria/classifications used to diagnose AKI.
Part 4: Is Documentation Present to Report Acute Kidney Injury/Failure? | AKI Series
In previous parts of this series we looked at the definitions of AKI/ARF, causes, coding and sequencing, and the common clinical indicators that patients present with that are diagnosed with this condition. In Part 4, we will look at the documentation that should be present to report the diagnosis without fear of denial, as well as when a query is needed to clarify the diagnosis.
Coding Tip: Z Code Reporting for COVID-19
If the facility does a COVID-19 test, and test is negative, do I need a diagnosis code. The answer is yes, you will report a Z-code. The Z-code depends on the record documentation and circumstances of testing. For any patient receiving a COVID-19 test, if negative, there MUST e a Z-code to describe why the test was taken. (Test negative for COVID-19 and MD does not override negative results).
Part 3: Clinical Indicators for Acute Kidney Injury/Failure | AKI Series
In the first parts of this series we looked at definitions of AKI/ARF, causes, coding and sequencing. In Part 3, we will look at what clinical indicators would possibly be present to support the diagnosis of AKI/ARF.
FY2021 Proposed Rule and Code Changes Highlights
The FY2021 IPPS Proposed Rule is out and here are some highlights from it regarding ICD-10 Code proposals. We will know if these changes are permanent after the public comment period is over on July 10, 2020 and CMS prepares the Final Rule, usually out by August 1.
Part 1: What is Acute Kidney Injury (AKI)? | AKI Series
This is part 1 in a series focused on coding of acute kidney injury (AKI) and/or acute renal failure (ARF). AKI/ARF is reported often, but is also one of the most common diagnosis found in denials.
Coding Tip: Covid-19 Diagnosis Coding Common Scenarios
With the proliferation of COVID-19 cases, we thought we would put together a quick reference listing of some of the common scenarios that coders have asked about. As with all coding, coders should follow Official Guidelines for Coding and Reporting and the COVD-19 Frequently Asked Questions document by the AHA.
Coding Tip: What is Single Path Coding?
The biggest reasons why some hospital systems are moving to single path coding is to eliminate duplicative processes and to optimize productivity. In addition, costs are reduced when only one coder “touches” the record and completes both types of coding.
Coding Tip: Reporting Vaping in ICD-10-CM | Effective on 4/1/2020
Effective with 4/1/2020 discharges, ICD-10-CM code U07.0 is used to report vaping -related disorders. ICD-10-CM code U07.0 (vaping related disorder) should be used when documentation supports that the patient has a lung-related disorder from vaping. This code is found in the new ICD-10-CM Chapter 22. U07.0 will be in listed in the ICD-10-CM manual under a new section: Provisional assignment of new disease of uncertain etiology or emergency use.
Telehealth and the Coronavirus
The US government and public-health officials are urging consumers to utilize telemedicine for remote treatment, fill prescriptions and get medical attention during the new coronavirus pandemic. The goal is to keep people with symptoms at home and to practice social distancing if their condition doesn’t warrant more intensive hospital care.
Coronavirus: Tips for Working from Home
Coronavirus: Tips for working from home. Companies around the world have told their employees to stay home and work remotely. Whether you’re a new to this concept or a work from home veteran, here’s some tips to staying productive from our #HIAfamily.
Part 3: Coder and CDI Communication Example | CDI Series
This is the final part of a three part series in which we address how coders can better interact with Clinical Documentation Improvement (CDI) professionals. In this part, we provide an actual example of an effective communication response to CDI.
Part 2: How Coders Can Address Coding Mismatches | CDI Series
This is part two of a three part series in which we address how coders can better interact with Clinical Documentation Improvement (CDI) professionals. In this part, we discuss mismatches and how to best go about resolving them. In part three we will provide a case example of best practice interaction.