A professional medical billing company based in the United States, Outsource Strategies International provides medical coding services for diverse specialties.

In today’s podcast, Meghann Drella, one of our Senior Solutions Managers, discusses the importance of good documentation for accurate coding of acute kidney injury.

Hello and welcome to our podcast series. My name is Meghann Drella and I'm a Senior Solutions Manager here at Outsource Strategies International (OSI). Today we'll be discussing acute kidney injury and supporting documentation for accurate coding.

Acute kidney injury (AKI) is a serious condition caused when the kidneys stop working suddenly over a very short period of time (usually 48 hours or less). Several U.S. studies have indicated an increasing incidence of dialysis-treated acute kidney injury since the late 1990s.

Acute kidney injury failure or acute renal failure also known as AKI may be reversible with immediate and proper treatment. Chronic kidney disease refers to lasting damage to the kidneys that can get worse over time and even lead to kidney failure, or end-stage renal disease (ESRD).

00:48 Criteria for validating diagnosis of AKI

The three main criteria used to validate a diagnosis of AKI:

  • RIFLE Classification-Risk, Injury, Failure, Loss and End-stage kidney disease. When using the RIFLE Classification system for staging of severity, AKI represents stage III.
  • AKIN Classification-Acute Kidney Injury Network. This modified version of the RIFLE criteria was established in 2007.
  • Classification-Kidney Disease Improving Global Outcomes. Released in 2012, this classification adds to the RIFLE and AKIN criteria already in use.

01:27 Clinical indicators for AKI diagnosis

When acute kidney injury (AKI) is documented, the clinical indicators for the condition should be met to report the correct ICD-10 code for AKI. The standardized clinical indicators to help diagnose AKI are based on the timing and amount of reduction in kidney function. The standardized clinical indicators for AKI diagnosis are as follows:

  • Decreased urine production
  • Edema
  • Confusion
  • Fatigue/lethargy
  • Nausea
  • Abdominal pain
  • Metal taste in mouth
  • Increased BUN
  • Increased serum creatinine
  • Increased potassium
  • Anemia
  • Proteinuria
  • Metabolic acidosis
  • Seizures
  • Coma
  • Abnormal GFR
  • Chest pain/pressure

However, experts point out that though the presence of these criteria in the documentation can help ensure the appropriateness of reporting a code for AKI, physician verification is necessary to use them to assign a code.

The Uniform Hospital Discharge Data Set (UHDDS) states that for a diagnosis to qualify for reporting, one of the following five criteria must be met:

  • Clinical evaluation
  • Therapeutic treatment
  • Diagnostic procedures
  • Extended length of hospital stay, and
  • Increased nursing care and/or monitoring

In order to assign the ICD-10 code for AKI as a principal diagnosis or co-morbidity or as a complication of care, the criteria for official coding guidelines, Uniform Hospital Discharge Data Set (UHDDS) definition, clinical criteria, and physician or other qualified health care professional documentation must be met.

While coders usually code correctly according to coding rules and regulations, payer denials of AKI in patients with CKD are attributed to lack of sufficient clinical support or documentation within the record or misdiagnosis by the physician, according to a 2019 article published by the Association of Clinical Documentation Integrity Specialists (ACDIS).

03:19 AKI coding tips

Some tips to accurately code AKI are as follows -

  • As there are several different codes to report the diagnosis of acute kidney injury and/or acute renal failure, code assignment should not be based on ancillary test results or therapies alone.
  • Diagnosis of AKI should be clearly documented and it should be validated by both the physician or other qualified health care professional documentation, and clinical criteria.
  • To be certain that the physician’s diagnosis is clinically validated, coders should know which criteria their facility uses to diagnose AKI.
  • The instructional notes within the ICD-10 Index as well as Exclude1 and Excludes2 notes should be followed when coding AKI/ARF.
  • The underlying condition/cause should be also reported if the cause of AKI/ARF has been identified.

I hope this helps, but always remember that documentation as well as a thorough knowledge of payer regulations and guidelines is critical to ensure accurate reimbursement for the procedures performed.

Thank you for joining me and stay tuned for my next podcast.