Q&A: Choosing between AKI and hypovolemia as principal diagnosis

Q: We recently had a situation where a patient was admitted for syncope workup and all the workups were negative except for incidental findings of acute kidney injury (AKI). The physician documented “AKI likely 2/2 hypovolemia. Treatment focus is to trend creatinine levels and hydration.” Would the AKI or hypovolemia be sequenced as the principal diagnosis in this case?

A: With the information in your question, I would likely identify the AKI as the reason for admission. It’s difficult to be certain without review of the entire record though. My reasoning is that the hypovolemia and the AKI were identified as both present on admission and the treatment was directed towards both.

When you look at the code for AKI within the tabular list (N17), there’s a note to “code also” that tells us to also code the associated underlying condition if known. “Code also” notes do not offer sequencing advice, so depending on the circumstances of the admission, either the AKI or the underlying condition could be sequenced first.

I’d also encourage you to review section 2, p. 102, of the Official Guidelines for Coding and Reporting, to brush up on the rules related to principal diagnosis selection.

Editor’s Note: Laurie L. Prescott, RN, MSN, CCDS, CDIP, CRC, CDI education director at HCPro in Middleton, Massachusetts, answered this question. Contact her at lprescott@hcpro.com. For information regarding CDI Boot Camps visit www.hcprobootcamps.com/courses/10040/overview.