From the forum: Coding AHRF with underlying etiology

Q: A patient was admitted for acute hypercapnic respiratory failure (AHRF) and acute heart failure with preserved ejection fraction exacerbation, hypertension, thought to be secondary to untreated obesity hypoventilation syndrome/obstructive sleep apnea (OHS/OSA) with improvement in respiratory status following diuresis and initiation of bilevel positive airway pressure.

Our providers believe the underlying etiology of the patient’s heart failure is due to their poorly treated OHS/OSA, and that the diagnosis should not go to the heart failure or respiratory failure code but possibly the OHS/OSA. What are your thoughts on the diagnosis for this case?

A: In any case where I am considering multiple diagnoses as my principal diagnosis, I like to first review the guidelines. The ICD-10-CM Official Guidelines for Coding and Reporting in section I A. 13 indicate that there are situations where conditions have both an underlying etiology and body system manifestations. There is a coding convention that requires the underlying condition be sequenced first, if applicable, followed by the manifestation. Wherever this combination exists, there's a “use additional code” note with the etiology code, and a “code first” note with the manifestation code. These instructional notes show the proper sequencing order of the codes, which is etiology followed by manifestation. None of the diagnoses in this scenario have those instructional notes.

The guidelines in section II also state, “The principal diagnosis is defined in the Uniform Hospital Discharge Data Set (UHDDS) as ‘that condition established after study to be chiefly responsible for occasioning the admission of the patient to the hospital for care.’ ” They go on to state in section II C., “In the unusual instance when two or more diagnoses equally meet the criteria for principal diagnosis as determined by the circumstances of admission, diagnostic workup and/or therapy provided, and the Alphabetic Index, Tabular List, or another coding guidelines does not provide sequencing direction, any one of the diagnoses may be sequenced first.”

Some things to consider when selecting the principal diagnosis with the guidelines in mind:

• Are the diagnoses clinically valid? Would they stand up to an audit?
• Which condition bought the bed? We know that if there are two or more conditions that are equally treated and present on admission, either could be the principal diagnosis.
• Which condition prompted the provider to admit the patient?
• What was the focus of the care or required the majority of resources?
• Did any condition require a higher level of care, like a telemetry or ICU bed? If so, which one?
• Which are acute conditions? (Chronic conditions are vulnerable to audits.)
• Could any of these conditions be treated without an inpatient admission? If so, I would rule that condition out as the principal diagnosis.

I hope this helps!

Editor’s note: Kelly Sutton, RN, BSN, MHL, CCDS, CCS, CDI education specialist at ACDIS/HCPro, answered this question on the ACDIS Forum. Contact her at kelly.sutton@hcpro.com. To learn more about participating on the Forum, click here.