Q&A: Coding hypoxic-ischemic encephalopathy

Q: Can you discuss the nuances of coding hypoxic-ischemic encephalopathy (HIE) in the newborn period and beyond?

A: We all know that CDI is rife with gray areas. In fact, it is what keeps many of us engaged in the quest for CDI truth, and that trait, rarely satisfied, is what keeps an expert CDI professional in a perpetual state of learning. As a result, I've done quite a bit of research on the clinical and coding history of HIE. In doing so, I discovered an often-overlooked caveat that I think minimizes the confusion in coding HIE beyond the newborn period.

When selecting a code for HIE, you are presented with options for unspecified, mild, moderate, or severe. HIE severity should be coded and calculated (at the time of presentation) using the Sarnat scale; however, it is important to understand the history of this scale to appropriately apply the HIE code.

The Sarnat scale is utilized to determine the severity of the HIE at a point in time for full-term or near full-term infants, typically through repeated evaluations within the first six hours of life. However, HIE is sometimes documented in preterm infants, and in such instances, it would not be appropriate to determine severity using the Sarnat scale. Additionally, the Sarnat scale should not be utilized when HIE is captured after the infant is 28 days old.

Some suggest that HIE should not be coded throughout the patient’s lifespan even when it is documented. The rationale is that coders should code only the outcome of the HIE, not the HIE itself. However, this is not supported by the ICD-10-CM Official Guidelines for Coding and Reporting guidance for carrying diagnoses throughout the lifespan (p. 72). Furthermore, following the integral/non-integral recommendations in the Official Guidelines for Coding and Reporting (p. 13), one could defensibly code HIE if properly documented along with its sequelae, as it is common for disabilities secondary to HIE to not present until the child is at least two years old and progressing (or not progressing) in development. Also, the manifestation of HIE-related disabilities varies, so truly, there isn’t a set of diagnoses that are integral to HIE; therefore, both the HIE and the outcomes could be coded if documented properly.

While many continue to wrestle with this topic, I believe this is the best guidance to give on this subject when asked.

Editor’s note: Amy Bush, BS, RN, MJ, CCDS, CCS, clinical documentation specialist III at Cooper Health answered this question. Contact her at bush-amy@CooperHealth.edu.