Cardiac Arrest in the ED: What to Document and Code

Coders need to know when and how the cardiac arrest occurred.

There are approximately 350,000-400,000 cases of cardiac arrest arising outside of the hospital setting per year, and not all of these patients make it to the emergency department. The incidence in any given hospital on any given shift is somewhere between zero and what you see on TV medical shows.

In March, I am doing a webinar on clinical documentation improvement (CDI) in the emergency department (ED), and I felt there were certain conditions or situations encountered in the ED that needed specific mention and attention. Cardiac arrest was the first one that came to mind.

The first scenario I considered was how to code a cardiac arrest with successful resuscitation or return to spontaneous circulation (ROSC), prehospital. I asked around and was surprised that I was not alone in being unsure whether you code the cardiac arrest if it had resolved by presentation.

On the one hand, the condition is no longer present. We have enough trouble getting confirmation and coding of diagnoses that resolve in the ED, in scenarios in which you might hear, “I don’t know if the patient had respiratory failure in the ED before they hit the floor. I didn’t see them down there.”

On the other hand, you are doing the workup because it occurred. If a patient has a symptom that elicits a work up, but it has resolved by the time they are brought into the ED, you still can code it, such as with syncope or altered mental status.

If there are residual issues or deficits, those could be definitive diagnoses. For instance, if the patient has anoxic brain damage and is in respiratory arrest and on a ventilator, those could be the captured diagnoses. However, I think leaving out the cardiac arrest would be leaving out a key part of the story.

Potentially you could use Z86.74, Personal history of sudden cardiac death, to add the element to the story, but if the patient is one of the lucky few who has complete recovery, this is not an acceptable principal diagnosis, and it really should be reserved for the subsequent encounter. Perhaps Z03.89, Encounter for observation for other suspected diseases and conditions ruled out?

I checked the ICD-10-CM Official Guidelines for Coding and Reporting for FY 2019. Nothing. I found guidelines regarding cardiac arrest in Coding Clinic from February 1988, updated in the ICD-10-CM and -PCS Coding Handbook, but these were all regarding patients who were still in arrest at the time of arrival to the ED.

This intellectual exercise reminded me of debates I had previously about whether you code cardiac arrest in the hospital if the patient is not successfully resuscitated. For that, I and Coding Clinic have a definitive answer. If a patient sustains cardiac arrest in the hospital and you attempt (or are successful at) resuscitation, you code it and the procedures performed. If the patient dies during the admission, the cardiac arrest will not serve as a major complication or comorbidity (MCC).

If the patient dies in-house from the cardiac arrest without attempt at resuscitation, such that the cardiac arrest is their terminal event, you do not code the arrest. The fact that the patient died in the hospital is embedded in their discharge status and there is an alternate mechanism to report inpatient deaths.

The cardiac arrest codes are found in I46. The options are I46.2, Cardiac arrest due to an underlying cardiac condition, I46.8, Cardiac arrest due to other underlying condition, and I46.9, Cardiac arrest, cause unspecified. I46.2 and I46.8 would be secondary diagnoses because if you establish the underlying cause, that defines the principal diagnosis. If the cause is not determined, the I46.9 code could serve as principal diagnosis.

Back to the original dilemma.

My conclusion is that even if the patient is resuscitated pre-hospital, the workup and treatment continue in the emergency department and intensive care unit. This is not a diagnosis that “relates to an earlier episode and has no bearing on the current hospital stay,” which would exclude it per Uniform Hospital Discharge Data Set (UHDDS) rules. I think a cardiac arrest is clinically relevant and should be coded.

The last facet of documenting the emergency department cardiac arrest is to be sure to take inventory of the resultant conditions. Did the patient fall and sustain fractures or lacerations? Were there fractured ribs from CPR? Are there sequelae such as coma or anoxic brain injury, respiratory failure or arrest, shock liver, acute kidney injury, etc.? Make precise, thorough, and exhaustive diagnoses with appropriate linkage.

If any of you have queried Coding Clinic about this pre-hospital resuscitation question and have their official response, please contact us at cbuck@medlearnmedia.com. I will update this article. Thanks!

Program Note:

Listen to Dr. Erica Remer report this story live today on Talk Ten Tuesday at 10 a.m. EST.

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