Q&A: Code sequencing for cardiac arrest and ventricular tachycardia

Q: A patient was admitted to the emergency department (ED) via ambulance. The emergency medical technician (EMT) noted that the patient was in full cardiac arrest, with ventricular tachycardia (VT). The EMTs shocked the patient via defibrillator en route to hospital. What would we assign for a principal diagnosis or secondary diagnosis?

A: If the patient was found in full cardiac arrest per the EMT notes, first use the information and/or clinical indicators within the EMT note to query the provider to make sure the physician carries over that diagnosis into the medical record. The only time coders can use information in an EMT note without having the provider state it in the medical record is for recording of the complete Glasgow coma scale. Usually, if the patient is transported via ambulance, the EMT note is scanned into the record, but not always. CDI staff should check and make sure a process is in place regarding the scanning of EMT reports into the medical record. Educate the emergency room staff on the importance of the information such documents contain.

In ICD-10-CM the codes would be I47.2, ventricular tachycardia, and code I46.9, Cardiac arrest, unspecified.

As far as the coding of these conditions, under (I46) cardiac arrest there is an Excludes 1 note for cardiogenic shock (R57.0), but if the cardiac arrest is due to an underlying cardiac condition (I46.2), there is a code first note for the underlying cardiac condition. If the cardiac arrest is due to “other” underlying condition (I46.8), the code first note is for the underlying condition, and we still have a code (I46.9) cardiac arrest, cause unspecified. There is also an Excludes 1 note for ventricular tachycardia, which states that if the documentation provides specificity regarding the type of tachycardia, don’t assign the unspecified code, and also a code first note when the tachycardia is complicating abortion, ectopic or molar pregnancy, or an obstetric procedure.

In this question, the patient, per EMT, was in full cardiac arrest with ventricular tachycardia. The CDI specialist needs to know if  the VT caused the cardiac arrest? If it did, then follow the instructions within the conventions of the code set. We want to make sure we are not (possibly due to our clinical background) assuming that one condition caused another. We want to make sure provider documentation states that conclusion, removing any subjectivity.

If cardiac arrest is the principal diagnosis with the ventricular tachycardia as a secondary diagnosis, the codes map to DRG 298 with a relative weight of 0.4395. If the ventricular tachycardia is the principal diagnosis and the cardiac arrest is a secondary diagnosis, it maps to DRG 310 with a relative weight of 0.5627.

Per the Official Guidelines for Coding and Reporting (Section II.C), 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 guideline does not provide sequencing direction, any one of the diagnosis may be sequenced first.

Translated, this means that the CDI staff need to determine the “focus” of treatment for this patient at the time of the admission. Some considerations to make prior to querying include:

• Severity of each condition
• The condition that puts the patient at greater risk
• The complexity of care
• Evaluation and management
• Level of care required for each condition

If, after taking everything into consideration, you remain unsure as to which condition should be coded as the principal diagnosis, “best practice” would be to query the provider and have them document the reason for admission.

Editor’s Note: Sharme Brodie RN, CCDS, CDI education specialist and CDI Boot Camp instructor for HCPro in Middleton, Massachusetts, answered this question. For information, contact her at sbrodie@hcpro.com. For information regarding CDI Boot Camps offered by HCPro, visit www.hcprobootcamps.com/courses/10040/overview.