Health Information Management

Q&A: Assigning a principal diagnosis for a patient with pneumonia and atrial fibrillation

JustCoding News: Inpatient, July 18, 2012

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QUESTION: A patient is admitted with pneumonia and atrial fibrillation and both are present on admission. The patient receives antibiotics for the pneumonia and a pacemaker during the stay, but undergoes no other procedures. Does the procedure automatically make ICD-9-CM code 427.31 for the atrial fibrillation the principal diagnosis?

ANSWER: As in any inpatient admission, we can only answer the question based on the information provided. In this particular scenario, a couple of specific coding guidelines would be helpful. First, if a patient is admitted for two conditions that are treated with equal intensities and no Alphabetic Index, Tabular List, or sequencing guidelines exist, the coder may select either condition as the principal diagnosis, according to Official Guidelines for Coding and Reporting. The exact language is as follows:

 Section II. Selection of Principal Diagnosis
C. Two or more diagnoses that equally meet the definition for principal diagnosis
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.
In this instance, no specific instructions or sequencing guidelines would apply. However, the two conditions likely would not be considered as equally treated during this admission because the physician performed a surgical procedure to treat the atrial fibrillation and managed the pneumonia medically with antibiotics.
Additionally, guidance from the AHA Coding Clinic, 2nd quarter 2011 states:
The principal procedure is one that was performed for definitive treatment rather than one performed for diagnostic or exploratory purposes, or was necessary to take care of a complication. If two procedures appear to meet this definition, then the one most related to the principal diagnosis should be selected as the principal procedure.
The principal procedure of a pacemaker implantation was directly correlated to a condition that meets the criteria of being a principal diagnosis (i.e. the atrial fibrillation). It would be highly unusual for this case to be viewed as meeting the criteria to assign pneumonia as the principal diagnosis with the principal procedure as a pacemaker implantation. When this admission is coded in such a manner it would likely be assigned to MS-DRG 981 (Extensive OR procedure Unrelated to Principal Diagnosis without MCC/CC – RW 1.7404 or ~$9,000) unless a another diagnosis is identified as a CC or MCC. It would appear more appropriate to assign this admission to MS-DRG 242 (Permanent Cardiac Pacemaker Implant with MC – RW 3.6835 or ~$20,000) given this limited information.
Editor’s Note: Shannon E. McCall, RHIA, CCS, CCS-P, CPC, CEMC, CPC-I, CCDS, director of HIM and coding for HCPro, Inc., in Danvers, Mass., answered the previous question.

This answer was provided based on limited information that was submitted to Be sure to review all documentation specific to your own individual scenario before determining appropriate code assignment.
Need expert coding advice? Submit your question to Senior Managing Editor Andrea Kraynak, CPC, at, and we’ll do our best to get an answer for you.

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