Pulmonology Coding Alert

Question: A patient with myasthenia gravis with acute exacerbation is admitted to the hospital due to acute respiratory failure. How should I code the diagnosis?

Montana Subscriber

Answer: Report 518.81 (Acute respiratory failure) as the primary diagnosis. For your secondary diagnosis, code 358.01 (Myasthenia gravis with [acute] exacerbation). Remember, you may designate acute respiratory failure as the principal diagnosis if it was the reason for admission, or you may list it as an associated condition if it occurs after admission. According to Coding Clinic (see Coding Clinic, first quarter 2005, page 4, and Coding Clinic, fourth quarter 2004, page 139), this applies to respiratory failure resulting from either a respiratory or nonrespiratory condition unless the ICD-9-CM manual's index or tabular list instructs otherwise.