Gastroenterology Coding Alert

Question: A patient had an ERCP and was sent home. Our doctor issued a prescription for the drug Axid to treat an ulcer he found during the procedure. Patient later presents at the emergency department with nausea and vomiting, and our doctor was called in to examine her. I plan to use 787.01 (nausea with vomiting) as the primary diagnosis, but would it be appropriate to use E879.9 (other procedures, without mention of misadventure at the time of procedure, as the cause of abnormal reaction of patient, or of later complication, unspecified procedure) in addition?

Georgia Subscriber  
Answer: The E code is probably inappropriate and unnecessary, especially since you do not know the exact cause of the patients nausea. E codes are a supplemental classification of external causes of injury or poisoning and can be reported only as a secondary diagnosis. Use of E codes among gastroenterology practices is probably limited to the following codes:
  E858.4 accidental poisoning by other drugs; agents primarily affecting gastrointestinal system
  E861 accidental poisoning by cleansing and polishing agents, disinfectants, paints, and varnishes
  E864 accidental poisoning by corrosives and caustics, not elsewhere classified
  E930-E949 drugs, medicinal and biological substances causing adverse effects in therapeutic use
  E950-E959 suicide and self-inflicted injury
  E980-E989 injury undetermined whether accidentally or purposely inflicted
  E985 injury by firearms, air guns and explosives, undetermined whether accidentally or purposely inflicted.  
Note: All codes should be coded to the highest level of specificity. Often a fourth digit is required.
 
The payer may interpret E879.9 to mean the gastroenterologist did something wrong to cause the patients nausea and deny payment for the emergency-room visit. And since the nausea could have been caused by many things, such as the Axid, you should not use this code unless specifically directed by the gastroenterologist to do so.