Pathology/Lab Coding Alert

Then use the coding scenarios to test your understanding

CPT revised five culture codes this year. By adding "aerobic" to code definitions, among other changes, CPT Codes 2004 clarifies the intent of existing blood, stool and other culture codes. Study the changes in the following table, which compares the new and old code definitions. Then try to code the following scenarios, and check yourself with the expert's solutions.

Use 3 Scenarios to Hone Your Coding Skills

Scenario 1: A physician requests a comprehensive enteric pathogens culture for a patient with diarrhea (787.91, Diarrhea NOS). The lab performs a stool culture for Salmonella/Shigella and additional plates for Campylo-bacter, Yersinia, and Vibrio. Findings were positive for Yersinia spp. The lab performs additional biochemical panels using Vitek Gram-Negative Identification (GNI) card, and identifies the isolate to the species level.

Solution 1: Code the screening culture for Salmonella/Shigella as 87045 (Culture, bacterial; stool, aerobic, with isolation and preliminary examination [e.g., KIA, LIA], Salmonella and Shigella species). Report one unit of 87046 (... stool, aerobic, additional pathogens, isolation and presumptive identification of isolates) for the three additional plates for Campylobacter, Yersinia and Vibrio. For the definitive identification of the Yersinia isolate to the species level using biochemical panels, report 87077 (... aerobic isolate, additional methods required for definitive identification, each isolate).

Scenario 2: A patient presents with diarrhea and red-tinged stools (578.1, Blood in stool). The physician requests a routine feces culture, also specifying a test for enterohemorragic E. coli based on bloody stool. The lab cultures for the organisms listed as "routine" on the requisition form: Salmonella, Shigella and Campylobacter. As requested, the lab performs an additional plate for E. coli 0157.

Solution 2: For the Salmonella/Shigella, report 87045. Regardless of the findings, also code one unit of 87046 for the Campylobacter and E. coli 0157 plates.

Scenario 3: A patient develops diarrhea on the fourth day of hospitalization with no previous gastro-intestinal symptoms. Suspecting hospital-related Clostridium difficile infection, the attending physician requests culture and antigen tests for "C-diff." The lab performs a culture for Clostridium difficile, and a direct test from the stool specimen for C. difficile toxin A by enzyme immunoassay (EIA) technique.

Solution 3: Report the culture as 87081 (Culture, presumptive, pathogenic organisms, screening only). Because the physician requested a culture to screen for a specific organism, not a general aerobic (87045) or anaerobic (87075) culture, you should use 87081.

And, report 87324 for toxin A (Infectious agent antigen detection by enzyme immunoassay technique, qualitative or semiquantitative, multiple step method; Clostridium difficile toxin[s]).

If the lab tested for C. difficile toxin A by an optical method, you would report 87803 (Infectious agent antigen detection by immunoassay with direct optical observation; Clostridium difficile toxin A). For toxin B testing by tissue culture, you would use 87230 (Toxin or antitoxin assay, tissue culture [e.g., Clostridium difficile toxin]).

-- William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore., helped prepare these scenarios and solutions.