A second look at the neostigmine morphine test.

In a prospective five-year study of 65 consecutive patients with upper abdominal pain the Neostigmine Morphine Test (NMT) was applied as a screen for biliary, ampullary, and pancreatic disease. Three facts emerged from this study: 1) the amylase and lipase were overly sensitive, but not specific and had only a 10 per cent predictive value for ampullary obstruction; 2) the bilirubin, alkaline phosphatase, and serum glutamic oxaloacetic transaminase (SGOT) were positive in patients with ampullary obstruction if they were postcholecystectomy but not so in patients with an intact gallbladder, which may be explained by the third observation; 3) the gallbladder can compensate for partial ampullary obstruction by dilatation five to ten times and by its ability to absorb 90 per cent of the water content of the bile. The Neostigmine Morphine Test is not a reliable screen for ampullary obstruction and positive findings must be confirmed by other studies.