Does this patient have acute cholecystitis?

CONTEXT Although few patients with acute abdominal pain will prove to have cholecystitis, ruling in or ruling out acute cholecystitis consumes substantial diagnostic resources. OBJECTIVE To determine if aspects of the history and physical examination or basic laboratory testing clearly identify patients who require diagnostic imaging tests to rule in or rule out the diagnosis of acute cholecystitis. DATA SOURCES Electronic search of the Science Citation Index, Cochrane Library, and English-language articles from January 1966 through November 2000 indexed in MEDLINE. We also hand-searched Index Medicus for 1950-1965, and scanned references in identified articles and bibliographies of prominent textbooks of physical examination, surgery, and gastroenterology. To identify relevant articles appearing since the comprehensive search, we repeated the MEDLINE search in July 2002. STUDY SELECTION Included studies evaluated the role of the history, physical examination, and/or laboratory tests in adults with abdominal pain or suspected acute cholecystitis. Studies had to report data from a control group found not to have acute cholecystitis. Acceptable definitions of cholecystitis included surgery, pathologic examination, hepatic iminodiacetic acid scan or right upper quadrant ultrasound, or clinical course consistent with acute cholecystitis and no evidence for an alternate diagnosis. Studies of acalculous cholecystitis were included. Seventeen of 195 identified studies met the inclusion criteria. DATA EXTRACTION Two authors independently abstracted data from the 17 included studies. Disagreements were resolved by discussion and consensus with a third author. DATA SYNTHESIS No clinical or laboratory finding had a sufficiently high positive likelihood ratio (LR) or low negative LR to rule in or rule out the diagnosis of acute cholecystitis. Possible exceptions were the Murphy sign (positive LR, 2.8; 95% CI, 0.8-8.6) and right upper quadrant tenderness (negative LR, 0.4; 95% CI, 0.2-1.1), though the 95% CIs for both included 1.0. Available data on diagnostic confirmation rates at laparotomy and test characteristics of relevant radiological investigations suggest that the diagnostic impression of acute cholecystitis has a positive LR of 25 to 30. Unfortunately, the available literature does not identify the specific combinations of clinical and laboratory findings that presumably account for this diagnostic success. CONCLUSIONS No single clinical finding or laboratory test carries sufficient weight to establish or exclude cholecystitis without further testing (eg, right upper quadrant ultrasound). Combinations of certain symptoms, signs, and laboratory results likely have more useful LRs, and presumably inform the diagnostic impressions of experienced clinicians. Pending further research characterizing the pretest probabilities associated with different clinical presentations, the evaluation of patients with abdominal pain suggestive of cholecystitis will continue to rely heavily on the clinical gestalt and diagnostic imaging.