To assess the ability of various clinical and laboratory parameters to predict the results of hepatobiliary scintigraphy (HBS) in patients with suspected acute cholecystitis.
This was a retrospective chart review of all patients referred from the emergency department for an HBS in 1993 to exclude acute cholecystitis. The setting was a university-affiliated tertiary care hospital with an annual census of approximately 42,000. The participants were 100 consecutive patients who were seen in the ED and had an HBS and obtainable medical records. Medical records of all patients referred from the ED for an urgent HBS in 1993 were retrospectively reviewed for the following information: demographics, historical information, physical findings, laboratory findings, biliary scintigraphic findings, and surgical pathologic findings. Comparisons were made between patients with a positive or negative HBS. Sensitivities, specificities, and positive and negative predictive values were calculated for dichotomous variables with a positive HBS as a control standard. A separate analysis was performed for patients with pathologically confirmed acute cholecystitis.
Fifty-three patients had a positive HBS, and 47 had a negative HBS. A history of fever had a positive predictive value of 100% and a sensitivity of 14.6%. The presence of Murphy's sign was both sensitive (97.2%) and highly predictive (93.3%) of a positive HBS yet was not documented in 35 cases. All other variables were not found to be helpful in predicting the results of HBS. Pathologic diagnoses were available in 44 patients. Of 40 patients with pathologically confirmed acute cholecystitis, fever and leukocytosis were absent at the time of presentation in 36 (90%) and 16 (40%) of the cases, respectively. Murphy's sign was absent in 3 (10%) of 29 of these patients. A stepwise analysis failed to identify any combination of clinical variables that was associated with a higher probability of a positive HBS.
No single or combination of clinical or laboratory findings at the time of ED presentation identified all patients with a positive HBS. Murphy's sign had the highest sensitivity and positive predictive value yet was poorly documented. Liberal use of biliary scintigraphy or ultrasound is encouraged to avoid underdiagnosis of acute cholecystitis.