The effect of prolonged fasting and total parenteral nutrition on hepatobiliary imaging with technetium-99m DISIDA.

Prolonged fasting (NPO) and total parenteral nutrition (TPN) have been reported to result in an unacceptable number of false-positive hepatobiliary scintigrams for acute cholecystitis. Based on these reports, the clinical usefulness of the hepatobiliary scan in diagnosing acute cholecystitis in the critically ill postoperative patient who has been NPO or on TPN has been questioned. Patients who were either on prolonged fasting or total parenteral nutrition and who had no history of hepatobiliary disease were prospectively studied to assess the value of the Tc-99m diisopropyl-iminodiacetic acid (DISIDA) scan without pretreatment with cholecystokinin (CCK) in such a setting. Of the 17 persons studied, nine had been on total parenteral nutrition for at least five days and eight had been fasting for at least five days prior to imaging. Seven of the nine individuals on TPN (78%) and six of the eight individuals who were NPO (75%) had normal hepatobiliary scintigraphy. The results suggest that hepatobiliary imaging with Tc-99m DISIDA has a lower false-positive rate in individuals on TPN or NPO than previously has been reported and that it has clinical efficacy in ruling out the diagnosis of acute cholecystitis in these individuals.