Postoperative gastric emptying in outpatient anesthesia: the effect of opioid supplementation

Acetaminophen (paracetamol) 20 mg/kg was administered orally to 45 gynecological outpatients who had received either alfentanil 5 micrograms/kg, fentanyl 1 microgram/kg, or no analgesic supplement immediately prior to the induction of general anesthesia. Postoperative gastric emptying, assessed by acetaminophen absorption, was significantly inhibited in those given alfentanil. This inhibition is unlikely to be of great clinical importance and was much less than that found in previous studies using longer-acting opioids such as morphine.