Propofol sedation and gastric emptying in volunteers

Background: The purpose of this study was to evaluate the effects of light propofol sedation on gastric emptying and orocecal transit time (OCT). Methods: Ten healthy male volunteers were studied on 2 occasions separated by at least 1 week and were randomly allocated to receive either propofol sedation or i.v. saline as a control. During propofol sedation the volunteers were sedated to grade 2-3 on a 5-grade scale. This was achieved by a propofol infusion of 5 mg kg(-1) h(-1) initially, which was then titrated down to a dose of 2.4+/-0.7 mg kg(-1) h(-1). Paracetamol absorption was used as an indirect measure of the rate of gastric emptying and OCT tvas determined by use of the hydrogen breath test after ingestion of raffinose, Student's t-test for paired samples was used and the results are presented as means+/-SD. Results: During propofol sedation the maximum concentration of paracetamol (C-max) was 115+/-26.8 mu mol/L, time to peak concentration (T-max) 50+/-38.8 min, and the area under the curve during the first 60 min (AUC(60)) 4793+/-1538 mu mol x min/L, versus C-max 99+/-20.8, T-max 69+/-41.9 and AUC(60) 3897+/-1310 during saline infusion. These differences were not statistically significant. OCT was significantly shorter during the control study, 180+/-32.4 min, than during propofol sedation, 217+/-64.9 (P<0.05). Conclusion: This study in volunteers has shown that gastric emptying of liquids seems uninfluenced by light propofol sedation. OCT was slightly prolonged during light propofol sedation. (C) Acta Anaesthesiologica Scandinavica 42 (1998).