Barrier pressure of the oesophagogastric junction during propofol induction with and without alfentanil: a double-blind, randomised, crossover study in volunteers.

Context: Practice varies regarding the use of opioids during rapid sequence induction. Controversy exists as to whether opioids may increase the risk of pulmonary aspiration by decreasing the barrier pressure (lower oesophageal sphincter-intragastric pressure).

Objectives: To evaluate the effects of adding alfentanil during anaesthesia induction with propofol with respect to the barrier pressure in the oesophagogastric junction.

Participants And Setting: Seventeen healthy volunteers (11 men and six women) participated in a double-blind, randomised, crossover trial at the University Hospital in Orebro, Sweden.

Interventions And Outcome Measures: The volunteers were anaesthetised on two different occasions, randomly assigned to receive either alfentanil 20 μg kg(-1) or an equivalent amount of isotonic saline, administered intravenously, 1 min before induction with propofol 2 mg kg(-1). One minute after propofol administration, a cricoid pressure of 30 N was applied. The primary outcome was the difference in the change in barrier pressure between the alfentanil and the placebo occasion 1 min after propofol administration. The secondary outcomes were differences in the changes in barrier pressure 1 min after alfentanil or placebo administration and during ongoing cricoid pressure application.

Results: There were no statistically significant differences in barrier pressure, at any time point, between anaesthesia induction with alfentanil and propofol compared with induction with placebo and propofol. The barrier pressure never decreased to less than 2.4 mmHg in any volunteer.

Conclusion: Our study showed no increased risk regarding the integrity of the gastro-oesophageal junction when alfentanil is added during an induction with propofol in volunteers. This supports the practice of adding opioids as adjuvants during rapid sequence induction.