Efficacy of low and standard midazolam doses for gastroscopy. A randomized, double-blind study

To evaluate the efficacy and safety of two different doses of intravenous midazolam (35 and 70 microg/kg) compared to placebo in patients undergoing gastroscopy.

Sixty patients scheduled for diagnostic gastroscopy were selected according to factors previously reported to affect tolerance (Eur J Gastroenterol Hepatol 1999; 11:201-204) and were randomly assigned to receive premedication with midazolam 35 microg/kg iv, midazolam 70 microg/kg iv or placebo iv. Oxygen saturation was continuously monitored during the procedure. Patients' tolerance, time to discharge and post-sedative inconvenience were evaluated using visual analogue scales and a questionnaire.

Patients receiving either dose of midazolam showed better tolerance of gastroscopy than those receiving the placebo. Fewer patients receiving 70 or 35 microg/kg of midazolam were reluctant to undergo a further gastroscopy compared to those receiving the placebo (2, 1 and 9 patients respectively, P = 0.01). Compared to patients receiving midazolam 70 microg/kg, those receiving midazolam 35 microg/kg were discharged earlier (29.3+/-14.4 versus 43.1+/-12.4 min respectively, P < 0.001), experienced less post-sedative inconvenience (8 versus 15 patients slept for > 1 h at home respectively, P = 0.02), and suffered fewer clinically relevant desaturation episodes (< 90%) (0 versus 5 patients respectively, P = 0.04).

Low doses of intravenous midazolam (35 microg/kg) are adequate and safe when sedation is indicated for gastroscopy.