UNLABELLED: Benzodiazepines are in wide use in out of hospital emergency medicine in at sea level, as well as in alpine rescue services. Ventilatory depression is a common side effect of high dose intravenous benzodiazepines. The objective of our study was to evaluate the effect of low dose benzodiazepines on ventilation at moderate altitude. DESIGN: Randomized, double blind, placebo controlled crossover trial. Blood gas analysis of 8 healthy subjects was performed before and one hour after 5 mg of oral diazepam or placebo at 171 m and at 3,000 m altitude. PaO2 and PaCO2 before and after diazepam or placebo medication at 171 m did not change significantly. At 3,000 m altitude. PaO2 decreased and PaCO2 increased significantly one hour after 5 mg of oral diazepam (PaO2 64.7 +/- 3.4 vs. 60.0 +/- 1.5 mmHg, PaCO2 28.3 +/- 2.3 vs. 33.3 +/- 1.8 mmHg, p < 0.05). Placebo did not influence PaO2 and PaCO2. CONCLUSION: Low dose diazepam inhibits ventilatory adaptation to mild hypoxia at moderate altitude. Caution in benzodiazepine use in moderate altitude is therefore necessary.
RCT Entities:
UNLABELLED: Benzodiazepines are in wide use in out of hospital emergency medicine in at sea level, as well as in alpine rescue services. Ventilatory depression is a common side effect of high dose intravenous benzodiazepines. The objective of our study was to evaluate the effect of low dose benzodiazepines on ventilation at moderate altitude. DESIGN: Randomized, double blind, placebo controlled crossover trial. Blood gas analysis of 8 healthy subjects was performed before and one hour after 5 mg of oral diazepam or placebo at 171 m and at 3,000 m altitude. PaO2 and PaCO2 before and after diazepam or placebo medication at 171 m did not change significantly. At 3,000 m altitude. PaO2 decreased and PaCO2 increased significantly one hour after 5 mg of oral diazepam (PaO2 64.7 +/- 3.4 vs. 60.0 +/- 1.5 mmHg, PaCO2 28.3 +/- 2.3 vs. 33.3 +/- 1.8 mmHg, p < 0.05). Placebo did not influence PaO2 and PaCO2. CONCLUSION: Low dose diazepam inhibits ventilatory adaptation to mild hypoxia at moderate altitude. Caution in benzodiazepine use in moderate altitude is therefore necessary.