Conscious sedation for gastroscopy: patient tolerance and cardiorespiratory parameters

Most patients receive conscious sedation for gastroscopy. However, the benefit of the most often used combination of low-dose intravenous midazolam and topical lidocaine on patient tolerance remains poorly defined and has not been shown to outweigh cardiorespiratory risks. To respond to these issues, a randomized, double-blind, placebo-controlled prospective study was performed.

Two hundred outpatients undergoing diagnostic gastroscopy were assigned to receive either (1) midazolam (35 micrograms/kg) and lidocaine spray (100 mg), (2) midazolam and placebo lidocaine, (3) placebo midazolam and lidocaine, or (4) placebo midazolam and placebo lidocaine.

Tolerance (visual analogue scale, 0-100 points; 0, excellent; 100, unbearable) improved as compared with placebo midazolam and placebo lidocaine by 23 points (95% confidence interval, 15-32) in group 1, 15 points (95% confidence interval, 7-24) in group 2, and 10 points (95% confidence interval, 2-18) in group 3. Increasing age (P < 0.001), low anxiety (P < 0.001), and male sex (P < 0.03), but not amnesia, were associated with better patient tolerance. Oxygen desaturation (< 1 minute) occurred in 8.2% and was not more frequent after midazolam treatment. Hypotension was rare (2.1%), and no adverse outcome occurred.

Both low-dose midazolam (35 micrograms/kg) and lidocaine spray have an additive beneficial effect on patients tolerance and rarely induce significant alterations in cardiorespiratory monitoring parameters, thus supporting the widespread use of conscious sedation.