Sedation, topical pharyngeal anesthesia and cardiorespiratory safety during gastroscopy

GOALS: In a prospective, double-blind study, we examined the effects of routine sedation and pharyngeal anesthesia on cardiorespiratory parameters during gastroscopy.

BACKGROUND: Intravenous sedation and topical pharyngeal anesthesia are used to alleviate the discomfort during upper gastrointestinal endoscopy. Cardiorespiratory changes during gastroscopy are common.

STUDY: Two hundred fifty two consecutive outpatients undergoing gastroscopy were assigned into 4 groups: (1) sedation with intravenous midazolam and placebo throat spray (midazolam group), (2) placebo sedation and pharyngeal anesthesia with lidocaine throat spray (lidocaine group), (3) placebo sedation and placebo throat spray (placebo group), and (4) no intravenous cannula nor throat spray (control group). Arterial oxygen saturation (SaO2), systolic and diastolic blood pressure and continuous electrocardiogram were recorded before, during, and after the endoscopic procedure.

RESULTS: Gastroscopy increased heart rate in all study groups. Premedication with intravenous midazolam or lidocaine spray alleviated this rise (P<0.001, repeated measures analysis of variance) and decreased the incidence of tachycardia. Similarly, sedation with midazolam or topical pharyngeal anesthesia decreased the rise in systolic blood pressure (P<0.001). Midazolam produced lower SaO2 values during gastroscopy compared with lidocaine, placebo or control groups (P<0.001). However, episodes of desaturation (SaO2 </=92) were no more common in the midazolam group than in other groups.

CONCLUSIONS: Premedication with midazolam alleviated the rise in heart rate and systolic blood pressure but induced a statistically significant decrease in arterial oxygen saturation. However, gastroscopy proved to be a safe procedure both with and without sedation.