Fig. 1. Laryngeal and respiratory responses to laryngeal stimulation in children anesthetized with sevoflurane (1 minimum alveloar concentration). Stimulation 1: baseline (fentanyl group, n = 50; saline group, n = 10). Stimulation 2: after application of one dose of 1.5 μg/kg fentanyl (n = 49) or saline (n = 10). Stimulation 3: after application of two doses of 1.5 μg/kg fentanyl (n = 45) or saline (n = 10).