Assessment Of Tracheal Intubation In Adults After Induction With Sevoflurane And Different Doses Of Propofol: A Randomly Controlled Trial

Intubation without prior administration of muscle relaxants is a common practice in children and adults with potential difficult airways. We aimed to investigate the effects of adding different doses of propofol on tracheal intubation and the time to return of spontaneous breathing during inhalation induction of patients. 150 patients undergoing operations were randomly given propofol IV at 1.0, 1.5 and 2.0 mg/kg (namely 1.0-propofol, 1.5-propofol and 2.0-propofol, respectively) after inhalational induction with sevoflurane. Tracheal intubating conditions, time to return of spontaneous breathing, postoperative hoarseness, end-tidal carbon dioxide concentration (PETCO2), and pulse oxygen saturations (SpO(2)) were assessed. Tracheal intubation was successful in all patients. Intubating conditions were acceptable in 31/50, 42/50 and 47/50 in those subjects given propofol 1.0, 1.5 or 2.0 mg/kg, respectively. Intubation scores were similar in groups 1.5-propofol and 2.0-propofol, and were significantly higher than in group 1.0-propofol (P = 0.013). Time to return of spontaneous breathing in group 2.0-propofol was significantly prolonged compared with groups 1.5-propofol and 1.0-propofol (197.0 +/- 49.4 sec vs. 130.4 +/- 32.7 sec, P < 0.001; 197.0 +/- 49.4 sec vs. 104.8 +/- 22.6 sec, P < 0.001, respectively). SpO2 in group 2.0-propofol was significantly lower than group 1.0-propofol and 1.5-propofol. However, PETCO2 in group 2.0-propofol was significantly higher than in groups 1.0-propofol or 1.5-propofol. Propofol at a dose of 1.5 mg/kg provides intubating conditions similar to propofol at 2.0 mg/kg in patients. Time to return of spontaneous breathing followed by a dose of 1.5 mg/kg propofol was significantly shorter than that followed by a dose of 2.0 mg/kg propofol.