• John Feiner, Tiscia Bernadette Stefanutto, Jens Krombach, Ronald Brown, and James E Caldwell.
• Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, California, USA. tishstef@gmail.com
• Anesth. Analg.. 2012 May 1;114(5):980-6.

BackgroundIn an earlier study investigating the "can't ventilate/can't intubate" clinical scenario, induction of anesthesia with thiopental 5 mg/kg and succinylcholine 1.0 mg/kg was associated with a significant risk of hemoglobin desaturation. It appeared that succinylcholine-induced apnea was responsible for the prolonged apnea. Our hypothesis was that using propofol and remifentanil for tracheal intubation might avoid prolonged apnea and subsequent desaturation attributable to muscle relaxation.MethodsTwenty-four healthy volunteers ages 18 to 45 years participated. After oxygen administration to end-tidal oxygen >90%, volunteers received 2 mg/kg propofol and remifentanil either 2 mcg/kg (group 1; n = 12) or 1.5 mcg/kg (group 2; n = 12). Oxygen saturation (SpO(2)) was measured at a finger, an ear lobe, and the forehead. If SpO(2) decreased below 80%, volunteers received chin lift and, if persistent, assisted ventilation.ResultsDesaturation (SpO(2) < 80%) occurred in 5 volunteers: 4 in the higher remifentanil dose (2 mcg/kg) group and 1 in the lower dose (1.5 mcg/kg) group. Chin lift and assisted ventilation was necessary in 3 volunteers. The lowest SpO(2) was 82.4 ± 10.5 (mean ± SD) in the higher-dose group vs. 92.4 ± 8.6 with the lower dose of remifentanil (P = 0.019). Apnea time was shorter (P = 0.0093) with the lower dose (4.7 ± 1.5) than with the higher dose of remifentanil (6.1 ± 1.0). Conditions for intubation were excellent or acceptable in 11 volunteers (92%; 95% confidence interval [CI], 65%-99%) in the higher-dose group, and in 8 (67%; 95% CI, 39%-86%) with the lower dose.ConclusionsAdministered with propofol 2 mg/kg, the remifentanil dose necessary to produce acceptable intubating conditions, 2 mcg/kg, produces apnea that carries a significant risk of desaturation, whereas a remifentanil dose of 1.5 mcg/kg does not reliably produce acceptable intubating conditions and does not eliminate the risk of desaturation.

40 keywords...

hide…