Effect of two different doses of fentanyl on intubating conditions with sevoflurane inhalation without neuromuscular blocking agents in adults

ABSTRACT

To compare the effect of two different doses of fentanyl on intubating conditions, after inhalational induction with sevoflurane in adults, without using neuromuscular blocking agents. In this prospective, randomized, double blind study, fifty six adult patients with ASA status I-II, without any airway problem and scheduled to undergo elective surgical procedures under general anesthesia requiring endotracheal intubation were selected. Patients with allergy to any of the drugs used, body mass index > 30 kg/m2 and anticipated difficult airway were excluded from the study. Patients were premedicated with midazolam 0.1mg/kg and ranitidine 150 mg PO two hours prior to surgery and received 0.2 mg of glycopyrrolate intravenously just before the start of inhalational induction. The patients were randomly divided into two groups. Group-I patients received fentanyl 2 micro g/kg and those in Group-Il received 3 micro g/kg intravenously one minute after the start of inhalational induction with 8% sevoflurane in 50% nitrous oxide and oxygen. After 4 minutes of start of inhalational induction, conditions for tracheal intubation were assessed based upon a set of criteria. Tracheal intubation was successful in all patients. Mean time to loss of consciousness was 47 sec in Group-I and 46 sec in Group-Il. Optimal intubating conditions were higher in the Group-II [89% vs. 54% P <0.01].The incidence of post-intubation coughing was lower in the Group-II as compared to Group-I [11% vs.39%] with P <0.02. We conclude that both doses of fentanyl along with inhalational induction with sevoflurane nitrous oxide mixture provided adequate conditions for tracheal intubation without using neuromuscular blocking agents. However, increasing the dose to fentanyl to 3 micro g/kg further improved the intubating conditions. Tracheal intubation using sevoflurane and fentanyl may be an alternative to traditional tracheal intubation with neuromuscular blocking agents