The Effects of 10% Lidocaine Spray on the Pharyngolarynx during the Endotracheal Intubation without Muscle Relaxants? / 대한마취과학회지

ABSTRACT

BACKGROUND: Tracheal intubation is usually carried out under a combination of general anesthesia and muscle relaxation. Recent sutdies have found satisfactory conditions for intubation of the trachea without using muscle relaxants. However, these studies have used large amounts of propofol or expensive opioids like alfentanil and remifentanil. In this study, we evaluated intubation conditions and success rate with midazolam, fentanyl, propofol and either 10% lidocaine applied topically into the larynx and trachea or not. METHODS: Forty patients of ASA class I or II were randomly allocated to one of two groups. All patients received glycopyrrolate 0.2 mg, midazolam 0.03 mg/kg and fentanyl 2 mcg/kg IV before induction of anesthesia and propofol 2 mg/kg IV for induction of anesthesia. Group I patients (n = 20) received 10% lidocaine into the larynx and trachea topically, and group II patients (n = 20) did not. After loss of the eyelid reflex, laryngoscopy and endotracheal intubation were attempted and airway conditions were graded. The success rate of intubation was evaluated. RESULTS: Intubation without a muscle relaxant was possible in 19 of 20 (95%) patients in group I and 8 of 20 (40%) patients in group II. There were no significant differences in scoring criteria for various airway conditions such as jaw tone, vocal cord exposure and cord position. CONCLUSIONS: Induction of anesthesia with midazolam 0.03 mg/kg, fentanyl 2 mcg/kg and propofol 2 mg/kg combined with 2 ml of 10% lidocaine spray into the larynx and trachea offered a satisfactory success rate of intubation without muscle relaxants.