Tracheal Intubation after Anesthetic Induction with Thiopental, Fentanyl and Lidocaine without Muscle Relaxants

Abstract

Objective: To investigate the possibility and feasibility of performing tracheal intubation after anesthetic induction with fentanyl, lidocaine and thiopental without the simultaneous use of muscle relaxants. Patients and Methods: Thirty patients of ASA physical status I with favorable airway anatomy scheduled for elective surgery were studied. Fentanyl 5 ug/kg, lidocaine 1.5 mg/kg and thiopental 4 mg/kg were given for anesthetic induction. Circulatory parameters including systolic and diastolic blood pressure, and heart rte were measured before (pre-induction) and after (post-induction) drug administration, and after tracheal intubation (post-intubation). Variables including jaw mobility, ease of manual ventilation, exposure of the glottis, position of the vocal cords, and toleration of the treacheal tube were assessed during anesthetic induction and tracheal intubation. Succinylcholine 1 mg/kg intravenously was employed to complete tracheal intubation when needed. Results: Our data showed that systolic and diastolic blood pressure and heart rate decreased significantly after drug administration compared with pre-induction levels. After tracheal intubation, however, these circulatory parameters returned to pre-induction levels. All patients had good jaw mobility and could be manually ventilated via mask. Direct laryngoscopy and intubation were possible in most patients.Exposure of the glottis was poor in 2 patients who were supplemented with succinlycholine for tracheal intubation. Vocal cord position was favorable (open or midpostion) in 22 patients. After tracheal intubation, 19 patients tolerated the tbue well. The rest of the patients suffered from persistent cough with or without movement of the upper extremities. Conclusion: Direct laryngoscopy and tracheal intubation after induction of anesthesia may be accomplished in mos patients with favorable airway anatomy using a combination of thiopental, fentanyl, and lidocaine without muscle relaxants.