Endotracheal Intubation with Thiopental/Succinylcholine or Sevoflurane-Nitrous Oxide Anesthesia in Adults: A Comparative Study

Abstract

Implications The three vital capacity inhaled anesthetic techniques with 8% sevoflurane and 66% N2O in O2 to receive 6% end-tidal sevoflurane may be an alternative for endotracheal intubation in adults who are at high risk from succinylcholine. We performed a double-blinded, prospective, randomized controlled trial to compare intubating conditions facilitated by succinylcholine or sevoflurane. One hundred twenty patients were randomized to receive either succinylcholine or sevoflurane for tracheal intubation. For the Succinylcholine group, patients were induced with thiopental 5 mg · kg−1 and tracheally intubated after administration of succinylcholine 1.5 mg · kg−1 IV. Patients receiving sevoflurane took three vital capacity breaths of 8% sevoflurane and 66% N2O in O2. At the loss of eyelash reflex, ventilation was assisted to establish end-tidal CO2 between 25–30 mm Hg, and intubation was performed when end-tidal sevoflurane was approximately 6%. Criteria of jaw relaxation, vocal cords position, and intubating response were used to assess intubation condition. If the intubation score was ≤6 of 12, it was described as acceptable, otherwise it was described as an unacceptable intubation condition. Tracheal intubation was successful in all patients. Intubator and observer blinded as to patient group judged that four patients (6.7%) in the Sevoflurane group and only one patient (1.7%) in the Succinylcholine group had an unacceptable intubation condition. However, there was no significant difference between groups (P > 0.05). Therefore, the three vital capacity breaths inhalation technique with sevoflurane may be an alternative for endotracheal intubation in adults.