Hemodynamic response to tracheal intubation after vital capacity rapid inhalation induction (VCRII) with different concentrations of sevoflurane

Abstract

Study objective: To evaluate the blood pressure (BP) and heart rate (HR) response to tracheal intubation after vital capacity rapid inhalation induction (VCRII) with four concentrations of sevoflurane followed by nitrous oxide (N2O) 50% and sevoflurane in concentrations administered by clinical judgment.

Design: Prospective, randomized study.

Setting: University teaching hospital.

Patients: 60 unpremedicated, ASA physical status I and II adult patients undergoing surgery with general anesthesia.

Interventions: After fentanyl 3 micrograms/kg, VCRII was accomplished with four concentrations of sevoflurane in O2: Group 1 (n = 15): sevoflurane 3%; Group 2 (n = 15): sevoflurane 4%; Group 3 (n = 15): sevoflurane 5%; and Group 4 (n = 15): sevoflurane 6%. At loss of consciousness, rocuronium 0.6 mg/kg was given, and intubation was performed 90 seconds later. Thereafter, anesthesia continued with N2O 50% and sevoflurane.

Measurements and main results: BP and HR measurements were made at the ward (baseline), at loss of consciousness, and just prior to, and each minute after, tracheal intubation during a 5-minute period. The hemodynamic profile among groups was similar, with a slight hypertensive and tachycardic response to intubation.

Conclusion: VCRII with sevoflurane 3% to 6% following fentanyl 3 micrograms/kg can be considered for blunting the hemodynamic response to tracheal intubation in healthy patients.