Fiberoptic intubation through laryngeal mask airway with an innovated tube under 5% sevoflurane anesthesia

BACKGROUND : Previously we had reported an intubation method using 52 cm innovated tube (I. D.=5.0) for patients with difficult airways, but hemodynamic change and anesthetic level were not evaluated during this procedure. In the present report we investigated heart rate, mean arterial pressure and bispectral index (BIS) during this procedure under volatile induction and maintainance of anesthesia (VIMA) with 5% sevoflurane without muscle relaxant. METHODS : We enrolled 6 patients considered having difficult airway. Airway management was performed under VIMA of 5% sevoflurane. After insertion of a laryngealmask airway (LMA), 52 cm-tube was intubated through LMA under bronchofiberscope. After LMA was removed, the endotracheal tube was passed through the 52 cm-tube into the trachea. Hemodynamic change was recorded at 1 min intervals and BIS at 5 sec intervals until 3 min after securing their airways. RESULTS : VIMA of 5% sevoflurane provides stable hemodynamic state during the procedure and suppressed body movement sufficiently on tracheal intubation. BIS was elevated due to cough on intubation in 4 cases. However no patient recalled the procedure. CONCLUSIONS : Sevoflurane 5% suppressed hemodynamic changes sufficiently with this procedure without muscle relaxants.