Comparing Intubating Conditions and Hemodynamic Changes Between Macintosh Laryngoscopy and Bonfils Fibrescope During Endotracheal Intubation Without Neuromuscular Blockade

BACKGROUND:

Neuromuscular blocking drugs (NMBDs) are believed to be the dominating antigens causing bronchospasm and anaphylaxis during anaesthesia. Avoidance of these drugs, however, renders compromised intubating conditions and higher morbidity with conventional Macintosh laryngoscopy. Thus, we compared Macintosh laryngoscopy with Bonfils intubation fibrescope without administering NMBDs.

METHODS:

Eighty male and female patients scheduled for elective surgery, aged 15 to 60 years, ASA class II or I, non-obese, with lower risk for difficult intubation were enrolled in this study. They were randomly allocated into the Bonfils group or the Macintosh group (40 each). Following adequate hydration and preoxygenation, midazolam 0.05 mg kg-1 was administered, followed by alfentanil 20 µg kg-1, lidocaine 1.5 mg kg-1, and propofol 2 mg kg-1 intravenously. Tracheal intubation was then carried out using Bonfils intubation fibrescope (Bonfils group) or employing conventional Macintosh laryngoscopy (Macintosh group). The primary outcome measure was the intubating condition, with mean arterial blood pressure and heart rate as secondary outcomes.