A Prospective Randomized Study Comparing Intubating Conditions With and Without Priming With Rocuronium

Rocuronium is widely used as an alternative to succinylcholine for facilitating endotracheal intubation, but at conventional doses its clinical onset may be slower. The priming technique has been proposed as a means of shortening the time to clinically acceptable intubation with non-depolarizing neuromuscular blocking agents.

In this prospective, randomized, double-blind study, 60 American Society of Anesthesiologists I-II patients aged 18-60 years undergoing elective surgery under general anesthesia were allocated into two groups (n = 30 each). The priming group received rocuronium 0.06 mg/kg intravenously, followed 3 min later by an intubating dose of rocuronium 0.6 mg/kg. The control group received normal saline followed 3 min later by rocuronium 0.6 mg/kg. The primary outcome was time to intubation after administration of the intubating dose. Intubating conditions, hemodynamic variables, oxygen saturation (SpO₂), and adverse effects were also assessed.

The time to intubation was significantly shorter in the priming group than in the control group (68.03 ± 1.19 s vs. 100.73 ± 3.40 s, P < 0.001). Excellent intubating conditions were observed in 16 (53.3%) patients in the priming group, whereas 0 (0.0%) patients in the control group achieved this grade; good conditions were observed in the remaining 14 (46.7%) patients in the priming group and in 28 (93.3%) patients in the control group, while poor conditions occurred only in 2 (6.7%) patients in the control group (P < 0.001). Following intubation, the hemodynamic response was generally greater and more sustained in the control group, whereas the priming group demonstrated better hemodynamic stability. SpO₂ remained stable in both groups, and no adverse effects were observed.

Rocuronium priming significantly reduced the time to successful tracheal intubation and improved intubating conditions compared with conventional administration without priming. It was also associated with a smaller hemodynamic response following intubation, with stable SpO₂ and no observed adverse effects.