The effects of succinylcholine or low-dose rocuronium to aid endotracheal intubation of adult sows.

This randomized, prospective, blinded study compared the use of succinylcholine or rocuronium to aid endotracheal intubation of 27 adult sows [mean body weight 261 ± 28 (standard deviation) kg]. Preliminary trials allowed development of the intubation technique and skills. The sows were premedicated with azaperone, atropine, and morphine, and anesthesia was induced with thiopental [6 mg/kg body weight (BW)]. Nine sows each received succinylcholine (1.0 mg/kg BW), rocuronium (0.5 mg/kg BW), or saline (15 mL) after induction. Increments of thiopental (1 mg/kg BW) were used if swallowing impaired intubation. Intubation was performed 45 s after injection of the test drug and was timed and scored. The intubation scores were analyzed with Kruskal-Wallis analysis of variance (ANOVA). Time taken for intubation, body weight, and total dose of thiopental were analyzed with ANOVA and Bonferroni's multiple-comparisons test. No significant differences (at P < 0.05) were found between the groups with regard to intubation score, time taken for intubation, or total thiopental dose. Thus, neuromuscular blocking agents did not aid endotracheal intubation of adult sows anesthetized with thiopental.