Evaluation of a rapid sequence induction technique in dogs with or without rocuronium

Objective: To determine, using a rapid sequence induction (RSI) technique, whether rocuronium improves the quality and speed of endotracheal intubation in healthy dogs. Study design: Randomized, crossover, experimental study. Animals: Six adult intact male Beagles (12.3 ± 0.4 kg). Methods: Dogs were premedicated with intravenous acepromazine (0.03 mg kg^–1) and hydromorphone (0.1 mg kg^–1). Ten minutes later, anesthesia was induced with intravenous propofol (2 mg kg^–1 over 5 seconds), followed by saline (0.06 mL kg^–1, CT group) or rocuronium (0.6 mg kg^–1, RT group), with orotracheal intubation attempted after 45 seconds. Intubation time (IT) and conditions (IC) were assessed. PaO₂, PaCO₂, arterial blood pH and serum cortisol were obtained before and after RSI. After endotracheal intubation, saline (0.04 mL kg^–1) or sugammadex (4 mg kg^–1) were administered intravenously in CT or RT groups, respectively. Spontaneous ventilation restoration was noted. Results: The IT was 54.3 ± 6.9 (mean ± SD) and 57.8 ± 5.2 seconds for CT and RT, respectively (p = 0.385). All laryngoscopies indicated good IC in both treatment groups. Heart rate was lower in CT group than in RT group (66 ± 16 versus 103 ± 39 beats minute^–1, p = 0.016). PaCO₂, pH, PaO₂ and cortisol did not differ between treatments. Compared with baseline, PaCO₂ increased from 47.7 ± 6.2 to 58.8 ± 5.8 (p < 0.001) and pH decreased from 7.35 ± 0.04 to 7.28 ± 0.04 (p = 0.003), independent of treatment. Dogs in both treatment groups returned to spontaneous ventilation within 30 seconds of RSI. Conclusions and clinical relevance: RSI resulted in respiratory acidosis without hypoxemia or increased cortisol. Rocuronium did not improve IT or IC. Spontaneous ventilation was observed immediately after administering saline or sugammadex. The co-administration of rocuronium showed no clinical benefits over propofol alone in RSI in healthy dogs.