Intubation following high-dose rocuronium in a cat with protracted laryngospasm

Abstract

Case summaryAn 11-year-old spayed female domestic shorthair cat with a history of laryngospasm at induction of general anesthesia presented for dental evaluation and treatment. The cat was premedicated with hydromorphone (0.05 mg/kg) and alfaxalone (0.5 mg/kg) intravenously, pre-oxygenated for 5 mins (3 l/min, face mask) and anesthesia was induced with alfaxalone (to effect) intravenously. Lidocaine (0.1 ml, 2%) was applied topically to the arytenoid cartilages following loss of jaw tone. Laryngospasm was not noted during or immediately following lidocaine application. However, after waiting 60 s for the onset of effect of the topical lidocaine, laryngospasm was apparent. Orotracheal intubation by direct visualization was unsuccessful after four attempts by three anesthetists (with increasing levels of experience). At this point, a failed intubation was declared and the non-depolarising neuromuscular blocking agent rocuronium (1 mg/kg IV) given, resulting in arytenoid abduction and appropriate conditions for intubation. Successful intubation occurred 9 mins after induction of anesthesia. Oxygen was continuously supplemented throughout and arterial hemoglobin saturation with oxygen was never <94%.Relevance and novel informationTo the authors’ knowledge, this is the first report of the use of high-dose rocuronium to successfully resolve prolonged laryngospasm at induction of general anesthesia in a cat. Despite laryngospasm and a delay in achieving orotracheal intubation, low values for arterial hemoglobin saturation with oxygen (indicative of hypoxemia) were not observed, highlighting the benefits of pre-oxygenation and apneic oxygenation. The principles of the Difficult Airway Society 2015 guidelines were followed in managing this difficult intubation.

Intravenous rocuronium 0.3 mg/kg improves the conditions for tracheal intubation in cats: a randomized, placebo-controlled trial

“…1,2 The use of NMBAs during intubation has also been evaluated in cats, showing that placement of the tracheal tube is facilitated with these agents. [3][4][5] However, non-depolarizing NMBAs at the doses commonly used almost invariable result in apnea of long duration, which may increase the risk of hemoglobin desaturation during induction and require the institution of positive pressure ventilation for prolonged periods. 4 A recent dose-finding study in a laboratory setting evaluating the NMBA rocuronium in cats showed that reducing the dose of this agent from 0.6 to 0.3 mg/kg intravenously (IV) can significantly limit the time of apnea while preserving the ability to blunt laryngospasm in response to laryngeal stimulation.…”

“…1,2 The use of NMBAs during intubation has also been evaluated in cats, showing that placement of the tracheal tube is facilitated with these agents. 3–5 However, non-depolarizing NMBAs at the doses commonly used almost invariable result in apnea of long duration, which may increase the risk of hemoglobin desaturation during induction and require the institution of positive pressure ventilation for prolonged periods. 4…”