Propofol for relief of extubation laryngospasm

Extubation laryngospasm is encountered frequently in children undergoing upper airway surgery. Different drugs have been used for its prevention and/or management such as intravenous or topical lidocaine [1–4], intravenous nitroglycerine [5], as well as intravenous or intramuscular succinylcholine [6]. The following case reports show that a subhypnotic dose of propofol 0.25 mg.kg−1 can successfully control extubation laryngospasm. A 6-year-old child was scheduled for tonsillectomy. Anaesthesia was induced by intravenous thiopental 4 mg.kg−1, fentanyl 1 µg.kg−1, lidocaine 1 mg.kg−1 and cisatracurium 0.1 mg.kg−1. Tracheal intubation was performed using a 5.5-mm (ID) cuffed tube. Anaesthesia was maintained with 60% nitrous oxide in oxygen supplemented with sevoflurane. At the end of surgery, sevoflurane was discontinued and neuromuscular block was reversed with a mixture of neostigmine and glycopyrronium. Following tracheal extubation, the child developed laryngospasm associated with a decrease of oxygen saturation. Intravenous propofol 0.25 mg.kg−1 was followed immediately by relief of the laryngospasm. A 3-year-old child was scheduled for tonsillectomy and adenoidectomy. Anaesthesia was induced with sevoflurane. Tracheal intubation was performed using a 4.5 mm cuffed tube. Anaesthesia was maintained with 60% nitrous oxide in oxygen supplemented with sevoflurane. At the end of surgery, nitrous oxide and sevoflurane were discontinued. Following tracheal extubation, the child developed severe laryngospasm associated with a decrease of oxygen saturation. Intravenous propofol 0.25 mg.kg−1 was immediately followed by relief of the laryngospasm. A 58-year-old female, 126 kg in body weight, who was a heavy smoker, was scheduled for removal of vocal cord polyps under suspension microlaryngoscopy. Anaesthesia was induced with intravenous propofol 1.5 mg.kg−1, lidocaine 1 mg.kg−1, fentanyl 1 µg.kg−1 and rocuronium 0.6 mg.kg−1. Tracheal intubation was performed using a 5-F microlaryngoscopy tube and anaesthesia was maintained with 60% nitrous oxide in oxygen, supplemented with sevoflurane. After surgery, anaesthesia was discontinued and neuromuscular block was reversed with glycopyrronium and neostigmine. Following tracheal extubation, the patient developed laryngospasm. The oxygen saturation decreased from 98% to 85%, despite a jaw-thrust manoeuvre and face-mask ventilation with 100% oxygen. Intravenous propofol 0.25 mg.kg−1 was followed by relief of the laryngospasm associated with an increase of oxygen saturation. A multitude of receptors are located throughout the larynx. Stimulation of these receptors can induce reflex laryngeal closure that protects the lungs from aspiration of foreign materials. The upper airway reflexes are modified by many factors such as sleep, levels of anaesthesia and background chemical ventilatory drive [7, 8]. A period of transient laryngeal hyperexcitability that increases the risk of laryngospasm is observed during recovery from general anaesthesia [9]. Previous reports have shown that an anaesthetic dose of propofol 2.5 mg.kg−1 which was associated with greater depressant effects on upper airway than thiopental may explain a lower incidence of laryngospasm after induction of anaesthesia [10]. Our report shows that a subhypnotic dose of propofol 0.25 mg.kg−1 may depress the hyperexcitable laryngeal reflexes during emergence from general anaesthesia, and can be used to control extubation laryngospasm.