Unilateral hypoglossal nerve paralysis following the use of the laryngeal mask airway

Abstract

Summary W e report a unilateral Iijpoglossal nerve paralpis following the use of a laryngeal mask airway in a 62 Key wordsComplications; paralysis, hypoglossal nerve. Equipment; laryngeal mask airway.As the use of laryngeal mask airway (LMA) increases [l, 23, so does the variety and incidence of complications [3-51. The LMA cuff is manufactured from silicone rubber, which absorbs volatile anaesthetics and nitrous oxide. Because the cuff is usually inflated with air, cuff volume and intracuff pressure increase temporarily during general anaesthesia with nitrous oxide [6]. A distended LMA cuff might damage the pharynx by compressing the soft pharyngeal tissue against a surrounding hard structure such as hyoid bone or vertebra. We report a case of hypoglossal nerve paralysis probably caused by Compression of the nerve between the LMA cuff and the hyoid bone. Case historyA 62-year-old female, 151 cm tall and weighing 36 kg, with a 22-year history of rheumatoid arthritis, had undergone bilateral total hip joint replacement in the preceding 3 years. As a result of increasing pain in her left shoulder she was scheduled for a left total shoulder joint replacement. The pre-operative physical examination showed limited neck extension and mouth opening as a result of her disease, so a difficult tracheal intubation was anticipated and therefore we elected to maintain the airway during anaesthesia with a size 3 LMA. Two hours before the induction of anaesthesia, she received diazepam 5 mg orally and pethidine 35 mg intramuscularly, as premedication. To maintain anaesthesia, we chose continuous cervical epidural anaesthesia combined with general anaesthesia. Epidural anaesthesia was induced with mepivacaine through a catheter inserted at the C, , interspace. Initially 10 ml of 2% mepivacaine was injected and 5 ml was added every 45 min. After determining the effects of epidural anaesthesia, general anaesthesia was induced with thiopentone 200 mg, and suxamethonium 40 mg was used to prevent laryngospasm during insertion of the LMA. Initially, we were unable to obtain a good seal with the LMA, but at the second attempt the correct position was achieved, although there was slight resistance during insertion. The recommended 20 ml of air was injected into the LMA cuff and during surgery the patient received intermittent positive pressure ventilation with 67% nitrous oxide in oxygen, supplemented with pethidine 70 mg and midazolam 2.5 mg. Since leakage around the cuff was not observed even when the peak airway pressure exceeded 15 cmHzO, we changed her position from supine to the right lateral using an additional bolus of suxamethonium 20 mg. The patient was supported in position carefully using soft cushions, with a donut-type pillow under her head to prevent it from tilting down. Surgery was completed uneventfully within 3 h, the total blood loss was 160 ml and fluid replacement was 2450 ml. No significant changes in cardiovascular or respiratory parameters occurred during the operation and when spontaneous respiration and

Laryngeal mask airway and tracheal tube cuff pressures in children: are clinical endpoints valuable for guiding inflation?

“…Potential morbidities range from sore throat to more serious complications such as laryngeal or tracheal lesions, vocal cord paralysis, hypoglossal and recurrent laryngeal nerve injury and even dislocation of the arytenoid cartilages [5,[9][10][11][12][13][14]. Many morbidities arise from reduced mucosal blood flow because of the raised intracuff pressure and high filling volumes [3,4].…”

Complications of Airway ManagementDiscussion

“…Reported soft tissue injuries from the LMA include tongue ischemia, 115 as well as both unilateral and bilateral recurrent laryngeal, 116,117 hypoglossal, 118 and lingual 119 nerve injuries. The proposed injurious mechanism is similar to that described with classic ETT injury: direct mechanical compression of the nerve between the LMA cuff and the cricoid as it ascends at the apex of the pyriform fossa.…”

Nitrous oxide diffusion into the cuffs of disposable laryngeal mask airways

“…An important concern when using the laryngeal mask airway during nitrous oxide supplemented anaesthesia is laryngo-pharyngeal morbidity caused by intracuff pressure increase and cuff overinflation [7][8][9][10][11][12].…”