Risk of Laryngospasm during Surgery: A Review

Laryngospasm, a sudden closure of the vocal cords, is a potentially life-threatening complication that can occur during surgery. It can lead to severe respiratory distress, oxygen deprivation, and even cardiac arrest if not promptly recognized and managed. This article aims to provide a comprehensive review of the risk factors, pathophysiology, prevention, and management strategies of laryngospasm during surgery.

During general anesthesia, Laryngospasm commonly occurs after the removal of the endotracheal tube or laryngeal mask airway, as the patient transitions from a controlled airway to spontaneous breathing. However, it can also happen during other stages of anesthesia, especially when the airway is irritated by foreign objects or secretions. Certain patient factors can increase the likelihood of laryngospasm, including pre-existing laryngeal pathology, such as vocal cord nodules or polyps, a history of previous laryngospasm episodes, and gastroesophageal reflux disease.

The pathophysiology of laryngospasm involves an exaggerated response of the laryngeal muscles to various stimuli. Stimulation of the superior laryngeal nerve, which supplies the laryngeal muscles, leads to the closure of vocal cords due to the contraction of the adductor muscles, mainly the lateral cricoarytenoid muscle. This reflex is intended to protect the airway from aspiration of secretions or foreign materials.

Prevention of laryngospasm primarily involves meticulous airway management. Induction of general anesthesia should be smooth, with adequate depth achieved before airway instrumentation. Proper suctioning of the oropharynx and avoiding excessive secretions are crucial. Maintaining an optimal depth of anesthesia and avoiding the use of irritant gases or fluids are also recommended strategies. When risk factors are identified, proactive measures such as using a mucosal vasoconstrictor, such as epinephrine, and administering antacid medications can reduce the risk of laryngospasm.

Recognizing laryngospasm promptly is essential for successful management. Clinically, it presents as an inability to ventilate despite adequate flow and pressure during bag-mask ventilation. The patient may exhibit signs of increased respiratory effort, inspiratory stridor, and inadequate chest rise. In severe cases, there may be cyanosis and progressive hypoxemia. It is crucial to differentiate laryngospasm from bronchospasm, as the management approaches differ.

Management of laryngospasm involves the administration of positive pressure ventilation, increasing the delivered oxygen concentrations, and deepening anesthesia to prevent patient triggering. If these measures fail, applying continuous positive airway pressure (CPAP) via a facemask or reintubation may be necessary. Intravenous muscle relaxants, such as succinylcholine or rocuronium, can relax the adductor muscles and facilitate airway opening. Close observation, adequate postoperative monitoring, and appropriate documentation of the event are essential for patient safety and medico-legal purposes.

In conclusion, laryngospasm is a potentially life-threatening complication during surgery, requiring prompt recognition and management. Understanding the risk factors, pathophysiology, and preventive strategies are crucial for anesthesiologists and other healthcare providers involved in perioperative care. By implementing appropriate preventive measures and promptly addressing laryngospasm, the associated morbidity and mortality can be minimized. Continuous professional education, multidisciplinary collaboration, and adherence to evidence-based practices are imperative to ensure patient safety during anesthesia.