Laryngospasm is an uncontrolled or involuntary muscular contraction ( spasm) of the

vocal folds In humans, the vocal cords, also known as vocal folds, are folds of throat tissues that are key in creating sounds through Speech, vocalization. The length of the vocal cords affects the pitch of voice, similar to a violin string. Open when brea ...

. It may be triggered when the vocal cords or the area of the

trachea The trachea (: tracheae or tracheas), also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all animals' lungs. The trachea extends from ...

below the vocal folds detects the entry of water, mucus, blood, or other substance. It may be associated with stridor or retractions.

Signs and symptoms

Laryngospasm is characterized by involuntary spasms of the laryngeal muscles. It is associated with difficulty or inability to breathe or speak, retractions, a feeling of suffocation, which may be followed by hypoxia-induced loss of consciousness. It may be followed by paroxysmal coughing and in partial laryngospasms, a stridor may be heard. It requires prompt identification to avoid possibly fatal complications. It may present with loss of end-tidal carbon dioxide (for mechanically ventilated patients), chest or neck retractions and paradoxical chest wall movements. The condition typically lasts less than 60 seconds, but in cases of partial blocking it may last 20 to 30 minutes and hinder inspiration, while exhalation remains easier.

Causes

Laryngospasm is a primitive protective airway reflex that functions to protect against aspiration. However, it may be detrimental if there is sustained closure of the

glottis The glottis (: glottises or glottides) is the opening between the vocal folds (the rima glottidis). The glottis is crucial in producing sound from the vocal folds. Etymology From Ancient Greek ''γλωττίς'' (glōttís), derived from ''γ ...

resulting in blockage of respiration that hinders the free flow of air. It may be triggered when the vocal cords or the area of the

below the vocal folds detects the entry of water, mucus, blood, or other substance. It is most often reported 1) post-operatively after endotracheal extubation or 2) after sudden reflux of gastric contents. It is common in drowning. It is estimated that in 10% of cases of drowning as a response to inhalation of water, death occurs due to asphyxia due to laryngospasm without any water in the lungs. It is also a symptom of hypoparathyroidism. It can sometimes occur during sleep, waking up the affected person. These episodic interruptions of sleep have been attributed to acute irritation due to gastro-oesophageal reflux. Laryngospasm is also an unlikely but possible side effect of

ketamine Ketamine is a cyclohexanone-derived general anesthetic and NMDA receptor antagonist with analgesic and hallucinogenic properties, used medically for anesthesia, depression, and pain management. Ketamine exists as its S- (esketamine) a ...

administration. Laryngospasm may happen in people with neurological disease. In children, rapid detection and management are imperative to prevent deadly complications such as cardiac arrest, hypoxia and bradycardia. Patients with a history of significant aspiration, asthma, exposure to airway irritants (smoke, dust, mold, fumes, use of Desflurane), upper respiratory infections, airway anomalies, light anesthesia and patients with acute mental status depression may be at increased risk.

Prevention

When gastroesophageal reflux disease (GERD) is the trigger, treatment of GERD can help manage laryngospasm. Proton pump inhibitors such as Dexlansoprazole (Dexilant), Esomeprazole (Nexium), and Lansoprazole (Prevacid) reduce the production of stomach acids, making reflux fluids less irritant. Prokinetic agents reduce the amount of acid available by stimulating movement in the digestive tract. Patients who are prone to laryngospasm during illness can take measures to prevent irritation such as antacids to avoid acid reflux. For acute context, making an upright position of the upper part of the body has been shown to shorten the spasm episodes. Fixation of the arms on stabilization of the body and slowing of breathing is also recommended.

Incidence

Incidence has been estimated at approximately 1% in both adult and pediatric populations. Its incidence is reported to be more than triple in the very young (birth to 3 months of age), increasing to 10% in those with reactive airways. Other sub-populations with high incidence of laryngospams include patients undergoing tonsillectomy and adenoidectomy (25%). It is likely that more than 10% of drownings involve laryngospasm, but the evidence suggests that it is not usually effective at preventing water from entering the trachea.

Treatment

Most minor laryngospasm get better on its own for most people. Laryngospasm is one of the most common intraoperative complications. It may be life-threatening as it involves reflex closure of the laryngeal muscles and thus results in inability to ventilate the patient. Treatment requires clearing secretions from the

oropharynx The pharynx (: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates, though its ...

, applying continuous positive airway pressure with 100%

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

, followed by deepening the plane of anaesthesia with propofol, and/or paralyzing with succinylcholine.

References

External links

{{Underwater diving, divmed Anesthesia Larynx disorders Otorhinolaryngology