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.^[4]

Signs and symptoms

The main symptom is choking and difficulty or inability to breathe or speak, a feeling of suffocation, which may be followed by hypoxia-induced loss of consciousness.^[3] As the airway reopens, breathing may cause a high-pitched sound called stridor. The episode seldom lasts over a couple of minutes before breathing is back to normal.^[3]

Causes

Various stimuli including asthma, allergies, exercise, stress, and irritants such as smoke, dust, fumes, liquids, and food can trigger laryngospasm.^[3] It is common in drowning, both as a direct response to inhalation of water, and as a complication during rescue and resuscitation due to aspiration of vomit.

In some individuals laryngospasm can occur spontaneously or as a result of reflux or impaired swallowing. GERD is a common cause of spontaneous laryngospasm.^[3] Treating GERD can lessen the frequency of spasms. The onset of spasms may be caused by a viral infection.{{cn|date=February 2017}}

It is also a complication associated with anesthesia. The spasm can happen often without any provocation, but tends to occur after tracheal extubation. In children, the condition can be particularly deadly, leading to cardiac arrest within 30–45 seconds, and is a possible cause of death associated with the induction of general anesthesia in the pediatric population.^[3] It can sometimes occur during sleep, waking up the sufferer. This usually occurs when the person has gastric acidity and develops re-flux during sleep, where the gastric acid causes irritation which will cause the spasm attack.^[3]

It is also a symptom of Hypoparathyroidism.{{cn|date=February 2017}}

Prevention

When laryngospasm is coincident with a cold or flu, it may be helpful for some sufferers to take acid reflux medication to limit the irritants in the area.{{cn|date=February 2017}} If a cough is present, then treat a wet cough; but limit coughing whenever possible, as it is only likely to trigger a spasm.{{cn|date=February 2017}} Drink water or tea to keep the area from drying up.{{cn|date=February 2017}} Saline drops also help to keep the area moist.{{cn|date=February 2017}} Pseudoephederine may also help to clear any mucus that may cause coughing and thereby triggering more spasms.{{cn|date=February 2017}}

Treatment

Minor laryngospasm will generally resolve spontaneously in the majority of cases.

Laryngospasm in the operating room is treated by hyperextending the patient's neck and administering assisted ventilation with 100% oxygen. In more severe cases it may require the administration of an intravenous muscle relaxant, such as Succinylcholine, and reintubation.{{cn|date=February 2017}}

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.^[3]

Spontaneous laryngospasm can be treated by staying calm and breathing slowly, instead of gasping for air. Drinking (tiny sips) of ice water to wash away any irritants that may be the cause of the spasm can also help greatly.{{cn|date=February 2017}}

Patients who are prone to laryngospasm during illness can take measures to prevent irritation such as antacids to avoid acid reflux, and constantly drinking water or tea keep the area clear of irritants.{{cn|date=February 2017}}

Additionally, laryngospasms can result from hypocalcemia, causing muscle spasms and/or tetany. Na+ channels remain open even if there is very little increase in the membrane potential. This affects the small muscles of the vocal folds.{{cn|date=February 2017}}

References