Laryngospasm
Laryngospasm is an uncontrolled or involuntary muscular contraction (spasm) of the vocal folds. The condition typically lasts less than 60 seconds, but in some cases can last 20–30 minutes and causes a partial blocking of breathing in, while breathing out remains easier. It may be triggered when the vocal cords or the area of the trachea below the vocal folds detects the entry of water, mucus, blood, or other substance.  It is characterized by stridor or retractions. Some people have frequent laryngospasms, whether awake or asleep. In an ear, nose, and throat practice, it is typically seen in people who have silent reflux disease. It is also a well known, infrequent, but serious perioperative complication.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.

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. 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.

Causes
Various stimuli including asthma, allergies, exercise, stress, and irritants such as smoke, dust, fumes, liquids, and food can trigger laryngospasm. 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. Gastroesophageal reflux disease (GERD) is a common cause of spontaneous laryngospasm.  Treating GERD can lessen the frequency of spasms.  The onset of spasms may be caused by a viral infection.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. These situations are not to be confused with the benign laryngospam events seen in infants after feeding or due to reflux.It can sometimes occur during sleep, waking up the affected person. 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.It is also a symptom of hypoparathyroidism.It can also be caused by some medications such as lurasidone.

Diagnosis
Prevention
Due to the shape of the stomach and position of the esophagus, sleep-related laryngospasms may be prevented by sleeping on the left side, which can help in keeping stomach acid from entering the esophagus and reaching the vocal cords.When laryngospasm is coincident with a cold or flu, it may be helpful for some with the condition to take acid reflux medication to limit the irritants in the area.  If a cough is present, then treat a wet cough; but limit coughing whenever possible, as it is only likely to trigger a spasm.  Drink water or tea to keep the area from drying up.  Saline drops also help to keep the area moist.  Pseudoephederine may also help to clear any mucus that may cause coughing and thereby triggering more spasms.

Treatment
Minor laryngospasm will generally resolve spontaneously in the majority of cases.Laryngospasm in the operating room is treated by hyperextending the patients 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.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.

See also
Laryngotracheal stenosis

References
External links

Larson, Philip C., "Laryngospam -The Best Treatment", Anesthesiology, 11 1998, Vol.89, 1293–1294