HICCUPS (Singultus)

Hiccups (singultus) are involuntary synchronous contractions of the intercostal muscles and the diaphragm that cause sudden inspiration. This leads to closure of the glottis and is accompanied by a characteristic sound.

Though usually a benign and self-limited annoyance, hic­cups may be persistent and a sign of serious underlying illness. In patients on mechanical ventilation, hiccups can trigger a full respiratory cycle and result in respiratory alkalosis.

Causes of benign, self-limited hiccups include gastric distention (carbonated beverages, air swallowing, overeat­ing), sudden temperature changes (hot then cold liquids, hot then cold shower), alcohol ingestion, and states of heightened emotion (excitement, stress, laughing). There are over 100 causes of recurrent or persistent hiccups due to gastrointestinal, central nervous system, cardiovascular, and thoracic disorders.

Treatment

A number of simple remedies may be helpful in patients with acute benign hiccups.

• Irritation of the nasophar­ynx by tongue traction, lifting the uvula with a spoon, catheter stimulation of the nasopharynx, or eating 1 tea­spoon (tsp) (7 g) of dry granulated sugar.
• Interruption of the respiratory cycle by breath holding, Valsalva maneu­ver, sneezing, gasping (fright stimulus), or rebreathing into a bag.
• Stimulation of the vagus by carotid massage.
• Irritation of the diaphragm by holding knees to chest or by continuous positive airway pressure during mechanical ventilation.
• Relief of gastric distention by belching or insertion of a nasogastric tube.

A number of drugs have been promoted as being useful in the treatment of hiccups. Chlorpromazine, 25–50 mg orally or intramuscularly, is most commonly used. Other agents reported to be effective include anticonvulsants (phenytoin, carbamazepine), benzodiazepines (lorazepam, diazepam), metoclopramide, baclofen, gabapentin, and occasionally general anesthesia.