Singult is the medical term for hiccups and comes from the Latin singultus which means sigh. Any human being at any time in his life has presented it; it has even been possible to detect this disorder in fetuses through ultrasounds in the third trimester of gestation, without affecting health.
Hiccups are considered acute when it is less than 48 hours; persistent when it lasts 48 hours to a month and intractable if it is greater than a month. In this article, we will focus on the persistent single as it can be a symptom of multiple pathologies.
How is the Singult or Hiccup produced?
Hiccups are produced by mostly unilateral, involuntary, and repeated contraction of the diaphragm, most frequently the one on the left side, this reflex can occur in three ways: an afferent pathway where the phrenic, vagus nerve, and the sympathetic chain are involved.
The reflex center is in the bulbar respiratory center, activating the reticular system, temporal lobes, and segments C3 to C5 and the efferent pathway is part of the phrenic nerve with efferent neural connections to the glottis and inspiratory costal muscles. The final response of these complex pathways is the sudden closure of the glottis, which slows the entry of air and causes the characteristic sound.
Causes of persistent singult:
• Psychogenic: Stress, schizophrenia, anorexia nervosa, irritation of the phrenic or vagus nerve.
• ENT: Goiter, pharyngitis, laryngitis, foreign body in the ear, cervical lesions, tumors.
• Thoracic: Acute myocardial infarction, pericarditis, mediastinitis, pericardial or pleural effusion, aortic aneurysm, pulmonary thromboembolism, pneumonia, herpes zoster, mechanical ventilation, pacemaker.
• Gastrointestinal: Esophagitis, gastritis, gastroesophageal reflux, peptic ulcer, hiatal hernia, gastric distention, intestinal obstruction, pancreatitis, cholecystitis, ascites, subdiaphragmatic abscess, inflammatory bowel disease, hepatitis.
• Postoperative: General anesthesia, intubation (glottis stimulation), neck extension, gastric distention, visceral traction.
• Oncological: Lung, gastrointestinal, liver, pancreatic, kidney cancer, lymphoma.
• Metabolic: Hypokalemia, hyponatremia, hypocalcemia, hyperglycemia, hypocapnia, uremia, Addison’s disease, fever Central nervous system Tumors, infections (encephalitis, meningitis, and abscesses), cerebrovascular event, arteriovenous malformations, multiple sclerosis, trauma, hydrocephalus, syringomyelia.
• Medications: Chemotherapy (carboplatin, cisplatin, etoposide), azithromycin, corticosteroids (dexamethasone), benzodiazepines, opioids, alpha-methyldopa, short-acting barbiturates, antiparkinsonians.
As you can see, every single persistent cult must be studied in-depth, due to the multiple causes that produce it. The doctor is interested in knowing the duration of the hiccups, the drugs tested, and the relationship of the onset with illness or surgeries
A thorough examination helps guide the diagnosis, look for concomitant digestive symptoms such as gastroesophageal reflux and swallowing difficulties, chest symptoms such as cough, fever or chest pain, and any neurological symptoms.
When a cause is not appreciated, a general laboratory test, electrocardiogram, chest X-ray, cranial and thoracoabdominal computed tomography, and gastroscopy are necessary to study possible underlying causes. Regarding the treatment, it must be specified according to the underlying cause, do not self-medicate.