Hiccups are a common and usually harmless phenomenon that can occur in people of all ages. For hospitalized patients, the etiology may be more sinister. To approach and manage such a case we need to know the etiology. Here's a 🧵 on the same. (1/17)
#hiccups #MedTwitter #MedEd

Hiccups (aka 'singultus')are involuntary contractions of the diaphragm muscle. When this happens, it causes a sudden intake of air, which results in the sound we know as a #hiccup.(2/17)

🔵Acute attack of hiccups last less than 48 hours
🔵 Persistent hiccups last more than 2 days
🔵 Intractable hiccups last more than 1 month
(3/17)

The reflex arc:
Brain, diaphragm, thoracic or abdominal viscera pathology can stimulate vagal or phrenic afferents that activate the ‘hiccup center’ in the midbrain, brainstem and proximal cervical cord. (4/17)

Repetitive myoclonic contractions of the diaphragm and other respiratory muscles are triggered via the phrenic and the intercostal nerves (diagram below). Immediately afterwards activation of the recurrent laryngeal nerve closes the glottis, producing hiccups. (5/17)
👇

The 'hiccup reflex' arc (6/17)

✴️The common causes of an acute attack of hiccups are
➡️ Distension of the stomach by a large meal, carbonated drinks and alcohol
➡️ Aerophagia caused by over excitement or anxiety
(7/17)

The following are the major etiologies of persistent or Intractable hiccups and needs a detailed evaluation:
A) CNS disorders:
✴️Wallenberg syndrome
✴️Demyelinating disease affecting medulla
✴️Syringomyelia
✴️Aneurysm
✴️Vascular malformations
(8/17)

B) Vagus/phrenic nerve irritation
✴️Gastroesophageal causes: gastric distension, GERD, gastritis/esophagitis, aerophagia, gastric/esophageal cancer
✴️ Postop causes: phrenic nerve irritation due to glottic stimulation during intubation or intraop visceral irritation.
(9/17)

✴️phrenic nerve irritation is also caused by
a) structural causes like neck, mediastinal tumors/lymph nodes, aortic aneurysm
b) infectious causes like pneumonia, pleuritis, empyema
c) inflammatory causes like pancreatitis, IBD
d) myocardial infarction and pericarditis
(10/17)

C) Medication induced:
✴️ Dexamethasone
✴️ Benzodiazepines like diazepam
✴️ Tramadol
✴️ Anti cancer drugs (oxaliplatin, carboplatin, fluorouracil)
✴️ Alpha methyldopa
(11/17)

D) Toxic Metabolic causes:
✴️ Uremia
✴️ Hyponatremia
✴️ Hypokalemia
✴️ Hypocalcemia
✴️ Hypocapnia
(12/17)

E) Psychogenic factors (diagnosis of exclusion):
Stress, anxiety, excitement and malingering.
(13/17)

Few physical maneuvers to rid oneself of hiccups (acute attacks) include:
🔵 Breath holding (5 seconds)
🔵 #Valsalva maneuvre
🔵 Cold water gargles
🔵 Pulling knees to chest
🔵 Biting 🍋 lemon
🔵 Forced inspiratory suction and swallow tool (14/17)
pubmed.ncbi.nlm.nih.gov/34143196/

For prolonged and Intractable hiccups, a diagnosed disease condition may already be present as discussed above or a thorough clinical evaluation needs to be done to find the etiology. (15/17)

Pharmacological management includes:
✴️First line - Baclofen, Gabapentin or Metoclopramide
✴️PPI - if GERD (sometimes given empirically for hiccups)
✴️ Chorpromazine (greater side effects)
✴️ AEDs - Phenytoin, valproic acid, pregabalin, carbamazepine
(16/17)

In conclusion, persistent or Intractable hiccups, a common referral condition to #medicine department, may be a presentation of an underlying sinister etiology and needs a thorough evaluation.
(17/17)