What is the significance of persistent hiccoughs in a ventilated ICU patient and how will you manage them?
Hiccoughs may be due to
- Irritation of diaphragm (subphrenic abscess, cholecystitis, pneumonia, pericarditis)
- Irritation of stomach wall (distension, ulcer, ileus)
- Phrenic nerve stimulation /irritation (neoplasm, goitre)
- Brainstem lesion (neoplasm, ischaemia, surgery)
- Metabolic (uraemia)
Management is often unsatisfactory:
- diagnosis and treatment of underlying cause (NG tube, drain subphrenic )
- many medications have been used, indicative of their poor efficacy (eg chlorpromazine, metaclopramide, haloperidol, phenytoin, carbamazapine)
- physical stimulation of posterior pharynx by NG tube may interrupt the reflex arc
In the event of persistent, fatiguing hiccoughs phrenic nerve block has been tried.
Never since this question have "hiccoughs" been asked about in the ICU fellowship paper. However, one must answer these things.
A hiccup, or singultus, or synchronous diaphragmatic flutter, is a myoclonic spasm of the diaphragm, which is stimulated by the prehinc nerve. The signal to hiccup is sent from the nucleus tractus solitarius. This signal can be stimulated by a number of pathological conditions. A brief review lays these bare:
- Foeign body in the external auditory canal
- Medullary lesions (especially PICA artery)
- Medullary demyelination
- Spinal syrinx
- Gastro-esophageal reflux
- Gastric distension
- Thoracic aortic aneurysm
- Mediastinal tumours
- Pleural and pericardial effusion
The review article remarks that "The more than 100 forms of physical or pharmacological treatment for intractable hiccups include prayers to St Jude, the patron saint of lost causes". As reliable remedies, the author recommends to raise the PaCO2 and to vigorously stimulate the posterior pharynx. Apparently, chlorpromazine remains the most consistently effective agent. Other lesser known solutions are discussed elsewhere.
Kolodzik, Paul W., and Mark A. Filers. "Hiccups (singultus): review and approach to management." Annals of emergency medicine 20.5 (1991): 565-573.
Howard, Robin S. "Persistent hiccups." BMJ: British Medical Journal 305.6864 (1992): 1237.