Bilateral Phrenic Nerve Block For the Treatment of Intractable Hiccup in a Palliative Care Patient: A Case Report

In babies in mother’s womb, hiccups are frequent and are considered as physiological. This is thought to be due to the preparation of the infant’s inspiratory respiratory muscles for respiration after birth. However, hiccups do not serve a physiological purpose in adults; they disturb the humans and the environment due to the sound emitted. Hiccup is a symptom accompanied by a sound which results from sudden and involuntary contractions of accessory respiratory muscles and diaphragm together with the simultaneous closure of the glottis. Hiccups are mostly benign and their frequency can range from 4 to 60 per minute and heal spontaneously in a short time (1). Hiccups are classified into 3 types: Hiccups ending up in 48 hours, persistent hiccups lasting 48 hours-1 month and intractable hiccups lasting more than 1 month (2). Persistent hiccups can cause extremely vital problems such as malnutrition, exhaustion, fatigue, weight loss, hypoxia, bradycardia, arrhythmia, heart block, disturbed sleep patterns, speech disorders, depression, weakness, and dehydration (3). Hiccup reflex arch is composed of afferent pathway consisting of sympathetic nervous system, phrenic and vagus nerves; and efferent pathway connected to glottis and accessory respiratory muscles; and central mediators.