Cyclic vomiting syndrome: contribution to dysphagic infant death.

Vomiting involves the simultaneous violent contraction of abdominal and diaphragm muscles to produce a high pressure on the stomach. The heart right atrium forms a through path from IVC to SVC, so the high intra-abdominal pressure will drive blood from abdominal contents into the head. Normally internal viscous drags in organs will limit the volume leaving them during a single vomiting event. However, repetitive vomiting such as occurs in cyclic vomiting syndrome (CVS) may drive sufficient blood into head veins to produce extreme venous hypertension. Dysphagic infant death is essentially a head vein hypertension malady, some features of which match those that are postulated for Shaken Baby Syndrome. CVS was described by Gee in 1882 but is still poorly understood. Recently a consensus statement has been released by the North American Society for Pediatric Gastroenterology Hepatology and Nutrition setting out key issues to be addressed. Understanding CVS may therefore have important implications beyond its gastroenterological aspects. A case demonstrating a sequence of features suggesting CVS and the effects of increasing abdominal muscle strength with age is presented. It showed (1) swallowing dysfunction, (2) grunting and apnoea (surfactant poisoning), (3) reflux, (4) diarrhoea, (5) apparently unprovoked prolonged screaming fits (migraine?), (6) petechiae (local capillary rupture), (7) skull growth abnormalities (hydrocephalus) and (8) unconscious "blank staring spells " (from which the infant would auto-resuscitate). Repetitive vomiting may also sensitise the epiglottis thus increasing the risk of laryngospasm, and making attempts at intubation hazardous, possibly leading to hypoxic brain death.