Ventriculopleural shunt obstruction and positive-pressure ventilation. Case report.

The authors report an unusual case of a patient with low-pressure hydrocephalus and a ventriculopleural shunt, in whom routine respiratory management performed using positive-pressure ventilation caused shunt obstruction and coma. While the patient received positive-pressure ventilation with external cerebrospinal fluid (CSF) drainage at subatmospheric pressure, the ventricles returned to normal size and the coma rapidly reversed. After the authors' recognition of the effect of positive-pressure ventilation on intrapleural pressure and ventriculopleural shunt function, and the subsequent removal of positive-pressure ventilation, CSF flow through the shunt resumed and the patient's coma resolved.