Pneumopericardium associated with high-frequency jet ventilation during laser surgery of the hypopharynx in a child.

A case of pneumopericardium, without concomitant pneumothorax, resulting from high frequency jet ventilation during laser surgery of the hypopharynx is described. The patient, a four-year-old boy, suffered cardiac arrest as a consequence of the incident. The pneumopericardium was likely to have been caused by obstruction to the expiratory flow during surgery. Other possible explanations for the incident are discussed.