Pneumoperitoneum associated with mechanical ventilation.

The true incidence of pneumoperitoneum associated with mechanical ventilation is unknown, but current estimates range from rare to 7 percent of intubated intensive care unit patients. This syndrome should be strongly suspected when pneumoperitoneum develops in a mechanically ventilated patient with a combination of (1) peak inspiratory pressure (PIP) greater than 40 cm H(2)O; (2) positive end expiratory pressure (PEEP) greater than 6 cm H(2)O; and (3) coexistent evidence of significant pulmonary barotrauma. An illustrative case report is presented where this entity was recognized and the patient managed without laparotomy. Controlled prospective studies should determine the true importance of this problem.