Use of high frequency jet ventilation during mechanical hyperventilation to reduce intracranial pressure in patients with multiple organ system injury.

Eleven patients with multiple organ system injury, including significant closed head injury, all required positive end-expiratory pressure (PEEP) for treatment of their pulmonary pathological condition. Additionally, the need for intracranial pressure (ICP) monitoring had previously been established on clinical evaluation by the Neurosurgery Service. Seven of the 11 patients met the criteria for invasive hemodynamic monitoring. Hemodynamic monitoring data are supplied for these 7 patients. All patients, after the initial institution of conventional means of hyperventilation, were transitioned to high frequency jet ventilation (HFJV) to evaluate the effects of HFJV during mechanical hyperventilation. There was a statistically significant decrease in ICP (mean decrease of 7.2 mm Hg). There was also a statistically significant fall in PaO2 from 131 to 101 torr. This was not associated with an appreciable decrease in oxygen delivery. There was no change in cardiac output or intrapulmonary shunt fraction. It is concluded that successful control of ICP was possible in all cases without impairment of cardiac output, oxygen delivery, or cerebral perfusion pressure, even when the pulmonary abnormality required the use of PEEP.