Effects of Hyperventilation and Hypoventilation on PaCO2 and Intracranial Pressure During Acute Elevations of Intraabdominal Pressure with CO2 Pneumoperitoneum: Large Animal Observations

Abstract

Acutely increased IAP displaces the diaphragm cranially, narrowing the IVC and increasing intrathoracic pressure. This increases CVP and increases ICP by venous stasis and increased pressure in the sagittal sinus with decreased resorption of cerebrospinal fluid. Hemodynamic changes are directly related to the rise in ICP. Hypoventilation and hypercarbia significantly increase ICP when compared with hyperventilation and hypocarbia. Hyperventilation does not significantly decrease ICP during acute elevations of IAP.