TY - JOUR
T1 - Effects of hyperventilation and hypoventilation on PaCO2 and intracranial pressure during acute elevations of intraabdominal pressure with CO2 pneumoperitoneum
T2 - Large animal observations
AU - Rosenthal, Raul J.
AU - Friedman, Richard L.
AU - Chidambaram, Arul
AU - Khan, Akram M.
AU - Martz, Joseph
AU - Shi, Qiuhu
AU - Nussbaum, Moses
PY - 1998
Y1 - 1998
N2 - Background: The side effects of acute elevations in intraabdominal pressure (IAP) are related to a multifactorial etiology. Previous studies have reported that acute elevations in IAP produce an immediate increase in intracranial pressure (ICP). This study was designed to analyze the reasons for increased ICP during acute elevations of IAP and to determine the combined effects of IAP and changes in ventilation indices on ICP and hemodynamic indices. Study Design: Five pigs were studied. A subarachnoid screw was placed for ICP monitoring. The jugular vein, femoral vein, and femoral artery were cannulated. Mean arterial pressure (MAP), central venous pressure (CVP), ICP, and arterial pressure of carbon dioxide (PaCO2) were monitored before and after carbon dioxide pneumoperitoneum was established at 0, 10, and 20 mmHg of IAP. Effects of hyperventilation and hypoventilation were recorded and compared with baseline ventilation. Cavography was performed to evaluate the morphology of the inferior vena cava (IVC) at different levels of IAP. Multiple regression and Student's t-test were used to examine the effects of IAP and ventilation on dependent variables. Results: The IVC showed a progressive narrowing at the level of the diaphragm as IAP was increased. There was a simultaneous increase in CVP, MAP, and ICP. The mean changes in ICP with hypoventilation were significantly larger than with hyperventilation. Conclusions: 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.
AB - Background: The side effects of acute elevations in intraabdominal pressure (IAP) are related to a multifactorial etiology. Previous studies have reported that acute elevations in IAP produce an immediate increase in intracranial pressure (ICP). This study was designed to analyze the reasons for increased ICP during acute elevations of IAP and to determine the combined effects of IAP and changes in ventilation indices on ICP and hemodynamic indices. Study Design: Five pigs were studied. A subarachnoid screw was placed for ICP monitoring. The jugular vein, femoral vein, and femoral artery were cannulated. Mean arterial pressure (MAP), central venous pressure (CVP), ICP, and arterial pressure of carbon dioxide (PaCO2) were monitored before and after carbon dioxide pneumoperitoneum was established at 0, 10, and 20 mmHg of IAP. Effects of hyperventilation and hypoventilation were recorded and compared with baseline ventilation. Cavography was performed to evaluate the morphology of the inferior vena cava (IVC) at different levels of IAP. Multiple regression and Student's t-test were used to examine the effects of IAP and ventilation on dependent variables. Results: The IVC showed a progressive narrowing at the level of the diaphragm as IAP was increased. There was a simultaneous increase in CVP, MAP, and ICP. The mean changes in ICP with hypoventilation were significantly larger than with hyperventilation. Conclusions: 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.
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U2 - 10.1016/S1072-7515(98)00126-4
DO - 10.1016/S1072-7515(98)00126-4
M3 - Article
C2 - 9660022
AN - SCOPUS:0031866850
SN - 1072-7515
VL - 187
SP - 32
EP - 38
JO - Journal of the American College of Surgeons
JF - Journal of the American College of Surgeons
IS - 1
ER -