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.
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.
Authors: Tovy Haber Kamine; Nassrene Y Elmadhun; Ekkehard M Kasper; Efstathios Papavassiliou; Benjamin E Schneider Journal: Surg Endosc Date: 2015-12-23 Impact factor: 4.584
Authors: Denise M D Özdemir-van Brunschot; Kees C J H M van Laarhoven; Gert-Jan Scheffer; Sjaak Pouwels; Kim E Wever; Michiel C Warlé Journal: Surg Endosc Date: 2015-08-15 Impact factor: 4.584
Authors: Dirk Varelmann; Thomas Muders; Jörg Zinserling; Ulf Guenther; Anders Magnusson; Göran Hedenstierna; Christian Putensen; Hermann Wrigge Journal: Crit Care Date: 2008-11-04 Impact factor: 9.097
Authors: Hannes G Kenngott; Felix Nickel; Anas A Preukschas; Martin Wagner; Shivalik Bihani; Emre Özmen; Philipp A Wise; Nadine Bellemann; Christof M Sommer; Tobias Norajitra; Bastian Graser; Christian Stock; Marco Nolden; Araineb Mehrabi; Beat P Müller-Stich Journal: Surg Endosc Date: 2021-01-04 Impact factor: 4.584