Effects of positive end-expiratory pressure on intracranial pressure in dogs with intracranial hypertension

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✓ Positive end-expiratory pressure (PEEP) is used to improve oxygenation in patients with the adult respiratory distress syndrome. Nevertheless, this treatment may increase intracranial pressure (ICP) and be detrimental to certain neurosurgical patients. This clinical situation was simulated by administering PEEP to dogs with normal and elevated ICP. Increases in PEEP increased ICP in all animals. However, the presence of intracranial hypertension diminished the increase in ICP seen at a given level of PEEP. Cerebral perfusion pressure also fell less in the presence of intracranial hypertension than it did in its absence, although in the former situation cerebral perfusion pressure was at the lower limits of the range of cerebral autoregulation. These findings suggest that PEEP is no more detrimental to patients with elevated ICP than it is to patients whose ICP is normal, assuming that their cerebral autoregulation is not impaired.

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Address reprint requests to: John Butler, M.D., Division of Respiratory Diseases, Mail Stop RM-12, University of Washington, Seattle, Washington 98195.

© AANS, except where prohibited by US copyright law.

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    Increases in intracranial pressure (ICP) with positive end-expiratory pressure (PEEP). Values are mean ± standard error of the mean. Group 1 included 12 animals with initial ICP less than 20 cm H2O; Group 2 included seven animals with initial ICP of 21 to 39 cm H2O; Group 3 included nine animals with initial ICP greater than 40 cm H2O.

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    Decreases in cerebral perfusion pressure (CPP) with positive end-expiratory pressure (PEEP). Values are mean ± standard error of the mean. Group 1 included 12 animals with initial ICP less than 20 cm H2O; Group 2 included seven animals with initial ICP of 21 to 39 cm H2O; Group 3 included nine animals with initial ICP greater than 40 cm H2O.

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    Schematic illustration of the intracranial space during raised intracranial pressure (ICP). The arrows indicate the position of the hypothesized Starling resistor. Here, the mean arterial pressure (MAP) is greater than ICP, which is greater than sagittal sinus pressure (SSP). Cortical vein pressure (Pcv) cannot fall below ICP, and thus flow is dependent on MAP — ICP, and independent of small changes in SSP.

References

  • 1.

    Huseby JSPavlin EGButler J: Effect of positive endexpiratory pressure on intracranial pressure in dogs. J Appl Physiol 44:25271978Huseby JS Pavlin EG Butler J: Effect of positive endexpiratory pressure on intracranial pressure in dogs. J Appl Physiol 44:25–27 1978

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  • 2.

    Nakagawa YTsuru MYada K: Site and mechanism for compression of the venous system during experimental intracranial hypertension. J Neurosurg 41:4274341974Nakagawa Y Tsuru M Yada K: Site and mechanism for compression of the venous system during experimental intracranial hypertension. J Neurosurg 41:427–434 1974

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  • 3.

    Permutt SRiley RL: Hemodynamics of collapsible vessels with tone: the vascular waterfall. J Appl Physiol 18:9249321963Permutt S Riley RL: Hemodynamics of collapsible vessels with tone: the vascular waterfall. J Appl Physiol 18:924–932 1963

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