The effect of propofol sedation on the intracranial pressure of patients with an intracranial space-occupying lesion

The fear of producing CO(2) retention and a secondary increase of intracranial pressure (ICP) sometimes precludes the use of sedation for the spontaneously breathing patient in the presence of an intracranial space-occupying lesion. In this study we assessed the effect of moderately deep propofol sedation on the ICP of patients undergoing stereotactic brain tumor biopsy under regional anesthesia. Thirty patients were randomized into 2 groups to receive propofol titrated to a level of 2 on the Observer's Assessment of Alertness/Sedation Scale or no sedation. ICP was measured via the biopsy needle. Preoperative data were similar in both groups. During surgery, patients receiving propofol had a higher arterial Pco(2) (48 +/- 8 mm Hg versus 41 +/- 3 mm Hg; P = 0.005) (95% confidence interval, 43-53 mm Hg and 39-43 mm Hg, respectively), resulting in a lower arterial pH (P = 0.002) than patients in the no-sedation group. The median ICP (95% confidence interval) for both groups was similar-13 mm Hg (8.2-16.2 mm Hg) and 15 mm Hg (8.3-21.7 mm Hg)-for the propofol and no-sedation groups, respectively (P = 0.66). Cerebral perfusion pressure was lower in the propofol group (76 +/- 18 mm Hg versus 89 +/- 18 mm Hg; P = 0.003). Moderately deep propofol sedation does not result in a higher ICP than no sedation in patients undergoing stereotactic brain tumor biopsy. Further studies are needed to assess the effect on ICP of other sedative medications.