Does propofol alter cerebral hemodynamics and metabolism in severely brain-injured patients?
In severely brain-injured patients, propofol administration reduces intracranial pressure but also significantly decreases cerebral perfusion pressure and regional cerebral blood flow.
The authors determined the effect of propofol on cerebral blood flow, intracranial pressure, and cerebral arteriovenous oxygen content difference in severely brain-injured patients during orthopedic treatment of fractures of the extremities. The Glasgow Coma Scale score was 6 or 7 at the time of the study. Data were collected in the operating room before and during (5 and 15 min) administration of propofol (2 mg/kg iv bolus immediately followed by a 150 micrograms.kg-1.min-1 infusion) before surgical stimulation. Propofol was infused during 41.4 +/- 7.3 min. After operation, the last set of measurements was made 15 min after propofol was stopped. The study was performed on 10 adults (age range, 15-40 yr) whose lungs were mechanically ventilated (air/O2) and who were sedated (phenoperidine, 1 mg/h), and was conducted using a radial artery cannula; a 7.5-Fr, thermodilution, flow-directed, pulmonary artery catheter; an intraventricular catheter; and a catheter in the jugular venous bulb. The 133xenon intra-internal carotid artery injection technique was used to determine regional cerebral blood flow (rCBF). Anesthetic blood concentration of propofol (3-5 micrograms/ml) was associated with decreases in cerebral perfusion pressure (CPP; from 82 +/- 14 to 59 +/- 7 mmHg; P less than 0.001), rCBF (from 35 +/- 6 to 26 +/- 5 ml.100 g-1.min-1; P less than 0.001), and intracranial pressure (ICP; from 11.3 +/- 2.6 to 9.2 +/- 2.5 mmHg; P less than 0.001). Cerebrovascular resistance and cerebral arteriovenous oxygen content difference were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)
Pinaud et al. (Sat,) studied this question.