Local O2 Balance in Cerebral Ischemia-Reperfusion Improved during Pentobarbital Compared with Isoflurane Anesthesia

J Stroke Cerebrovasc Dis. 2015 Jun;24(6):1196-203. doi: 10.1016/j.jstrokecerebrovasdis.2015.01.016. Epub 2015 Apr 11.

Abstract

Background: Most anesthetics affect cerebral blood flow and metabolism. We compared microregional O2 balance in cerebral ischemia-reperfusion during pentobarbital and isoflurane anesthesia.

Methods: After 1 hour of middle cerebral artery occlusion and a 2-hour reperfusion under isoflurane (1.4%, n = 14) or pentobarbital (50 mg/kg, n = 14) anesthesia in rats, regional cerebral blood flow using (14)C-iodoantipyrine autoradiography, microregional arterial and venous O2 saturation (20-60 μm in diameter) using cryomicrospectrophotometry, and the size of cortical infarct were determined.

Results: Ischemia-reperfusion decreased the average cortical venous O2 saturation in both pentobarbital and isoflurane groups (P < .0001), which was higher (P < .05) with pentobarbital despite a similar average regional cerebral blood flow and O2 consumption. The heterogeneity of venous O2 saturation reported as a coefficient of variation (100 × standard deviation/mean) was smaller (P < .005) with pentobarbital than that with isoflurane (7.5 versus 16.1). The number of veins with low venous O2 saturation (<50%) was smaller (P < .005) with pentobarbital (5 of 80 versus 24 of 80). The percentage of cortical infarct in total cortex was smaller with pentobarbital (5.2 ± 2.5% versus 12.3 ± 2.6%, P < .001).

Conclusions: In the cerebral ischemic-reperfused cortex, the average venous O2 saturation was higher, and its heterogeneity and the number of veins with low O2 saturation were smaller under pentobarbital than isoflurane anesthesia. This improvement in microregional O2 balance with pentobarbital was accompanied by the reduced cortical infarct. Our data suggest that the neurologic outcome could vary during cerebral ischemia-reperfusion depending on the anesthetics used.

Keywords: cerebral O(2) supply/consumption balance; cerebral blood flow and metabolism; cerebral venous O(2) saturation; ischemia/reperfusion injury/neuroprotection; isoflurane; pentobarbital.

Publication types

  • Comparative Study

MeSH terms

  • Anesthetics, Inhalation / pharmacology*
  • Animals
  • Brain / blood supply
  • Brain / drug effects
  • Brain / metabolism
  • Brain Ischemia / metabolism*
  • Cerebrovascular Circulation / drug effects*
  • Infarction, Middle Cerebral Artery / metabolism
  • Isoflurane / pharmacology*
  • Male
  • Oxygen / metabolism
  • Oxygen Consumption / drug effects*
  • Pentobarbital / pharmacology*
  • Rats
  • Rats, Inbred F344

Substances

  • Anesthetics, Inhalation
  • Isoflurane
  • Pentobarbital
  • Oxygen