Effects of cerebral air embolism on brain metabolism in pigs

Objectives - Cerebral air embolism was induced in pigs and changes in intracranial pressure (ICP), brain oxygen (PbrO(2)), brain carbon dioxide (PbrCO(2)), brain pH (brpH) and glucose, lactate and pyruvate levels were used to characterize this model. Methods - In seven anesthetized pigs, ICP, PbrO(2), PbrCO(2) and brpH were measured continuously with multiparameter sensors and brain glucose metabolism by microdialysis. After injection of air into the internal carotid artery, these parameters were recorded for 2 h. Results - ICP increased (433%) from 12 +/- 1 to 52 +/- 8 mmHg (P < 0.05). PbrO(2) decreased from 25.7 +/- 6.2 to 11.9 +/- 5.2 mmHg. PbrCO(2) increased (109%) from 57.7 +/- 2.7 to 120.4 +/- 21.5 mmHg (P < 0.05). Brain glucose decreased (38%) from 3.05 +/- 0.91 to 1.91 +/- 0.55 mmol, while brain lactate increased (384%) from 1.36 +/- 0.15 to 5.22 +/- 0.53 mmol/l (P < 0.05).<LF>Conclusions - Cerebral air embolism has a deleterious effect on ICP and brain metabolism. Therefore, this model may be suitable for testing therapeutic regimens in cerebral air embolism.