Exposure of the cat brain surface to neurosurgical irrigation fluids, hydrogen peroxide and air. Quantitative assay of blood-brain barrier dysfunction.

The effect of different irrigation fluids used in neurosurgery and of cortical exposure to air or hydrogen peroxides on the cat brain surface was tested by quantitative assay of extravasated albumen in the cortex and the white matter. Ringer's solution and Elliott's solution B induced no major blood-brain barrier (BBB) dysfunction after closed subdural perfusion for 3 hours. Normal saline induced slight BBB dysfunction extending throughout the cortex into the white matter after the same time of exposure. When these three solutions were applied to the brain surface via pledgets during exposure for 3 hours no further damage was induced. If 15 minutes exposure to air preceded the open perfusion via pledgets with Ringer's solution or Elliott's solution B for 2 hours and 45 minutes, no significant cortical BBB dysfunction was induced. There was a manifold increase in BBB dysfunction after perfusion with Ringer's solution or Elliott's solution B for 2 hours and 45 minutes followed by exposure to three per cent hydrogen peroxide for 5 minutes and a further 10 minutes perfusion with the previous irrigation fluid. Thus, normal saline was found unsuitable for neurosurgical irrigation purposes, due to disturbance of the BBB. Ringer's solution and Elliott's solution B protected the brain adequately even if only applied in pledgets. A short period of exposure to air had no effect on the BBB in the cortex, whilst exposure to hydrogen peroxide was detrimental to the BBB.