EXTRACORPOREAL GLASS-WOOL FILTRATION OF WHOLE-BLOOD ENHANCES POST-ISCHEMIC RECOVERY OF THE CORTICAL SENSORY EVOKED-RESPONSE

In 20 dogs anticoagulated with heparin 300 units/kg, the right cortical sensory evoked response (CSER) to contralateral median nerve stimulation was suppressed during 60 min ischemia induced by periodic infusion of 50-100 .mu.l increments of air via the right internal carotid artery. The postischemic recovery of the CSER was followed for an additional 60 min in 19 of these animals divided into 2 groups: 10 dogs subjected to glass-wool filtration of their blood by extracorporeal shunting from femoral artery to femoral vein for 1 h prior to infusing air and 9 dogs not receiving glass-wool filtration. Post-ischemic recovery of CSER amplitude, a quantifiable electrophysiologic index of neuronal function, was significantly greater in the filtered group than in the non-filtered group. 14C-antipyrine autoradiographic blood flow studies were performed in 3 dogs. At the end of a 60 min ischemic CSER suppression period 1 was studied and showed severe flow disruption by air embolism; 2 dogs, 1 from each group, were studied at the conclusion maintenance while cortical flow rates in the unfiltered animal fell below the threshold. The enhanced postischemic neuronal recovery in the filtered group as indicated by the CSER is due to the preservation of injury zone nutrient blood flow supported by collateral circulation.