Effects of different temperature management strategies on blood-brain barrier and post-operative cognitive dysfunction in patients undergoing spinal fixation surgery / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effects of different temperature management strategies on blood-brain barrier (BBB) and postoperative cognitive dysfunction (POCD) in the patients undergoing spinal fixation surgery.Methods:Ninety-six patients, aged 44-78 yr, weighing 45-104 kg, of American Society of Anesthesiology physical status Ⅰ-Ⅲ, undergoing spinal fixation surgery with combined intravenous-inhalational anesthesia, were divided into 3 groups ( n=32 each) by the simple randomization warming blood transfusion and infusion group (group WBI), active warming group (group AW) and active warming plus selective brain cooling group (group SBC). In WBI group, the fluid for intraoperative intravenous infusion was warmed to 37 ℃ using a medical blood transfusion-infusion warmer.In AW group, warming was maintained using the fluid warming combined with the body surface warming blanket until the end of operation, and the target temperature of the warming blanket was set at 38 ℃.In SBC group, the warming protocol were similar to those previously described in AW group, and selective brain cooling was performed through an electronic ice cap with a set temperature of 4 ℃.Blood samples were collected from the median cubital vein at the end of operation, brain microvascular endothelial cells were isolated and identified by immunomagnetic bead, and the target cells were counted with a fluorescence microscope.The concentration of C-reactive protein in peripheral blood was measured by rate nephelometry on the first day after operation.The extubation time, length of post-anesthesia care unit (PACU) stay, total length of hospital stay, thermal comfortableness score, shivering in PACU, agitation and postoperative fever were recorded.The postoperative recovery was assessed using the 40-item Quality-of-Recovery scale on 7th day after surgery. Results:Compared with WBI group, the incidence of POCD and shivering in PACU, extubation time, length of PACU stay, and serum C-reactive protein concentrations were significantly decreased, and thermal comfortableness score and 40-item Quality-of Recovery scale score were increased in AW group and SBC group ( P<0.05). Compared with AW group, the count of brain microvascular endothelial cells was significantly decreased in SBC group ( P<0.05). Conclusions:Active warming produces no damage to the structure of BBB, and can reduce the development of POCD; active warming combined with selective brain cooling can improve the structural integrity of BBB, but it cannot reduce the development of POCD in the patients undergoing spinal fixation surgery.