PETCO2监测过度通气水平对脑外伤患者脑血流、脑代谢和脑灌注的影响

Effect of hyperventilation on cerebral blood flow, brain metabolism and cerebral perfusion in patients with traumatic brain injury byPETCO2 monitoring

目的探讨呼吸末二氧化碳分压（PETCO2）监测下过度通气水平对颅脑外伤患者术中脑血流、脑代谢和脑灌注的影响。方法选择东营鸿港医院神经外科自2009年1月至2012年6月急诊行脑外伤开颅去骨瓣减压血肿清除术的患者70例，按随机数字表法分为A、B2组．每组35例，A组患者P。#02控制在20-25mmHg之间，动脉血二氧化碳分压（PaC02）维持在22～25ITlmHg之间，B组患者PETCO2控制在25～30mmHg之间，P．C02维持在30～45mmHg之间，比较手术开始去骨瓣前2组患者血气分析结果、平均动脉压、颅内压、脑氧分压、脑灌注压和脑氧供需平衡以及代谢产物神经元特异性稀醇化酶（NSE）、葡萄糖、乳酸的变化。结果手术开始去骨瓣前A组患者的PaCO2水平、平均动脉压、颅内压、NSE、葡萄糖和乳酸水平显著低于B组，差异有统计学意义（P〈0．05）；2组患者脑氧分压和脑灌注压、动脉血氧含量（CaO2）、静脉血氧含量（CjvO2）和脑氧摄取率（CERO2）比较差异无统计学意义（P＞0．05）。结论术中将PETCO2控制在20～25mmHg之间，能有效维持患者脑血流灌注和脑氧供需平衡．降低病理性代谢产物水平．值得临床重视。

Objective To investigate the effect of hyperventilation on cerebral blood flow, brainmetabolism and cerebral perfusion in patients with traumatic brain injury by end tidal pressure of COz （PETCO2） monitoring. Methods Seventy patients with traumatic brain injury, admitted to our hospital from January 2009 to June 2012 and performed decompressive craniectomy, were chosen in our study; they were randomly divided into group A and group B （n=35）; patients in the group A accepted PETCO2 within 20-25 mm Hg and arterial partial pressure of carbon dioxide （PaCO2） within 22-25 mm Hg, and patients in the group B received PETCO2 within 25-30 mm Hg and PaCO2 within 30-45 mm Hg. The blood gas pressure, mean artery pressure, cerebral oxygen partial pressure, cerebral perfusion pressure, cerebral oxygen supply and demand balance, and changes of neuron specific enolase （NSE）, glucose and lactic acid were compared between the two groups at the beginning of craniectomy. Results The PaCO2 level, mean artery pressure, intracranial pressure, and levels of NSE, glucose and lactic acid in group A were significantly lower than those in group B （P〈0.05）; while the brain oxygen partial pressure, cerebral perfusion pressure, arterial oxygen content （CaO2）, venous oxygen content （CjvO2） and cerebral oxygen uptake rate （CEROz） showed no significant difference between the two groups （P〉0.05）. Conclusion PETCO2 controlling within 20-25 mm Hg can effectively maintain the cerebral blood perfusion and cerebral oxygen supply and demand balance of the patients; it can also reduce the pathological metabolite effect on the brain tissue; therefore, its clinical value is worthy for attention.