3%高渗盐水在择期颅脑外科手术中对脑氧供需平衡的影响

目的探讨3％高渗盐水(HTS)在择期颅脑外科手术中对脑氧供需平衡的影响。方法选择40例择期行大脑半球胶质瘤切除术的患者,全麻诱导前行L3-4穿插置管测脑脊液压力(CSFP)。采用静吸复合麻醉,异氟醚呼出浓度达最低肺泡有效浓度(1 MAC)后,15 min内输注完毕3％HTS。分别检测输注前及输注后30、60、120 min的颅内压、平均动脉压、颈静脉球部和桡动脉血气分析,计算脑灌注压(CPP)、动-静脉氧含量差(Da-jvO2)、脑氧摄取率(OER)。结果输注3％HTS后30 min,CSFP为(11.00±2．31)mm Hg(1 mm Hg= 0．133 kPa),较输注前的(15．57±2．76)mm Hg显著降低(P<0．05);CPP为(69．57±3．78)mm Hg,虽有下降趋势,但与输注前的(72．71±5．09)mm Hg差异无显著性(P>0．05);Da-jvO2和OER与输注前比较均有下降趋势,但仅输注后60、120 min与输注前的差异有显著性(P值均<0.05)。结论3％HTS具有降颅内压的作用,并可改善脑血流代谢耦联,可安全地应用于择期颅脑外科手术。

Effect of 3% hypertonic saline on balance of cerebral oxygen consumption and supply in selective supratentorial gliomata surgery

Objective To appraise the effect of 3% hypertonic saline(HTS) on cerebral oxygen consumption and supply during selective neurosurgery. Method 20 patients were subjected to operative excision of supratentorial gliomata. Cerebrospinal fluid pressure(CSFP) was estimated through a 17G epidural catheter inserted in the subarachnoid space under local anesthesia at L3-4 interspace. When the exhalant concentration of isoflulence reached 1 MAC, all patients received an equiosmolar bolus of i. v. 3% hypertonic saline within 15 minutes. Before the infu sion(T0), and 30, 60,90, 120 minutes after completion of infusion(T1 , T2 , T3 ) , mean arterial pressure(MAP), CSFP, body temperature were measured, together with cerebral perfusion pressure(CPP) calculated. Blood samples were taken from the radial artery and internal jugular bulb to determine the cerebral arteriovenous oxygen differences [D(a-j)O2] and cerebral oxygen extraction(OER). Results CSFP dropped significantly from T1 till T3 in all patients and CPP was not affected. D(a-j)O2 and OER decreased after delivery of HTS, especially in T2 and T3 . Conclusion Infusion of HTS not only decreases intracranial pressure without a negative pressure on CPP but also improves cerebral blood flow-metabolism coupling in selective supratentorial gliomata surgery. (Shanghai Med J, 2006, 29:721-724)