激光多普勒监测重型颅脑创伤患者脑血流的临床研究

A clinical research of monitoring cerebral blood flow with laser doppler flowmetry in patients with severe traumatic brain injury

目的探讨重型颅脑创伤患者伤后急性期脑血流变化规律。方法利用激光多普勒脑血流仪(LDF)监测36例重型颅脑创伤患者急性期的局部脑血流(rCBF)及颅内压(ICP),通过观察rCBF的变化趋势及LDF值与脑灌注压(CPP)的相关系数r,分析rCBF的变化及脑血流自动调节功能。结果在监测第一阶段(0-12h)16例(44%)为低灌注;在第二阶段(12-24h)9例(25%)为低灌注;在第三阶段(24h以后)6例(17%)为低灌注。随着时间的推移,局部脑血流灌注量呈逐渐上升趋势。将CPP与LDF值的相关系数r作为评价脑血流自动调节功能的指数,15例(42%)至少出现一次自动调节功能受损,其中GCS 3～5分11例,GCS 6～8分4例。结论重型颅脑创伤患者在伤后急性期多发生低灌注,随着时间的推移,局部脑血流量逐渐上升。患者伤后多发生暂时性的脑血管调节功能受损,特重型颅脑创伤自动调节功能受损的发生率要高于重型颅脑创伤。

Objective To explore the rules of changes of cerebral blood flow （CBF） in patients with severe traumatic brain injury （sTBI） in acute stage. Methods With laser doppler flowmetry （ LDF）, regional cerebral blood flow （rCBF） and intral cranial pressure （ICP） were measured in 36 patients with sTBI in acute stage. The changes and autoregulation of CBF were analyzed based on rCBF data and correlation coefficient between LDF value and cerebral perfusion pressure （CPP）. Results At the first stage （0-12 hours）, hypoperfusion was found in 16 cases （44%）, while 9 cases （25%） at the second stage （ 12-24 hours） and 6 cases （ 17% ） at the third stage （24 hours later）. A trend of gradual higher rCBF perfusion was found as time went on. The correlation coefficient between LDF value and CPP was used as an index to estimate autoregulation. Impaired autoregulation was observed at least one time in 15 cases （42%）, including 11 cases of GCS 3 ～ 5, and 4 cases of GCS 6 - 8. Conclusion Hypoperfusion occurs frequently at the acute stage in patients with sTBI and rCBF turns higher gradually as time goes on. Many patients suffer transient impairment of autoregulation and the occurrence rate of impaired autoregulation in super severe traumatic brain injury （sTBI） was statistically higher than that in sTBI.