摘要
目的观察不同水平呼气末正压通气(positive end-expiratory pressure,PEEP)对犬额叶脑内血肿颅内高压的影响。方法18只犬随机分为正常颅压组(Ⅰ组,颅内压<18mmHg)、颅压中度增高组(Ⅱ组,颅内压25～40mmHg)和颅压高度增高组(Ⅲ组,颅内压>40mmHg)3组(每组各6只),全麻,气管切开插管,应用肌松剂,机械通气,右额叶脑内注入自体血制成颅内高压模型,PEEP从0开始每次增加3cmH2O,直到18cmH2O,每个水平持续20min,在对侧用光纤颅内压探头监测脑内颅内压(ICP)的变化,记录平均动脉压(MAP)和中心静脉压(CVP)并计算出脑灌注压(CPP)。结果随着PEEP的递增,Ⅰ组颅内压上升,脑灌注压下降;Ⅱ、Ⅲ组颅内压略有下降,但Ⅱ组MAP、CPP上升,而Ⅲ组MAP下降,CPP下降;3组CVP都随PEEP增加而升高,但Ⅲ组上升幅度明显大于另两组(P<0·01)。结论应用PEEP通气时由于中心静脉压升高、脑静脉回流受阻和血流动力学改变,进而影响ICP和CPP。在正常颅内压状态下,PEEP使颅内压上升,在已有颅内高压存在时,PEEP对颅内压影响不明显,但在重度高颅压情况下,PEEP使CPP明显下降,提示在重度颅内高压需要应用PEEP通气时必须维持MAP,以保证足够的CPP。
Objective To evaluate the influence of positive end-expiratory pressure （PEEP） on intracranial pressure and cerebral perfusion pressure in dogs with or without intracranial hypertension caused by frontal intracerebral hematoma. Methods Eighteen dogs were randomly divided into three groups. In Group B and Group C, the intracranial hypertension was respectively higher than 25 mmHg but less than 40 mmHg and higher than 40 mmHg induced by autoblood clotting injection into the right frontal lobe, while Group A as control was of normal intracranial pressure. PEEP was applied in increment of 3 cmH2O from 0 to 18 cmH2O, each level lasting 20 min. The intracranial pressure （ICP） was monitored by an optical fiber transducer implanted into left frontal lobe. Mean arterial pressure （ MAP）, heart rate （ HR）, and central venous pressure （CVP） were recorded simultaneously. Cerebral perfusion pressure （CPP） was calculated by the equation （ CPP = MAP - ICP）. Results With increasing PEEP level, ICP increased and CPP fell in Group A; ICP fell, MAP and CPP increased in Group B ; ICP fell, MAP and CPP increased in Group C. CVP increased in all groups, and the increment was significantly higher in Group C than the other two groups （ P 〈 0. 01 ）. Conclusion During PEEP, the alteration of ICP and CPP results from CVP increase, delayed blood return from brain vein and hemodynamic change. ICP increased when PEEP level rose under normal intracranial pressure, but showed no changes under intracranial hypertension, even decreased under severe intracranial hypertension, indicating MAP should be carefully maintained when under severe intracranial hypertension in order to guarantee the adequate CPP.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2007年第6期513-515,共3页
Journal of Third Military Medical University
基金
上海市医学领先专业重点学科建设基金(319630304102)~~
关键词
颅内压
呼气末正压
脑内血肿
intracranial pressure
positive end-expiratory pressure
intracerebral hematoma
