The Clinical Research Of The Treatment Of Acute High Intracranial Pressure By Using Hyperventilation

Objective:Compare the clinical effect of the treatment for patientswith acute high intracranial pressure by usinghyperventilation, to explore the optimal PaCO2level andduration.Methods:Choose104patients with acute high intracranial pressurecaused by severe brain disease and required assistedventilation by ventilator, were randomly divided into fourgroups, were given routine therapy (dehydration, nutritionalsupport). Group1for the control group (n=20): normalmechanical ventilation, no excessive ventilation intervention;group2to mild hyperventilation (n=34):30mmHg <PaCO2<35mmHg; group3to moderate hyperventilation (n=30):25mmHg<PaCO2<30mmHg; group4received severe hyperventilation(n=20): PaCO2≤20mmHg <25mmHg. The time of hyperventilationfor all patients last4-6hours, maintaining PaO2between150mmHg and200mmHg,In0,1,2,4,6hours after hyperventilationmonitoring of ICP, CPP, MCA mean blood flow velocity, BIS, GCSscore, measuring BIS,GCS score again after a week. Statistical analysis, draw the conclusion.Result:1.Compare with the control group, different degrees ofhyperventilation could all decrease ICP,(P<0.05); In light,medium and severe group, the level of decreasing ICP had nosignificant difference (P>0.05);Group comparison,differentdegrees of hyperventilation,1,2,4and6hours, ICP declinesmore significantly than begining (P<0.05);Different degrees ofhyperventilation,1,2,4,6hours,the extent of decreasingICP had no significant difference (P>0.05).2.Compare with the control group, hyperventilation,duration of1hours, medium and severe hyperventilation coulddecrease CPP (P<0.05), mild group had no significant change(P>0.05); In light, medium and severe group,2、4、6hourcompared with1hour of hyperventilation CPP decreasedsignificantly (P<0.05).3.Compare with the control group, different degrees ofhyperventilation could all induce MCA mean blood flow velocitydecreased (P<0.05), mild group decreased less than medium andsevere group (P<0.05), it had no significant difference betweenmedium and severe group (P>0.05);mild hyperventilation groupcontinued more than1hours, MCA mean blood flow velocity close to normal, medium and severe hyperventilation group in eachperiod, mild hyperventilation group continued more than2hours,MCA mean blood flow velocity was significantly lower thannormal, and had significant difference (P<0.05).4.1weeks after the intervention, mild hyperventilateiongroup lead to BIS, GCS score more increased than controlgroup (P<0.05), it had no significant difference between mediumand severe group(P>0.05).Conclution:1.The optimal degree of hyperventilation: light, mediumand severe hyperventilation can decrease ICP; medium and severehyperventilation could cause CPP and CBF decreased,mildhyperventilation had little influence on CPP and CBF;1weeksafter the intervention, mild hyperventilation group lead to BIS,GCS score more increased than control group. To sum up, thetreatment effect of mild hyperventilation (30mmHg <PaCO2<35mmHg) is better.2.The optimal duration of hyperventilation: The durationof hyperventilation had no influence on the level of decreasingICP; the duration of hyperventilation was more than2hours,it can cause CPP decreased; mild hyperventilation groupcontinued more than1hours, MCA mean blood flow velocity close to the normal; medium and severe hyperventilation groupin each period, mild hyperventilation group continued more than2hours, MCA mean blood flow velocity was significantly lowerthan normal, it suggest that CBF has gone down. To sum up,thetreatment effect of mild hyperventilation continued for1houris better.