The Characteristics Of Intracranial Pressure And Cerebral Perfusion Pressure After Traumatic Brain Injury In Children

Background：Traumatic Brain Injury（TBI） is one of the majorcontributor for children mortality and disability worldwide. The mostcommon pathophysiology reaction is intracranial hypertension (ICH) whichis associated with the poor outcome, so intracranial pressure (ICP)monitoring is a cornerstone of care for TBI. However the clinical researchon ICP and cerebral perfusion pressure (CPP) in TBI children is few. TheAmerican Brain Trauma Foundation (BTF) advise use of intracranialpressure (ICP) monitoring may be considered in infants and children withsevere traumatic brain injury (TBI)(Level Ⅲ).Objective: Retrospectively analyze the characteristics of ICP and CPPin TBI children, and reveal the relationship in ICP or CPP and outcome.Some theory basis for clinical management of ICH in pediatric TBI may beprovided according to this research.Method: Retrospectively analyze the ICP and CPP distinction indifferent age groups、 periods after surgery、injury severity and outcomeof68TBI children cases who have underwent continuous invasive ICPmonitoring，and then reveal the associated factors for ICH and low CPP. Result: The ICP is at a relatively low level in early time after pediatricTBI surgery，but it ascend to the peak point rapidly in24hrs, then descendgradually and trend to stable in3rd～5th day. Similarly CPP is at arelatively high level in early time after surgery and descend to the valleyin24hrs, then raise slightly and trend to stable in2nd～3rd day. Theaverage ICP in different age groups:Infant group(13cases)(6.1±1.64)mmHg; Toddler group(33cases)(16.93±1.59)mmHg;School age group(22cases)(19.85±1.54); statistical significance can befound between any two groups(P<0.01). Similarly，average CPP indifferent groups:Infant group (52.5±2.30)mmHg; Toddler group(54.33±1.74)mmHg; School age group (58.02±1.85); there are statisticalsignificance between any two groups(P<0.01). The ICP level in severetrauma group is significantly higher than the moderate or mildgroup[(20.55±1.50)mmHg vs (16.12±1.62)mmHg and(15.89±1.55)mmHg; P<0.01， P<0.01]； the CPP level in severe ormoderate trauma group is significantly lower than that in mildgroup[（54.76±1.84） mmHg and （54.92±2.44） mmHg vs(55.59±1.49)mmHg，P<0.01，P<0.01].ICP above30mmHg and CPPbelow40mmHg are associated with poor outcome (r=0.398，P<0.01；r=0.352，P<0.01). The ICH persistent time of unfavorable outcome groupis significantly longer than that in favorable outcome group[(82.90±36.97)h vs (24.36±36.80)h，P<0.01], but low CPP persistent time is found no statistical significance in different outcome groups [(26.38±30.06)h vs (16.93±1.59)h，P＞0.05]. Logistic regression reveal that thereis a positive relationship between traumatic subarachnoid hemorrhage(tSAH)，coma and ICP above30mmHg（r=1.996，P<0.05;r=4.947，P<0.05）, however the relationship between intracranial hematoma(Supratentorial hematoma>25ml; Subtentorial hematoma<10ml) and ICPabove30mmHg is negative(r=-2.447，P<0.05). None analyzed factors isassociated with CPP lower than40mmHg.Conclusion:（1）In early time after pediatric TBI surgery，the ICP isat relative low level and the CPP is at relative high level，but ICP ascend topeak point and CPP descend to valley at24hrs after surgery，then theformer descend gradually in3rd～5th day and the latter ascend slightly2nd～3rd day.（2）The elder of TBI children, the higher ICP and CPP.(3)The more severe, the higher ICP and lower CPP.(4)The longerpersistent time of ICH, the poorer outcome.(5) ICP above30mmHg andCPP below40mmHg are associated poor outcome.(6)TSAH and coma isassociated with ICP above30mmHg positively.(7) Age-specific ICP andCPP thresholds should be be adopted and ICP monitoring can contribute tothe judgement clinical situation and outcome, especially in the early stageafter TBI surgery.