The relation between acute physiological variables and outcome on the Glasgow Outcome Scale and Disability Rating Scale following severe traumatic brain injury

The relation between outcome and duration of adverse physiological events was studied, using suggested critical physiological values. Subjects were 184 patients with severe traumatic brain injury who received continuous monitoring of intracranial pressure (ICP), mean arterial pressure (MAP), cerebral perfusion pressure (CPP), and jugular venous oxygen saturation. Longer durations of adverse physiological events were significantly related to Glasgow Outcome Scale (GOS) scores and Disability Rating Scale (DRS) scores for all variables at all timepoints postinjury. When analyses excluded patients who died, the relation between adverse physiological events and GOS was nonsignificant; however, duration of ICP, MAP, and CPP still accounted for a significant portion of the variance in DRS scalres. The relative sensitivity of the GOS and DRS is discussed.     

Relationship of cerebral perfusion pressure and survival in pediatric brain-injured patients

BACKGROUND: Adult brain injury studies recommend maintaining cerebral perfusion pressure (CPP) above 70 mm Hg. We evaluated CPP and outcome in brain-injured children. METHODS: We retrospectively reviewed the hospital courses of children at two Level I trauma centers who required insertion of intracranial pressure (ICP) monitors for management of traumatic brain injury. ICP, CPP, and mean arterial pressure were evaluated hourly, and means were calculated for the first 48 hours after injury. RESULTS: Of 188 brain-injured children, 118 had ICP monitors placed within 24 hours of injury. They suffered severe brain injury, with average admitting Glasgow Coma Scale scores of 6 +/- 3. Overall mortality rate was 28%. No patient with mean CPP less than 40 mm Hg survived. Among patients with mean CPP in deciles of 40 to 49, 50 to 59, 60 to 69, or 70 mm Hg, no significant difference in Glasgow Outcome Scale distribution existed. CONCLUSION: Low mean CPP was lethal. In children with survivable brain injury (mean CPP > 40 mm Hg), CPP did not stratify patients for risk of adverse outcome.     

动态CT扫描联合TCD检查预测外伤性蛛网膜下腔出血患者预后

目的动态CT扫描联合TCD预测外伤性蛛网膜下腔出血（tSAH）患者预后。方法对155例外伤性蛛网膜下腔出血患者给予动态CT扫描及TCD监测脑血流,6个月后行GOS评分（预后评分）。结果CT扫描tSAH出血量多、Hidjra分型13分以上、出血部位位于颅底大血管周围（外侧裂池、基底池、鞍上池、环池、四叠体池）,合并明显颅内损伤,颅内压较高及TCD监测的大脑中动脉血流明显增快者GOS评分低,预后较差。结论tSAH患者动态CT表现严重、TCD血流增速明显者,预后差。     

Management morbidity and mortality in grade IV and V patients with aneurysmal subarachnoid haemorrhage

Summary Intracranial haemodynamics were studied in 20 patients with diffuse and focal brain injury and experimental animals with acute intracranial hypertension by the use of TCD ultrasound. The mean flow velocity in the middle cerebral artery (MCA) commonly decreased on the side of the haematoma depending on intracranial pressure (ICP) elevation and cerebral perfusion pressure (CPP) reduction in focal injury. The decrease of the MCA flow velocity returned to normal after treatment. The flow velocities decreased bilaterally and there was no difference between the right and left side in diffuse injury. But the velocities increased in spite of ICP elevation when diffuse cerebral swelling developed. Cerebrovascular CO₂ reactivity was impaired in two groups of patients with low Glasgow Coma Scale (GCS) scores. The mean velocity of the MCA and blood flow in the internal carotid artery exhibited flow patterns which changed correlatively depending on CPP reduction in experimental animals. Noninvasive study by use of TCD ultrasound can provide valuable information on variant haemodynamic phenomena in patients with diffuse and focal brain injury.     

Cerebral oxygenation, vascular reactivity, and neurochemistry following decompressive craniectomy for severe traumatic brain injury

OBJECT: This study addresses the changes in brain oxygenation, cerebrovascular reactivity, and cerebral neurochemistry in patients following decompressive craniectomy for the control of elevated intracranial pressure (ICP) after severe traumatic brain injury (TBI). METHODS: Sixteen consecutive patients with isolated TBI and elevated ICP, who were refractory to maximal medical therapy, underwent decompressive craniectomy over a 1-year period. Thirteen patients were male and 3 were female. The mean age of the patients was 38 years and the median Glasgow Coma Scale score on admission was 5. RESULTS Six months following TBI, 11 patients had a poor outcome (Group 1, Glasgow Outcome Scale [GOS] Score 1-3), whereas the remaining 5 patients had a favorable outcome (Group 2, GOS Score 4 or 5). Decompressive craniectomy resulted in a significant reduction (p < 0.001) in the mean ICP and cerebrovascular pressure reactivity index to autoregulatory values (< 0.3) in both groups of patients. There was a significant improvement in brain tissue oxygenation (PbtO(2)) in Group 2 patients from 3 to 17 mm Hg and an 85% reduction in episodes of cerebral ischemia. In addition, the durations of abnormal PbtO(2) and biochemical indices were significantly reduced in Group 2 patients after decompressive craniectomy, but there was no improvement in the biochemical indices in Group 1 patients despite surgery. CONCLUSIONS: Decompressive craniectomy, when used appropriately in protocol-driven intensive care regimens for the treatment of recalcitrant elevated ICP, is associated with a return of abnormal metabolic parameters to normal values in patients with eventually favorable outcomes.     

Cerebral hemodynamic changes gauged by transcranial Doppler ultrasonography in patients with posttraumatic brain swelling treated by surgical decompression

OBJECT: The use of decompressive craniectomy has experienced a revival in the previous decade, although its actual benefit on patients' neurological outcome remains the subject of debate. A better understanding of the intracranial pressure dynamics, as well as of the metabolic and hemodynamic brain processes, may be useful in assessing the effect of this surgery on the pathophysiology of the swollen brain. The aim of this study was to use transcranial Doppler (TCD) ultrasonography to examine the hemodynamic changes in the brain after decompressive craniectomy in patients with head injury, in addition to examining the relationship between such hemodynamic changes and the patient's neurological outcome. METHODS: Nineteen patients presenting with traumatic brain swelling and cerebral herniation syndrome who had undergone decompressive craniectomy with dural expansion were studied prospectively. The TCD ultrasonography measurements were performed bilaterally in both the middle cerebral artery (MCA) and in the distal portion of the cervical internal carotid artery (ICA) immediately prior to and after surgical decompression. After surgery, the mean blood flow velocity (BFV) rose to 175 +/- 209% of preoperative values in the MCA of the operated side, while rising to 132 +/- 183% in the contralateral side; the difference between the mean BFV increase in in the MCA of both the decompressed and the opposite side reached statistical significance (p < 0.05). The mean BFV of the extracranial ICA increased to 91 +/- 119% in the surgical side and 45 +/- 60% in the opposite side. Conversely, the MCA pulsatility index (PI) values decreased, on average, to 33 +/- 36% of the preoperative value in the operated side and to 30 +/- 34% on the opposite side; the MCA PI value reductions were significantly greater in the decompressed side when compared with the contralateral side (p < 0.05). The PI of the extracranial ICA reduced, on average, to 37 +/- 23% of the initial values in the operated side and to 24 +/- 34%, contralaterally. No correlation was verified between the neurological outcome and cerebral hemodynamic changes seen on TCD ultrasonography. CONCLUSIONS: Decompressive craniectomy results in a significant elevation of cerebral BFV in most patients with traumatic brain swelling and transtentorial herniation syndrome. The increase in cerebral BFV may also occur in the side opposite the decompressed hemisphere; the cerebral BFV increase is significantly greater in the operated hemisphere than contralaterally. Concomitantly, PI values decrease significantly postoperatively, mainly in the decompressed cerebral hemisphere, indicating reduction in cerebrovascular resistance.     

Intracranial pressure levels and single wave amplitudes, Glasgow Coma Score and Glasgow Outcome Score after subarachnoid haemorrhage

Summary Object. To relate intracranial pressure (ICP) levels and single ICP wave amplitudes to the acute clinical state (Glasgow Coma Score, GCS) and final clinical outcome (Glasgow Outcome Score, GOS) in patients with subarachnoid haemorrhage (SAH). Methods. Twenty-seven consecutive patients with severe SAH had their ICP and arterial blood pressure (ABP) continuously monitored during days 1–6 after SAH. The acute clinical state could be assessed in 11 non-sedated cases using the Glasgow Coma Scale, while outcome was assessed in all cases after 6 months using the Glasgow Outcome Scale. The ICP/ABP recordings were stored as raw data files and analyzed retrospectively. For every consecutive 6 seconds time window, mean ICP, mean cerebral perfusion pressure (CPP) and the mean ICP wave amplitude were computed. Results. The GCS during days 1–6 after SAH was significantly related to the mean ICP wave amplitude, but not to the mean ICP or mean CPP. There was also a strong relationship between the mean ICP wave amplitude and GOS 6 months after SAH, with mean ICP wave amplitudes being significantly lower in those with moderate disability/good recovery, as compared with those with severe disability and death. Mean ICP was significantly higher in those who died than in the group with moderate disability/good recovery whereas mean CPP was not different between outcome groups. Conclusions. In this small patient group the mean ICP wave amplitude during days 1–6 after SAH was related to the acute clinical state (GCS) as well as to the clinical outcome (GOS) 6 months after SAH. Similar relationships were not found for mean ICP or the mean CPP, except for a higher mean ICP in those who died than in those with moderate disability/good recovery.     

Hyperemia prior to acute brain swelling during rewarming of patients who have been treated with moderate hypothermia for severe head injuries

OBJECT: The goal of this study was to elucidate the optimal time for rewarming of patients who have been treated with hypothermia for severe head injury. METHODS: Eleven patients with severe head injuries who had been treated by hypothermia underwent transcranial Doppler (TCD) ultrasonography examinations. The patients were divided into two groups: Group A consisted of three patients in whom acute brain swelling occurred during the rewarming period and Group B was composed of eight patients who displayed no significant intracranial hypertension during or after hypothermia therapy. In all patients, the mean flow velocity of the middle cerebral artery (FV(MCA)) recorded transcranially and the mean flow velocity of the internal carotid artery (FV(ICA)), recorded high in the neck, were monitored at 24-hour intervals after the patient was admitted to the hospital. In Group A, the FV(MCA) was normal at 48 hours (maintenance state of hypothermia) in each patient, and abnormal increases and peak values (> 100 cm/second) occurred from 96 to 144 hours postinjury (rewarming period). The FV(ICA), which was monitored concurrently also varied as the FV(MCA) increased. The pulsatility indices in the arteries decreased at the time of the peak FV(MCZ). The enhanced FV(MCA) was consistent with hyperemia because of the low FV(MCA)/FV(ICA) ratios (< 3). Two patients in whom jugular venous oxygen saturation was monitored were found to have high values (> 80%), representing hyperemia. All intracranial pressures (ICPs) that lay within the normal range at 48 hours postinjury elevated acutely after the peak FV(MCA). In Group B, both FV(MCA) and FV(ICA) values were normal at 48 hours postinjury and remained stable throughout the rewarming period. Values of ICP were also maintained within the normal range until the patients were weaned from hypothermia therapy. CONCLUSIONS: Hyperemia, detectable by TCD ultrasonography, may serve as an index in the prediction of acute brain swelling, and rewarming should be terminated when such a hemodynamic phenomenon is observed.     

Glial fibrillary acidic protein in serum after traumatic brain injury and multiple trauma

BACKGROUND: This study aimed to determine whether glial fibrillary acidic protein (GFAP) is released after traumatic brain injury (TBI), whether GFAP is related to brain injury severity and outcome after TBI, and whether GFAP is released after multiple trauma without TBI. METHODS: This prospective study enrolled 114 patients who had TBI with or without multiple trauma (n = 101) or multiple trauma without TBI (n = 13), as verified by computerized tomography. Daily GFAP measurement began at admission (<12 hours after trauma) and continued for the duration of intensive care (1-22 days). Documentation included categorization of computerized tomography according to Marshall classification, based on daily highest intracranial pressure (ICP), lowest cerebral perfusion pressure (CPP), lowest mean arterial pressure (MAP), and 3-month Glasgow Outcome Score (GOS). RESULTS: The GFAP concentration was lower for diffuse injury 2 than for diffuse injury 4 (p < 0.0005) or nonevacuated mass lesions larger than than 25 mL (p < 0.005), lower for a ICP less than 25 mm Hg than for a ICP of 25 mm Hg or more, lower for a CPP of 60 mm Hg or more than for a CPP of 60 mm Hg or less, lower for a MAP of 60 mm Hg or more than for a MAP less than 60 mm Hg (all p < 0.0005), and lower for a GOS of 1 or 2 than for a GOS of 3, 4 (p < 0.05), or 5 (p < 0.0005). After TBI, GFAP was higher in nonsurvivors (n = 39) than in survivors (n = 62) (p < 0.005). After multiple trauma without TBI, GFAP remained normal. CONCLUSIONS: The findings showed that GFAP is released after TBI, that GFAP is related to brain injury severity and outcome after TBI, and that GFAP is not released after multiple trauma without brain injury.     

Aspects on decompressive craniectomy in patients with traumatic head injuries

In patients with traumatic brain injury (TBI), intracranial hypertension secondary to cerebral edema is a major problem. A last-tier treatment in these cases is decompressive craniectomy. The aim of the present retrospective investigation was to (1) study the long-time outcome in patients with traumatic head injuries with intracranial hypertension treated with decompressive craniectomy; (2) examine the effects on intracranial pressure (ICP) by the craniectomy; and (3) investigate the possible relationship between the size of the removed bone-flap and the effects on ICP. Among the about 150 patients with severe TBI treated at our neurointensive care unit during 1997-2002, 19 patients were treated with decompressive craniectomy. All patients were young (mean 22 +/- 11 years, range 7-46 years), and 68% were male. The mean ICP was reduced from 29.2 +/- 3.5 before to 11.1 +/- 6.0 mm Hg immediately after the craniectomy; at 24 h after the craniectomy, the mean ICP was 13.9 +/- 9.7 mm Hg. Paired-samples t-test revealed a statistically significant decrease, both when comparing the preoperative values to the values immediately postoperative as well as to the values after 24 h (p < 0.01). A significant correlation between the size of the craniectomy and the decrease in ICP was found using Pearson regression analysis. The outcome of all patients could be assessed. The survival rate was 89%. Two patients died (both day 4 after the trauma); 68% of the patients had a favorable outcome (Glasgow Outcome Scale [GOS] score of 4 or 5); 16% were severely disabled (GOS score of 3); and one patient (5%) was left in a vegetative state.     

经颅多普勒超声检查对重型颅脑损伤预后的判断价值

【摘要】〓目的〓探讨经颅多普勒超声检查(TCD)对重型颅脑损伤患者预后的判断价值。方法〓以2013 年2月至2014年10月在我院进行治疗的62例重型颅脑损伤患者作为病例组,并收集患者受伤后(术后)第1、3、7、14、21 d大脑中动脉的血流数据,以大脑中动脉收缩期血流速度(Vs)、舒张期血流速度(Vd)、博动指数(PI)作为观察指标;将同时期在我院接受TCD检查的健康44名对象作为对照组;将两组数据进行对比。结果〓患者受伤后(术后)第1 d脑血流速度即可发生改变;Vs和Vd值在第7 d降至最低,随后逐级恢复;PI指标则与脑血流速度变化趋势相反;第7 d的Vs是颅脑损伤的一个保护性因素。结论〓通过TCD检测的脑血流速度能反映重型颅脑损伤患者的颅内压力变化及预后情况,对颅脑损伤的治疗具有指导价值。     

Carbon dioxide reactivity, pressure autoregulation, and metabolic suppression reactivity after head injury: a transcranial Doppler study.

OBJECT: Contemporary management of head-injured patients is based on assumptions about CO2 reactivity, pressure autoregulation (PA), and vascular reactivity to pharmacological metabolic suppression. In this study, serial assessments of vasoreactivity of the middle cerebral artery (MCA) were performed using bilateral transcranial Doppler (TCD) ultrasonography. METHODS: Twenty-eight patients (mean age 33 +/- 13 years, median Glasgow Coma Scale score of 7) underwent a total of 61 testing sessions during postinjury Days 0 to 13. The CO2 reactivity (58 studies in 28 patients), PA (51 studies in 23 patients), and metabolic suppression reactivity (35 studies in 16 patients) were quantified for each cerebral hemisphere by measuring changes in MCA velocity in response to transient hyperventilation, arterial blood pressure elevation, or propofol-induced burst suppression, respectively. One or both hemispheres registered below normal vasoreactivity scores in 40%, 69%, and 97% of study sessions for CO2 reactivity, PA, and metabolic suppression reactivity (p < 0.0001), respectively. Intracranial hypertension, classified as intracranial pressure (ICP) greater than 20 mm Hg at the time of testing, was associated with global impairment of CO2 reactivity, PA, and metabolic suppression reactivity (p < 0.05). A low baseline cerebral perfusion pressure (CPP) was also predictive of impaired CO2 reactivity and PA (p < 0.01). Early postinjury hypotension or hypoxia was also associated with impaired CO2 reactivity (p < 0.05), and hemorrhagic brain lesions in or overlying the MCA territory were predictive of impaired metabolic suppression reactivity (p < 0.01). The 6-month Glasgow Outcome Scale score correlated with the overall degree of impaired vasoreactivity (p < 0.05). CONCLUSIONS: During the first 2 weeks after moderate or severe head injury, CO2 reactivity remains relatively intact, PA is variably impaired, and metabolic suppression reactivity remains severely impaired. Elevated ICP appears to affect all three components of vasoreactivity that were tested, whereas other clinical factors such as CPP, hypotensive and hypoxic insults, and hemorrhagic brain lesions have distinctly different impacts on the state of vasoreactivity. Incorporation of TCD ultrasonography-derived vasoreactivity data may facilitate more injury- and time-specific therapies for head-injured patients.     

Transcranial Doppler sonography in adult hydrocephalic patients

Transcranial Doppler sonography (TCD) is a noninvasive technique for measurement of cerebral blood flow velocity (CBFV) in the major arteries of the circle of Willis. Dynamic changes in the pulsatility index (PI) and the resistance index (RI), as calculated from TCD data, allow for an assessment of the forces acting on the terminal vasculature of the brain. The present study was designed to investigate a possible relationship between TCD parameters and intracranial pressure (ICP) changes in adult patients with hypertensive hydrocephalus. Blood flow velocity in the middle cerebral artery (MCA) was studied by TCD in 29 hydrocephalus patients and in 20 healthy controls. ICP was measured in the patient group before ventricular shunting and was correlated with TCD data. The mean CBFV in hydrocephalic patients prior to ventriculoperitoneal shunting was significantly lower than in the control group. Compared to normal persons, systolic and end-diastolic CBFV values in patients were significantly decreased, suggesting an increased distal cerebrovascular resistance. PI and RI values in patients with elevated ICP prior to shunting were significantly increased in comparison to those of normal persons. There was a statistically significant positive correlation of preshunting ICP and mean preshunting values of RI (r=0.50, P<0.01) in hydrocephalic patients, but no significant correlation between PI and ICP, and between CBFV and ICP. Immediately after shunting, ICP returned to normal, and PI and RI values decreased significantly, while the mean CBFV increased. In a subgroup of hydrocephalic patients with a preshunting ICP value >35 mm Hg (n=6), the changes described above were more pronounced than in the subgroup with preshunting ICP values <35 mm Hg, which suggests an exponential degree of influence of ICP on TCD parameters. In conclusion, TCD may provide a tool for assessment of ICP in adult patients with occlusive hydrocephalus, although an exact noninvasive measurement of ICP by TCD seems impossible. Changes in the RI and PI indices appear to be useful indicators of elevated ICP. Received: 2 June 1998 / Accepted: 26 May 1999     

Intracranial pressure versus cerebral perfusion pressure as a marker of outcomes in severe head injury: a prospective evaluation

Background

Intracranial pressure (ICP) monitoring is a standard of care in severe traumatic brain injury when clinical features are unreliable. It remains unclear, however, whether elevated ICP or decreased cerebral perfusion pressure (CPP) predicts outcome.

Methods

This is a prospective observational study of patients sustaining severe blunt head injury, admitted to the surgical intensive care unit at the Los Angeles County and University of Southern California Medical Center between January 2010 and December 2011. The study population was stratified according to the findings of ICP and CPP. Primary outcomes were overall in-hospital mortality and mortality because of cerebral herniation. Secondary outcomes were development of complications during the hospitalization.

Results

A total of 216 patients met Brain Trauma Foundation guidelines for ICP monitoring. Of those, 46.8% (n = 101) were subjected to the intervention. Sustained elevated ICP significantly increased all in-hospital mortality (adjusted odds ratio [95% confidence interval]: 3.15 [1.11, 8.91], P = .031) and death because of cerebral herniation (adjusted odds ratio [95% confidence interval]: 9.25 [1.19, 10.48], P = .035). Decreased CPP had no impact on mortality.

Conclusions

A single episode of sustained increased ICP is an accurate predictor of poor outcomes. Decreased CPP did not affect survival.     

Noninvasive cerebrovascular autoregulation assessment in traumatic brain injury: validation and utility

A moving correlation index (Mx-CPP) of cerebral perfusion pressure (CPP) and mean middle cerebral artery blood flow velocity (CBFV) allows continuous monitoring of dynamic cerebral autoregulation (CA) in patients with severe traumatic brain injury (TBI). In this study we validated Mx-CPP for TBI, examined its prognostic relevance, and assessed its relationship with arterial blood pressure (ABP), CPP, intracranial pressure (ICP), and CBFV. We tested whether using ABP instead of CPP for Mx calculation (Mx-ABP) produces similar results. Mx was calculated for each hemisphere in 37 TBI patients during the first 5 days of treatment. All patients received sedation and analgesia. CPP and bilateral CBFV were recorded, and GOS was estimated at discharge. Both Mx indices were calculated from 10,000 data points sampled at 57.4Hz. Mx-CPP > 0.3 indicates impaired CA; in these patients CPP had a significant positive correlation with CBFV, confirming failure of CA, while in those with Mx < 0.3, CPP was not correlated with CBFV, indicating intact CA. These findings were confirmed for Mx-ABP. We found a significant correlation between impaired CA, indicated by Mx-CPP and Mx-ABP, and poor outcome for TBI patients. ABP, CPP, ICP, and CBFV were not correlated with CA but it must be noted that our average CPP was considerably higher than in other studies. This study confirms the validity of this index to demonstrate CA preservation or failure in TBI. This index is also valid if ABP is used instead of CPP, which eliminates the need for invasive ICP measurements for CA assessment. An unfavorable outcome is associated with early CA failure. Further studies using the Mx-ABP will reveal whether CA improves along with patients' clinical improvement.     

Transcranial Doppler sonography pulsatility index (PI) reflects intracranial pressure (ICP)

BACKGROUND: In patients with intracranial pathology, especially when comatose, it is desirable to have knowledge of the intracranial pressure (ICP). To investigate the relationship between ICP and transcranial Doppler (TCD) derived pulsatility index (PI) in neurosurgical patients, a prospective study was performed on patients admitted to our neurointensive care unit. METHODS: Daily TCD mean flow velocity (mFV) measurements were made. TCD measurements were routinely performed bilaterally on the middle cerebral artery (MCA). PI (peak systolic-end diastolic velocities/mean flow velocity) was calculated. RESULTS: Eighty-one patients with various intracranial disorders who had an intraventricular catheter for registration of the ICP were investigated: 46 (57%) patients had subarachnoid hemorrhage, 21 (26%) patients had closed head injury, and 14 (18%) patients had other neurosurgical disorders. A total of 658 TCD measurements were made. ICP registrations were made parallel with all TCD measurements. A significant correlation (p < 0.0001) was found between the ICP and the PI with a correlation coefficient of 0.938: ICP = 10.93 x PI - 1.28. In the ICP interval between 5 to 40 mm Hg the correlation between ICP and PI enabled an estimation of ICP from the PI values with an SD of 2.5. The correlation between the cerebral perfusion pressure (CPP) and PI was significant (p < 0.0001) with a correlation coefficient of -0.493. When separating the measurements in severely elevated (>120 cm/s) and subnormal (<50 cm/s) TCD mFV values, the correlation coefficient between ICP and PI was 0.828 (p < 0.002) and 0.942 (p < 0.638), respectively. CONCLUSIONS: Independent of the type of intracranial pathology, a strong correlation between PI and ICP was demonstrated. Therefore, PI may be of guiding value in the invasive ICP placement decision in the neurointensive care patient.     

Early Glasgow Outcome Scale scores predict long-term functional outcome in patients with severe traumatic brain injury

Patients sustaining severe traumatic brain injury (TBI) have variable long-term outcomes. We examined the association between Glasgow Outcome Scale (GOS) assessed at 3 months and long-term outcomes at 12 months after TBI. We studied 159 patients with severe, closed traumatic brain injuries (Glasgow Coma Scale [GCS] 相似文献   

Reduced mortality rate in patients with severe traumatic brain injury treated with brain tissue oxygen monitoring

OBJECT: An intracranial pressure (ICP) monitor, from which cerebral perfusion pressure (CPP) is estimated, is recommended in the care of severe traumatic brain injury (TBI). Nevertheless, optimal ICP and CPP management may not always prevent cerebral ischemia, which adversely influences patient outcome. The authors therefore determined whether the addition of a brain tissue oxygen tension (PO2) monitor in the treatment of TBI was associated with an improved patient outcome. METHODS: Patients with severe TBI (Glasgow Coma Scale [GCS] score < 8) who had been admitted to a Level I trauma center were evaluated as part of a prospective observational database. Patients treated with ICP and brain tissue PO2 monitoring were compared with historical controls matched for age, pathological features, admission GCS score, and Injury Severity Score who had undergone ICP monitoring alone. Therapy in both patient groups was aimed at maintaining an ICP less than 20 mm Hg and a CPP greater than 60 mm Hg. Among patients whose brain tissue PO2 was monitored, oxygenation was maintained at levels greater than 25 mm Hg. Twenty-five patients with a mean age of 44 +/- 14 years were treated using an ICP monitor alone. Twenty-eight patients with a mean age of 38 +/- 18 years underwent brain tissue PO2-directed care. The mean daily ICP and CPP levels were similar in each group. The mortality rate in patients treated using conventional ICP and CPP management was 44%. Patients who also underwent brain tissue PO2 monitoring had a significantly reduced mortality rate of 25% (p < 0.05). CONCLUSIONS: The use of both ICP and brain tissue PO2 monitors and therapy directed at brain tissue PO2 is associated with reduced patient death following severe TBI.     

Pressure reactivity as a guide in the treatment of cerebral perfusion pressure in patients with brain trauma

OBJECT: The aim of this study was to compare the effects of two different treatment protocols on physiological characteristics and outcome in patients with brain trauma. One protocol was primarily oriented toward reducing intracranial pressure (ICP), and the other primarily on maintaining cerebral perfusion pressure (CPP). METHODS: A series of 67 patients in Uppsala were treated according to a protocol aimed at keeping ICP less than 20 mm Hg and, as a secondary target, CPP at approximately 60 mm Hg. Another series of 64 patients in Edinburgh were treated according to a protocol aimed primarily at maintaining CPP greater than 70 mm Hg and, secondarily, ICP less than 25 mm Hg for the first 24 hours and 30 mm Hg subsequently. The ICP and CPP insults were assessed as the percentage of monitoring time that ICP was greater than or equal to 20 mm Hg and CPP less than 60 mm Hg, respectively. Pressure reactivity in each patient was assessed based on the slope of the regression line relating mean arterial blood pressure (MABP) to ICP. Outcome was analyzed at 6 months according to the Glasgow Outcome Scale (GOS). The prognostic value of secondary insults and pressure reactivity was determined using linear methods and a neural network. In patients treated according to the CPP-oriented protocol, even short durations of CPP insults were strong predictors of death. In patients treated according to the ICP-oriented protocol, even long durations of CPP insult-mostly in the range of 50 to 60 mm Hg--were significant predictors of favorable outcome (GOS Score 4 or 5). Among those who had undergone ICP-oriented treatment, pressure-passive patients (MABP/ICP slope > or = 0.13) had a better outcome. Among those who had undergone CPP-oriented treatment, the more pressure-active (MABP/ICP slope < 0.13) patients had a better outcome. CONCLUSION: Based on data from this study, the authors concluded that ICP-oriented therapy should be used in patients whose slope of the MABP/ICP regression line is at least 0.13, that is, in pressure-passive patients. If the slope is less than 0.13, then hypertensive CPP therapy is likely to produce a better outcome.     

Transcranial Doppler pulsatility index is not a reliable indicator of intracranial pressure in children with severe traumatic brain injury

BackgroundThe TCD-derived PI has been associated with ICP in adult studies but has not been well investigated in children. We examined the relationship between PI and ICP and CPP in children with severe TBI.MethodsData were prospectively collected from consecutive TCD studies in children with severe TBI undergoing ICP monitoring. Ipsilateral ICP and CPP values were examined with Spearman correlation coefficient (mean values and raw observations), with a GEE, and as binary values (1 and 20 mm Hg, respectively).ResultsThirty-four children underwent 275 TCD studies. There was a weak relationship between mean values of ICP and PI (P = .04, r = 0.36), but not when raw observations (P = .54) or GEE (P = .23) were used. Pulsatility index was 0.76 when ICP was lower than 20 mm Hg and 0.86 when ICP was 20 mm Hg or higher. When PI was 1 or higher, ICP was lower than 20 mm Hg in 62.5% (25 of 40 studies), and when ICP was 20 mm Hg or higher, PI was lower than 1 in 75% (46 of 61 studies). The sensitivity and specificity of a PI threshold of 1 for examining the ICP threshold of 20 mm Hg were 25% and 88%, respectively. The relationship between CPP and PI was stronger (P = .001, r = ?0.41), but there were too few observations below 50 mm Hg to examine PI at this threshold.ConclusionThe absolute value of the PI is not a reliable noninvasive indicator of ICP in children with severe TBI. Further study is required to examine the relationship between PI and a CPP threshold of 50 mm Hg.