Surgical exploration before computed tomography scanning in children with traumatic tentorial herniation

Seventeen consecutive children with early clinical signs of tentorial herniation after head injury underwent immediate burr-hole exploration before computed tomography scanning. In nine children (53%), a subdural hematoma was discovered and immediately evacuated. In one, a small intracerebral hemorrhage was diagnosed by intraoperative ultrasonography. Postoperative studies showed that no intraaxial or extraaxial hematoma was missed by surgical exploration. Nine children (53%) survived; eight (47%) died. The survival rate was higher among patients with a mass lesion than among those without. Seven children had a good recovery, and two were moderately disabled (mean follow-up, 15.2 months). We conclude that a significant proportion of head-injured children with clinical signs of tentorial herniation have extraaxial hematomas that can be readily identified and evacuated by immediate surgical exploration. The survival rate and extent of recovery in children appear to be better than in similarly injured adults.     

Proteolytic enzyme activity in patients with severe head injury and the effect of a proteinase inhibitor

Summary A study was performed to detect the inhibitory effect of intravenously administered aprotinin (Trasylol^®) on brain and CSF protease activity in 25 patients with severe head injury. The data presented include measurements of CSF protease activity, alpha-1-antitrypsin, alpha-2-macroglobulin, haptoglobulin, polyacrylamidgel-electrophoresis pattern, total protein and hemoglobin content. The results indicate that increased protease activity is present and that this induces autolytic processes which can be inhibited by aprotinin treatment. The survival rate was higher after aprotinin treatment. Total CSF protein content was significantly higher in nonsurvivors than in survivors.Dedicated to Professor Dr. F. Spath on occasion of his 80th birthday     

Ruptures of arteriovenous malformations in children associated with trivial head trauma

Three cases of ruptured arteriovenous malformations (AVMs) in childhood associated with trivial head trauma are reported. These patients represented 12.5% of 25 consecutive patients with cerebral AVMs. The patients' ages ranged from 5 to 9 years; the patients were younger than their nontraumatic counterparts. The force of the trauma was presumably received in an anteroposterior or posteroanterior direction in all cases. Hematomas accompanying the AVMs were located in the subcortical area of the parietal or temporal lobe and angiographically their feeding arteries were all from the anterior cerebral artery or middle cerebral artery. The possible mechanisms for the rupture of AVMs after trivial head trauma are discussed.     

Moderate hypothermia therapy for patients with severe head injury

ＳＤｅｐａｒｔｍｅｎｔｏｆＮｅｕｒｏｓｕｒｇｅｒｙ ,ＣｈｅｎｇｄｕＧｅｎｅｒａｌＨｏｓｐｉｔａｌｏｆＣｈｅｎｇｄｕＭｉｌｉｔａｒｙＣｏｍｍａｎｄ ,Ｃｈｅｎｇｄｕ 6 10 0 83,Ｃｈｉｎａ (ＣｈｅｎＬＧ ,ＰｉａｏＹＸ ,ＺｅｎｇＦＪ ,ＬｕＭ ,ＫｕａｎｇＹＱａｎｄＬｉＸ)ｉｎｃｅ 1990ｓ ,ｉｔｈａｓｂｅｅｎｐｒｏｖｅｄｂｙｃｌｉｎｉｃａｌｓｔｕｄｉｅｓａｔｈｏｍｅａｎｄａｂｒｏａｄｔｈａｔＭＨＴｉｓａｎｅｆｆｅｃｔｉｖｅａｎｄｓａｆｅｍｅｔｈｏｄ .1 3Ｔｏｂｅｔｔｅｒｕｎｄｅｒｓｔａｎｄｉｔｓｅｆｆｅｃｔａｎ…     

The fundamentals of head injury

In the Western world, trauma is the commonest cause of death in the under-40s, and, head injury is the leading component of this. Traumatic brain injury (TBI) is not a single disease, but a number of pathologies that can occur in isolation (e.g. an extradural haematoma) or co-exist (a subdural haematoma with diffuse axonal injury). TBI has important social, emotional and financial consequences, both for the individual, their families and society. Despite this, there is a great deal we do not know about brain injuries and how best to manage them. This article outlines the fundamental principles of pathophysiology, diagnosis and management.     

Maxillary sinusitis in patients ventilated for a severe head injury and with nostrils free of any foreign body

Background

This study aims to determine the frequency of maxillary sinusitis in the patients with traumatic head injury and nostrils free of any foreign body. In addition, the sensitivity and specificity of ultrasonography (US) for the detection of the presence of fluid in maxillary sinuses were evaluated.

Patients and methods

Forty patients with severe traumatic head injury were included in the study. The patients who had displaced maxillary sinus fracture at the medial wall and naso-tracheal and/or naso-gastric tube were excluded. Paranasal computed tomography (CT) was performed along with the routine cranial CT scanning or in case of unknown source of infection and compared with the results of ultrasonographic examination of maxillary sinuses performed by a single radiologist who was unaware of the CT results. In the patients, who had clinical and radiological signs of sinusitis, a trans-nasal puncture was performed using sinoject (SinoJect^®, ATOS Medical, Sweden), a spring-activated puncture instrument, to take a sample for microbiologic examination and to drain maxillary sinuses.

Results

Eighty-five percent of the patients were tracheotomised on the fifth day (on average) of their intensive care unit (ICU) stay. The frequency of sinusitis in the study group was found to be 32.5% (13 patients). The most frequently isolated species were Pseudomonas spp. (37.5%), Escherichia coli (20.8%) and Peptostreptococcus (16.7%). Five of the aspirates were polymicrobial. The sensitivity, specificity, positive predictive value and negative predictive value of B-mode US, compared with CT for the detection of fluid presence in maxillary sinuses in a 100 maxillary sinus examinations, were 92.2%, 81.6%, 83.9% and 90.9%, respectively.

Conclusion

Maxillary sinusitis should be considered as a source of infection or sepsis in patients with traumatic head injury because of its high frequency. US is likely to be used as the first-line diagnostic tool for the determination of fluid in maxillary sinuses, especially in patients who do not require CT or cannot be transported to a radiology unit for CT.     

Electrical injury and the frequency of cardiac complications

A retrospective review of the patients with electrical injuries admitted over a 5-year period was performed to establish the frequency of cardiac complications. There were 145 admissions during this time. A total of 128 (88 per cent) were low voltage injuries and 17 (12 per cent) were high voltage (> 1000 V) injuries. Of the 145 admissions, 104 (72 per cent) had a 12-lead electrocardiogram (ECG) recorded within 24 h of their injury. Of these patients, 73 (75 per cent) were then observed on a cardiac monitor for at least 24 h post-injury. Cardiac abnormalities were noted in four patients (3 per cent) during this period. Three patients had occasional ectopic beats which settled spontaneously over a 24 h period post-injury. The fourth patient developed atrial fibrillation (AF) after a high voltage injury which resolved following intravenous digoxin. Cardiac complications were more frequent in those who had experienced a loss of consciousness at the time of injury and in those who suffered a high voltage electrical injury. All of the patients with cardiac complications had these at the time of admission to hospital.

This suggest that if there is no history of a loss of consciousness and the 12-lead ECG recorded on attendance at the hospital is normal, it is unlikely that the patient will go on to develop cardiac problems.     

Transcranial doppler waveform differences in hyperemic and nonhyperemic patients after severe head injury

Although increased cerebral blood flow velocity is readily measured by transcranial doppler ultrasonography (TCD), the causes of the velocity elevation may differ. After severe head injury, increased blood flow velocity can develop both in patients with global hyperemia (suggestive of vasodilation) and in those without hyperemia (suggestive of vasospasm). The present study attempts to determine whether TCD can differentiate these two mechanisms of velocity increase.

Fourteen severely brain-injured patients who developed increased middle cerebral artery blood flow velocity (time-averaged mean velocity > 100 cm/s) were studied. Eight cases were nonhyperemic and six were hyperemic as defined by arterial-jugular venous oxygen content differences of more than 4 mL/dL and less than 4 mL/dL, respectively. The TCD waveform of all eight nonhyperemic cases showed a diastolic notch, which was absent in all six hyperemic patients (p = 0.00066). TCD waveform profile appears to provide a noninvasive means of differentiating at the bedside the two causes of increased flow velocity. If associated with raised intracranial pressure, these require different treatment.     

Sequential computerized tomography changes and related final outcome in severe head injury patients

Summary The authors analysed the serial computerized tomography (CT) findings in a large series of severely head injured patients in order to assess the variability in gross intracranial pathology through the acute posttraumatic period and determine the most common patterns of CT change. A second aim was to compare the prognostic significance of the different CT diagnostic categories used in the study (Traumatic Coma Data Bank CT pathological classification) when gleaned either from the initial (postadmission) or the control CT scans, and determine the extent to which having a second CT scan provides more prognostic information than only one scan.92 patients (13.3% of the total population) died soon after injury. Of the 587 who survived long enough to have at least one control CT scan 23.6% developed new diffuse brain swelling, and 20.9% new focal mass lesions most of which had to be evacuated. The relative risk for requiring a delayed operation as related to the diagnostic category established by using the initial CT scans was by decreasing order: diffuse injury IV (30.7%), diffuse injury III (30.5%), non evacuated mass (20%), evacuated mass (20.2%), diffuse injury II (12.1%), and diffuse injury I (8.6%).Overall, 51.2% of the patients developed significant CT changes (for worse or better) occurring either spontaneously or following surgery, and their final outcomes were more closely related to the control than to the initial CT diagnoses. In fact, the final outcome was more accurately predicted by using the control CT scans (81.2% of the cases) than by using the initial CT scans (71.5% of the cases only). Since the majority of relevant CT changes developed within 48 hours after injury a pathological categorization made by using an early control CT scan seems to be most useful for prognostic purposes.Prognosis associated with the CT pathological categories used in the study was similar independently of the moment of the acute posttraumatic period at which diagnoses were made.     

An outcome study of severe traumatic head injury using the "Lund therapy" with low-dose prostacyclin

Background: There are two independent head injury outcome studies using the “Lund concept”, and both showed a mortality rate of about 10%, and a favourable outcome (Glasgow outcome scale, GOS 4 and 5) of about 70%. The Lund concept aims at controlling intracranial pressure, and improving microcirculation around contusions. Intracranial pressure is controlled by maintaining a normal colloid osmotic pressure and reducing the hydrostatic capillary pressure. Microcirculation is improved by ensuring strict normovolaemia and reducing sympathetic discharge. The endogenous substance prostacyclin with its antiaggregatory/antiadhesive effects may further improve microcirculation, which finds support from a microdialysis‐based clinical study and an experimental brain trauma study. The present clinical outcome study aims at evaluating whether the previously obtained good outcome with the Lund therapy can be reproduced, and whether the addition of prostacyclin has any adverse side‐effects. Methods: All 31 consecutive patients with severe head injury, Glasgow coma scale (GCS) ≤8, admitted to the University Hospital of Umeå during 1998 were included. The Lund therapy including prostacyclin infusion for the first three days at a dose of 0.5 ng kg^?1 min^?1. Outcome was evaluated according to the GOS >10 months after the injury. Results: One patient died, another suffered vegetative state and 7 severe disability. Of the 22 patients with favourable outcome, 19 showed good recovery and 3 moderate disability. No adverse side‐effects of prostacyclin were observed. Conclusion: The outcome results from previous studies using the Lund therapy were reproduced, and no adverse side‐effects of low‐dose prostacyclin were observed.     

Increased risk of death associated with hypotension is not altered by the presence of brain injury in pediatric trauma patients

BACKGROUND: Hypotension is a well-known predictor of mortality in pediatric trauma patients. However, it is unknown whether the mortality rate is higher in patients with traumatic brain injury (TBI) than in those without TBI. We hypothesized that systemic hypotension increases mortality in pediatric patients with TBI more than it does in pediatric patients with extracranial injuries only. METHODS: Multivariate logistic regression was used to determine the relationship between hypotension and the risk of death. Patients were then divided into 2 groups: TBI and No-TBI and the model was applied separately to each group. RESULTS: Overall mortality was 2%. After adjusting for confounding variables, hypotension remained a strong independent predictor of mortality. However, the increased risk of death was similar in patients with and without TBI. CONCLUSION: Hypotension is an important predictor of death in pediatric trauma patients. The increased risk of death associated with hypotension is similar with or without traumatic brain injury.     

高血糖对中重型颅脑损伤患者预后的影响

目的了解高血糖与颅脑损伤严重程度之间的关系以及控制血糖对颅脑损伤预后的影响。方法我们前瞻性地研究了146例中重型颅脑损伤患者(格拉斯哥昏迷评分GCS3~12分)的血糖,并将血糖高于11.1mmol/L的患者随机分为两组,一组接受强化胰岛素治疗,将血糖控制在6.11mmol/L以下,另一组不接受胰岛治疗,以明确血糖水平同损伤严重程度之间的关系以及控制血糖对预后的影响。结果重型颅脑损伤患者的血糖水平明显高于中型颅脑损伤患者,并且颅内压水平同血糖水平显著相关。同血糖水平高于11.1mmol/L的患者相比,血糖控制在6.11mmol/L以下的患者预后明显改善。结论早期高血糖是颅脑损伤后应激反应的一个组成部分,是预测损伤严重度的一个重要指标,控制血糖可改善颅脑损伤患者的预后。     

重型脑伤病人脑氧和脑温监护及其临床意义

目的研究急性重型脑伤患者亚低温期间,脑组织氧分压(PbtO2)及脑温(Tb)变化规律的临床意义及手术对脑温的影响。方法选择重脑伤患者116例随机分为两组:亚低温组和常温对照组各58例。进行亚低温治疗同时,用Licox-II型PbtO2、Tb监测仪,监测PbtO2、Tb1～7天,平均86小时,同时监测肛温、颅内压(ICP)、脑灌注压(CPP)、动脉氧分压(PaO2)、动脉二氧化碳分压(PaCO2)。随访6个月,以GOS评估法判断预后。结果116例严重脑伤病人24小时PbtO2均值13.7±4.94,比正常值偏低,亚低温组比常温对照组PbtO2恢复到平均低值时间缩短10±4.15小时(P<0.05)。降温组成活率60.43%,高于对照组46.55%。复温后PbtO2随脑温升高而增加。肛温(Tr)与Tb的变化:手术组低于正常差距,占66.7%;非手术组高于正常差距,占52.9%,两组有显著性差异。结论PbtO2、Tb直接监测技术安全可靠,对严重脑伤病人判定病情和指导治疗有重要意义。     

再灌注初期控制性降压对肝叶切除术病人肝缺血再灌注损伤的影响

目的 评价再灌注初期控制性降压对肝叶切除术病人肝缺血再灌注损伤的影响.方法 择期行肝叶切除术病人40例,性别不限,年龄30～60岁,体重40～70kg,ASA分级Ⅱ或Ⅲ级,将病人按分层随机方法分为2组(n=20),对照组(C组)开放肝门后10 min期间维持MAP 75～100mm Hg,控制性降压组(H组)于开放肝门前2 min开始静脉输注硝酸甘油3～6μg·kg-1·min-1实施控制性降压,再灌注10 min期间维持MAP 60～70 mm Hg.分别于缺血前(基础状态)、缺血15 min和再灌注25min时采集静脉血样,测定血浆内皮素(ET)、一氧化氮(NO)、TNF-α和IL-1的浓度.结果 与基础值比较,两组缺血15 min和再灌注25min时血浆ET、TNF-α和IL-1的浓度升高,血浆N0浓度降低(P＜0.05);与C组比较,H组再灌注25min时血浆ET、TNF-α和IL-1的浓度降低,血浆NO浓度升高(P＜0.05).结论 再灌注初期控制性降压10 min可减轻肝叶切除术病人肝缺血再灌注损伤,其机制与调节肝窦内皮细胞ET和NO的平衡及抑制炎性反应有关.

Abstract：

Objective To evaluate the effect of controlled hypotension at the beginning of reperfusion on ischemia-reperfusion (I/R) injury of the liver in patients undergoing hepatectomy. Methods Forty ASA Ⅱ or Ⅲ patients aged 30-60 yr weighing 40-70 kg undergoing elective partial hepatectomy for liver cancer were randomly divided into 2 groups ( n = 20 each): group C normal BP and group H controlled hypotension. Hepatic portal was occluded during operation. In group C normal BP was maintained during reperfusion while in group H controlled hypotension (MAP was maintained at 60-70 mm Hg) was performed for 10 min since the beginning of reperfusion.Venous blood samples were taken before hepatic ischemia (T0 ,baseline) and at 15 min of ischemia (T1) and 25 min of reperfnsion (T2 ) for determination of plasma endothelin (ET), nitric oxide(NO), TNF-α and IL-1 concentrations. Results I/R of the liver led to significant increase in plasma ET, TNF-α and IL-1 concentrations and decrease in plasma NO concentration at T1,2 as compared with the baseline values at T0 in both groups. Plasma ET,TNF-α and IL- 1 concentrations were significantly lower while plasma NO concentration was significantly higher at T2 in group H than in group C. Conclusion Ten minutes controlled hypotension in the initial stage of reperfusion can attenuate I/R-induced injury to the liver in patients undergoing hepatectomy by balancing ET with NO and inhibiting inflammation response.     

Clinical value of serial computed tomography with severe head injury

Serial computed tomography (CT) scanning was performed on 138 patients suffering from severe head injuries (i.e., with scores of 8 or less on Glasgow Coma Scale). Standard practice called for scans to be done upon admission (within hours of the injury) and after 1, 3, and 7 days and 1 month. Subsequent CT scans depended on the patient's condition. Clinical results at the time of discharge were graded according to the Glasgow Outcome Scale. During the serial CT scan, there were new findings (not visualized on the initial CT scan but appearing on subsequent scans) in 91 of the 138 patients. These new findings were classified into seven types: (1) decreased density collection in the subdural space; (2) ventricular dilatation; (3) intracerebral hematoma; (4) intraventricular hemorrhage; (5) extracerebral hematoma; (6) edema; and (7) infarction. We defined intracerebral hematoma, intraventricular hemorrhage, extracerebral hematoma, edema, and infarction as new lesions. Of the 60 patients with new lesions, 12 had a good outcome and 48 had a poor outcome. Of 78 patients who did not have any new lesions, 60 had a good outcome and 18 had a poor outcome. A significant correlation was found between good outcome and the absence of new lesions and between bad outcome and the development of new lesions (p < 0.001; x² = 44.038). We conclude that serial CT scanning can help predict the outcome of patients with severe head injuries and may be very important in their examination and care.     

Prospective survey on neurosurgical intensive care for patients with severe head injury

ＴＤｅｐａｒｔｍｅｎｔｏｆＮｅｕｒｏｓｕｒｇｅｒｙ ,ＧｅｎｅｒａｌＨｏｓｐｉｔａｌｏｆＴｉａｎｊｉｎＭｅｄｉｃａｌＵｎｉｖｅｒｓｉｔｙ ,Ｔｉａｎｊｉｎ 30 0 0 5 2 ,Ｃｈｉｎａ (ＹａｎｇＸＪ ,ＹａｎｇＳＹ ,ＷａｎｇＭＬａｎｄＧａｏＹＺ)ｈｅｍａｒｋｅｄｉｍｐｒｏｖｅｍｅｎｔｏｆｃｕｒａｔｉｖｅｏｕｔｃｏｍｅｆｏｒｓｅｖｅｒｅｈｅａｄｉｎｊｕｒｙｉｓａｓｃｒｉｂｅｄｔｏｕｎｄｅｒｓｔａｎｄｉｎｇｏｆｉｔｓｐａｔｈｏｐｈｙｓｉｏｌｏｇｙａｎｄａｄｏｐｔｉｎｇａｎｉｎｔｅｎｓｉｖｅａｐｐｒｏａｃｈｆｏｒｐ…     

Early ischaemia after severe head injury preliminary results in patients with diffuse brain injuries

Summary Ischaemic brain lesions still have a high prevalence in fatally head injured patients and are the single most important cause of secondary brain damage. The present study was undertaken to explore the acute phase of severely head injured patients in order to detect early ischaemia using Robertson's approach of estimating cerebral blood flow (CBF) from calculated arterio-jugular differences of oxygen (AVDO₂), lactates (AVDL), and the lactate-oxygen index (LOI).Twenty-eight cases with severe head injury were included (Glasgow Coma Scale Score below or equal to 8). All patients but one had a non-missile head injury. All the patients had a diffuse brain injury according to the admission CT scan. ICP measured at the time of admission was below 20 mmHg in 17 cases (61%). All patients were evaluated with the ischaemia score (IS) devised in our center to evaluate risk factors for developing ischaemia. Mean time from injury to the first AVDO₂/AVDL study was 23.9±9.9 hours.According to Robertson's criteria, 13 patients (46%) had a calculated LOI (-AVDL/AVDO₂) value above or equal to 0.08 and therefore an ischaemia/infarction pattern in the first 24 hours after the accident. Of the 15 patients without the ischaemia/infarction pattern, in three cases the CBF was below the metabolic demands and therefore in a situation of compensated hypoperfusion. No patient in our series had hyperaemia. Comparing different variables in ischaemic and non-ischaemic patients, only arterial haemoglobin and ischaemia score (IS) was significantly different in both groups. The ischaemia score had mean of 4.3±1.7 in the ischaemic group and 2.7±1.4 in non-ischaemic patients (p=0.01). It is concluded that ischaemia is highly prevalent in the early period after severe head injury. Factors potentially responsible of early ischaemia are discussed.     

Chronic epidural hematoma—Report on eight cases and review of the literature

The authors report eight cases of chronic epidural hematoma, classified according to macroscopical operative findings and histological studies of the hematomas. Clinical, radiological, and pathological findings are described. A review of 63 cases of the literature is presented, and the accepted concepts for classification and management of these lesions are discussed.     

广泛减压颅骨切除术救治急性重型颅脑损伤

广泛减压颅骨切除术(large decompression craniectomy)(即去大骨瓣减压术)是治疗各类急性重型颅脑损伤的一个重要手段。如果颅骨骨瓣去除的不够大，不能为脑组织的水肿创造一个充分的减压空问，就难以达到充分减压的目的，不仅降低了手术成功率，并且术后病人的脑组织膨出、嵌顿，导致了死亡率、致残率的上升。本文对363例手术治疗的各类急性重型颅脑损伤进行了临床分析。     

Cerebral lactate production in relation to intracranial pressure,cranial computed tomography findings,and outcome in patients with severe head injury

Summary Severe head injury is frequently associated with focal or global disturbances of cerebral blood flow and metabolism. Routine monitoring of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in these patients does not provide information about critically reduced local or global cerebral blood flow. Measurements of cerebral lactate difference, Lactate-Oxygen-Index (LOI) and cerebral oxygen extraction were evaluated for advanced monitoring by comparing these parameters with ICP, cranial computed tomography (CCT) findings, and outcome in a group of severely head-injured patients.In 21 patients with severe brain trauma (GCS 8), arterial as well as jugular venous lactate levels and oxygen saturation were measured in vitro every 6 h after admission of patients to the intensive care unit (ICU) throughout the acute course of treatment. Arterial blood pressure, blood gases, and ICP were assessed by standard monitoring measurements. CCT was performed initially after admission of the patients to the hospital, during the acute period in the ICU, if indicated, and 10 to 14 days after trauma. Outcome was classified according to the Glasgow outcome scale (GOS) at six months after injury. Data were averaged in each patient for every day after trauma and over the entire monitoring period. Resulting values were tested for correlation by regression analysis. Additionally, the data of the group of patients with normal to minimally elevated mean ICP (ICP<20 mmHg, n=12) were compared to those of the patients with increased mean ICP (ICP>20 mmHg, n=9).The cerebral lactate difference in all patients on the day of trauma was significantly increased as compared to the later period (0.20 vs. 0.11-0.07 mmol/L, p<0.05), but was not different with high or normal to minimally elevated ICP. In patients with intracranial hypertension, the cerebral lactate difference remained significantly increased from the first to the fifth day after injury, whereas it normalized in this period in the group with normal to minimally elevated ICP. Averaged over the acute course, patients with increased ICP had significantly higher mean lactate differences (0.18±0.16 vs. 0.067±0.025 mmol/L, p=0.001) and higher mean LOIs (0.072±0.071 vs. 0.028±0.013, p=0.011). There was a significant correlation of increased mean cerebral lactate difference to poor outcome (r=0.46, p=0.035). Cerebral oxygen extraction in all patients tended to increase on the day of trauma (36.7% vs. 29.2% to 31.5% during the subsequent course), but this difference was not significant. The initial degree of brain swelling, classified by CCT according to Marshallet al. (1991), showed no correlation with cerebral lactate differences, ICP, O₂-extraction, or outcome. Neither was there a correlation of cerebral oxygen extraction to ICP nor to outcome.In conclusion, the severity of brain trauma and outcome of patients was reflected by increased cerebral lactate production. Unchanged values of global cerebral oxygen extraction suggest that the regulatory mechanisms of brain oxygen supply were not impaired by trauma. Measurements of cerebral lactate differences and brain oxygen extraction may contribute to advanced monitoring in severe head injury.