Hyperoxemia and long-term outcome after traumatic brain injury

Introduction

The relationship between hyperoxemia and outcome in patients with traumatic brain injury (TBI) is controversial. We sought to investigate the independent relationship between hyperoxemia and long-term mortality in patients with moderate-to-severe traumatic brain injury.

Methods

The Finnish Intensive Care Consortium database was screened for mechanically ventilated patients with a moderate-to-severe TBI. Patients were categorized, according to the highest measured alveolar-arterial O₂ gradient or the lowest measured PaO₂ value during the first 24 hours of ICU admission, to hypoxemia (<10.0 kPa), normoxemia (10.0 to 13.3 kPa) and hyperoxemia (>13.3 kPa). We adjusted for markers of illness severity to evaluate the independent relationship between hyperoxemia and 6-month mortality.

Results

A total of 1,116 patients were included in the study, of which 16% (n = 174) were hypoxemic, 51% (n = 567) normoxemic and 33% (n = 375) hyperoxemic. The total 6-month mortality was 39% (n = 435). A significant association between hyperoxemia and a decreased risk of mortality was found in univariate analysis (P = 0.012). However, after adjusting for markers of illness severity in a multivariate logistic regression model hyperoxemia showed no independent relationship with 6-month mortality (hyperoxemia vs. normoxemia OR 0.88, 95% CI 0. 63 to 1.22, P = 0.43; hyperoxemia vs. hypoxemia OR 0.97, 95% CI 0.63 to 1.50, P = 0.90).

Conclusion

Hyperoxemia in the first 24 hours of ICU admission after a moderate-to-severe TBI is not predictive of 6-month mortality.     

Neuropsychologic and functional outcome after complicated mild traumatic brain injury

Kashluba S, Hanks RA, Casey JE, Millis SR. Neuropsychologic and functional outcome after complicated mild traumatic brain injury.

Objective

To investigate the extent to which neuropsychologic and functional outcome after complicated mild traumatic brain injury (TBI) parallels that of moderate TBI recovery.

Design

A longitudinal study comparing neuropsychologic and functional status of persons with complicated mild TBI and moderate TBI at discharge from inpatient rehabilitation and at 1 year postinjury.

Setting

Rehabilitation hospital with a Traumatic Brain Injury Model System.

Participants

Persons with complicated mild TBI (n=102), each with an intracranial brain lesion documented through neuroimaging and a highest Glasgow Coma Scale (GCS) score in the emergency department between 13 and 15, and 127 persons with moderate TBI.

Interventions

Not applicable.

Main Outcome Measures

FIM instrument, Disability Rating Scale, Community Integration Questionnaire, Wechsler Memory Scale logical memory I and II, Rey Auditory Verbal Learning Test, Trail-Making Test, Controlled Oral Word Association Test, Symbol Digit Modalities Test, Wisconsin Card Sorting Test, and block design.

Results

Few differences in neuropsychologic performance existed between the TBI groups. Less severely impaired information processing speed and verbal learning were seen in the complicated mild TBI group at rehabilitation discharge and 1 year postinjury. Despite overall improvement across cognitive domains within the complicated mild TBI group, some degree of impairment remained at 1 year postinjury on those measures that had identified participants as impaired soon after injury. No differences on functional ability measures were found between the TBI groups at either time period postinjury, with both groups exhibiting incomplete recovery of functional status at the 1-year follow-up.

Conclusions

When classifying severity of TBI based on GCS scores, consideration of a moderate injury designation should be given to persons with an intracranial bleed and a GCS score between 13 and 15.     

Glucose variability negatively impacts long-term functional outcome in patients with traumatic brain injury

Purpose

Significant glycemic excursions (so-called glucose variability) affect the outcome of generic critically ill patients but has not been well studied in patients with traumatic brain injury (TBI). The purpose of this study was to evaluate the impact of glucose variability on long-term functional outcome of patients with TBI.

Material and Methods

A noncomputerized tight glucose control protocol was used in our intensivist model surgical intensive care unit. The relationship between the glucose variability and long-term (a median of 6 months after injury) functional outcome defined by extended Glasgow Outcome Scale (GOSE) was analyzed using ordinal logistic regression models. Glucose variability was defined by SD and percentage of excursion (POE) from the preset range glucose level.

Results

A total of 109 patients with TBI under tight glucose control had long-term GOSE evaluated. In univariable analysis, there was a significant association between lower GOSE score and higher mean glucose, higher SD, POE more than 60, POE 80 to 150, and single episode of glucose less than 60 mg/dL but not POE 80 to 110. After adjusting for possible confounding variables in multivariable ordinal logistic regression models, higher SD, POE more than 60, POE 80 to 150, and single episode of glucose less than 60 mg/dL were significantly associated with lower GOSE score.

Conclusions

Glucose variability was significantly associated with poorer long-term functional outcome in patients with TBI as measured by the GOSE score. Well-designed protocols to minimize glucose variability may be key in improving long-term functional outcome.     

Concomitant injuries and its influence on functional outcome after traumatic brain injury

Abstract

Purpose: This study aims to describe the presence and severity of extracranial concomitant injuries in traumatic brain injury (TBI) patients and to ascertain their effect on long-term functional outcome.

Method: A retrospective cohort study was performed in a single-center recruiting patients with first episode of TBI. The types and severity of extracranial concomitant injuries were documented for patients who fulfilled the inclusion criteria. Injuries with Abbreviated Injury Scale (AIS) grade 3–6 were considered to be high grade. A cross-sectional functional assessment was conducted at 18 months post-injury using Glasgow Outcome Scale.

Results: A total of 100 patients were included in the analysis. Extracranial concomitant injuries were seen in 78% of the patients. Three commonest injuries were facial (44%), lower extremity (20%) and upper extremity (12%) injuries. Among the AIS grade?≥?3, injury involving the chest was most common (41%). Presence of extracranial concomitant injuries AIS grade?≥?3 was significantly associated with disability in TBI patients at 18 months (OR 12.74, 95% CI 2.39–67.95, p?=?0.003).

Conclusion: Presence of extracranial concomitant injuries was high. In TBI survivors, extracranial concomitant injuries AIS grade?≥?3 influenced the long-term functional outcome at 18 months, causing moderate and severe disabilities.

• Implications for Rehabilitation

• Concomitant injuries should be suspected in patients with traumatic brain injury, especially in a high-speed trauma mechanisms as the incidence can be as high as 78% as in this study and may interfere with the long term rehabilitation and outcome.

• This study shows that severe extra cranial concomitant injuries are associated with a poor long term functional outcome even in the mild traumatic brain injury patients and therefore need to be addressed early in the rehabilitation of this group of patients.

• Early diagnosis and management of severe concomitant injuries is warranted and may improve the functional gains in the long term after traumatic brain injury.

     

颅内压监测在颅脑损伤患者中的应用与护理

目的探讨经颅内引流管行颅内压（ICP）监测对颅脑损伤疾病治疗的应用价值与护理。方法对2009年2月至2011年1月入住ICU的因颅脑损伤已行颅内引流术的患者,在常规监护、治疗基础上,在颅内引流管外侧端接三通管,行ICP监测。对ICP〉2.0 kPa者予加强脱水,ICP〈0.5 kPa者提高引流袋水平,减少脱水剂用量及使用时间。结果共53例患者行ICP监测,死亡6例,死亡率11.32%;较同期未行ICP监测病例死亡率26.53%明显下降。监测结果及表现图谱与病程发展相符。结论颅脑损伤术后患者经颅内引流管行ICP监测操作简便,达到ICP监测技术要求,具有明显的临床意义。     

创伤性颅脑损伤后并发癫痫患者的长期预后研究

目的探讨脑外伤后合并癫痫的预后及对生活质量的影响。方法对1993年9月~2004年9月住院康复治疗的225例脑外伤患者,进行回顾性分析和随访研究。结果合并有癫痫31例(13.8%)。在伤后2~5年,合并癫痫者19.4%预后不良,不合并癫痫者预后不良发生率为12.5%。平均生活质量指数得分为(5.23±2.25),不合并癫痫者为(7.05±2.28)。两者在生活质量指数得分上有显著性差异。结论癫痫对脑外伤患者的远期预后和生活质量都可能造成非常不利的影响。     

Predictors of driving outcome after traumatic brain injury

OBJECTIVE: To examine predictors of driving status and fitness to drive after traumatic brain injury (TBI). DESIGN: Retrospective and prospective follow-up of a cohort ranging from 4 months to 10 years post-TBI. SETTING: A Midwestern, urban university-affiliated rehabilitation hospital. PARTICIPANTS: Seventy-one pairs of adults who had sustained a TBI and their significant others. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Driving status (whether the patient resumed driving), driving frequency (estimated miles driven per week), and postinjury driving records compiled by the Department of Motor Vehicles. RESULTS: Logistic and hierarchical regression analyses indicated that the significant other's perceptions of the patient's fitness to drive were the strongest predictor of patients' driving status and driving frequency. However, years postinjury, disability at discharge, and current neuropsychologic functioning best predicted postinjury driving safety as measured by actual incidents. The relation between perception of patients' fitness and actual driving incidents, however, was modest. CONCLUSIONS: Neuropsychologic and medical information available by traditional methods showed unique value in predictive driving safety. However, caregiver perception of patients' fitness was the overwhelming determinant of whether and how much patients drive. The bases on which caregivers form their opinions affect the safety of patients and the public. The rehabilitation setting is a unique resource for family education regarding abilities essential to safe driving.     

Changes in intracranial pressure and cerebral autoregulation in patients with severe traumatic brain injury

BACKGROUND: Impaired cerebral autoregulation is frequent after severe traumatic head injury. This could result in intracranial pressure fluctuating passively with the mean arterial pressure. OBJECTIVE: This study examines the influence of autoregulation on the amplitude and direction of changes in intracranial pressure in patients with severe head injuries during the management of cerebral perfusion pressure. DESIGN: Prospective study. SETTING: Neurosurgical intensive care unit PATIENTS: A total of 42 patients with severe head injuries. INTERVENTIONS: Continuous recording of cerebral blood flow velocity, intracranial pressure, and mean arterial pressure during the start or change of continuous norepinephrine infusion. MEASUREMENTS AND MAIN RESULTS: Cerebrovascular resistance was calculated from the cerebral perfusion pressure and middle cerebral artery blood flow velocity. The strength of autoregulation index was calculated as the ratio of the percentage of change in cerebrovascular resistance by the percentage of change in cerebral perfusion pressure before and after 121 changes in mean arterial pressure at constant ventilation between day 1 and day 18 after trauma. The strength of autoregulation index varied widely, indicating either preserved or severely perturbed autoregulation during hypotensive or hypertensive challenge in patients with or without intracranial hypertension at the basal state (strength of autoregulation index, 0.51 +/- 0.32 to 0.71 +/- 0.25). The change in intracranial pressure varied linearly with the strength of autoregulation index. There was a clinically significant change in intracranial pressure (> or =5 mm Hg) in the same direction as the change in mean arterial pressure in five tracings of three patients. This was caused by the mean arterial pressure dropping below the identified lower limit of autoregulation in three tracings for two patients. It seemed to be caused by a loss of cerebral autoregulation in the remaining two tracings for one patient. CONCLUSION: Cerebral perfusion pressure-oriented therapy can be a safe way to reduce intracranial pressure, whatever the status of autoregulation, in almost all patients with severe head injuries.     

Sex differences in injury severity and outcome measures after traumatic brain injury

OBJECTIVE: To investigate the effect of a patient's sex on various measures of injury severity and outcome after rehabilitation in a matched sample of patients with traumatic brain injury (TBI). DESIGN: Retrospective data were retrieved from a database that contains information routinely collected on all patients admitted for inpatient rehabilitation. SETTING: Inpatient rehabilitation unit of major teaching hospital in Australia. PARTICIPANTS: Fifty-four women with TBI after a motor vehicle crash (MVC) were identified from the Brain Injury Rehabilitation Database. An equal number of men were then matched for age and years of education. All subjects met the study admission criteria of having being involved in a high-speed MVC. Exclusion criteria included history of a previous head injury, chronic amnesia, psychiatric disturbance, and significant alcohol and/or substance abuse. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Differences, by sex, in patient scores on measures of injury severity and outcome after TBI. RESULTS: Men had significantly greater levels of injury severity as indicated by the Glasgow Coma Scale scores (U=994.0, P=.002) and length of posttraumatic amnesia (U=880.0, P=.016) when compared with women. No significant sex differences existed in the outcome measures or in injuries not associated with the central nervous system. CONCLUSIONS: Few investigations exist on the effect of patient sex on measures of injury severity and outcome after a TBI. In the present study, men's levels of injury severity were greater than women's despite the same admission criteria (high-speed MVC) being applied to both sexes.     

Effect of intracranial pressure monitoring and targeted intensive care on functional outcome after severe head injury

OBJECTIVE:: Intracranial hypertension after severe head injury is associated with case fatality, but there is no sound evidence that monitoring of intracranial pressure (ICP) and targeted management of cerebral perfusion pressure (CPP) improve outcome, despite widespread recommendation by experts in the field. The purpose was to determine the effect of ICP/CPP-targeted intensive care on functional outcome and therapy intensity levels after severe head injury. DESIGN:: Retrospective cohort study with prospective assessment of outcome. SETTING:: Two level I trauma centers in The Netherlands from 1996 to 2001. PATIENTS:: Three hundred thirty-three patients who had survived and remained comatose for >24 hrs, from a total of 685 consecutive severely head-injured adults. INTERVENTIONS:: In center A (supportive intensive care), mean arterial pressure was maintained at approximately 90 mm Hg, and therapeutic interventions were based on clinical observations and computed tomography findings. In center B (ICP/CPP-targeted intensive care), management was aimed at maintaining ICP <20 mm Hg and CPP >70 mm Hg. Allocation to either trauma center was solely based on the site of the accident. MEASUREMENTS AND MAIN RESULTS:: We measured extended Glasgow Outcome Scale after >/=12 months. Patient characteristics were well balanced between the centers. ICP monitoring was used in zero of 122 (0%) and 142 of 211 (67%) patients in centers A and B, respectively. In-hospital mortality rate was 41 (34%) vs. 69 (33%; p = .87). The odds ratio for a more favorable functional outcome following ICP/CPP-targeted therapy was 0.95 (95% confidence interval, 0.62-1.44). This result remained after adjustment for potential confounders. Sedatives, vasopressors, mannitol, and barbiturates were much more frequently used in center B (all p < .01). The median number of days on ventilator support in survivors was 5 (25th-75th percentile, 2-9) in center A vs. 12 (7-19) in center B (p < .001). CONCLUSIONS:: ICP/CPP-targeted intensive care results in prolonged mechanical ventilation and increased levels of therapy intensity, without evidence for improved outcome in patients who survive beyond 24 hrs following severe head injury.     

Effects of hypertonic arginine on cerebral blood flow and intracranial pressure after traumatic brain injury combined with hemorrhagic hypotension

Hypertonic saline solutions improve cerebral blood flow (CBF) when used for acute resuscitation from hemorrhagic hypotension accompanying some models of traumatic brain injury (TBI); however, the duration of increased CBF is brief. Because the nitric oxide synthase substrate l-arginine provides prolonged improvement in CBF after TBI, we investigated whether a hypertonic resuscitation fluid containing l-arginine would improve CBF in comparison to hypertonic saline without l-arginine in a model of moderate, paramedian, fluid-percussion TBI followed immediately by hemorrhagic hypotension (mean arterial pressure [MAP] = 60 mm Hg for 45 min). Sprague-Dawley rats were anesthetized with 4.0% isoflurane, intubated and ventilated with 1.5%-2.0% isoflurane in oxygen/air (50:50). After preparation for TBI and measurement of CBF using laser Doppler flowmetry and measurement of intracranial pressure (ICP) using an implanted transducer, rats were subjected to moderate (2.0 atm) TBI, hemorrhaged for 45 min, and randomly assigned to receive an infusion of hypertonic saline (7.5%, 2,400 mOsm total; 6 mL/kg; n = 6) or hypertonic saline with 50, 100, or 300 mg/kg L-arginine (2,400 mOsm; 6 mL/kg; n = 6 in each of the three dose groups) and then monitored for 120 min after the end of infusion. CBF was measured continuously and calculated as a percent of the pre-TBI baseline during the hemorrhage period, after reinfusion of one of the hypertonic arginine solutions, and 30, 60, and 120 min after reinfusion. All four hypertonic solutions initially improved MAP, which, by 120 min after infusion, had decreased nearly to the levels observed during hemorrhage. ICP remained below baseline levels during resuscitation in all groups, although ICP was slightly greater (P = NS) than baseline in the hypertonic saline group. CBF increased similarly in all groups during infusion and then decreased similarly in all groups. At 120 min after infusion, CBF was highest in the group infused with hypertonic saline, but the difference was not significant. We conclude that the improvement of MAP, ICP, and CBF produced by hypertonic saline alone after TBI and hemorrhagic hypotension is not significantly enhanced by the addition of L-arginine at these doses.     

Effect of granulocyte colony-stimulating factor on functional and histopathologic outcome after traumatic brain injury in mice

OBJECTIVE: Granulocyte colony-stimulating factor has been used to reduce the risk of sepsis in patients with traumatic brain injury. However, granulocyte colony-stimulating factor exerts potent pro- and anti-inflammatory effects that could influence secondary injury, and outcome, after traumatic brain injury. Our objective was to determine the effect of granulocyte colony-stimulating factor on histopathologic, motor, and cognitive outcome after experimental traumatic brain injury in mice. DESIGN: Experimental study. SETTING: Research laboratory at the Massachusetts General Hospital, Boston, MA. SUBJECTS: Forty-eight adult male C57Bl/6 mice. INTERVENTIONS: Mice (8 wks of age, n = 16/group) were administered granulocyte colony-stimulating factor or saline subcutaneously twice per day for 7 days after controlled cortical impact or sham injury (n = 16). Absolute neutrophil counts, motor function, Morris water maze performance, and lesion volume were determined after controlled cortical impact or sham injury. MEASUREMENTS AND MAIN RESULTS: At the time of controlled cortical impact, body weight, brain and body temperature, and systemic absolute neutrophil counts did not differ between groups. Compared with control, systemic absolute neutrophil count was increased more than ten-fold in granulocyte colony-stimulating factor-treated mice on posttrauma days 2 and 7 (p < .05, repeated-measures analysis of variance) but did not differ between groups by day 14. There were no differences between groups in tests of motor function or histopathologic outcome. However, compared with control, mice given granulocyte colony-stimulating factor had improved Morris water maze performance after controlled cortical impact (p < .05, repeated-measures analysis of variance) but not sham injury. CONCLUSIONS: The data suggest a small beneficial effect of granulocyte colony-stimulating factor on functional outcome after traumatic brain injury in adult mice but do not show differences in histopathology or motor outcome between treated and control groups.     

颅内压动态变化监测在颅脑外伤术后的作用及临床意义

目的探讨颅内压(ICP)动态变化监测在颅脑外伤术后的作用及临床意义。方法选取2012年12月至2014年12月于黄冈市中心医院接受颅脑外伤手术患者200例,根据颅内压监测结果将所有患者分为颅内压正常组(A组)、颅内压轻度升高组(B组)、颅内压中度升高组(C组)及颅内压重度升高组(D组),各50例。对各组均实施颅内压动态变化监测,且A组不给予脱水剂治疗,B组给予半剂量脱水剂治疗,C、D组给予全剂量脱水剂治疗,比较患者的预后并分析颅内压动态变化监测的临床作用及意义。结果 A、B、C、D组患者治疗预后良好率分别为98.00%、86.00%、70.00%、6.00%,组间比较差异有统计学意义(P0.05);预后良好的患者颅内压[(16.76±3.02)mm Hg]低于预后恶劣的患者[(26.52±3.90)mm Hg],组间比较差异有统计学意义(P0.05);A、B、C、D组患者GOS评分组间比较差异有统计学意义(P0.05);颅内压与GOS评分呈负相关(r=-0.521 0,P0.05)。结论在颅脑外伤术后及早地进行颅内压动态变化监测,有助于指导和调整治疗方法,提高临床疗效,同时有助于评估疾病预后的发展。     

Barbiturates for the treatment of intracranial hypertension after traumatic brain injury

In their article on the use of barbiturates for the treatment of intracranial hypertension after traumatic brain injury, Perez-Barcena and colleagues conclude that thiopental was more effective than pentobarbital in decreasing intracranial pressure. Here we discuss the limitations of this study and review areas of controversy surrounding barbiturate use in neurocritical care.