A Systematic Review of the Effects of Body Temperature on Outcome After Adult Traumatic Brain Injury

Biophysiologic Monitoring for the Neurosurgical Patient

Biophysiologic monitoring exists as a method of collecting objective information about the neurosurgical patient throughout their treatment and recovery process. Such data is crucial for an improved understanding of the disease processes while providing the surgeon additional clarity as they decipher the next best steps in decision-making and medical recommendations. In the current review article, the authors discuss the commonly used wearable and placeable monitoring devices and the biophysiological data that can be collected to monitor, as well as, assess the neurosurgical patient. Special focus is placed on invasive and non-invasive neurologic monitoring devices, but important and commonly used monitors for the rest of the body are also discussed as they relate to the neurosurgical patient. Last, the authors review new, as well as, upcoming devices and measurements to better analyze the neurosurgical patient's bodily function and physiologic status as needed. The synthesis of methods contained herein may provide meaningful guidance for neurosurgeons in effectively monitoring and treating their patients while also helping to guide their future efforts in patient biophysiologic monitoring developments within neurosurgery.

The S-100B level, intracranial pressure, body temperature, and transcranial blood flow velocities predict the outcome of the treatment of severe brain injury

This study evaluates the applicability of S100B levels, mean maximum velocity (Vmean) over time, pulsatility index (PI), intracranial pressure (ICP), and body temperature (T) for the prediction of the treatment of patients with traumatic brain injury (TBI). Sixty patients defined by the Glasgow Coma Scale score ≤ 8 were stratified using the Glasgow Coma Scale into 2 groups: favorable (FG: Glasgow Outcome Scale ≥ 4) and unfavorable (UG: Glasgow Outcome Scale < 4). The S100B concentration was at the time of hospital admission. Vmean was measured using transcranial Doppler. PI was derived from a transcranial Doppler examination. T was measured in the temporal artery. The differences in mean between FG and UG were tested using a bootstrap test of 10,000 repetitions with replacement. Changes in S100B, Vmean, PI, ICP, and T levels stratified by the group were calculated using the one-way aligned rank transform for nonparametric factorial analysis of variance. The reference ranges for the levels of S100B, Vmean, and PI were 0.05 to 0.23 µg/L, 30.8 to 73.17 cm/s, and 0.62 to 1.13, respectively. Both groups were defined by an increase in Vmean, a decrease in S100B, PI, and ICP levels; and a virtually constant T. The unfavorable outcome is defined by significantly higher levels of all parameters, except T. A favorable outcome is defined by S100B < 3 mg/L, PI < 2.86, ICP > 25 mm Hg, and Vmean > 40 cm/s. The relationships provided may serve as indicators of the results of the TBI treatment.

A Case Series of Clinical Limitations to the Clinical Course of Neurogenic Fever

Nurses play a vital role in the care of neurocritical patients. Fever is a common and dangerous occurrence, and there is a substantial lack of consistency in how to maintain normothermia in these patients. We present five cases in which patients were confirmed to have neurogenic fever (NF) and the documented interventions. In all five cases, temperature and interventions were not documented consistently, making it difficult to assess how nurses acted to avoid hyperthermia in these patients. Additional research is needed to determine interventions, processes, procedures, and documentation of NF in neurocritical patients.

Traumatic brain injury: Association between the Glasgow Coma Scale score and intensive care unit mortality

Background

Traumatic brain injury (TBI) prevalence in Botswana is high and this, coupled with a small population, may reduce productivity. There is no previous study in Botswana on the association between mortality from TBI and the Glasgow Coma Scale (GCS) score although global literature supports its existence.

Objectives

Our primary aim was to determine the association between the initial GCS score and the time to mortality of adults admitted with TBI at the Princess Marina Hospital, Gaborone, Botswana, between 2014 and 2019. Secondary aims were to assess the risk factors associated with time to mortality and to estimate the mortality rate from TBI.

Methods

This was a retrospective cohort design, medical record census conducted from 1 January 2014 to 31 December 2019.

Results

In total, 137 participants fulfilled the inclusion criteria, and the majority, 114 (83.2%), were male with a mean age of 34.5 years. The initial GCS score and time to mortality were associated (adjusted hazard ratio (aHR) 0.69; 95% confidence interval (CI) 0.508 - 0.947). Other factors associated with time to mortality included constricted pupil (aHR 0.12; 95% CI 0.044 - 0.344), temperature (aHR 0.82; 95% CI 0.727 - 0.929), and subdural haematoma (aHR 3.41; 95% CI 1.819 - 6.517). Most cases of TBI (74 (54%)) were due to road traffic accidents. The number of deaths was 48 (35% (95% CI 27.1% - 43.6%)), entirely due to severe TBI.

Conclusion

The study confirmed significant association between GCS and mortality. Males were mainly involved in TBI. These findings lack external validity because of the small sample size, and therefore a larger multicentre study is required for validation.

Contributions of the study

This study informs the relevant stakeholders in Botswana about sociodemographics, clinical characteristics, management and outcomes of patients admitted to the ICU with severe TBI on the backdrop of scarce ICU resources. It provides a basis for a larger study to inform its external validation.

Current understanding of thermo(dys)regulation in severe burn injury and the pathophysiological influence of hypermetabolism, adrenergic stress and hypothalamic regulation—a systematic review

Background

In this systematic review, we summarize the aetiology as well as the current knowledge regarding thermo(dys)regulation and hypothermia after severe burn trauma and aim to present key concepts of pathophysiology and treatment options. Severe burn injuries with >20% total body surface area (TBSA) affected commonly leave the patient requiring several surgical procedures, prolonged hospital stays and cause substantial changes to body composition and metabolism in the acute and long-term phase. Particularly in severely burned patients, the loss of intact skin and the dysregulation of peripheral and central thermoregulatory processes may lead to substantial complications.

Methods

A systematic and protocol-based search for suitable publications was conducted following the PRISMA guidelines. Articles were screened and included if deemed eligible. This encompasses animal-based in vivo studies as well as clinical studies examining the control-loops of thermoregulation and metabolic stability within burn patients

Results

Both experimental animal studies and clinical studies examining thermoregulation and metabolic functions within burn patients have produced a general understanding of core concepts which are, nonetheless, lacking in detail. We describe the wide range of pathophysiological alterations observed after severe burn trauma and highlight the association between thermoregulation and hypermetabolism as well as the interactions between nearly all organ systems. Lastly, the current clinical standards of mitigating the negative effects of thermodysregulation and hypothermia are summarized, as a comprehensive understanding and implementation of the key concepts is critical for patient survival and long-term well-being.

Conclusions

The available in vivo animal models have provided many insights into the interwoven pathophysiology of severe burn injury, especially concerning thermoregulation. We offer an outlook on concepts of altered central thermoregulation from non-burn research as potential areas of future research interest and aim to provide an overview of the clinical implications of temperature management in burn patients.

Hypoxia-Responsive Subtype Cells Differentiate Into Neurons in the Brain of Zebrafish Embryos Exposed to Hypoxic Stress

Severe hypoxia results in complete loss of central nervous system (CNS) function in mammals, while several other vertebrates, such as zebrafish, can regenerate after hypoxia-induced injury of CNS. Since the cellular mechanism involved in this remarkable feature of other vertebrates is still unclear, we studied the cellular regeneration of zebrafish brain, employing zebrafish embryos from transgenic line huORFZ exposed to hypoxia and then oxygen recovery. GFP-expressing cells, identified in some cells of the CNS, including some brain cells, were termed as hypoxia-responsive recovering cells (HrRCs). After hypoxia, HrRCs did not undergo apoptosis, while most non-GFP-expressing cells, including neurons, did. Major cell types of HrRCs found in the brain of zebrafish embryos induced by hypoxic stress were neural stem/progenitor cells (NSPCs) and radial glia cells (RGs), that is, subtypes of NSPCs (NSPCs-HrRCs) and RGs (RGs-HrRCs) that were induced by and sensitively responded to hypoxic stress. Interestingly, among HrRCs, subtypes of NSPCs- or RGs-HrRCs could proliferate and differentiate into early neurons during oxygen recovery, suggesting that these subtype cells might play a critical role in brain regeneration of zebrafish embryos after hypoxic stress.

Evaluation of Evidence-Based Guidelines for Fever Management in Critically Ill Adult Patients With Brain Injury

PURPOSE

The aim of this study was to evaluate the effectiveness of evidence-based guidelines for fever management of critically ill adult patients with brain injury.

METHODS

We used a pretest-posttest design with 48 patients 19 years or older admitted to an intensive care unit after surgery for brain injury. We applied evidence-based guidelines only to an experimental group of 24 patients and compared with 24 control patients who did not receive evidence-based guidelines. Experimental and control groups were matched 1:1 using the Acute Physiology and Chronic Health Evaluation II score. Data included the proportion of patients with reduced fever and time to normalized temperature.

RESULTS

The proportion of patients whose temperature fell to normal after fever was 4.5 times higher in the experimental group than in the control group. The time it took the patients' highest fever to fall to normal during their intensive care unit stay was 4.84 times faster in the experimental group than in the control group (hazard ratio, 4.84; 95% confidence interval, 1.79-13.11; P = .002).

CONCLUSION

Evidence-based guidelines for fever management in patients with a brain injury can be used in nursing practice with rapid response, improving healthcare efficiency and contributing to better outcomes for critically ill patients.

Impact of body temperature at admission on inhospital outcomes in patients with takotsubo syndrome: insights from the Tokyo Cardiovascular Care Unit Network Registry

Background:

Takotsubo syndrome occasionally occurs in patients with fever due to underlying diseases. However, the impact of body temperature on inhospital prognosis of patients with takotsubo syndrome remains unknown.

Methods:

Using the patient cohort in the Tokyo Cardiovascular Care Unit Network Registry from 2013 to 2015, we identified 421 eligible patients whose data on body temperature at admission were available and classified them into three groups: high body temperature group (≥37.5°C; n=27), normal body temperature group (36.0–37.4°C; n=319), and low body temperature group (≤35.9°C; n=75). We compared the patient characteristics and inhospital outcomes among the three groups.

Results:

On admission, the high body temperature group showed a higher proportion of men and preceding physical triggers, higher heart and respiratory rates, and higher C-reactive protein level than the other groups. Inhospital all-cause mortality was significantly higher in the high body temperature group than in the normal or low body temperature group (18.5% vs. 2.2% vs. 4.0%, respectively, P&lt;0.001). Both cardiac mortality (11.1% vs. 1.3% vs. 1.3%, P=0.001) and non-cardiac mortality (7.4% vs. 0.9% vs. 2.7%, P=0.031) were also significantly higher in the high body temperature group. Multivariable logistic regression analysis showed that high body temperature (reference: normal body temperature) was significantly associated with higher inhospital mortality (adjusted odds ratio 4.22; 95% confidence interval 1.15–15.51; P=0.030).

Conclusions:

Our findings suggest that high body temperature at admission is a strong predictor of inhospital mortality in patients with takotsubo syndrome. Febrile takotsubo syndrome patients may need to be managed with recognition of life-threatening conditions from the time of diagnosis, no matter what the causes of fever are.

Hyperglycemia as a positive predictor of mortality in major trauma

Background:

Hyperglycemia in the acute phase after trauma is a stress response and a metabolic reflection in humans with injury, which could adversely affect outcome in trauma patients. In this study, we attempted to identify if hyperglycemia a reliable predictor for mortality in major trauma patients.

Objectives:

In order to identify if hyperglycemia a reliable predictor for mortality in major trauma, we designed and proformed a prospective observational study in a tertiary hospital.

Method:

We performed a prospective observational study to review the records of 601 patients with major trauma (injury severity scores >15) who visited our hospital’s emergency department from August 2012 to July 2015. Logistic regression was performed to assess the effect of hyperglycemia on mortality.

Result:

Major trauma patients in the hyperglycemia group had low systolic/diastolic blood pressure at triage, low initial Glasgow Coma Scale score, high incidence of hypotension episodes, coagulopathy, acidosis, and anemia. Hyperglycemia was significantly correlated with mortality in major trauma patients in this study (odds ratio: 1.97, 95% confidence interval: 1.04–3.74).

Conclusion:

In major trauma patients with injury severity scores >15, hyperglycemia has a positive correlation with mortality, which could be a predictor of mortality in clinical practice.

Management of Intracranial Pressure Part II: Nonpharmacologic Interventions

Pharmacologic and nonpharmacologic interventions are available to treat patients who experience serious elevations in intracranial pressure (ICP). In some cases, patients may experience ICP that is refractory to treatment. Significant negative effects on cerebral blood flow, tissue oxygenation, and cerebral metabolism occur as a result of intracranial hypertension, leading to secondary brain injury. In part 2 of this series, nonpharmacologic interventions for ICP and ICP refractory to treatment are discussed. Interventions include neurologic monitoring (bedside assessment and multimodal monitoring), ventilatory support, fluid and electrolyte maintenance, targeted temperature management, and surgical intervention. Technology is always evolving, and the focus of multimodal monitoring here includes devices to monitor ICP, brain tissue oxygen tension, and cerebral blood flow and cerebral microdialysis monitors. Nursing care of these patients includes perspicacious assessment and integration of data, monitoring ventilatory and hemodynamic functioning, and appropriate patient positioning. Nurses must collaborate with the interprofessional care team to ensure favorable patient outcomes while utilizing an evidence-based guideline for the management of ICP.

Systemic Inflammatory Response Syndrome (SIRS) Score Independently Predicts Poor Outcome in Isolated Traumatic Brain Injury

INTRODUCTION

Systemic inflammatory response syndrome (SIRS) is frequently observed after various types of acute cerebral injury and has been linked to clinical deterioration in non-traumatic brain injury (TBI). SIRS scores have also been shown to be predictive of length of stay and mortality in trauma patients. We aimed to determine the prognostic utility of SIRS present at admission in trauma patients with isolated TBI.

METHODS

This was a 5-year retrospective cohort study of adults (≥18 years) with isolated TBI admitted to a Level II trauma center. The prognostic value of SIRS, total SIRS scores, and each SIRS criterion was examined by Χ ² and logistic regression analyses.

RESULTS

Of the 330 patients identified, 50 (15.2%) met SIRS criteria. SIRS was significantly associated with poor outcome (P < 0.001). Relative risk of poor outcome was 2.7 times higher in patients with a SIRS score of 2 on admission (P = 0.007) and increased significantly to 6.5 times in patients with a SIRS score of 3 (P = 0.002). Logistic regression demonstrated SIRS and each criterion to be significant independent prognostic factors (SIRS, P = 0.030; body temperature, P = 0.006; tachypnea, P = 0.022, tachycardia P = 0.023).

CONCLUSION

SIRS at admission is an independent predictor of poor outcome in isolated TBI patients. These data demonstrate SIRS to be an important clinical tool that may be used in facilitating prognostication, particularly in elderly trauma patients. Future prospective studies aimed at therapeutic interventions to mitigate SIRS in TBI patients are warranted.

LEVEL OF EVIDENCE

Prognostic, Level III.

Risk Factors for Persistent Cognitive Impairment After Critical Illness, Nested Case-Control Study

OBJECTIVES

Persistent cognitive impairment after critical illness is an important healthcare problem forecasted to worsen in the near future. However, the epidemiology is insufficiently explored. We aimed to determine potentially modifiable risk factors during ICU hospitalization that play a significant role in developing persistent cognitive impairment.

DESIGN

An observational case-control study.

SETTINGS

Mayo Clinic ICUs between July 1, 2004, and November 20, 2015.

PATIENTS

We conducted a study nested in a large cohort of 98,227 adult critically ill patients. Using previously validated computable phenotypes for dementia and cognitive impairment, we determined the onset of cognitive impairment relative to ICU hospitalization and associated risk factors. The primary endpoint of the study was new and persistent cognitive impairment documented between 3 and 24 months after ICU discharge.

INTERVENTIONS

Unadjusted and adjusted analyses were performed to identify potentially modifiable risk factors during ICU hospitalization.

MEASUREMENTS AND MAIN RESULTS

Among 21,923 unique patients identified as cognitively impaired (22% of the entire ICU cohort), 2,428 (2.5%) developed incident new and persistent cognitive dysfunction after the index ICU admission. Compared with age- and sex-matched ICU controls (2,401 pairs), cases had higher chronic illness burden (Charlson Comorbidity Index, 6.2 vs 5.1; p < 0.01), and were more likely to have multiple ICU stays (22% vs 14%; p < 0.01). After adjustment for baseline differences, new and persistent cognitive dysfunction was associated with higher frequency of acute brain failure in the ICU, a higher exposure to severe hypotension, hypoxemia, hyperthermia, fluctuations in serum glucose, and treatment with quinolones or vancomycin. Association with sepsis observed in univariate analysis did not persist after adjustment.

CONCLUSIONS

Cognitive dysfunction is highly prevalent in ICU patients. Incident new and persistent cognitive impairment is less common but important, potentially preventable problem after critical illness. Chronic comorbidities and number of ICU stays increase the risk of post-ICU cognitive dysfunction irrespective of age. Modifiable ICU exposures were identified as potential targets for future prevention trials.

Therapeutic hypothermia to reduce intracranial pressure after traumatic brain injury: the Eurotherm3235 RCT

BACKGROUND

Traumatic brain injury (TBI) is a major cause of disability and death in young adults worldwide. It results in around 1 million hospital admissions annually in the European Union (EU), causes a majority of the 50,000 deaths from road traffic accidents and leaves a further ≈10,000 people severely disabled.

OBJECTIVE

The Eurotherm3235 Trial was a pragmatic trial examining the effectiveness of hypothermia (32-35 °C) to reduce raised intracranial pressure (ICP) following severe TBI and reduce morbidity and mortality 6 months after TBI.

DESIGN

An international, multicentre, randomised controlled trial.

SETTING

Specialist neurological critical care units.

PARTICIPANTS

We included adult participants following TBI. Eligible patients had ICP monitoring in place with an ICP of > 20 mmHg despite first-line treatments. Participants were randomised to receive standard care with the addition of hypothermia (32-35 °C) or standard care alone. Online randomisation and the use of an electronic case report form (CRF) ensured concealment of random treatment allocation. It was not possible to blind local investigators to allocation as it was obvious which participants were receiving hypothermia. We collected information on how well the participant had recovered 6 months after injury. This information was provided either by the participant themself (if they were able) and/or a person close to them by completing the Glasgow Outcome Scale - Extended (GOSE) questionnaire. Telephone follow-up was carried out by a blinded independent clinician.

INTERVENTIONS

The primary intervention to reduce ICP in the hypothermia group after randomisation was induction of hypothermia. Core temperature was initially reduced to 35 °C and decreased incrementally to a lower limit of 32 °C if necessary to maintain ICP at < 20 mmHg. Rewarming began after 48 hours if ICP remained controlled. Participants in the standard-care group received usual care at that centre, but without hypothermia.

MAIN OUTCOME MEASURES

The primary outcome measure was the GOSE [range 1 (dead) to 8 (upper good recovery)] at 6 months after the injury as assessed by an independent collaborator, blind to the intervention. A priori subgroup analysis tested the relationship between minimisation factors including being aged < 45 years, having a post-resuscitation Glasgow Coma Scale (GCS) motor score of < 2 on admission, having a time from injury of < 12 hours and patient outcome.

RESULTS

We enrolled 387 patients from 47 centres in 18 countries. The trial was closed to recruitment following concerns raised by the Data and Safety Monitoring Committee in October 2014. On an intention-to-treat basis, 195 participants were randomised to hypothermia treatment and 192 to standard care. Regarding participant outcome, there was a higher mortality rate and poorer functional recovery at 6 months in the hypothermia group. The adjusted common odds ratio (OR) for the primary statistical analysis of the GOSE was 1.54 [95% confidence interval (CI) 1.03 to 2.31]; when the GOSE was dichotomised the OR was 1.74 (95% CI 1.09 to 2.77). Both results favoured standard care alone. In this pragmatic study, we did not collect data on adverse events. Data on serious adverse events (SAEs) were collected but were subject to reporting bias, with most SAEs being reported in the hypothermia group.

CONCLUSIONS

In participants following TBI and with an ICP of > 20 mmHg, titrated therapeutic hypothermia successfully reduced ICP but led to a higher mortality rate and worse functional outcome.

LIMITATIONS

Inability to blind treatment allocation as it was obvious which participants were randomised to the hypothermia group; there was biased recording of SAEs in the hypothermia group. We now believe that more adequately powered clinical trials of common therapies used to reduce ICP, such as hypertonic therapy, barbiturates and hyperventilation, are required to assess their potential benefits and risks to patients.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN34555414.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 45. See the NIHR Journals Library website for further project information. The European Society of Intensive Care Medicine supported the pilot phase of this trial.

The neurointensive nursery: concept, development, and insights gained

PURPOSE OF REVIEW

With the advent of therapeutic hypothermia for treatment of hypoxic ischemic encephalopathy, and improvements in neuroimaging and bedside neuromonitoring, a new era of neonatal brain-focused care has emerged in recent years. We describe the development of the first neurointensive care nursery (NICN) as a model for comanagement of neonates with identified neurologic risk factors by a multidisciplinary team constituted of neurologists, neonatologists, specialized nurses, and others with the goal of optimizing management, preventing secondary injury and maximizing long-term outcomes.

RECENT FINDINGS

Optimizing brain metabolic environment and perfusion and preventing secondary brain injury are key to neurocritical care. This includes close management of temperature, blood pressure, oxygenation, carbon dioxide, and glucose levels. Early developmental interventions and involvement of physical and occupational therapy provide additional assessment information. Finally, long-term follow-up is essential for any neurocritical care program.

SUMMARY

The NICN model aims to optimize evidence-based care of infants at risk for neurologic injury. Results from ongoing hypothermia and neuroprotective trials are likely to yield additional treatments. New technologies, such as functional MRI, continuous neurophysiological assessment, and whole genomic approaches to rapid diagnosis may further enhance clinical protocols and neonatal precision medicine. Importantly, advances in neurocritical care improve our ability to provide comprehensive information when counseling families. Long-term follow-up data will determine if the NICN/Neuro-NICU provides enduring benefit to infants at risk for neurologic injury.

Targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke: consensus recommendations

BACKGROUND

A modified Delphi approach was used to identify a consensus on practical recommendations for the use of non-pharmacological targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke with non-infectious fever (assumed neurogenic fever).

METHODS

Nine experts in the management of neurogenic fever participated in the process, involving the completion of online questionnaires, face-to-face discussions, and summary reviews, to consolidate a consensus on targeted temperature management.

RESULTS

The panel's recommendations are based on a balance of existing evidence and practical considerations. With this in mind, they highlight the importance of managing neurogenic fever using a single protocol for targeted temperature management. Targeted temperature management should be initiated if the patient temperature increases above 37.5°C, once an appropriate workup for infection has been undertaken. This helps prevent prophylactic targeted temperature management use and ensures infection is addressed appropriately. When neurogenic fever is detected, targeted temperature management should be initiated rapidly if antipyretic agents fail to control the temperature within 1 h, and should then be maintained for as long as there is potential for secondary brain damage. The recommended target temperature for targeted temperature management is 36.5-37.5°C. The use of advanced targeted temperature management methods that enable continuous, or near continuous, temperature measurement and precise temperature control is recommended.

CONCLUSIONS

Given the limited heterogeneous evidence currently available on targeted temperature management use in patients with neurogenic fever and intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke, a Delphi approach was appropriate to gather an expert consensus. To aid in the development of future investigations, the panel provides recommendations for data gathering.

The currency, completeness and quality of systematic reviews of acute management of moderate to severe traumatic brain injury: A comprehensive evidence map

OBJECTIVE

To appraise the currency, completeness and quality of evidence from systematic reviews (SRs) of acute management of moderate to severe traumatic brain injury (TBI).

METHODS

We conducted comprehensive searches to March 2016 for published, English-language SRs and RCTs of acute management of moderate to severe TBI. Systematic reviews and RCTs were grouped under 12 broad intervention categories. For each review, we mapped the included and non-included RCTs, noting the reasons why RCTs were omitted. An SR was judged as 'current' when it included the most recently published RCT we found on their topic, and 'complete' when it included every RCT we found that met its inclusion criteria, taking account of when the review was conducted. Quality was assessed using the AMSTAR checklist (trichotomised into low, moderate and high quality).

FINDINGS

We included 85 SRs and 213 RCTs examining the effectiveness of treatments for acute management of moderate to severe TBI. The most frequently reviewed interventions were hypothermia (n = 17, 14.2%), hypertonic saline and/or mannitol (n = 9, 7.5%) and surgery (n = 8, 6.7%). Of the 80 single-intervention SRs, approximately half (n = 44, 55%) were judged as current and two-thirds (n = 52, 65.0%) as complete. When considering only the most recently published review on each intervention (n = 25), currency increased to 72.0% (n = 18). Less than half of the 85 SRs were judged as high quality (n = 38, 44.7%), and nearly 20% were low quality (n = 16, 18.8%). Only 16 (20.0%) of the single-intervention reviews (and none of the five multi-intervention reviews) were judged as current, complete and high-quality. These included reviews of red blood cell transfusion, hypothermia, management guided by intracranial pressure, pharmacological agents (various) and prehospital intubation. Over three-quarters (n = 167, 78.4%) of the 213 RCTs were included in one or more SR. Of the remainder, 17 (8.0%) RCTs post-dated or were out of scope of existing SRs, and 29 (13.6%) were on interventions that have not been assessed in SRs.

CONCLUSION

A substantial number of SRs in acute management of moderate to severe TBI lack currency, completeness and quality. We have identified both potential evidence gaps and also substantial research waste. Novel review methods, such as Living Systematic Reviews, may ameliorate these shortcomings and enhance utility and reliability of the evidence underpinning clinical care.

Hypothermia Reduces Mortality, Prevents the Calcium Plateau, and Is Neuroprotective Following Status Epilepticus in Rats

Status Epilepticus (SE) is a major neurological emergency and is considered a leading cause of Acquired Epilepsy (AE). We have shown that SE produces neuronal injury and prolonged alterations in hippocampal calcium levels ([Ca²⁺]_i) that may underlie the development of AE. Interventions preventing the SE-induced Ca²⁺ plateau could therefore prove to be beneficial in lowering the development of AE after SE. Hypothermia is used clinically to prevent neurological complications associated with Traumatic Brain Injury, cardiac arrest, and stroke. Here, we investigated whether hypothermia prevented the development of Ca²⁺ plateau following SE. SE was induced in hippocampal neuronal cultures (HNC) by exposing them to no added MgCl₂ solution for 3 h. To terminate SE, low Mg²⁺ solution was washed off with 31°C (hypothermic) or 37°C (normothermic) physiological recording solution. [Ca²⁺]_i was estimated with ratiometric Fura-2 imaging. HNCs washed with hypothermic solution exhibited [Ca²⁺]_i ratios, which were significantly lower than ratios obtained from HNCs washed with normothermic solution. For in vivo SE, the rat pilocarpine (PILO) model was used. Moderate hypothermia (30–33°C) in rats was induced at 30-min post-SE using chilled ethanol spray in a cold room. Hypothermia following PILO-SE significantly reduced mortality. Hippocampal neurons isolated from hypothermia-treated PILO SE rats exhibited [Ca²⁺]_i ratios which were significantly lower than ratios obtained from PILO SE rats. Hypothermia also provided significant neuroprotection against SE-induced delayed hippocampal injury as characterized by decreased FluoroJade C labeling in hypothermia-treated PILO SE rats. We previously demonstrated that hypothermia reduced Ca²⁺ entry via N-methyl-D-aspartate and ryanodine receptors in HNC. Together, our studies indicate that by targeting these two receptor systems hypothermia could interfere with epileptogenesis and prove to be an effective therapeutic intervention for reducing SE-induced AE.

Effect of target temperature management at 32-34 °C in cardiac arrest patients considering assessment by regional cerebral oxygen saturation: A multicenter retrospective cohort study

AIM

Target temperature management (TTM) is used in comatose post-cardiac arrest patients, but the recommended temperature range is wide. This study aimed to assess the effectiveness of TTM at 32-34 °C while considering the degree of cerebral injury and cerebral circulation, as assessed by regional cerebral oxygen saturation (rSO₂).

METHODS

This is a secondary analysis of prospectively collected registry data from comatose patients who were transferred to 15 hospitals in Japan after out-of-hospital cardiac arrest (OHCA) from 2011 to 2013. The primary outcome was all-cause mortality at 90 days after OHCA, and the secondary outcome was favorable neurological outcomes as evaluated according to the Cerebral Performance Category. We monitored rSO₂ noninvasively with near-infrared spectroscopy, which could assess cerebral perfusion and the balance of oxygen delivery and uptake.

RESULTS

We stratified 431 study patients into three groups according to rSO₂ on hospital arrival: rSO₂ ≤40% (n = 296), rSO₂ 41-60% (n = 67), and rSO₂ ≥61% (n = 68). Propensity score analysis revealed that TTM at 32-34 °C decreased all-cause mortality in patients with rSO₂ 41-60% (average treatment effect on treated [ATT] by propensity score matching [PSM] -0.51, 95%CI -0.70 to -0.33; ATT by inverse probability of treatment weighting [IPW] -0.52, 95%CI -0.71 to -0.34), and increased favorable neurological outcomes in patients with rSO₂ 41-60% (ATT by PSM 0.50, 95%CI 0.32-0.68; ATT by IPW 0.52, 95%CI 0.35-0.69).

CONCLUSION

TTM at 32-34 °C effectively decreased all-cause mortality in comatose OHCA patients with rSO₂ 41-60% on hospital arrival in Japan.

Therapeutic hypothermia and targeted temperature management for traumatic brain injury: Experimental and clinical experience

Traumatic brain injury (TBI) is a worldwide medical problem, and currently, there are few therapeutic interventions that can protect the brain and improve functional outcomes in patients. Over the last several decades, experimental studies have investigated the pathophysiology of TBI and tested various pharmacological treatment interventions targeting specific mechanisms of secondary damage. Although many preclinical treatment studies have been encouraging, there remains a lack of successful translation to the clinic and no therapeutic treatments have shown benefit in phase 3 multicenter trials. Therapeutic hypothermia and targeted temperature management protocols over the last several decades have demonstrated successful reduction of secondary injury mechanisms and, in some selective cases, improved outcomes in specific TBI patient populations. However, the benefits of therapeutic hypothermia have not been demonstrated in multicenter randomized trials to significantly improve neurological outcomes. Although the exact reasons underlying the inability to translate therapeutic hypothermia into a larger clinical population are unknown, this failure may reflect the suboptimal use of this potentially powerful therapeutic in potentially treatable severe trauma patients. It is known that multiple factors including patient recruitment, clinical treatment variables, and cooling methodologies are all important in yielding beneficial effects. High-quality multicenter randomized controlled trials that incorporate these factors are required to maximize the benefits of this experimental therapy. This article therefore summarizes several factors that are important in enhancing the beneficial effects of therapeutic hypothermia in TBI. The current failures of hypothermic TBI clinical trials in terms of clinical protocol design, patient section, and other considerations are discussed and future directions are emphasized.

[Recommendation on temperature management after cardiopulmonary arrest and severe traumatic brain injury in childhood beyond the neonatal period : Statement of the German Society for Neonatology and Pediatric Intensive Care Medicine (GNPI) and the scientific Working Group for Paediatric Anaesthesia (WAKKA) of the German Society of Anaesthesiology and Intensive Care (DGAI)]

The available data on the effectiveness of therapeutic hypothermia in different patient groups are heterogeneous. Although the benefits have been proven for some collectives, recommendations for the use of hypothermia treatment in other groups are based on less robust data and conclusions by analogy. This article gives a review of the current evidence of temperature management in all age groups and based on this state of knowledge, recommends active temperature management with the primary aim of strict normothermia (36-36.5 °C) for 72 hours after cardiopulmonary arrest or severe traumatic brain injury for children beyond the neonatal period.

Combination Treatment with Methylene Blue and Hypothermia in Global Cerebral Ischemia

Therapeutic hypothermia (TH) is the most potent therapeutic strategy for global cerebral ischemia (GCI), usually induced by cardiac arrest. TH has been shown both to suppress the delayed neuronal cell death in the vulnerable hippocampal CA1 subregion and to improve neurological outcomes in experimental animals after GCI. However, given the multiple adverse effects resulting from TH, application of such a therapy is typically limited. In recent years, methylene blue (MB) has emerged as a potential therapeutic drug for the treatment of neurodegenerative diseases. In this study, we investigated the beneficial effects of mild TH combined with MB treatment after GCI. We report that both the neuronal survival in the hippocampal CA1 region and the hippocampus-dependent spatial learning and memory in the combined treatment animals were enhanced compared to those in the single treatment animals. Mechanistic studies revealed that combined TH and MB treatment significantly attenuated mitochondrial dysfunction induced by GCI in the hippocampus CA1 region. The combined treatment also markedly suppressed GCI-induced reactive gliosis and inflammation and reduced oxidative stress while enhancing the antioxidant capacity of hippocampal CA1 neurons. Finally, combining TH and MB synergistically attenuated the intrinsic cytochrome c/caspase-3 apoptotic pathway induced by GCI. Our results suggest that TH and MB act synergistically to protect the ischemic brain and suppress cognitive impairment caused by GCI.

Targeted Temperature Modulation in the Neuroscience Patient

There are many approaches to and opportunities for implementing temperature modulation in critically ill patients, but barriers also exist. Conceptually, the process of cooling is rather straightforward; however, targeted temperature management is anything but simplistic. The need for a collaborative approach (physicians champions, nursing support, respiratory therapists, pharmacists, laboratory personnel, and supply chain representatives) to address definitions of normothermia and fever, patient inclusion/exclusion criteria for therapy based on underlying neurorelated pathologies, determination of methods of induction/maintenance, monitoring required, education planning, and strategies to minimize potential complications are warranted.

Surgical Neurostimulation for Spinal Cord Injury

Traumatic spinal cord injury (SCI) is a devastating neurological condition characterized by a constellation of symptoms including paralysis, paraesthesia, pain, cardiovascular, bladder, bowel and sexual dysfunction. Current treatment for SCI involves acute resuscitation, aggressive rehabilitation and symptomatic treatment for complications. Despite the progress in scientific understanding, regenerative therapies are lacking. In this review, we outline the current state and future potential of invasive and non-invasive neuromodulation strategies including deep brain stimulation (DBS), spinal cord stimulation (SCS), motor cortex stimulation (MCS), transcutaneous direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) in the context of SCI. We consider the ability of these therapies to address pain, sensorimotor symptoms and autonomic dysregulation associated with SCI. In addition to the potential to make important contributions to SCI treatment, neuromodulation has the added ability to contribute to our understanding of spinal cord neurobiology and the pathophysiology of SCI.

Clinical Outcomes after Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of death and disability that often affects young people. After injury, the degree of recovery can be highly variable, with some people regaining near complete function while others remain severely disabled. Understanding what factors influence recovery is important for counseling patients and families in the acute period after injury and can help guide therapeutic decisions in the acute period following injury. In this review, prognostic algorithms useful for clinicians are discussed. Tools for grading patient outcomes, their role in clinical care and research studies, and their limitations are reviewed. Ongoing work focusing on the development of biomarkers to track TBI recovery and the refinement of clinical outcome metrics is summarized.

Magnitude of temperature elevation is associated with neurologic and survival outcomes in resuscitated cardiac arrest patients with postrewarming pyrexia

PURPOSE

Avoidance of pyrexia is recommended in resuscitation guidelines, including after treatment with targeted temperature management (TTM). Which aspects of postresuscitation pyrexia are harmful and modifiable have not been conclusively determined.

MATERIALS AND METHODS

This retrospective multicenter registry study collected serial temperatures during 72 hours postrewarming to assess the relationship between 3 aspects of pyrexia (maximum temperature, pyrexia duration, timing of first pyrexia) and neurologic outcome (primary) and survival (secondary) at hospital discharge. Adult TTM-treated patients from 13 US hospitals between 2005 and 2015 were included.

RESULTS

One hundred seventy-nine of 465 patients had at least 1 temperature greater than or equal to 38°C. Pyrexic temperatures were associated with better survival than nonpyrexic temperatures (adjusted odds ratio [aOR], 1.54; 95% confidence interval [CI], 1.00-2.35). Higher maximum temperature was associated with worse outcome (neurologic aOR, 0.30 [95% CI, 0.10-0.84]; survival aOR, 0.25 [95% CI, 0.10-0.59]) in pyrexic patients. There was no significant relationship between pyrexia duration and outcomes unless duration was calculated as hours greater than or equal to 38.8°C, when longer duration was associated with worse outcomes (neurologic aOR, 0.86 [95% CI, 0.75-1.00]; survival aOR, 0.82 [95% CI, 0.72-0.93]).

CONCLUSIONS

In postarrest TTM-treated patients, pyrexia was associated with increased survival. Patients experiencing postrewarming pyrexia had worse outcomes at higher temperatures. Longer pyrexia duration was associated with worse outcomes at higher temperatures.

Management of Status Epilepticus in Children

Status epilepticus is a common pediatric neurological emergency. Management includes prompt administration of appropriately selected anti-seizure medications, identification and treatment of seizure precipitant(s), as well as identification and management of associated systemic complications. This review discusses the definitions, classification, epidemiology and management of status epilepticus and refractory status epilepticus in children.

Therapeutic hypothermia and targeted temperature management in traumatic brain injury: Clinical challenges for successful translation

The use of therapeutic hypothermia (TH) and targeted temperature management (TTM) for severe traumatic brain injury (TBI) has been tested in a variety of preclinical and clinical situations. Early preclinical studies showed that mild reductions in brain temperature after moderate to severe TBI improved histopathological outcomes and reduced neurological deficits. Investigative studies have also reported that reductions in post-traumatic temperature attenuated multiple secondary injury mechanisms including excitotoxicity, free radical generation, apoptotic cell death, and inflammation. In addition, while elevations in post-traumatic temperature heightened secondary injury mechanisms, the successful implementation of TTM strategies in injured patients to reduce fever burden appear to be beneficial. While TH has been successfully tested in a number of single institutional clinical TBI studies, larger randomized multicenter trials have failed to demonstrate the benefits of therapeutic hypothermia. The use of TH and TTM for treating TBI continues to evolve and a number of factors including patient selection and the timing of the TH appear to be critical in successful trial design. Based on available data, it is apparent that TH and TTM strategies for treating severely injured patients is an important therapeutic consideration that requires more basic and clinical research. Current research involves the evaluation of alternative cooling strategies including pharmacologically-induced hypothermia and the combination of TH or TTM approaches with more selective neuroprotective or reparative treatments. This manuscript summarizes the preclinical and clinical literature emphasizing the importance of brain temperature in modifying secondary injury mechanisms and in improving traumatic outcomes in severely injured patients. This article is part of a Special Issue entitled SI:Brain injury and recovery.