Project description:Traumatic brain injury (TBI) is recognized as the significant cause of mortality and morbidity in the world. To reduce unfavorable outcome in TBI patients, many researches have made much efforts for the innovation of TBI treatment. With the results from several basic and clinical studies, targeted temperature management (TTM) including therapeutic hypothermia (TH) have been recognized as the candidate of neuroprotective treatment. However, their evidences are not yet proven in larger randomized controlled trials (RCTs). The main aim of this review is thus to clarify specific pathophysiology which TTM will be effective in TBI. Historically, there were several clinical trials which compare TH and normothermia. Recently, two RCTs were able to demonstrate the significant beneficial effects of TTM in one specific pathology, patients with mass evacuated lesions. These suggested that TTM might be effective especially for the ischemic-reperfusional pathophysiology of TBI, like as acute subdural hematoma which needs to be evacuated. Also, the latest preliminary report of European multicenter trial suggested the promising efficacy of reduction of intracranial pressure in TBI. Conclusively, TTM is still in the center of neuroprotective treatments in TBI. This therapy is expected to mitigate ischemic and reperfusional pathophysiology and to reduce intracranial pressure in TBI. Further results from ongoing clinical RCTs are waited.
Project description:BackgroundLittle is known about the prevalence of altered CAR in anoxic brain injury and the association with patients' outcome. We aimed at investigating CAR in cardiac arrest survivors treated by targeted temperature management and its association to outcome.MethodsRetrospective analysis of prospectively collected data.Inclusion criteriaadult cardiac arrest survivors treated by targeted temperature management (TTM).Exclusion criteriatrauma; sepsis, intoxication; acute intra-cranial disease; history of supra-aortic vascular disease; severe hemodynamic instability; cardiac output mechanical support; arterial carbon dioxide partial pressure (PaCO2) > 60 mmHg; arrhythmias; lack of acoustic window. Middle cerebral artery flow velocitiy (FV) was assessed by transcranial Doppler (TCD) once during hypothermia (HT) and once during normothermia (NT). FV and blood pressure (BP) were recorded simultaneously and Mxa calculated (MATLAB). Mxa is the Pearson correlation coefficient between FV and BP. Mxa > 0.3 defined altered CAR. Survival was assessed at hospital discharge. Cerebral Performance Category (CPC) 3-5 assessed 3 months after CA defined unfavorable neurological outcome (UO).ResultsWe included 50 patients (Jan 2015-Dec 2018). All patients had out-of-hospital cardiac arrest, 24 (48%) had initial shockable rhythm. Time to return of spontaneous circulation was 20 [10-35] min. HT (core body temperature 33.7 [33.2-34] °C) lasted for 24 [23-28] h, followed by rewarming and NT (core body temperature: 36.9 [36.6-37.4] °C). Thirty-one (62%) patients did not survive at hospital discharge and 36 (72%) had UO. Mxa was lower during HT than during NT (0.33 [0.11-0.58] vs. 0.58 [0.30-0.83]; p = 0.03). During HT, Mxa did not differ between outcome groups. During NT, Mxa was higher in patients with UO than others (0.63 [0.43-0.83] vs. 0.31 [- 0.01-0.67]; p = 0.03). Mxa differed among CPC values at NT (p = 0.03). Specifically, CPC 2 group had lower Mxa than CPC 3 and 5 groups. At multivariate analysis, initial non-shockable rhythm, high Mxa during NT and highly malignant electroencephalography pattern (HMp) were associated with in-hospital mortality; high Mxa during NT and HMp were associated with UO.ConclusionsCAR is frequently altered in cardiac arrest survivors treated by TTM. Altered CAR during normothermia was independently associated with poor outcome.
Project description:Sudden cardiac arrest leads to a significantly increased risk of severe neurological impairment and higher mortality rates in survivors due to global brain tissue injury caused by prolonged whole-body ischemia and reperfusion. The brain undergoes various deleterious cascading events. Among these damaging mechanisms, neuroinflammation plays an especially crucial role in the exacerbation of brain damage. Clinical guidelines indicate that 33 °C and 36 °C are both beneficial for targeted temperature management (TTM) after cardiac arrest. To clarify the mechanistic relationship between TTM and inflammation in transient global ischemia (TGI) and determine whether 36 °C produces a neuroprotective effect comparable to 33 °C, we performed an experiment using a rat model. We found that TTM at 36 °C and at 33 °C attenuated neuronal cell death and apoptosis, with significant improvements in behavioral function that lasted for up to 72 h. TTM at 33 °C and 36 °C suppressed the propagation of inflammation including the release of high mobility group box 1 from damaged cells, the activation and polarization of the microglia, and the excessive release of activated microglia-induced inflammatory cytokines. There were equal neuroprotective effects for TTM at 36 °C and 33 °C. In addition, hypothermic complications and should be considered safe and effective after cardiac arrest.
Project description:Therapeutic hypothermia inhibits organ damage by suppressing metabolism, which makes it a therapy of choice for treating various diseases. Specifically, it is often used to treat conditions involving central nervous system disorders where it is expected to positively impact functional prognosis. Although keeping the body temperature at a hypothermic level has been conventionally used, how to manage the body temperature correctly remains a topic of debate. Recently, the concept of temperature management has been proposed to improve the quality of body temperature control and avoid hyperthermia. This review focuses on the effect of temperature on the central nervous system in conditions involving central nervous system disorders and the practice of temperature management in clinical situations.
Project description:Targeted temperature management (TTM) has been investigated experimentally and used clinically for over 100 years. The initial rationale for the clinical application of TTM, historically referred to as therapeutic hypothermia, was to decrease the metabolic rate, allowing the injured brain time to heal. Subsequent research demonstrated the temperature dependence of diverse cellular mechanisms including endothelial dysfunction, production of reactive oxygen species, and apoptosis. Consequently, modern use of TTM centers on neuroprotection following focal or global neurologic injury. Despite a solid basic science rationale for applying TTM in a variety of disease processes, including cardiac arrest, traumatic brain injury, ischemic stroke, neonatal ischemic encephalopathy, sepsis-induced encephalopathy, and hepatic encephalopathy, human efficacy data are limited and vary greatly from disease to disease. Ten years ago, two landmark investigations yielded high-quality data supporting the application of TTM in comatose survivors of out-of-hospital cardiac arrest. Additionally, TTM has been demonstrated to improve outcomes for neonatal patients with anoxic brain injury secondary to hypoxic ischemic encephalopathy. Trials are currently under way, or have yielded conflicting results in, examining the utility of TTM for the treatment of ischemic stroke, traumatic brain injury, and acute myocardial infarction. In this review, we place TTM in historic context, discuss the pathophysiologic rationale for its use, review the general concept of a TTM protocol for the management of brain injury, address some of the common side effects encountered when lowering human body temperature, and examine the data for its use in diverse disease conditions with in-depth examination of TTM for postarrest care and pediatric applications.
Project description:Although specific temperature targets are debated, targeted temperature management (TTM) is a common treatment for postcardiac arrest patients. However, consistently implementing a TTM protocol is challenging, especially in a community hospital. Often, the protocols described in the literature include labor- and cost-intensive methods that are not feasible or sustainable in many health care settings. Esophageal temperature management (ETM) is a TTM method that can be easily utilized alone or combined with surface methods. We sought to evaluate ETM in a cohort of patients treated with TTM after cardiac arrest. Chart reviews were conducted of all patients treated with ETM after cardiac arrest at our community medical center. Initial patient temperature, time to target, supplemental methods (water blankets, chest wraps, or head wraps), and patient survival were extracted for analysis. A total of 54 patients were treated from August 2016 to November 2018; 30 received ETM only, 22 received supplemental cooling, and 2 had treatment discontinued before reaching target due to recovery. Target temperatures ranged from 32°C to 36°C, depending on provider preference. The median time to target temperature for the entire cohort was 219 minutes (interquartile range [IQR] 81-415). For the cohorts without, and with, supplemental cooling modalities, the median time to attain target temperature was 128 minutes (IQR 71-334), and 285 minutes (IQR 204-660), respectively. Survival to intensive care unit discharge was 51.9% for the entire cohort. Survivors exhibited longer times to achieve goal temperature (median 180 minutes in nonsurvivors vs. 255 minutes in survivors). ETM attains target temperature at a rate consistent with current guidelines and with similar performance to alternative modalities. As in other studies, surviving patients required longer times to reach target temperature.
Project description: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.
Project description: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.
Project description:Evolution toward brain death (BD) in out-of-hospital cardiac arrest patients with targeted temperature management (TTM) provides opportunities for organ donation. However, knowledge regarding BD in these patients is limited. We retrospectively analyzed the TTM registry of one hospital where life-sustaining therapy was not withdrawn. In-hospital death patients were categorized into BD and non-BD groups. We explored the process of evolution toward BD and its predictors by comparing the serial measurements of clinical variables and the results of various prognostic tests between the two groups. Of the 121 patients who died before hospital discharge, 19 patients (15.7%) developed BD at a median of 6 (interquartile range, 5.0-7.0) days after cardiac arrest. Four patients with pupillary light reflexes at 48 h eventually developed BD. The area under the curves of the gray-to-white matter ratio (GWR) on early brain computed tomography images and the level of S100 calcium-binding protein B (S100B) at 72 h were 0.67 (95% CI, 0.55-0.77) and 0.70 (95% CI, 0.55-0.83), respectively. In conclusion, approximately one-sixth of all in-hospital deaths were diagnosed with BD at a median of 6 days after cardiac arrest. The use of GWR and serial S100B measurements may help to screen potential BD.
Project description:ObjectiveTo determine the clinical feasibility of novel serum biomarkers in out-of-hospital cardiac arrest (OHCA) patients treated with target temperature management (TTM).MethodsThis study was a prospective observational study conducted on OHCA patients who underwent TTM. We measured conventional biomarkers, neuron‑specific enolase and S100 calcium-binding protein (S-100B), as well as novel biomarkers, including tau protein, neurofilament light chain (NFL), glial fibrillary acidic protein (GFAP), and ubiquitin C-terminal hydrolase-L1 (UCH-L1), at 0, 24, 48, and 72 h after the return of spontaneous circulation identified by SIMOA immunoassay. The primary outcome was poor neurological outcome at 6 months after OHCA.ResultsA total of 100 patients were included in this study from August 2018 to May 2020. Among the included patients, 46 patients had good neurologic outcomes at 6 months after OHCA. All conventional and novel serum biomarkers had the ability to discriminate between the good and poor neurological outcome groups (p < 0.001). The area under the curves of the novel serum biomarkers were highest at 72 h after cardiac arrest (CA) (0.906 for Tau, 0.946 for NFL, 0.875 for GFAP, and 0.935 for UCH-L1). The NFL at 72 h after CA had the highest sensitivity (77.1%, 95% CI 59.9-89.6) in predicting poor neurological outcomes while maintaining 100% specificity.ConclusionNovel serum biomarkers reliably predicted poor neurological outcomes for patients with OHCA treated with TTM when life-sustaining therapy was not withdrawn. Cutoffs from two large existing studies (TTM and COMACARE substudy) were externally validated in our study. The predictive power of the novel biomarkers was the highest at 72 h after CA.