Prehospital Hypothermia Research Articles

Early withdrawal of life-sustaining treatments after out-of-hospital cardiac arrest: a sub-analysis of a randomized trial of prehospital hypothermia (S17.005)

Early withdrawal of life-sustaining treatments after out-of-hospital cardiac arrest: a sub-analysis of a randomized trial of prehospital hypothermia (S17.005)

Predictors of poor outcome after extra-corporeal membrane oxygenation for refractory cardiac arrest (ECPR): A post hoc analysis of a multicenter database

BackgroundThe objective was to assess predictors for unfavorable neurological outcome (UO) in out-of-hospital (OHCA) and in-hospital (IHCA) cardiac arrest patients treated with Extracorporeal cardiopulmonary resuscitation (ECPR). MethodsA post hoc analysis of retrospective data from five European ECPR centers (January 2012–December 2016) was performed. The primary composite endpoint was 3-month UO defined as survival with a cerebral performance category (CPC) of 3–4 or death (CPC 5). ResultsA total of 413 patients treated with ECPR were included (median age was 57 [48–65] years, male gender 78%): 61% of patients (n = 250) suffered OHCA. The median time from collapse to ECMO placement was 63 [45–82] minutes. Overall, 81% patients (n = 333) showed unfavorable UO, which was higher in OHCA patients (90% vs 66%), as compared to IHCA. In OHCA, prolonged time from collapse to ECMO initiation (OR 1.02, p < 0.01) and higher ECMO blood flow (OR 1.99, p = 0.01) were associated with UO while initial shockable rhythm (OR 0.04, p < 0.01), previous heart disease (OR 0.20, p < 0.01) and pre-hospital hypothermia (OR 0.08, p < 0.01) had a protective role. In IHCA, prolonged time from arrest to ECMO implantation (OR 1.02, p = 0.03), high lactate level on admission (OR 1.15, p < 0.01) and higher body weight (OR 1.03, p < 0.01) were independently associated with UO. ConclusionsIHCA and OHCA patients receiving ECPR have different predictors of UO at presentation, suggesting that selection criteria for ECPR should be decided according to the location of CA. After ECMO initiation, ECMO blood flow management and mean arterial pressure targets might also impact neurological recovery.

Trauma Prehospital Hypothermia Prevention and Treatment: An Observational Study.

Hypothermia in trauma patients causes increased morbidity and mortality. Swift recognition and treatment are important to prevent any further heat loss. In addition, patient discomfort from cold decreases satisfaction with care. The administration of active and passive rewarming measures is important in the prevention and treatment of hypothermia, but their use in prehospital trauma patients in Portugal has not been previously reported. To assess the prevalence of hypothermia, the impact of rewarming measures, and the management of the discomfort caused by cold. This is a prospective cohort study conducted in Immediate Life Support Ambulances in Portugal between March 1, 2019, and April 30, 2020. This study included records of 586 trauma patients; of whom, 66.2% were men. Cranioencephalic trauma was the most common trauma observed, followed by lower limb and thoracic traumas. Mean body temperature increased 0.12 °C between the first and last assessments (p < .05). Most patients experiencing a level of discomfort of 5 or more on a 0-10 scale reported improvement (from 17.2% to 2.4% after nurses' intervention). Warmed intravenous fluids proved to be effective (p < .05) in increasing body temperature, and passive rewarming measures were effective in preventing hypothermia. Hypothermia management has to consider the initial temperature, the season, the available rewarming measures, and the objectives to be achieved. The optimization of resources for the monitoring and treatment of hypothermia should be a priority in prehospital assistance. The implementation of rewarming measures improves patients' outcomes and decreases the discomfort caused by cold in prehospital care.

Heating Intravenous Fluid Tubing in an Experimental Setting for Prehospital Hypothermia

ObjectiveHypothermia secondary to environmental exposure is a serious condition. Active external warming measures to treat it may prove challenging in the prehospital setting. We conducted an experimental study to measure the ability of commercially available heating elements to warm intravenous (IV) fluids during infusion. Methods250-milliliter bags of dextrose 10% solution were suspended inside a refrigerator. IV tubing was coiled, and the tubing output was placed inside a thermally insulated cup. The tubing was heated directly with a hand warmer, a meals ready-to-eat heater, or a heating blanket. Fluids were run through the IV line. The temperature of the fluid at the tubing output was measured. The initial and final infusion temperatures for the methods were compared. ResultsThe use of hand warmers, meals ready-to-eat heaters, and heating blankets to warm IV tubing did increase the temperature of the fluids but was ineffective at achieving the desired mean infusion temperature of 35°C to 42°C. ConclusionAlthough the mean temperature increase did not meet the established experimental threshold, further research is needed to determine whether the fluid warming effect of these commercial heating elements used in the prehospital environment is significant enough to limit heat loss while repleting the dextrose of a hypothermic, hypoglycemic patient.

Pre-hospital hypothermia is associated with transfusion risk after traumatic injury.

In traumatically injured patients, excessive blood loss necessitating the transfusion of red blood cell (RBC) units is common. Indicators of early RBC transfusion in the pre-hospital setting are needed. This study aims to evaluate the association between hypothermia (<36°C) and transfusion risk within the first 24 hours after arrival to hospital for a traumatic injury. We completed an audit of all traumatically injured patients who had emergent surgery at a single tertiary care center between 2010 and 2014. Using multivariable logistic regression analysis, we evaluated the association between pre-hospital hypothermia and transfusion of ≥1 unit of RBC within 24 hours of arrival to the trauma bay. Of the 703 patients included to evaluate the association between hypothermia and RBC transfusion, 203 patients (29%) required a transfusion within 24 hours. After controlling for important confounding variables, including age, sex, coagulopathy (platelets and INR), hemoglobin, and vital signs (blood pressure and heart rate), hypothermia was associated with a 68% increased odds of transfusion in multivariable analysis (OR: 1.68; 95% CI: 1.11-2.56). Hypothermia is strongly associated with RBC transfusion in a cohort of trauma patients requiring emergent surgery. This finding highlights the importance of early measures of temperature after traumatic injury and the need for intervention trials to determine if strategies to mitigate the risk of hypothermia will decrease the risk of transfusion and other morbidities.

Managing accidental hypothermia: a UK-wide survey of prehospital and search and rescue providers

AimThe management of hypothermic casualties is a challenge faced by all prehospital and search and rescue (SAR) teams. It is not known how the practice of these diverse teams compare....

Targeted Temperature Management After Cardiac Arrest: Systematic Review and Meta-analyses.

Targeted temperature management (TTM) with therapeutic hypothermia is an integral component of postarrest care for survivors. However, recent randomized controlled trials (RCTs) have failed to demonstrate the benefit of TTM on clinical outcomes. We sought to determine if the pooled data from available RCTs support the use of prehospital and/or in-hospital TTM after cardiac arrest. A comprehensive search of SCOPUS, Elsevier's abstract and citation database of peer-reviewed literature, from 1966 to November 2016 was performed using predefined criteria. Therapeutic hypothermia was defined as any strategy that aimed to cool post-cardiac arrest survivors to a temperature ≤34°C. Normothermia was temperature of ≥36°C. We compared mortality and neurologic outcomes in patients by categorizing the studies into 2 groups: (1) hypothermia versus normothermia and (2) prehospital hypothermia versus in-hospital hypothermia using standard meta-analytic methods. A random effects modeling was utilized to estimate comparative risk ratios (RR) and 95% confidence intervals (CIs). The hypothermia and normothermia strategies were compared in 5 RCTs with 1389 patients, whereas prehospital hypothermia and in-hospital hypothermia were compared in 6 RCTs with 3393 patients. We observed no difference in mortality (RR, 0.88; 95% CI, 0.73-1.05) or neurologic outcomes (RR, 1.26; 95% CI, 0.92-1.72) between the hypothermia and normothermia strategies. Similarly, no difference was observed in mortality (RR, 1.00; 95% CI, 0.97-1.03) or neurologic outcome (RR, 0.96; 95% CI, 0.85-1.08) between the prehospital hypothermia versus in-hospital hypothermia strategies. Our results suggest that TTM with therapeutic hypothermia may not improve mortality or neurologic outcomes in postarrest survivors. Using therapeutic hypothermia as a standard of care strategy of postarrest care in survivors may need to be reevaluated.

Impact of Prehospital Hypothermia on the Outcomes of Severely Burned Patients.

When treating burn injuries, to date, there still remains significant disagreement whether presence of hypothermia (HT) on burn centers' intensive care unit (BICU) admission improves or worsens outcomes. The presented single burn center experiences set out to further evaluate the incidence, cause, and potential effects of HT on outcomes in severely burned patients. Between January 2015 and February 2017, 142 severely burned patients were admitted to a BICU. Temperature at BICU admission of <36.0°C was defined as HT and ≥36.0°C as normothermia (NT). The cases were divided into two groups: HT vs NT. Fifty-four patients met inclusion criteria and were analyzed retrospectively regarding encountered complications, time of hospitalization, and overall survival. The overall incidence of HT on arrival was 62.9%. Mean duration from burn accident to BICU admission did not differ significantly, but the groups showed significant differences regarding total body surface area (TBSA; P < .05). Both groups showed a similar distribution, regarding number of surgeries, duration until first burn excision, length of ventilation, and mortality rate of patients (P > .05). However, time until death was significantly shorter in the HT group. HT at admission remains a common problem following burn injury. Main risk factors include inappropriate temperature management after injury and during transport, extent of TBSA burn, and quantity of resuscitation. Given the high incidence, the involved health care and, especially, also prehospital providers should be further educated about existing recommendations and guidelines to prevent HT.

The use of bubble wrap for the management of pre-hospital hypothermia

The use of bubble wrap for the management of pre-hospital hypothermia

Do emergency services focus enough on pre-hospital hypothermia management?

Do emergency services focus enough on pre-hospital hypothermia management?

Cooling techniques in mild hypothermia after cardiac arrest.

: Therapeutic hypothermia has been shown to reduce brain damage due to postcardiac arrest syndrome. Actually, there is no agreement on which is the best device to perform therapeutic hypothermia. The 'ideal' device should not only 'cool' patient until 33-34°C as fast as possible, but also maintain the target temperature and reverse the therapeutic hypothermia. For out-of-hospital cardiac arrest, there are devices that allow starting of therapeutic hypothermia on the field (prehospital hypothermia). On hospital arrival, these prehospital devices can be quickly and easily replaced with other devices more suitable for the management of therapeutic hypothermia in ICUs (in-hospital hypothermia). Some studies have compared surface and endovascular devices and found no substantial differences in neurologic outcome or survival at hospital discharge. On a clinical ground, the knowledge of the technical aspects of therapeutic hypothermia (such as characteristics of devices) is mandatory for clinicians who have to perform therapeutic hypothermia in cardiac arrest patients because the timing of therapeutic hypothermia, the choice of the device for the single patients, and avoidance of temperature fluctuation have shown to affect outcome in these patients (also in terms of reducing the incidence of complications).

Therapeutic Hypothermia for Patients with Out-of-Hospital Cardiac Arrest in North Carolina

Introduction: While therapeutic hypothermia has been the standard of care for patients who suffer out-of-hospital cardiac arrest (OHCA), recent trials have led to an advisory statement recommending a focus on targeted in-hospital temperature management and against initiation of prehospital hypothermia with rapid infusion of cooled saline. The aim of this study is to review the experience with therapeutic hypothermia in North Carolina. Methods: We studied patients who suffered OHCA in North Carolina in 2012 captured in the CARES database as part of the Heart Rescue Project. We excluded patients without return of spontaneous circulation and patients without an advanced airway placed in the field to reduce selection bias. Bivariate distributions and multivariate logistic regression models were used to examine differences in survival to discharge and positive neurological outcome. Results: 847 patients were included in the analysis of pre-hospital hypothermia. Of these patients, 55% received prehospital hypothermia. Prehospital initiation of hypothermia was associated with higher survival to hospital discharge (OR 1.55, 95% CI 1.03–2.32) and improved neurologic outcome at discharge (OR 1.56 95% CI 1.01–2.40). In patients who survived to hospital admission (n = 537), in-hospital hypothermia was associated with a non-significant trend toward better survival to discharge (p = 0.18). Conclusion: We found that patients who received prehospital hypothermia had improved outcomes, a finding that may be due to a greater likelihood of receiving in-hospital hypothermia or a reflection of higher quality of pre-hospital care. These findings support ongoing efforts to improve all aspects of the chain of survival after cardiac arrest.

Effects of prehospital hypothermia on transfusion requirements and outcomes: a retrospective observatory trial

ObjectivesPrehospital hypothermia is defined as a core temperature <36.0°C and has been shown to be an independent risk factor for early death in patients with trauma. In a retrospective study,...

Prehospital hypothermia is associated with increased mortality

Trauma is leading cause of death among people under the age of 40.[1] Accidental hypothermia, acidosis, and coagulopathy represent the lethal triad in severely injured patients. [2] There is good evidence that unintended hypothermia worsens outcomes after major trauma.[3] We aimed to audit the frequency of hypothermia among seriously injured patients presenting to a UK major trauma centre.

Effect of prehospital induction of mild hypothermia on 3-month neurological status and 1-year survival among adults with cardiac arrest: long-term follow-up of a randomized, clinical trial.

BackgroundRandomized trials of prehospital cooling after cardiac arrest have shown that neither prehospital cooling nor targeted temperature management differentially affected short‐term survival or neurological function. In this follow‐up study, we assess the association of prehospital hypothermia with neurological function at least 3 months after cardiac arrest and survival 1 year after cardiac arrest.Methods and ResultsThere were 508 individuals who were discharged alive from hospitals in King County, Washington; 373 (73%) were interviewed by telephone 123±43 days after the initial event. Overall, 59% of the treatment group and 58% of the control group had Cerebral Performance Category (CPC) 1 or 2 (P=0.70), and 50% of the treatment group and 49% of the control group had slight disability or better by the Modified Rankin Scale (MRS; (P=0.35). One‐year survival was 87% in the treatment group and 84% in the control group (P=0.42). Of those with CPC 1 at hospital discharge, 68% had CPC 1 or 2 at follow‐up, and 59% had MRS of slight disability or better. Of 41 patients with CPC 3 or 4 at discharge, only 12% had CPC 2 at follow‐up, and just 5% had MRS of slight disability or better. One‐year survival was 92% for CPC 1 at discharge, but only 40% for CPC 4.ConclusionIn addition to excellent survival, patients who had good neurological function at discharge continued to have good function at least 3 months after the event.Clinical Trial RegistrationURL: Clinicaltrials.gov. Unique identifier: NCT00391469

Abstract 19708: Pre-Hospital Initiation of Therapeutic Hypothermia Associated With Better Survival and Neurologic Outcome in a Broad Population of Patients in North Carolina

Introduction: Out-of-hospital cardiac arrest (OHCA) has less than 10% hospital survival. While therapeutic hypothermia resulted in a 16%-24% improvement in neurologic outcome in patients with ventricular fibrillation (VF) in prior trials, recent trials have not shown benefit of pre-hospital initiation hypothermia or of hospital cooling to 33 vs 36 degrees. Methods: We studied patients who suffered OHCA in North Carolina from 2012-2013 captured in the CARES database as part of the Heart Rescue Project. To limit selection bias, we excluded patients without return of spontaneous circulation after arrest and without intubation in the field as they may have regained consciousness. Results: 847 patients were included in the analysis of pre-hospital hypothermia. The patients that received pre-hospital hypothermia had more bystander initiated CPR (p-value &lt; 0.45). Pre-hospital hypothermia was associated with a significant increase in survival to hospital discharge (OR 1.55, 95% CI 1.03-2.32) and neurologic outcome at discharge (OR 1.56 95% CI 1.01-2.40). When looking at arrest types, the significant association was seen after VF arrest (figure). 537 patients survived to hospital admission and included in the analysis of in-hospital hypothermia. Patients who received hospital hypothermia were younger, had more VF, more witnessed arrest and more pre-hospital hypothermia. Hypothermia showed a non-significant trend toward better survival to discharge. Conclusions: The association between pre-hospital hypothermia after VF arrest and improved survival, in light of randomized data showing no effect, may be due to confounding or to a greater likelihood of in-hospital hypothermia in this group. The trend in better outcome using in-hospital hypothermia is consistent with a benefit from temperature management. These findings suggest the need for ongoing efforts to understand the value of hypothermia in context of other efforts to improve survival from cardiac arrest.

Early neuroprotection after cardiac arrest

Many efforts have been made in the last decades to improve outcome in patients who are successfully resuscitated from sudden cardiac arrest. Despite some advances, postanoxic encephalopathy remains the most common cause of death among those patients and several investigations have focused on early neuroprotection in this setting. Therapeutic hypothermia is the only strategy able to provide effective neuroprotection in clinical practice. Experimental studies showed that therapeutic hypothermia was even more effective when it was started immediately after the ischemic event. In human studies, the use of prehospital hypothermia was able to reduce the time to target temperature but did not result in higher survival rate or neurological recovery in patients with out-of-hospital cardiac arrest, when compared with standard in-hospital therapeutic hypothermia. Thus, intra-arrest hypothermia (i.e., initiated during cardiopulmonary resuscitation) may be a valid alternative to improve the effectiveness of therapeutic hypothermia in this setting; however, more clinical data are needed to demonstrate any potential benefit of such intervention on neurological outcome. Together with cooling, early hemodynamic optimization should be considered to improve cerebral perfusion in cardiac arrest patients and minimize any secondary brain injury. Nevertheless, only scarce data are available on the impact of early hemodynamic optimization on the development of organ dysfunction and neurological recovery in such patients. Some new protective strategies, including inhaled gases (i.e., xenon, argon, nitric oxide) and intravenous drugs (i.e., erythropoietin) are emerging in experimental studies as promising tools to improve neuroprotection, especially when combined with therapeutic hypothermia. Early cooling may contribute to enhance neuroprotection after cardiac arrest. Hemodynamic optimization is mandatory to avoid cerebral hypoperfusion in this setting. The combination of such interventions with other promising neuroprotective strategies should be evaluated in future large clinical studies.

Pre-hospital and initial management of head injury patients: An update

Background:Most of the bad outcomes in patients with severe traumatic brain injury (TBI) are related to the presence of a high incidence of pre-hospital secondary brain insults. Therefore, knowledge of these variables and timely management of the disease at the pre-hospital period can significantly improve the outcome and decrease the mortality. The Brain Trauma Foundation guideline on “Prehospital Management” published in 2008 could provide the standardized protocols for the management of patients with TBI; however, this guideline has included the relevant papers up to 2006.Methods:A PubMed search for relevant clinical trials and reviews (from 1 January 2007 to 31 March 2013), which specifically discussed about the topic, was conducted.Results:Based on the evidence, majority of the management strategies comprise of rapid correction of hypoxemia and hypotension, the two most important predictors for mortality. However, there is still a need to define the goals for the management of hypotension and inclusion of newer difficult airway carts as well as proper monitoring devices for ensuring better intubation and ventilatory management. Isotonic saline should be used as the first choice for fluid resuscitation. The pre-hospital hypothermia has more adverse effects; therefore, this should be avoided.Conclusion:Most of the management trials published after 2007 have focused mainly on the treatment as well as the prevention strategies for secondary brain injury. The results of these trials would be certainly adopted by new standardized guidelines and therefore may have a substantial impact on the pre-hospital management in patients with TBI.

Impact of prehospital hypothermia on transfusion requirements and outcomes

Prehospital hypothermia (PH) is known to increase mortality following traumatic injury. PH relationship with transfusion requirements has not been documented. The purpose of this investigation was to analyze the impact of PH on blood product requirements and subsequent outcomes. The Los Angeles County Trauma System Database was queried for all patients admitted between 2005 and 2009. Demographics, physiologic parameters, and transfusion requirements were obtained and dichotomized by admission temperatures with a core temperature of less than 36.5 °C considered hypothermic. Multivariate analysis was performed to determine factors contributing to transfusion requirements and to derive adjusted odds ratios (AORs) for mortality and rates of adult respiratory distress syndrome and pneumonia. A total of 21,023 patients were analyzed in our study with 44.6% presenting with PH. Hypothermic patients required 26% more fluid resuscitation (p < 0.001) in the emergency department and 17% more total blood products (p < 0.001) than those who were admitted with a normal temperature. There was a trend toward an increase in emergency department transfusion (8%, p = 0.06). PH was independently associated with the need for a transfusion (AOR, 1.1; p = 0.047), increased mortality (AOR, 2.0; p < 0.01), as well as incidence of adult respiratory distress syndrome (AOR, 1.8; p < 0.05) and pneumonia (AOR, 2.6; p < 0.01). PH is associated with increased transfusion and fluid requirements and subsequently worse outcomes. Interventions that correct hypothermia may decrease transfusion requirements and improve outcomes. Prospective studies investigating correction of hypothermia in trauma patients are warranted. Prognostic/epidemiologic study, level III.

Abstract 289: Continuum of Care of Prehospital to Hospital Hypothermia Therapy, Outcomes in a Large Prehospital System in Conjunction With a Major Metropolitan Hospital.

Introduction: Hypothermia in patients after Return of Spontaneous Circulation (R.O.S.C.) was recommended in the 2005 American College of Cardiology/American Heart Association Guidelines. Prehospital use of cold saline (32-34°c) and ice packs to the proximal extremities, has been used for patients with R.O.S.C.. In hospital use of intravascular cooling and heart catheterization yield the best neurological and cardiac outcomes as recommended by the A.C.C./A.H.A. 2008 guidelines. METHODS: A retrospective chart review was conducted spanning 3/2009 to 9/2010. Including prehospital run sheets and hospital records. Prehospital provider protocols for 968 paramedics (11 municipalities) were modified to allow the providers to place ice packs at the proximal extremities and to start iced saline I.V. (temp 32-34°c) for victims of cardiorespiratory arrest with R.O.S.C. On arrival to the hospital the cardiologist and the emergency physicians started internal cooling of these patients. The cardiologist and the catheterization team diagnosed and treated preexisting coronary disease in the catheterization laboratory. Cooling was continued for twenty four hours. The patients were then evaluated to determine their level of neurological function prior to discharge. Results: 31 patients were brought in by paramedics after starting the prehospital hypothermia protocol, after R.O.S.C. 26 men and 5 women. All patients were admitted through the emergency department to the heart catheterization laboratory where central cooling was started and coronary angiography was performed, with angioplasty and stenting was done when indicated. Cooling was at 32°c and was maintained for 24 hours. 13/31 patients expired prior to discharge (42%) from the hospital. 5/31 patients were transferred for hospice care or to long term-care facilities (16%). 12/31 patients left the hospital neurologically intact (39%). Conclusion: The sequential use of prehospital cooling and inhospital intravascular cooling for victims of cardiorespiratory arrest with R.O.S.C. is feasible, safe and effective. Our results for neurologically intact hospital discharges of 39%, is higher than that reported by prior investigators.