Hypothermia In Cardiac Arrest Survivors Research Articles

Náš článek po 10 letech: The practice of therapeutic mild hypothermia in cardiac arrest survivors in the Czech Republic

V roce 2010 byly v casopise Minerva Anestesiologica publikovany výsledky narodniho dotaznikoveho průzkumu o použivani terapeuticke mirne hypotermie u pacientů uspěsně resuscitovaných pro nahlou zastavu oběhu na jednotkach intenzivni pece v Ceske republice. Tento clanek reflektuje výsledky prace v kontextu znalosti v době publikace a z pohledu soucasneho poznani.

P1708Therapeutic hypothermia in cardiac arrest survivors with pre-existing heart failure is nephroprotective

Abstract Introduction The impact of therapeutic hypothermia on kidneys in cardiac arrest survivors with known congestive heart failure (CHF) is not known. Weak evidence suggests higher risk of acute kidney injury with hypothermia. Purpose The effect of hypothermia on organ function in cardiac arrest patients with preexisting CHF Methods This analysis includes 1417 comatose cardiac arrest survivors that achieved achieved return of spontaneous circulation on hospitalization and had a previous left ventricular ejection fraction (LVEF) assessment within last 1 year. Detailed chart review of these patients was performed. CHF was defined as either prior episode of congestive heart failure or presence of LVEF <50%. Odds ratio (OR) and 95% confidence intervals (CI) for association of hypothermia and acute kidney injury as well as hemodialysis at discharge among patients with and without CHF were computed using multivariable adjusted logistic regression. Results Overall, 1417 cardiac arrest patients (mean age 62.5±14.6 years, 60.2% males, 67.2% white and 29.7% black) were included in this analysis, out of which 467 (33.0%) were treated with therapeutic hypothermia and known CHF was present in 624 (44%). AKI developed in 25.2% of CHF patients that were not treated with hypothermia while, only in 18.0% among CHF patients treated with hypothermia (OR 0.56; 95% CI 0.32–0.96, p=0.03). There was an decrease in trend of requiring hemodialysis at discharge among CHF patients treated with hypothermia compared with CHF patients that were not treated with hypothermia (8.1% vs. 19.62%, p=0.019) among CHF patients not treated with hypothermia. However, there was no significant result. Conclusions Hypothermia is associated with nephroprotective effects among patients with cardiac survivors with pre-existing CHF. Future research is needed to identify subgroups that derive benefit from therapeutic hypothermia after cardiac arrest.

Impact of hypothermia on cardiac performance during targeted temperature management after cardiac arrest

IntroductionTargeted temperature management (TTM) is a well-accepted neuro-protective intervention in the management of comatose survivors of cardiac arrest (CA). However, the impact of TTM on cardiac performance has not been adequately evaluated. MethodsWe reviewed data on consecutive CA survivors undergoing TTM at a quaternary cardiac intensive care unit between January 2015 and June 2017. Enrollment was restricted to cases with invasive hemodynamics (iHDs) at TTM initiation, every 8 h at target temperature (32–34 °C) and at completion of rewarming (>36 °C), unless precluded by mortality. Cardiac index and cardiac index-derived variables were adjusted for a decreased oxygen consumption during hypothermia. We assessed the serial impact of cooling on iHDs and cardiac performance utilizing longitudinal data analysis accounting for the effects of time as surrogate for the expected change from the post arrest syndrome and instituted treatments. A Frank–Starling construct was used to evaluate changes in cardiac contractility. ResultsWe evaluated the effects of cooling on iHDs and cardiac performance in 46 CA survivors. Heart rate decreased with cooling (p < 0.001), to return to baseline after rewarming (p = 0.6). Mean arterial pressure and pulmonary wedge pressure decreased by cooling (p < 0.001 for both), with sustained improvement after rewarming (p < 0.001 for both). Systemic vascular resistance was unaffected by hypothermia (p > 0.05). Left stroke work index increased with cooling (p < 0.001), with return to baseline after rewarming (p = 0.6). Cooling was associated with a left-upward shift in the Frank–Starling curve indicative of increased contractility. ConclusionMild hypothermia in CA survivors appears associated to positive changes in iHDs and cardiac performance, including a potential increase in cardiac contractility. Larger studies are needed to conclusively confirm these findings.

Therapeutic hypothermia in cardiac arrest survivors: is rebound hyperthermia a significant issue with intravascular cooling?

Therapeutic hypothermia in cardiac arrest survivors: is rebound hyperthermia a significant issue with intravascular cooling?

Improving neurological outcome after cardiac arrest: Therapeutic hypothermia the best treatment.

Cardiac arrest, irrespective of its etiology, has a high mortality. This event is often associated with brain anoxia which frequently causes severe neurological damage and persistent vegetative state. Only one out of every six patients survives to discharge following in-hospital cardiac arrest, whereas only 2-9% of patients who experience out of hospital cardiac arrest survive to go home. Functional outcomes of survival are variable, but poor quality survival is common, with only 3-7% able to return to their previous level of functioning. Therapeutic hypothermia is an important tool for the treatment of post-anoxic coma after cardiopulmonary resuscitation. It has been shown to reduce mortality and has improved neurological outcomes after cardiac arrest. Nevertheless, hypothermia is underused in critical care units. This manuscript aims to review the mechanism of hypothermia in cardiac arrest survivors and to propose a simple protocol, feasible to be implemented in any critical care unit.

Abstract 77: Tachycardia During Hypothermia as a Marker of Poor Outcomes in Cardiac Arrest Survivors

Hypothesis: Therapeutic hypothermia in cardiac arrest survivors is typically associated with bradycardia. We investigated clinical and demographic variables and outcomes associated with tachycardia in patients treated with therapeutic hypothermia. Methods: Demographic and clinical data, and ECGs of 26 consecutive cardiac arrest survivors (9 females, 58+/-18 years old, 5 with history diabetes, and 6 with history of coronary artery disease) on admission, during and after therapeutic hypothermia were reviewed. Analyses of variance, chi-square, and logistic regression were used. The study was approved by the IRB. Results: Tachycardia (heart rate &gt; 100 bpm, 81% sinus, no VT-VFib) was observed in 40% of ECG tracings before or during hypothermia or after re-warming. Tachycardia was more common in females (55 vs. 32%, p=0.044), patients with pulmonary disease (39 vs. 13%, p=0.009), or when pre-resuscitation rhythm was PEA (60 vs. 27%, p=0.003) or asystole (23 vs. 15%, p=0.003). Diabetes, myocardial ischemia, LV systolic dysfunction, acute infection, renal insufficiency, treatment with ACE inhibitors or diuretics were not associated with tachycardia. There were multiple biochemical abnormalities associated with tachycardia, including decreased pH (p&lt;0.0001) and decreased hemoglobin (p=0.028), increased glucose (p&lt;0.001), sodium (p=0.078), potassium (p=0.044), or creatinine (p=0.108). Tachycardia was associated with significantly increased hospital mortality (53% vs. 28%, p=0.029), regardless whether it was observed on admission (63 vs. 38%), during hypothermia (67% vs. 33%), or after the re-warming (67 vs. 33%). In multivariate logistic regression analysis only cardiac arrest rhythm (HR of death with PEA-Asystole 11.1, 95%CI 3.2-38.4, p&lt;0.001), but not demographic or biochemical variables or tachycardia (HR 1.7, 95%CI 0.5-5.8, p=0.391) were predictive of mortality. Conclusion: Tachycardia in cardiac arrest survivors undergoing therapeutic hypothermia is a marker of poor prognosis, likely reflective of severe metabolic abnormalities, especially in patients presenting with pulseless electrical activity or asystole. More studies of this important subject are needed.

Nitrotyrosine and Nitrate/Nitrite Levels in Cardiac Arrest Survivors Treated With Endovascular Hypothermia

The protective effect of therapeutic hypothermia in cardiac arrest survivors (CAS) has been previously well documented. Animal studies have indicated that attenuation of tissue oxidative stress (OS) may be involved in the mechanisms that lead to the beneficial effect of hypothermia. The extent of OS and nitric oxide (NO) production in adult CAS treated with endovascular hypothermia is, however, unknown. A total of 11 adult patients who experienced cardiac arrest out of hospital were included in the present study, and all were treated with mild hypothermia using the Thermogard XP (Alsius, USA) endovascular system. A target core temperature of 33 °C was maintained for 24 hours, with a subsequent rewarming rate of 0.15 °C per hour, followed by normothermia at 36.8 °C. Blood samples for the measurement of nitrotyrosine and nitrate/nitrite levels were drawn at admission and every 6 hours thereafter for two days. During the hypothermic period, the levels of nitrotyrosine and nitrates/nitrites were comparable with baseline values. During the rewarming period, serum levels of both parameters gradually increased and, during the normothermic period, the levels were significantly higher compared with hypothermic levels (nitrotyrosine, P<0.001; nitrates/nitrites, P<0.05). In our study, significantly lower levels of nitrotyrosine and nitrates/nitrites were demonstrated during hypothermia compared with levels during the normothermic period in adult CAS. These data suggest that attenuation of OS and NO production may be involved in the protective effect of hypothermia in adult CAS.

Infectious complications in out-of-hospital cardiac arrest patients in the therapeutic hypothermia era*

Infectious complications are frequently reported in critically ill patients, especially after cardiac arrest. Recent and widespread use of therapeutic hypothermia has raised concerns about increased septic complications, but no specific reappraisal has been performed. We investigated the infectious complications in cardiac arrest survivors and assessed their impact on morbidity and long-term outcome. Retrospective review of a prospectively acquired intensive care unit database. A 24-bed medical intensive care unit in a French university hospital. Between March 2004 and March 2008, consecutive patients admitted for management of resuscitated out-of-hospital cardiac arrest were considered. Patients dying within 24 hrs were excluded. All patients' files were reviewed to assess the development of infection. None. Of the 537 patients admitted after cardiac arrest, 421 were included and 281 patients (67%) presented 373 infectious complications. Pneumonia was the most frequent (318 episodes), followed by bloodstream infections (35 episodes) and catheter-related infections (11 episodes). When grouped together, Gram-negative bacteria were the most frequently isolated infectious germs (64%), but the main pathogen detected was Staphylococcus aureus (57 occurrences). Both application itself (83 vs. 73%; p = .02) and duration (1244 vs. 1176 mins; p = .05) of therapeutic hypothermia were significantly more frequent in infected patients. Infection was associated with increased mechanical ventilation duration (6 [2-9] vs. 3 [2-5.5] days; p < .001) and intensive care unit length of stay (7 [4-10] vs. 3 [2-7] days; p < .001). Nonetheless, there was no impact on intensive care unit mortality (174 [62%] vs. 92 [66%] patients; p = .45) or on favorable neurologic outcome (cerebral performance category 1-2, 102 [36%] vs. 47 [34%] patients; p = .58). Infectious complications are frequent after cardiac arrest and may be even more frequent after therapeutic hypothermia. Despite increase in care costs, long-term and clinically relevant outcomes do not seem to be impaired. This should not discourage the use of therapeutic hypothermia in cardiac arrest survivors.

A knowledge translation collaborative to improve the use of therapeutic hypothermia in post-cardiac arrest patients: protocol for a stepped wedge randomized trial

BackgroundAdvances in resuscitation science have dramatically improved survival rates following cardiac arrest. However, about 60% of adults that regain spontaneous circulation die before leaving the hospital. Recently it has been shown that inducing hypothermia in cardiac arrest survivors immediately following their arrival in hospital can dramatically improve both overall survival and neurological outcomes. Despite the strong evidence for its efficacy and the apparent simplicity of this intervention, recent surveys show that therapeutic hypothermia is delivered inconsistently, incompletely, and often with delay.Methods and designThis study will evaluate a multi-faceted knowledge translation strategy designed to increase the utilization rate of induced hypothermia in survivors of cardiac arrest across a network of 37 hospitals in Southwestern Ontario, Canada. The study is designed as a stepped wedge randomized trial lasting two years. Individual hospitals will be randomly assigned to four different wedges that will receive the active knowledge translation strategy according to a sequential rollout over a number of time periods. By the end of the study, all hospitals will have received the intervention. The primary aim is to measure the effectiveness of a multifaceted knowledge translation plan involving education, reminders, and audit-feedback for improving the use of induced hypothermia in survivors of cardiac arrest presenting to the emergency department. The primary outcome is the proportion of eligible OHCA patients that are cooled to a body temperature of 32 to 34°C within six hours of arrival in the hospital. Secondary outcomes will include process of care measures and clinical outcomes.DiscussionInducing hypothermia in cardiac arrest survivors immediately following their arrival to hospital has been shown to dramatically improve both overall survival and neurological outcomes. However, this lifesaving treatment is frequently not applied in practice. If this trial is positive, our results will have broad implications by showing that a knowledge translation strategy shared across a collaborative network of hospitals can increase the number of patients that receive this lifesaving intervention in a timely manner.Trial RegistrationClinicalTrials.gov Trial Identifier: NCT00683683

Transcranial Doppler ultrasound in therapeutic hypothermia for cardiac arrest survivors

Critical Care Medicine: April 2010 - Volume 38 - Issue 4 - p 1230-1231 doi: 10.1097/CCM.0b013e3181d422af

Transcranial Doppler ultrasound in therapeutic hypothermia for cardiac arrest survivors

Hospiten-Rambla Hospital, Unit of Neurosonology and Cerebral Hemodynamics, Santa Cruz de Tenerife, Canary Islands, Spain

Prehospital therapeutic hypothermia for comatose survivors of cardiac arrest: a randomized controlled trial

Intravenous infusion of ice-cold fluid is considered a feasible method to induce mild therapeutic hypothermia in cardiac arrest survivors. However, only one randomized controlled trial evaluating this treatment exists. Furthermore, the implementation rate of prehospital cooling is low. The aim of this study was to evaluate the efficacy and safety of this method in comparison with conventional therapy with spontaneous cooling often observed in prehospital patients. A randomized controlled trial was conducted in a physician-staffed helicopter emergency medical service. After successful initial resuscitation, patients were randomized to receive either +4 degrees C Ringer's solution with a target temperature of 33 degrees C or conventional fluid therapy. As an endpoint, nasopharyngeal temperature was recorded at the time of hospital admission. Out of 44 screened patients, 19 were analysed in the treatment group and 18 in the control group. The two groups were comparable in terms of baseline characteristics. The core temperature was markedly lower in the hypothermia group at the time of hospital admission (34.1+/-0.9 degrees C vs. 35.2+/-0.8 degrees C, P<0.001) after a comparable duration of transportation. Otherwise, there were no significant differences between the groups regarding safety or secondary outcome measures such as neurological outcome and mortality. Spontaneous cooling alone is insufficient to induce therapeutic hypothermia before hospital admission. Infusion of ice-cold fluid after return of spontaneous circulation was found to be well tolerated and effective. This method of cooling should be considered as an important first link in the 'cold chain' of prehospital comatose cardiac arrest survivors.

Hospital-Based Use of Therapeutic Hypothermia after Cardiac Arrest in Adults

Improving survival and brain function after initial resuscitation from cardiac arrest remains a critical challenge with few therapeutic options. The publication of several randomized controlled trials supporting the use of therapeutic hypothermia in cardiac arrest survivors has provided a remarkable opportunity to reduce mortality and neurologic disability from this leading cause of death. On the strength of these trials, therapeutic hypothermia has now been incorporated in the American Heart Association guidelines for post-resuscitation care. This review will focus on the hospital-based application of therapeutic hypothermia in adult cardiac arrest survivors, with special attention to practical aspects of cooling, protocol development, and evaluation of recent data from "real world" experiences using hypothermia as a treatment option. Finally, remaining research questions and directions for future improvements in therapy will be discussed.

Induction of mild hypothermia in cardiac arrest survivors presenting with cardiogenic shock syndrome

Induction of mild hypothermia in cardiac arrest survivors presenting with cardiogenic shock syndrome

The use of induced hypothermia after cardiac arrest: a survey of Canadian emergency physicians

Inducing mild hypothermia in survivors of cardiac arrest has been demonstrated to improve outcomes. Despite this, other studies have found that few resuscitation physicians have used hypothermia in clinical practice. The objective of this study was to characterize the use of induced hypothermia by Canadian emergency physicians. An internet-based survey was distributed to all members of the Canadian Association of Emergency Physicians (CAEP). Participants were asked about their experience with, methods for and barriers to inducing hypothermia. Of the 1328 CAEP members surveyed, 247 (18.6%) responded, with the majority working in academic centres (60.3%). Ninety-five out of 202 respondents (47.0%, 95% confidence interval [CI] 40.8%-53.2%) indicated that they had induced hypothermia in clinical practice and 86 of 212 (40.6%, 95% CI 34.0%-47.2%) worked in a department that had a policy or protocol for the use of induced hypothermia. The presence of a departmental policy or protocol was strongly associated with the use of induced hypothermia (unadjusted odds ratio 10.5, 95% CI 5.3-20.8). Barriers against induced hypothermia cited by respondents included a lack of institutional policies and protocols (38.9%), and of resources (29.4%). Lack of support from consultants was relatively uncommon (8.7%) in Canadian practice. Only one-half of Canadian emergency physicians report that they have used therapeutic hypothermia in practice. Emergency departments should develop policies or protocols for inducing hypothermia in cardiac arrest survivors to optimize patient outcomes.

Induction of mild hypothermia in cardiac arrest survivors presenting with cardiogenic shock syndrome

Induction of mild hypothermia (MH) in patients resuscitated from cardiac arrest improves their outcome. However, benefits and risks of MH in patients who remain in cardiogenic shock after the return of spontaneous circulation (ROSC) are unclear. We analysed all cardiac arrest survivors who were treated with MH in our intensive coronary care unit (CCU) and compared the outcome of patients with cardiogenic shock syndrome (CSS) with those who were circulatory stable. We performed retrospective analysis of all consecutive cardiac arrest survivors treated by MH in our CCU from November 2002 to August 2006. They were classified into two groups, according to whether they met the criteria for cardiogenic shock or not before MH initiation. Out of 56 consecutive patients, 28 fulfilled criteria of cardiogenic shock before MH initiation (group A) and 28 were relatively stable (group B). In-hospital mortality was 57.1% in group A and 21.4% in group B patients (P=0.013). Favourable neurological outcome anytime during hospitalization was found in 67.9% of group A patients and in 82.1% of group B subjects (P=0.355). Favourable discharge neurological outcome was reached in 39.3% in group A and in 71.4% in group B (P=0.031). The complication rate in both groups did not differ. While in-hospital mortality in cardiac arrest survivors treated by MH was expectably higher in those with cardiogenic shock than in stable patients, the favourable neurological outcome during hospitalization was comparable in both groups. Therefore, induction of MH should be considered in cardiac arrest survivors with CSS after ROSC.

Induction of mild hypothermia in cardiac arrest survivors with cardiogenic shock syndrome

Induction of mild hypothermia (MH) in patients resuscitated from cardiac arrest can improve their outcome. However, benefits and risks of MH induction in patients who remain in cardiogenic shock after the return of spontaneous circulation (ROSC) are unclear. We therefore analysed a group of all cardiac arrest survivors who were indicated for MH induction in our coronary care unit (CCU) and compared the outcome of patients with cardiogenic shock syndrome after ROSC with the outcome of those who were relatively haemodynamically stable.

Therapeutic hypothermia after cardiac arrest: Unintentional overcooling is common using ice packs and conventional cooling blankets

Although therapeutic hypothermia for cardiac arrest survivors has been shown to improve neurologically intact survival, optimal methods to ensure controlled induction and maintenance of cooling are not clearly established. Precise temperature control is important to evaluate because unintentional overcooling below the consensus target range of 32-34 degrees C may place the patient at risk for serious complications. We sought to measure the prevalence of overcooling (<32 degrees C) in postarrest survivors receiving primarily noninvasive cooling. Retrospective chart review of postarrest patients. Three large teaching hospitals. Cardiac arrest survivors receiving therapeutic hypothermia. Charts were reviewed if primarily surface cooling was used with a target temperature goal between 32 degrees C and 34 degrees C. Of the 32 cases reviewed, overcooling lasting for >1 hr was identified as follows: 20 of 32 patients (63%) reached temperatures of <32 degrees C, 9 of 32 (28%) reached temperatures of <31 degrees C, and 4 of 32 (13%) reached temperatures of <30 degrees C. Of those with overcooling of <32 degrees C, 6 of 20 (30%) survived to hospital discharge, whereas of those without overcooling, 7 of 12 (58%) survived to hospital discharge (p = not significant). The majority of the cases reviewed demonstrated unintentional overcooling below target temperature. Improved mechanisms for temperature control are required to prevent potentially deleterious complications of more profound hypothermia.

Hypothermia for cardiac arrest

Therapeutic hypothermia for cardiac arrest survivors has emerged as a highly effective means of improving neurologic outcome. There are a number of purported mechanisms by which it is felt to be effective, but the exact mechanism is unknown. This article reviews the biochemical mechanisms of injury occurring in cardiac arrest, as well as the avenues that hypothermia takes to combat this injury. It also reviews the animal model data in support of this, as well as the newer animal studies that may help to improve the field. Several human studies of hypothermia in cardiac arrest have been performed, and this article reviews these for their methods and shortcomings. Our currently recommended guidelines for performing therapeutic hypothermia are presented. With therapeutic hypothermia comes potential risks to the patient, primarily affecting cardiac, metabolic, and hematologic systems, and these risks and their management are discussed. Multiple methods of cooling exist, including selective cranial as well as systemic cooling by internal or external approaches. Finally, the article discusses the current research in the field of hypothermia for cardiac arrest and implications for future practice.