Clinical paperCooling methods of targeted temperature management and neurological recovery after out-of-hospital cardiac arrest: A nationwide multicenter multi-level analysis☆
Introduction
Severe neurologic injury after cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA) patients has been known to be the most common cause of death [1]. The formation of free radicals and other mediators in the reperfusion phase can cause a neurologic injury cascade [2]. Although several randomized controlled trials attempted and failed to show significant improvement by specific medical interventions [[3], [4], [5]], targeted temperature management (TTM) has shown improvement in outcomes as a neuroprotective treatment in post-resuscitation care [[6], [7]].
The potential mechanisms of TTM that improve neurologic outcomes are as follows: a lower cerebral metabolic rate for oxygen, suppression of the chemical reaction associated with reperfusion injury, or activation of anti-apoptotic mechanisms via cooling or control of the temperature using specific methods [[8], [9]]. Those TTM methods were divided into the following four main categories according to the approach to cooling: 1) external conventional cooling (ECC), 2) external device cooling (EDC), 3) intravascular cooling (IVC), and 4) intracavitary (ICC) cooling [10]. ECC, such as crushed ice or an ice bag, have the disadvantage of unintentional cooling below the target temperature, which can have deleterious effects and is less effective in maintaining temperature [[11], [12]]. Maintenance of temperature is difficult and shivering is more common in this method of cooling. [13]. Although IVC showed a similar effect on outcome compared to EDC [[14], [15], [16], [17]], adverse events can occur, such as a catheter-related bloodstream infection, venous thrombosis, and vascular procedure-related complications [[16], [18]]. IVC and EDC methods incorporate more advanced technology and provide easy operation for maintaining temperature; however, these methods are more expensive than conventional cooling methods such as ECC or ICC.
Few studies have compared the effects of the four different types of cooling methods on outcomes. We hypothesized that the cooling methods for TTM are associated with outcomes after OHCA. This study aimed to compare the effect among the four cooling method groups for TTM on neurological outcomes after OHCA.
Section snippets
Methods
The study was approved by the Institutional Review Board at the research site, and the Korea Center for Disease Control and Prevention (CDC) approved the use of the data in this study.
Study design and setting
The study is a cross-sectional analysis using a nationwide OHCA registry. The study was performed in Korea, which has a population of 50 million people. Single-tiered and government-based emergency medical services (basic-to-intermediate level) are supported by 17 provincial fire departments with a total of 1400 ambulance stations. Emergency medical technicians provide basic life support and the use of an automatic defibrillator for OHCA patients in the field and transport all patients to the
Demographic findings
From the 4886 eligible OHCA patients who received TTM, the following patients were excluded: patients younger than 18 years of age at the time of cardiac arrest (N = 109), patients with traumatic cause of arrest (N = 134), and patients with unknown cooling method (N = 397). The remaining 4246 patients were included in the final analysis. (Fig. 1) The total number of TTMs decreased, but the number of EDCs increased and was relatively larger than the number of ECCs, IVCs, and ICCs. (Fig. 2)
Of the
Discussion
The study found that there were no significant differences in neurological recovery after OHCA by three TTM cooling methods (ECC, EDC, and IVC) except only intracavitary cooling method in entire patient dataset. The findings were consistent in the subgroups that had information for propensity score-matched samples that were extracted to be comparable for risk factors between cooling methods.
The cooling methods showed similar clinical outcomes, although the cooling methods were very different in
Conclusion
In this study, using multilevel analysis of the OHCA database population, there was no significant difference in good neurologic recovery among the four cooling methods (external device cooling, intravascular device cooling, intracavitary cooling compared to external conventional cooling). Individual comparisons between the two TTM methods using propensity score matched samples showed poor neurological recovery from external device cooling (rather than external conventional cooling) and poor
Conflict of interest
There are no conflicts of interest for all authors in this study.
Acknowledgments
The study was funded by the Korea Centers for Disease Control and Prevention (CDC). The Korea CDC and National Emergency Management Agency (national fire department) have been collaborating to collect OHCA data.
References (27)
- et al.
Therapeutic hypothermia after cardiac arrest: a retrospective comparison of surface and endovascular cooling techniques
Resuscitation
(2010) - et al.
Endovascular cooling catheter related thrombosis in patients undergoing therapeutic hypothermia for out of hospital cardiac arrest
Resuscitation
(2014) - et al.
The impact of downtime on neurologic intact survival in patients with targeted temperature management after out-of-hospital cardiac arrest: national multicenter cohort study
Resuscitation
(2016) - et al.
The impact of hospital experience with out-of-hospital cardiac arrest patients on post cardiac arrest care
Resuscitation
(2017) - et al.
Impact of case volume on outcome and performance of targeted temperature management in out-of-hospital cardiac arrest survivors
Am J Emerg Med
(2015) - et al.
Effect of therapeutic hypothermia on the outcomes after out-of-hospital cardiac arrest according to initial ECG rhythm and witnessed status: a nationwide observational interaction analysis
Resuscitation
(2016) - et al.
Interaction effects between hypothermia and diabetes mellitus on survival outcomes after out-of-hospital cardiac arrest
Resuscitation
(2015) - et al.
Mode of death after admission to an intensive care unit following cardiac arrest
Intensive Care Med
(2004) Postresuscitation disease
Crit Care Med
(1988)Randomized clinical study of thiopental loading in comatose survivors of cardiac arrest. Brain resuscitation clinical trial I study group
N Engl J Med
(1986)
A randomized clinical study of a calcium-entry blocker (lidoflazine) in the treatment of comatose survivors of cardiac arrest. Brain resuscitation clinical trial II study group
N Engl J Med
Nimodipine after resuscitation from out-of-hospital ventricular fibrillation A placebo-controlled, double-blind, randomized trial
JAMA
Targeted temperature management at 33 degrees C versus 36 degrees C after cardiac arrest
N Engl J Med
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Optimal temperature in targeted temperature management without automated devices using a feedback system: A multicenter study
2022, American Journal of Emergency MedicineCitation Excerpt :In this study, 16.7% of post-cardiac arrest patients received TTM without temperature feedback devices. Commercial surface cooling or intravascular temperature management equipment and automated thermostat systems are often costly and not fully covered by health insurance programs [9]. Moreover, the high density of post-cardiac arrest patients in a few advanced hospitals results in the shortage of TTM equipment, and the demand for technologically sophisticated devices for TTM often exceeds their availability [11,12].
Management of temperature control in post-cardiac arrest care: an expert report
2021, Medicina IntensivaEnd stage renal disease modifies the effect of targeted temperature management after out-of-hospital cardiac arrest
2020, American Journal of Emergency MedicineEffects of moderate hypothermia versus normothermia on survival outcomes according to the initial body temperature in out-of-hospital cardiac patients: A nationwide observational study
2020, ResuscitationCitation Excerpt :Data on level of ED and post-resuscitation care, including percutaneous coronary intervention and extracorporeal membrane oxygenation,23 were also collected. The cooling methods of TTM were categorised into four types as follows: (1) existing conventional cooling: use of a cooling blanket, a water jet pan, or an underarm ice pack; (2) external device cooling: use of a specific device such as Arctic Sun® (Medivance Corp, Louisville, KY, USA), Gaymar (Gaymar Industries, Orchard Park, NY, USA), Blanketrol® III (Cincinnati Sub-Zero Products, Cincinnati, OH, USA), or emcools Flex.Pad™ (EMCOOLS, Traiskirchen, Austria); (3) intravascular cooling: inserting an intravascular catheter into a large blood vessel; and (4) intracavitary cooling: stomach cooling using a nasogastric tube, bladder cooling using a Foley catheter, and cavitary cooling by inserting a percutaneous catheter into the abdominal cavity or pleural cavity.24,25 Time from ED arrival to TTM initiation, time from TTM initiation to target temperature, time from target temperature to TTM termination, and time from ED arrival to TTM termination were also collected.
Efficacy of the cooling method for targeted temperature management in post-cardiac arrest patients: A systematic review and meta-analysis
2020, ResuscitationCitation Excerpt :The full-text articles of these 45 studies were then retrieved. We excluded 36 studies for irrelevant population (n = 13), irrelevant control group (n = 10), irrelevant outcome measure (n = 7), data duplicated from the same studies (n = 2), and case reports (n = 4), leaving 9 studies (4,401 patients) for inclusion in the final meta-analysis.1,8,10,16–21 Of 9 studies, there were 2 RCT and 7 OS, and the main attributes are summarised in Table 1.
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A Spanish translated version of the abstract of this article appears as Appendix in the final online version at https://doi.org/10.1016/j.resuscitation.2018.01.043.