Clinical paperEarly- versus late-initiation of therapeutic hypothermia after cardiac arrest: Preliminary observations from the experience of 17 Italian intensive care units☆
Introduction
Mild therapeutic hypothermia has been shown to improve the neurologic outcome of patients experiencing return of spontaneous circulation (ROSC) after an episode of cardiac arrest.1, 2 Therapeutic hypothermia is therefore an important and clinically useful measure to implement during the immediate post-resuscitation care period.3, 4
Several laboratory trials have suggested that neurologic outcome might be improved by a rapid initiation of therapeutic cooling5, 6, 7, 8 but, despite the results of several clinical trials, the best timing to start therapeutic hypothermia remains unknown.9, 10, 11, 12
In this observational prospective multicentre study (ICE study), we aimed at investigating, in a population of cardiac arrest patients admitted to several Italian intensive care units after experiencing return of spontaneous circulation, the effects of the timing of initiation of therapeutic hypothermia on both survival and neurologic outcome.
Section snippets
Study design
The ICE (Italian Cooling Experience) study was designed as an observational prospective clinical study. The main aim of the study was to investigate the relationship between the timing of initiation of therapeutic hypothermia (TH) and both patient survival or neurologic outcome.
It was conceived as multicentre study conducted at 17 intensive care units (ICU) in Italy. All patients (not matching exclusion criteria) admitted to these units after an episode of cardiac arrest were included in the
Cardiac arrest patient population
Between January 2009 and September 2009, 174 patients experiencing return of spontaneous circulation (ROSC) after an episode of cardiac arrest were admitted to the 17 intensive care units participating in the study. Return of spontaneous circulation (ROSC) was attained a median of 20 [10–30] min after cardiac arrest. Out-of-hospital cardiac arrest had occurred in 73.7% of cases.
Therapeutic hypothermia
The most relevant characteristics of patients undergoing therapeutic hypothermia are reported in Table 1. In the
Discussion
The ICE study was conducted at a group of intensive care units routinely using therapeutic hypothermia to manage patients experiencing cardiac arrest. In our experience, a large number of comatose cardiac arrest patients – after experiencing return of spontaneous circulation (ROSC) – underwent therapeutic hypothermia (69.7%) within a short time frame (median time to initiate cooling: 90 [50–160] min). The response time of the participating centres was indeed exceptionally short, especially in
Conclusions
In conclusion, while in Italy therapeutic hypothermia is marginally employed as a therapeutic strategy – as noted in a recent survey by Bianchin et al.20 – the centres participating in the ICE study have shown considerable expertise into it with ability to rapidly implement therapeutic hypothermia in cardiac arrest patients admitted to their intensive care units after return of spontaneous circulation. A surprising finding of this study was that starting hypothermia early was associated with
Conflicts of interest
All the authors declare they have no financial or personal conflicts of interest.
Acknowledgements
We are grateful to all physicians and nurses who cared after the patients enrolled in this study.
References (20)
- et al.
Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A Scientific Statement from the International Liaison Committee on Resuscitation; the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; the Council on Stroke
Resuscitation
(2008) - et al.
Post-cardiac arrest temperature manipulation alters early EEG bursting in rats
Resuscitation
(2008) - et al.
Intra-arrest cooling with delayed reperfusion yields higher survival than earlier normothermic resuscitation in a mouse model of cardiac arrest
Resuscitation
(2008) - et al.
A prospective, multicenter pilot study to evaluate the feasibility and safety of using the CoolGard System and Icy catheter following cardiac arrest
Resuscitation
(2004) - et al.
Early achievement of mild therapeutic hypothermia and the neurologic outcome after cardiac arrest
Int J Cardiol
(2009) - et al.
Assessment of outcome after severe brain damage
Lancet
(1975) - et al.
Effective lactate clearance is associated with improved outcome in post-cardiac arrest patients
Resuscitation
(2007) Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest
N Engl J Med
(2002)- et al.
Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia
N Engl J Med
(2002) Hypothermia and neurological outcome after cardiac arrest: state of the art
Eur J Anaesthesiol (Suppl)
(2008)
Cited by (46)
Thermoregulation in post-cardiac arrest patients treated with targeted temperature management
2021, ResuscitationCitation Excerpt :Due to TTM's neuroprotective effect,6,7 many researchers have hypothesized that quicker time to target temperature following initiation of TTM would yield better outcomes. Prior studies in animals have supported this hypothesis8–10 but studies in humans have provided mixed results.11–13 One potential explanation for the inconclusive findings in humans is the heterogeneity of the patients included in the studies.
Post-cardiac arrest care and targeted temperature management: A consensus of scientific statement from the Taiwan Society of Emergency & Critical Care Medicine, Taiwan Society of Critical Care Medicine and Taiwan Society of Emergency Medicine
2021, Journal of the Formosan Medical AssociationCitation Excerpt :Worse outcome was noted if the targeted temperature was reached faster in a retrospective study. However, there is no intervention study showing that delayed onset or slower rate of cooling can improve outcome.51 The conflicts of results may come from the different severities of brain injury.
Efficacy of the cooling method for targeted temperature management in post-cardiac arrest patients: A systematic review and meta-analysis
2020, ResuscitationCitation Excerpt :Only 2 studies reported the time interval from CPR to cooling of TTM; therefore, the effect of earlier cooling on TTM patient outcome was not evaluated in this study. Previous human studies that have assessed the relationship between cooling time and outcomes have shown inconsistent results concerning the benefits of earlier cooling.45–53 Therefore, we postulated that the time to cooling could affect the outcome for TTM patients but not significantly.
- ☆
A Spanish translated version of the summary of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2011.12.002.
- a
The individual investigators who participated in the study as the Italian Cooling Experience Study Group are listed in Appendix A. Salvatore Alongi, M.D. (U.O. Anestesia e Rianimazione, Fondazione IRCCS – Ospedale Maggiore Policlinico, Milan, Italy, e-mail: [email protected], tel.: +39 02 5503 3232) assumes the overall responsibility for the integrity of the report.