We thank Bartlett and Nichol for their important comments on our article. We acknowledge that there have been previous studies such as the one by Salter et al.
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indicating that treatment below 34 °C degrees may be beneficial compared to 36 °C or no TTM which we discuss in the article. Our findings suggest a similar difference in the group with ventricular fibrillation although it is not statistically significant. This seems in particular to be the case for the subgroup of patient with ventricular fibrillation fulfilling the initial HACA criteria (witnessed, age 18–75 years, presumed cardiac cause, EMS response time <15 min).The risk of selection bias is always difficult to avoid in an observational study. After the comments from Barlet and Nichol we have conducted further analysis and included the patients, as far as we know, did not receive any form of TTM.
For all patients (treated with and without TTM) we found a 30 days survival of 265/717 (37.0%) for the period of TTM36 and 729/2182 (33.4%) for the period of TTM33. For the subgroup of patients who did not receive any form of TTM the corresponding numbers were 127/425 (29.9%) for the period of TTM36 and 217/1072 (20.2%) for the period of TTM33. In other words, this crude data demonstrates that the 30 days survival was higher for the time period following the transition to TTM36 compared with TTM33 for both the entire cohort as well as the patients with no TTM treatment. This is in contradiction to the results found by Salter et al.
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However, our crude data is difficult to interpret as it cannot confirm nor dismiss selection bias or under reporting.Finally, regarding the time to reach target temperature. We did not have the possibility to report times in regard to different temperatures in our study as this is not registered in the Swedish Intensive Care Registry. This would of course have been of value.
Conflicts of interest statement
We declare not conflict of interest.
References
- Changes in temperature management of cardiac arrest patients following publication of the target temperature management trial.Crit Care Med. 2018; 46: 1722-1730
Article info
Publication history
Published online: November 07, 2019
Received:
October 30,
2019
Publication stage
In Press Journal Pre-ProofIdentification
Copyright
© 2019 Elsevier B.V. All rights reserved.