Volume 19 Supplement 1
Hemodynamic targets during therapeutic hypothermia after cardiac arrest: a prospective observational study
© Ameloot et al.; licensee BioMed Central Ltd. 2015
Published: 16 March 2015
In analogy with sepsis, current postcardiac arrest (post-CA) guidelines recommend to target mean arterial pressure (MAP) above 65 mmHg and SVO2 above 70%. This is unsupported by mortality or cerebral perfusion data. The aim of this study was to explore the associations between MAP, SVO2, cerebral oxygenation and survival.
A prospective, observational study during therapeutic hypothermia (24 hours -33°C) in 82 post-CA patients monitored with near-infrared spectroscopy.
Forty-three patients (52%) survived in CPC 1 to 2 until 180 days post CA. The mean MAP range associated with maximal survival was 76 to 86 mmHg (OR = 2.63, 95% CI (1.01; 6.88), P = 0.04). The mean SVO2 range associated with maximal survival was 67 to 72% (OR = 8.23, 95% CI (2.07; 32.68), P = 0.001). In two separate multivariate models, a mean MAP (OR = 3.88, 95% CI (1.22; 12.33), P = 0.02) and a mean SVO2 (OR = 8.79, 95% CI (1.69; 18.36), P = 0.01) in the optimal range persisted as independently associated with increased survival after correction for presence of early bystander CPR and presenting shockable rhythm. Based on more than 1,625,000 data points, we found a strong linear relation between SVO2 (range 40 to 90%) and average cerebral saturation (R2 = 0.86) and between MAP and average cerebral saturation for MAPs between 40 and 87 mmHg (R2 = 0.70). Based on our hemodynamic model, the optimal MAP and SVO2 were determined to be 87 mmHg and 72%.
The optimal SVO2 (72%) and MAP (87 mmHg) derived from our hemodynamic model matched with the observed SVO2 (67 to 72%) and MAP (76 to 86 mmHg) associated with maximal survival. Prospective interventional studies to reach or maintain these targets are needed to confirm these findings.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.