Hemodynamic targets during therapeutic hypothermia after cardiac arrest: A prospective observational study. (June 2015) - Ameloot, K.
Abstract: Aim: In analogy with sepsis, current post-cardiac arrest (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. Methods: Prospective, observational study during therapeutic hypothermia (24 h – 33 °C) in 82 post-CA patients monitored with near-infrared spectroscopy. Results: Forty-three patients (52%) survived in CPC 1–2 until 180 days post-CA. The mean MAP range associated with maximal survival was 76–86 mmHg (OR 2.63, 95%CI [1.01; 6.88], p = 0.04). The mean SVO2 range associated with maximal survival was 67–72% (OR 8.23, 95%CI [2.07; 32.68], p = 0.001). In two separate multivariate models, a mean MAP (OR 3.72, 95% CI [1.11; 12.50], p = 0.03) and a mean SVO2 (OR 10.32, 95% CI [2.03; 52.60], p = 0.001) in the optimal range persisted as independently associated with increased survival. Based on more than 1 625 000 data points, we found a strong linear relation between SVO2 (range 40–90%) and average cerebral saturation ( R 2 0.86) and between MAP and average cerebral saturation for MAP's between 45 and 101 mmHg ( R 2 0.83). Based on our hemodynamic model, the MAP and SVO2 ranges associated with optimal cerebral oxygenation were determined to be 87–101 mmHg and 70–75%. Conclusion: we showed that a MAP range between 76–86 mmHg and SVO2 range between 67% and 72% were associated with maximal survival. Optimal cerebral saturation was achieved with a MAP between 87–101 mmHg and a SVO2 between 70% and 75%. Prospective interventional studies are needed to investigate whether forcing MAP and SVO2 in the suggested range with additional pharmacological support would improve outcome.