Purpose: We hypothesized that a targeted temperature of 33 °C as compared to that of 36 °C would increase survival and reduce the severity of circulatory shock in patients with shock on admission after out-of-hospital cardiac arrest (OHCA).
Methods: The recently published Target Temperature Management trial (TTM-trial) randomized 939 OHCA patients with no difference in outcome between groups and no difference in mortality at the end of the trial in a predefined subgroup of patients with shock at admission. Shock was defined as a systolic blood pressure of <90 mm Hg for >30 min or the need of supportive measures to maintain a blood pressure ≥90 mmHg and/or clinical signs of end-organ hypoperfusion. In this post hoc analysis reported here, we further analyzed the 139 patients with shock at admission; all had been randomized to receive intervention at 33 °C (TTM33; n = 71) or 36 °C (TTM36; n = 68). Primary outcome was 180-day mortality. Secondary outcomes were intensive care unit (ICU) and 30-day mortality, severity of circulatory shock assessed by mean arterial pressure, serum lactate, fluid balance and the extended Sequential Organ Failure assessment (SOFA) score.
Results: There was no significance difference between targeted temperature management at 33 °C or 36 °C on 180-day mortality [log-rank test, p = 0.17, hazard ratio 1.33, 95 % confidence interval (CI) 0.88-1.98] or ICU mortality (61 vs. 44 %, p = 0.06; relative risk 1.37, 95 % CI 0.99-1.91). Serum lactate and the extended cardiovascular SOFA score were higher in the TTM33 group (p < 0.01).
Conclusions: We found no benefit in survival or severity of circulatory shock with targeted temperature management at 33 °C as compared to 36 °C in patients with shock on admission after OHCA.