Influence of mild therapeutic hypothermia on the inflammatory response after successful resuscitation from cardiac arrest

Purpose

Although animal studies document conflicting data on the influence of hypothermia on cytokine release in various settings, no data exist if hypothermia affects the inflammatory response after successful cardiopulmonary resuscitation.

Materials and Methods

Arrest- and treatment-related variables of 71 patients were documented, and serum samples were analyzed for levels of interleukin 6, tumor necrosis factor-α, C-reactive protein, and procalcitonin immediately after hospital admission and after 6, 24, and 120 hours. At day 14, patients were dichotomized in those with good and bad neurological outcome.

Results

Regardless of outcomes, interleukin 6 levels were significantly elevated by the use of hypothermia (n = 39). The rate of bacterial colonization was significantly higher in hypothermic patients (64.1 vs 12.5 %; P < .001). On the contrary, procalcitonin levels were, independent of the use of hypothermia, only significantly elevated in patients with bad neurological outcome. Hypothermic patients showed a strong trend to reduced mortality. However, there was no influence on neurological recovery.

Conclusions

In this observational study, hypothermia influenced the inflammatory response after cardiopulmonary resuscitation and lead to a higher rate of bacterial colonization without altering ultimate neurologic recovery.