Abstract 202: Fast Hypothermia Induced by Continuous Renal Replacement Therapy Alleviates Systemic Inflammation and Intestinal Injury After Cardiopulmonary Resuscitation in Swine

Abstract

Introduction: Systemic inflammation and intestinal injury contribute to post-resuscitation multiple organ dysfunction and death in cardiac arrest victims, and they can be partly alleviated by therapeutic hypothermia. Recently, continuous renal replacement therapy (CRRT) was shown to be an effective cooling method to induce fast hypothermia. In this study, we investigated the effects of CRRT cooling (CRRT-C) on systemic inflammation and intestinal injury after cardiopulmonary resuscitation (CPR) in swine. Hypothesis: Fast hypothermia induced by CRRT-C would alleviate post-resuscitation systemic inflammation and intestinal injury better than surface cooling (SC). Methods: Twenty-seven male domestic swine weighing 36 ± 2 kg were utilized. Ventricular fibrillation was induced for 8 mins while defibrillation was attempted after 5 mins of CPR. At 5 mins after resuscitation, the animals were randomized to receive either CRRT-C, SC or normotherma (NT). In the two hypothermic groups, the animals were cooled by either the combination of 8-hr CRRT and 16-hr SC or the whole 24-hr SC. In animals treated with CRRT-C, a higher rate of 180 ml/min of blood flow was initially set with the infusion line submerged in 4 °C of ice water. The temperature was normally maintained in the NT group. Results: After resuscitation, the rate of temperature decrease was significantly faster in the CRRT-C group than in the SC group (9.8±1.6 vs. 1.5±0.4 °C/h, p <0.01). The serum levels of tumor necrosis factor-α, interleukin-6, intestinal fatty acid binding protein and diamine oxidase after resuscitation were significantly lower in the two hypothermic groups compared with the NT group. However, post-resuscitation systemic inflammation and intestinal injury were further significantly alleviated in the CRRT-C group compared to the SC group (Table). Conclusion: Fast hypothermia induced by CRRT-C was superior to SC in alleviating post-resuscitation systemic inflammation and intestinal injury.