PAEDIATRIC SURGERY: PS01RESCUE HYPOTHERMIA REDUCES ILEAL INJURY IN EXPERIMENTAL INTESTINAL ISCHAEMIA AND REPERFUSION

Moderate hypothermia is beneficial when applied throughout intestinal ischaemia-reperfusion (IR). However, therapeutic intervention is usually possible only after ischaemia has occurred. The aim of this study was to evaluate the efficacy of hypothermia as a rescue therapy for intestinal IR. Adult rats were ventilated via a tracheostomy and underwent either intestinal ischaemia-reperfusion (60 min superior mesenteric artery occlusion, and 120 min reperfusion) or sham operation. Rats in the hypothermia groups were maintained at normothermia (36-38°C) throughout ischaemia, and were cooled at the beginning of reperfusion until reaching target temperature (moderate hypothermia: 30-32 deg C). Four groups (n = 8 each) were studied: 1) control normothermia; 2) IR normothermia; 3) control hypothermia; 4) IR rescue hypothermia. The degree of histological injury in terminal ileum was assessed on a semi-quantitative scale (1 = low; 5 = high) by three blinded observers. Data (median [IQ range]) were compared by Kruskal-Wallis test with Dunn's post-test. Intestinal IR at normothermia caused severe injury to the ileum (4.5 [4-5]) compared to both normothermic (2 [1.5-2], p < 0.01 vs. IR normothermia) and hypothermic controls (2 [1.5-2], p < 0.01 vs. IR normothermia). However, rescue hypothermia offered considerable protection from IR injury, so that intestinal architecture was partly preserved (3 [2.5-4], p = n.s. vs. control normothermia; p = n.s. vs. control hypothermia). Moderate hypothermia reduces the extent of tissue injury following intestinal ischaemia, even when applied as a rescue therapy. It could be considered as a possible therapy in clinical conditions associated with intestinal IR. [PUBLICATION ABSTRACT]