Effects Of Systemic And Regional Hypothermia On Early Inflammatory Reaction After Trauma

Objective To observe the effect of systemic hypothermia(mild and moderate hypothermia) and regional hypothermia on serum concentrations of TNF α ,IL-1 β ,IL-6,and IL-10 after trauma and hemorrhage. To approach whether mild and moderate hypothermia, and regional hypothermia can inhibit inflammatory reaction, accelerate anti-inflammatory reaction, relieve organ damage in the early period after trauma to provide instructions to clinical treatment of trauma.Methods Thirty-eight healthy Newzealand rabbits were randomly divided into five groups: normal control group(group Ⅰ ,n=6), normal temperature group(group Ⅱ ,n=8), mild hypothermia group(groupⅢ,n=8), moderate hypothermia group(groupⅣ,n=8), regional hypothermia group(groupⅤ,n=8).The right femurs of the animals in groups Ⅱ ,Ⅲ,Ⅳ, and Ⅴ were broken by a vise, and blood was drawn from the cervical vein to establish traumatic and hemorrhagic shock models. The body temperature of the animals was maintained at normal level in group Ⅱ, reduced to and maintained at 36-37℃ in group Ⅲ, and reduced to and maintained at 32-33℃ in group Ⅳ.Regional hypothermia was performed on the animals in groupⅤ. Blood samples were obtained in groups Ⅱ ,Ⅲ,Ⅳ, and Ⅴ at 2,4,6,8 hours after trauma respectively. Blood samples were obtained in group I at 2,4,6,8 hours after puncturing the carotid artery and vein respectively. Serum levels of TNF α ,IL-1 β ,IL-6, and IL-10 were measured with ELISA. Serum concentrations of GOT and GPT were measured with chromatometry. Lung tissues were obtained to determinate the W/D after withdrawing blood samples.Results (1) Serum levels of TNF α IL-1 β ,IL-6, and IL-10 increased significantly in the early period after trauma. (2) Serum levels of TNF α and IL-1 β in groupsⅢ,Ⅳ and Ⅴ were significantly lower than those of group Ⅱ; and those in groups Ⅲ and Ⅴ were lower than those of groupⅣ within 8 hours after trauma. (3) Serum levels of IL-6 werelower in groupIII,IV and V than in group II at 2,4, and 6 hours after trauma, At 8 hours after trauma, the serum level of IL-6 were still lower in groupIII but higher in group IV andV than in group II, and lower in groupsIII and IV than in group V (4) Serum levels of IL-10 were significantly higher in groups III,IV andV than in group II. (5) The mean arterial blood pressures were higher and respiratory rates were slower in groups III,IVandV than those in group II after fluid resuscitation. (6) Serum concentrations of GOT and GPT in groups III,IV and V were lower than those in group II within 8 hour after trauma. (7) The lung water contents increased significantly after trauma and hemorrhage. The lung water contents was lower in groups III,IV and V than in group II, and lower in groups III and IV than in group V. (8) Within 8 hours after trauma and hemorrhage, the mortality rate in group II was 25%, the survival rates in groups III and IV were 100%. and the mortality rate in group V was 12.5%.Conclusions (1) Both mild and moderate hypothermia can inhibit inflammatory reaction and accelerate anti-inflammatory reaction, but side effects of moderate hypothermia are more severe than those of mild hypothermia. (2) Regional hypothermia can significantly reduce production of TNF a and IL-1 3 , increase production of IL-10, relieve organ damage after trauma and improve the survival rate.(3) Serum level of IL-6 is the sensitive maker of the severity degree of tissue injury. (4) This study demonstrates that mild hypothermia and regional hypothermia can inhibit post-traumatic systemic inflammatory reaction, which provides new measure to prevent SIRS and MODS, however whether mild hypothermia and regional hypothermia can prevent SIRS and MODS is confirmed with advanced researches.