Different Degrees Of Hypothermia On Protein C System Of Heat Stress

Objective:Firstly,to investigate the changes of coagulation of severe heatstress patients in the early stage of hospitalization;then to examined whether cooling could improve PC pathway in HS.Materials and methods:Part one clinical study:Data were obtained on the first day of hospitalization for 87 patients with severe heatstress.Patients who were alive at 28 days after admission were considered as survivors.The corrrelation between ISTH DIC score and MODS score were calculated.Part two-animal study:45 anesthetized rats were warmed to achieve heat stress(Tc 42?).These rats were divided into 3 groups:(1)HS+Ice-water blanket group:(HS+I:n=15);(2)HS+Cold-water blanket group:(HS+C:n=15);(3)HS group:(HS:n=15).Mortality of HS rats were observed at 180 minutes and 480minutes after heat stress.Part three-animal study:64 rats were divided into 8 groups:(1)normal control group for 15minutes(NC:15minutes n=8);(2)NC:180minutes n=8;(3)HS+I:15minutes n=8;(4)HS+I:180 minutes n=8;(5)HS+C:15minutes n=8;(7)HS+C:180 minutes n=8;(8)HS:15minutes n=8;(9)HS:180 minutes n=8 3 hours n=8.Plasma PC,activated protein C(APC),and soluble thrombomodulin(sTM)levels were tested at both times.Result:Part one:In the early stage of hospitalization,there was significant difference in hemostastic parameters between the two groups.The correlation between ISTH DIC score and MODS score was 0.745.Part two:After cooling,the Tcs of HS+I and HS+C groups decreased significantly compared with the HS group,with the Tcs significantly lower in HS+I than HS+C group(p<0.05);The mortality rate was the highest in HS group and lowest in HS+I group.Part three:PT in HS+I group was shorter than that in HS and HS+C group(p<0.05).The sTM levels of HS group were highest among the groups at both times.Plasma PC and APC levels increased after HS.In HS+I and HS+C groups,plasma APC levels and APC/PC ratio significantly increased at both times,Although the proportions were significantly higher in the HS+I group compared with the HS+C group,there was no further increase after the time extensions.and there was no significant increase in the APC/PC in the HS group.Conclusion:Part one:In the early stage of admission,patients in non-survival group showed more serious abnormalities than survival group.The severity of multiple organ dysfunction is associated with coagulation dysfunction.Part two:Cooling treatment could improve the mortality of HS rats.Part three:Cooling exerts an anticoagulant effect following HS by increasing APC levels.Ice-water blanket therapy is more effective than cold-water blanket therapy in increasing APC levels.