Evaluation On The Prognosis Of Coagulation Disorder In The Early Stage Of Heat Stroke And Preliminary Exploration Of Its Mechanism

Objective: To analyze the clinical characteristics of early coagulation disorder in patients with Heat Stroke(HS)and explore the relationship between coagulation disorder and death in HS patients.Animal model of HS-induced coagulation disorder were established to monitor the changes of coagulation and fibrinolysis system parameters.To explore the role of circulating histones in HS coagulation and fibrinolytic system disorder,and to clarify the effect of rapid cooling intervention on coagulation and fibrinolytic system disorder and discuss the possible mechanism of it.Methods: 1.Clinical data of 175 HS patients were retrospectively analyzed,including the parameters which reflect coagulation activation,the Disseminated intravascular coagulation(DIC)score,and the parameters of Thromboelastography(TEG)after 72 h of onset.The coagulation parameters were compared between the death group and the survival group.2.Evaluate the value of the above three coagulation parameters or methods for the judgment of death,and re-judge the critical value.Stratified analysis was performed to identify confounding or interactive effects of liver injury on the relationship between early coagulation activation and death.To analyze the related factors of coagulation disorder in HS patients.3.After running exercise,HS animal model were established by using a thermostatic hot chamber.Changes of coagulation and fibrinolysis parameters at different time points(0.5h,2h and 4h)in running exercise group and HS group were monitored.4.Cell death and histone leakage in HS animal model were analyzed.To explore the relationship between circulating histone levels and coagulation disorders.The difference between HS group and Heat Stroke+Cold water cooling(HS+C)group was compared to clarify the influence of cold water cooling intervention on HS coagulation and fibrinolytic system and discuss the possible mechanism.Results: 1.42.9% of HS patients developed coagulation defects within 24 h of onset,and39.4% HS patients developed DIC within 72 h of onset.Compared with the survival group,the levels of platelets(PLT)in the death group were significantly lower within 24 h,24 to 48 h,and48 to 72 h,while Prothrombin time-international normalized ratio(PT-INR)and Activated partial thromboplastin time(APTT)were significantly increased(P<0.01).The bleeding rate of patients with overt DIC increased(P<0.05).The results of TEG showed that 43.6% of HS patients showed abnormal coagulation status within 72 h of onset,among which 88.23% showed hypocoagulation status.The risk of bleeding and death were increased in patients with hypocoagulable state(P<0.05).2.(1)PT-INR and APTTwithin 24 h of onset were independent risk factors for death of HS patients(P<0.05),with diagnostic thresholds of 1.7 and 51.45 s,respectively.Patients with PT-INR≥1.7 and APTT≥51.45 s had significantly shorter survival time regardless of liver injury(P<0.01).The level of PT-INR was correlated with the duration of hyperthermia,the levels of Antithrombin III,Interleukin-6 and C-reactive protein(P<0.05),APTT was also correlated with von Willebrand factor levels(P<0.05).(2)DIC score within72 h of onset(OR=1.69,P<0.01)was also an independent risk factor for death in HS patients.The threshold for predicting death was consistent with the diagnostic threshold for overt DIC.HS patients with DIC score ≥5 had significantly increased core body temperature,prolonged duration of high temperature,and significantly increased levels of C-reactive protein and Interleukin-6(P<0.01).(3)None of the parameters in the TEG was an independent risk factor for the 28 d death of HS patients(P>0.05).3.The core body temperature of HS rats increased rapidly,with a peak of 42.6±0.6℃.It was accompanied by structural changes and functional abnormalities of multiple organs and with a median survival time of 286.0min.Compared with the Control group,the levels of Thrombin-antithrombin complex in HS rats were continuously increased at 0.5h,2h and 4h.At 4h,PT-INR and APTT levels increased,while prothrombin activity decreased(P<0.05).At 2h and 4h,the levels of tissue plasminogen activator and Ddimer in HS rats increased(P<0.05).There was no significant difference in coagulation indexes between running exercise group and Control group at each time point(P>0.05).4.With the occurrence of coagulation and fibrinolytic disorder,the relative expression level of Cysteinyl aspartate specific proteinase-3 protein in HS group was significantly increased(P<0.01),Histone H2 A.X was stained outside the nucleus,and the levels of circulating histone H1,H2 B and H3 were increased at different time points.The level of circulating histone H1 and H2 B were related to multiple index of blood coagulation(Thrombin-antithrombin complex,PT-INR,PLT,tissue plasminogen activator,Plasminogen activator inhibitor-1),viscera function(e.g.,Alanine aminotransferase,creatinine,creatine kinase),inflammation medium(Interleukin-6)and endothelial injury(Thrombomodulin)and other parameters were correlated(P<0.05).Compared with HS group,the relative expression level of Cysteinyl aspartate specific proteinase-3 protein in HS+C group was decreased(P<0.05),histone H2 A.X was in the nucleus,and the levels of circulating histone H1 and H2 B were decreased at different time points(P<0.05).The levels of PT-INR,APTT,Thrombin-antithrombin complex,D-dimer,tissue plasminogen activator and plasminogen activator inhibitor-1 were decreased,while the level of prothrombin activity was increased(P<0.05).Compared with HS group,Congestion,hemorrhage and thrombosis of organs and tissues for HS+C group were alleviated significantly,and survival time was prolonged significantly(P<0.01).Conclusion: 1.About 40% of HS patients developed coagulation defects within 24 h of onset,and developed into overt DIC within 72 h.The results of TEG showed that more than half of HS patients showed abnormal coagulation state within 72 h of onset,and most of them showed hypocoagulable state.2.PT-INR ≥1.7 and APTT≥51.45 s within 24 h of onset,or DIC score ≥5 within 72 h of onset,have predictive value for death.In the early stage of HS,the poor prognosis of patients with activation of coagulation system has nothing to do with liver injury,but may be related to the impaired endothelial function and systemic inflammatory response caused by continuous hyperthermia.3.After running exercise,the rat model of HS-induced coagulation disorder can be successfully constructed.Coagulation system activation appeared within 0.5h of HS onset and lasted until 4h,when it showed signs of comsumptivecoagulopathy.The disorder of fibrinolytic system appeared within 2h of HS onset.At room temperature,lowfrequency running exercise for 5d had no effect on the coagulation and fibrinolytic system functions of rats.4.The activation of coagulation system and the imbalance of fibrinolytic system in HS rats were related to the release of histones caused by cell death.Rapid cooling can reduce cell death and histone release,reduce circulating histone levels,improve coagulation and fibrinolytic system disorders,and prolong survival time.