Risk Factors For Hypoxemia Atfer Stanford Type A Aortic Dissection Surgery

Objective: Hypoxemia is very common after Stanford type A aortic dissectionsurgery. We tried to determine the independent risk factors associated withpostoperative hypoxemia and discuss the mechanism to provide basis for formulatingprevention and treatment measures.Methods: We reviewed our institutional data to identify patients who underwentsurgery for acute type A dissection from January2005to October2012,there were66patients who were divided into hypoxemia group (PaO2/FiO2≤200) n1=33andnon-hypoxemia group (PaO2/FiO2>200) n2=33, We tried to collect the preoperative,intraoperative and postoperative clinical data to determine the independent risk factorsassociated with postoperative hypoxemia by using the single factor and multiple logisticregression analysis.Results: The ventilation time, ICU stay and the average hospitalization time weresignificantly longer in the hypoxemia group than in the non-hypoxemia group.Thesignificant differences(P <0.05, α=0.05) between postoperative hypoxemia group andnon-hypoxemia were the value of age、BMI≥25、PaO2/FiO2≤300、deep hypothermiccirculatory arrest（DHCA）time、intraoperative Fluid balance、red blood cell volume、fresh frozen plasma volume、platelet volume,cryoprecipitation volume、24-h fluidbalance、postoperative hyperglycemia、the acid-base imbalance、electrolyte disturbance、postoperative pulmonary infection. Logistic regression identified the followingvariables as predictors for postoperative hypoxemia: body mass index (BMI)≥25(OR=7.0395%; CI,1.842-26.835; P=0.004), preoperative oxygenation index(PaO2/FiO2)≤300(OR=6.168;95%CI,1.408-27.022; P=0.016; r=0.580), the volumeof transfused blood>8U(OR=5.461;95%CI,1.055-28.280; P=0.043)、the Mass volumeof transfused platelet (OR=3.607;95%CI,1.117-11.643; P=0.032), postoperative hyperglycemia (OR=6.159;95%CI,1.243-30.526; P=0.026).Conclusion:1.The study concluded that the hypoxemia after Stanford type A dissectionsurgery related with systemic inflammation,in order to reduce incidence ofhypoxemia,the patients especially with the oxygenation index decreasing and (or)overweight should be given early treatment.2. According to indications，reducing the unnecessary volume of blood transfusedwhich should not exceed8U and avoiding the mass transfusion of blood products canreduce the incidence of postoperative hypoxemia.3.Strictly controlling the postoperative hyperglycemia can reduce complications.