Analysis And Treatment Of Hypoxemia After Off-pump Coronary Artery Bypass Grafting

Objectives: Coronary artery bypass grafting is an effective method being universally accepted for the treatment of coronary heart disease.OPCAB is used more and more in patients with high risk of coronary heart disease,the application of OPCAB is more and more widely used,but the effect of surgical treatment is affected by many factors.Hypoxemia after OPCAB is an important factor to reduce the effect of surgical treatment,and its prevention and treatment has become an important part of surgical treatment of coronary heart disease.In this study,we analyzed the medical records of patients with OPCAB in our hospital in order to find the risk factors of hypoxemia after OPCAB to reduce the incidence of hypoxemia after OPCAB.Otherwise,we can analys of the treatment methods of patients with severe hypoxemia to reduce the adverse effects of hypoxemia.Methods: We retrospectively analyzed the clinical data of patients undergoing off-pump coronary artery bypass grafting(CABG)in the Affiliated Hospital of Hebei University from February 2004 to November 2015.There were a total of 332 patients,among them,including 242 males and 90 femals.The patients were divided into hypoxic group(n=133)and non hypoxic group(n=199)Based on the occurrence of hypoxemia.Refer to EuroSCORE,ACC/AHA guide,reports of hypoxemia after cardiac surgery and combineded with our clinical experience,the gender,age,obesity,allergies,heart function,smoking,diabetes,chronic lung disease,PCI history,history of myocardial infarction,valvular heart disease,left ventricular aneurysm,left main coronary artery disease,pleural effusion etc.38 factors were select.Firstly,univariate analysis was performed.The second,using the form of logistics analysis of regression to compare with relevant elements and hypoxemia.The independent risk factors of hypoxemia after OPCAB were found.All patients were divided into the NPPV group(n=36)and the IPPV group(n=32)based on postoperative ventilation mode.Physiological data were recorded from all the patients with heart rate(HR),blood pressure(BP),respiration(RR),cardiac functional grading,arterial blood gas analysis-including arterial partial pressure of oxygen(PaO2)and the partial pressure of arterial carbon dioxide(PaCO2).Postoperative complications were also analyzed.Result:(1)A total of 332 patients were analyzed,of which,7 patients died,the mortality rate was 2.11%;(2)133 cases of postoperative hypoxemia occurred,the incidence was 40.06%.Among them,31 cases of patients with mild hypoxemia(9.34%),34 cases of patients with moderate hypoxemia(10.24%)and 68 cases of patients with severe hypoxemia(20.48%);(3)Univariate analysis: gender,obesity,diabetes,chronic lung disease,postoperative pleural effusion,and postoperative hypotension were risk factors for hypoxemia after OPCAB(P<0.05);(4)Logistic regression analysis: obesity(OR=1.948,95%CI 1.367-2.778),diabetes mellitus(OR=2.051,95%CI 1.271-3.311),chronic lung disease(OR=3.043,95%CI 1.484-6.239)and postoperative pleural effusion(OR=2.387,95%CI 1.489-3.826)were independent risk factors of hypoxemia after OPCAB(P < 0.01);(5)The incidence of complications of MODS and delayed wound healing in patients with hypoxemia after OPCAB was significantly higher than that in patients without hypoxemia(P<0.05).The ICU stay time(P<0.01)and the time of postoperative hospital stay(P < 0.05)were significantly prolonged in patients with hypoxemia than those without hypoxemia;(6)Both in NPPV group and IPPV group,the PaO2 was significantly improved,the PaCO2 was decreased and pH was slight increased at the same time.And there were no significant differences in both group.In NPPV group,HR and mean arterial pressure(MAP)were decreased after 6 hours treatment.Ventilator associated pneumonia(P<0.05),ICU stay time(P<0.01)and the time of hospital stay(P<0.01)were significantly reduced in BiPAP group than in tracheal intubation group.Conclusions:(1)The incidence of hypoxemia in obesity,diabetes,chronic lung disease and postoperative pleural effusion was significantly increased,which were an independent risk factor for postoperative hypoxemia in patients with OPCAB.(2)The incidence of complications of MODS and delayed wound healing in patients with hypoxemia after OPCAB was significantly higher than that in patients without hypoxemia.The ICU stay time and the time of postoperative hospital stay were significantly prolonged in patients with hypoxemia than those without hypoxemia.(3)BiPAP noninvasive ventilation is a safe and effective treatment,which can quickly improve the level of arterial oxygen pressure,reduce postoperative complications,ICU stay time and postoperative hospital stay.BiPAP noninvasive ventilation should be actively used in patients with hypoxemia after OPCAB.