Clinical Observation On The Changes Of Pericardial And Mediastinal Drainage Volume After Cardiac Valve Replacement Under Cardiopulmonary Bypass

Objective:To observe the changes of pericardial and mediastinal drainage volume after cardiac valve replacement by extracorporeal circulation(CPB),and to provide a theoretical basis for the diagnosis and management of abnormal wound bleeding during perioperative period after cardiac surgery.Methods:From October 2016 to October 2018,there were 121 patients(58 males and 63females)undergoing cardiac valve replacement under cardiopulmonary bypass(CPB)in our center.The mean age was(59.6 ±6.1)years(50 years),78 years old(mean:59.6 ± 6.1years).Before operation,coagulation dysfunction,hepatic and renal insufficiency,coronary heart disease,hypertension,diabetes,all patients underwent cardiac valve replacement under mild hypothermic cardiopulmonary bypass,pericardium and mediastinal drainage tubes were placed after operation.The volume of drainage fluid in the drainage tube was calculated and the color was observed since the sternum was closed by steel wire.The hemoglobin and red blood cell count of the drainage fluid were analyzed and compared with the corresponding indexes of the blood.Results:The drainage fluid volume was summed up every hour after the wire closed sternum,and the drainage tube was unobstructed,and the color of drainage fluid was observed.1.Pericardial and mediastinal catheters were placed for 34 h and 89 h,with a median of 41 h.2.The total drainage volume was 146 ~ 890 ml(average 472 ml).3.The first 6 hours of drainage accounted for 42% of the total drainage volume.4.The amount of drainage fluid in the first hour was the most and the difference between individuals was obvious,but the change trend was the same.The number of red blood cells,hemoglobin and hematocrit in the drainage fluid at the first and second hours were close to that of the whole blood.The drainage volume began to decrease at the 3rd hour,and the color of the drainage fluid was still similar to that of the whole blood.The drainage fluid decreased significantly at the 4th hour,and the drainage fluid decreased significantly at the 6th hour.After that,the drainage fluid was mainly serous exudation,and the proportion of blood cell components was very small.24 hours later,the drainage fluid was dominated by serous fluid.5.The number of red blood cells in the drainage fluid was similar to that in the whole blood at the first 3 hours after cardiac valve replacement,and then decreased gradually,and the number of red blood cells in the drainage fluid was very low at the6 th hour after the operation.Red blood cells,hemoglobin and hematocrit in drainage fluid were compared with circulating blood at 3 hours(T 1),6 to 8 hours(T 2)after operation,and the results showed that 3 hours after operation(T 1),hemoglobin and hematocrit in drainage fluid were compared with those in circulating blood.There was no significant difference in the number of red blood cells with that in circulating blood,but there were significant differences in hemoglobin,hematocrit and red blood cell count in drainage fluid 6 hours after operation(T 2)compared with circulating blood.There were significant differences in hemoglobin,hematocrit and red blood cell count between drainage tube and circulating blood at 3 h after operation compared with 6 h after operation(T 2).Conclusion:The volume of pericardial and mediastinal drainage was the highest in the first 3hours after cardiac valve replacement by extracorporeal circulation.The volume of drainage fluid decreased and increased in transition period from 4 to 6 hours,but the bleeding and exudation decreased significantly at 6 hours after cardiac valve replacement.It is suggested that the first 6 hours after cardiac surgery is the keyperiod to observe whether there is active bleeding or not.