Effects Of Normothermia And Pulsatile Perfusion During Cardiopulmonary Bypass On Pregnant Women And Fetal Outcomes

Objectives: The mortality of pregnant women undergoing cardiopulmonary bypass(CPB)is now similar with those who are non-pregnant,but the fetal mortality is still high.Nonphysical blood flow during CPB can damage the recovery of mothers and also growth and development of fetus.The purpose of our study is to explore the effect of pulsatile perfusion(PP)and normothermia during CPB on pregnant women and fetal outcomes,and to provide clinical evidences for optimizing CPB management during pregnancy.Methods: All 33 patients undergoing CPB surgery during pregnancy at Guangdong Provincial People’s Hospital,from Jan.1st2014 to Dec.31st2020,were identified.Four groups were divided according to two factors containing perfusion modes and the lowest temperature during CPB.Perfusion modes included nonpulsatile perfusion(NP)and PP.The lowest nasopharyngeal temperature was divided into hypothermia and normothermia by 35℃.NP with hypothermia was defined as group A,while NP with normothermia was defined as group B,and PP with hypothermia was defined as group C,while PP with normothermia was defined as group D.Thus,there were 7,4,4 and 18 patients in group A,B,C and D respectively.Prime solution and arterial-venous cannulus were chosen routinely.After heparinization,CPB was initiated following activated clotting time larger than 480 s with target flow rate above 80-100ml/kg/min and mean arterial pressure around 60-80 mm Hg.Cold blood cardioplegia was applied to all patients while either systemic hypothermia or normothermia was maintained.NP was performed throughout the CPB in NP group.In PP group,PP was performed immediately after aortic cross-clamp and ended 10 min after cross clamp releasing,and NP was implemented for the rest.PP was establised using a Stockert S5 modular CPB machine.Pulse mode was enabled with initial pulse parameters set as follows: pulse frequency,60/min;pulse width,30%;and base flow,30%.Preoperative and intraoperative data of all patients was collected.Cardiac automatic rebeating rate were monitored.The maternal mortality,complete blood counts,coagulation function,renal function,cardiac function,hepatic function,pleural drainage,and lactate acid concentration(Lac)24h postoperatively were gathered.Meanwhile,the highest Lac within 24 h after surgery,incubation time,length of intensive care unit stay,length of hospital stay and complications of all patients were also recorded.The fetal survival rate,gestation age at delivery,birth weight,the Apgar score,length of neonatal intensive care unit stay,numbers of infants in neonatal intensive care unit as well as fetal complications before and after delivery.All maternal data of postoperative electrocardiogram,postoperative New York Heart Association heart function grade and complications were collected during follow-up,and complications,hereditary diseases of all surviving infants were also recorded.Mental development index(MDI)and psychomotor development index(PDI)of Bailey Scales of Infant Development were assessed for all surviving infants both elder than 3 months and less than 36 months.Results: The main effect of NP and PP on maternal hemoglobin 24 h after operations showed statistically significant difference,which were 9.83g/L(95%CI:0.80-18.86)higher in PP group than in NP group,p<0.05.The main effect of NP and PP on maternal prothrombin time 24 h after operations showed statistically significant difference,which were 2.25s(95%CI: 0.45-4.05)less than in PP group than in NP group,p<0.05.The main effect of NP and PP on maternal highest Lac within 24 h after operations,which were 1.96mmol/L(95%CI: 0.25-3.66)less than in PP group than in NP group,p < 0.05.The main effect of hypothermia and normothermia on maternal white blood cell 24 h after operations,which were 6.34*10^9/L(95%CI: 1.37-11.31)higher in normothermia group than in hypothermia group,p<0.05.The main effect of hypothermia and normothermia on maternal length of hospital stay,which were 5.26days(95%CI: 3.49-22.67)less than in normothermia group than in hypothermia group,p<0.05.The ratio of using venous diuretics after surgery differed from 4 groups,p<0.05,where the ratio of group D was lower than that of group A.Perfusion modes and temperature had neither interaction effect nor main effect on maternal general characteristics during CPB and other postoperative data,p>0.05.The survival rate of all fetuses was 61.76%.The difference of fetal survival rate 28 days after maternal operations among 4 groups was statistically significant,p < 0.05,where survival rate of group D was higher than group A.The difference of fetal survival rate at birth among 4 groups was statistically significant,p<0.05,where survival rate of group D was higher than both group A and C.The difference of fetal total survival rate among 4 groups was statistically significant,p<0.05,where survival rate of group D was higher than both group A and C.Perfusion modes and temperature had neither interaction effect nor main effect on clinical indexes of suriving infants,p>0.05.There was no serious hereditary disease or complication found in these infants and there were no statistically differences in MDI and PDI of Bailey Scales of Infant Development,p>0.05.Conclusions: PP and normothermia in CPB during pregnancy can decrease blood damage,improve maternal coagulation and renal function,and reduce the length of hospital stay.PP and normothermia can also enhance fetal survival rates,and maintain MDI and PDI of surviving infants at normal level.