A Retrospective Analysis On Predictive Factors For Intraoperative Blood Loss And Blood Transfusion In Surgeries For Correction Of Scoliosis

OBJECTIVETo evaluate the association of clinical variables in patients undergoing elective surgery for correction of idiopathic or congenital scoliosis,with the aim of identifying markers predictiveof intraoperative blood loss and perioperative packedred blood cell transfusions.METHODBased on the review of medical charts at Shandong Provincial Hospital,this retrospective studyevaluated whether the following variables were predictive of intraoperative blood loss and perioperative blood transfusions during scoliosis surgery using Pearson correlation analysis and multiple linear regression analysis:age,height,weight,BMI,extent of arthrodesis(numberof fused levels),number of pedicular screws used,surgery duration,sex,type of scoliosis(congenital oridiopathic),use of tranexamic acid,postoperative drainage on the day of surgery,postoperative day one drainage,preoperative hemoglobin level.Perioperative blood transfusions were measured by the number of packed red blood cell used during surgery and within three days postoperatively.RESULTSThe volume of intraoperative blood loss was significantly associated with number of fused levels,number of pedicular screws used,surgery duration,sex,use of tranexamic acid,and type of scoliosis(congenital or idiopathic)in Pearson correlation analysis.The variables included in the final predictive multiple linear regression model for intraoperative blood loss were number of pedicular screws used,surgery duration,type of scoliosis and use of tranexamic acid.The number of packed red blood cell was significantly associated with number of fused levels,number of pedicular screws used,surgery duration,intraoperative blood loss,postoperative drainage on the day of surgery,postoperative day one drainage and sex in Pearson correlation analysis.The variables included in the final predictive multiple linear regression model for perioperative blood transfusion were surgery duration,intraoperative blood loss,postoperative drainage on the day of surgery and sex.In this study,I tried to find out the factors determining the volume of drainage on the day of surgery.However,there is no obvious linear relationship between the volume of postoperative drainage and other clinical factors.It is hard to establish a predictive multiple linear regression model for the volume of drainage on the day of surgery.CONCLUSIONThis study revealsthat a larger number of pedicular screws used,prolonged operative duration,surgery for correction of congenital scoliosis(versus idiopathic scoliosis)were predictive of larger volume of intraoperative blood loss while the use of tranexamic acid reduced intraoperative bleeding.This study also shows evidence of a significant association between a larger number of packed RBC transfused and female(versus male),prolonged operative duration,more intraoperative blood loss,or more postoperative drainage on the day of surgery.Close monitoring of postoperative drainage on the day of surgery is of great clinical significance,as it is an independent predictor of perioperative blood transfusion.Pitifully,it does not have strong linear association with intraoperative blood loss or any other clinical variables in the study,making it difficult for anesthesiologist to make an estimation of the postoperative drainage volume through preop evaluation.