Associated Factors Of Drainage After Posterior Spinal Orthopaedic Surgery For Adolescent Scoliosis:A Retrospective Study

Objective To identify associated factors that influence the drainage after posterior spinal orthopaedic surgery for adolescent scoliosis.Methods Between November 2010 and October 2015,patients diagnosed with adolescent scoliosis from 11 to 18 years old who underwent first posterior spinal orthopaedic surgery in affiliated Drum Tower Hospital,Medical School of Nanjing University were retrospectively reviewed.Patients were categorized on the basis of massive or normal drainage,with the boundary 30th percentile of drainage/estimated blood volume.Preoperative factors including age,gender,body mass index(BMI),ASA physical status,diagnostic type of scoliosis,main Cobb angle,laboratory tests,intraoperative factors including the number of fusion level and screws,drugs used or not,use of thoracoplasty,hemivertebrectomy and osteotomy,use of cell salvage technology,duration of operation,the volume of urine output,blood loss,fluid therapy and transfusion,postoperative factors including the length of hospital stay,the number of transfusion,the volume of drainage,time of drain were collected.Univariate and multivariate analyses were used to determine which factors were independently associated with massive drainage.Analyses were also conducted in the main diagnostic subgroup including adolescent idiopathic scoliosis,congenital scoliosis and neuromuscular scoliosis.Results A total of 1461 patients were studied.The median drainage was 820 mL,in the range of 90 mL to 3570 mL.479(32.8%)patients had massive drainage(drainage≥30%of drainage/estimated blood volume).Multivariate analysis identified risk factors of massive drainage:BMI<17.63 kg/m2(odds ratio[OR]=2.90),preoperative platelet count<190*10^9/L(OR=1.67),preoperative main Cobb angle≥55 degrees(OR=1.66),number of intraoperative fusion levels≥11(OR=2.33),number of intraoperative screws≥15(OR=1.73),use of osteotomy(OR=1.54),intraoperative volume of crystalloids>35.63 mL/kg(OR=1.40),intraoperative volume of colloids≥28.92 mL/kg(OR=1.82),intraoperative volume of transfusion≥19.55 mL/kg(OR=1.72),while the use of tranexamic acid(OR=0.26)was the protective factor.The incidence rate of massive drainage in patients diagnosed with neuromuscular scoliosis(45.3%)was higher than congenital scoliosis(32.8%)or idiopathic scoliosis(28.5%).In subgroup diagnosed with idiopathic scoliosis,BMI<17.63 kg/m2(OR=3.14),preoperative platelet count<194*10^9/L(OR= 1.62),number of intraoperative fusion levels≥11(OR=2.78),number of intraoperative screws≥15(OR=2.52),use of osteotomy(OR=2.06),intraoperative volume of crystalloids≥34.37 mL/kg(OR=1.65),intraoperative volume of colloids>28.36 mL/kg(OR=2.10),intraoperative rate of autologous transfusion in the total transfusion>30.2%(OR=2.15)increased the incidence rate of massive drainage,while the use of tranexamic acid(OR=0.14)decreased it.In subgroup diagnosed with congenital scoliosis,BMI<17.16 kg/m2(OR=2.96),preoperative main Cobb angle≥50 degrees(OR=3.11),preoperative prothrombin time>12.2 s(OR=2.93),number of intraoperative fusion levels≥11(OR=3.61),intraoperative volume of transfusion≥26.08 mL/kg(OR=3.52)increased the incidence rate of massive drainage,while the use of dexmedetomidine(OR=0.45)decreased it.In subgroup diagnosed with neuromuscular scoliosis,the risk factors of massive drainage were:BMI<18.39 kg/m2(OR=4.24),duration of operation≥257 min(OR=4.01)and intraoperative volume of crystalloids≥38.59 mL/kg(OR=6.67).Conclusion BMI<17.63 kg/m2,preoperative platelet count<190*10^9/L,preoperative main Cobb angle≥55 degrees,number of intraoperative fusion levels≥11,number of intraoperative screws>15,use of osteotomy,intraoperative volume of crystalloids≥35.63 mL/kg,intraoperative volume of colloids≥28.92 mL/kg,intraoperative volume of transfusion≥19.55 mL/kg were risk factors associated with massive drainage after posterior spinal orthopaedic surgery for adolescent scoliosis,while the use of tranexamic acid could decrease the possibility of massive drainage.In patients of adolescent idiopathic scoliosis,intraoperative rate of autologous transfusion in the total transfusion>30.2%increased the possibility of massive drainage after the surgery.In patients of adolescent congenital scoliosis,preoperative prothrombin time≥12.2 s increased the possibility of massive drainage after the surgery while the use of dexmedetomidine decreased it.