title: Blood Loss and Transfusion Requirements in Metastatic Spinal Tumor Surgery: Evaluation of Influencing Factors.
abstract: Metastatic spine tumor surgery (MSTS) can be associated with significant blood loss. Previous studies did not provide comprehensive data on blood loss in MSTS. Thorough study elaborating the blood loss, transfusion requirement, and their influencing factors is required. This study aimed to investigate the estimated blood loss and transfusion requirements associated with various surgical approaches and surgically managed vertebral levels for spinal metastases from different primary tumors.
  
  
  
  The study retrospectively evaluated 243 patients who underwent surgery for metastatic spine tumors at the authors' institution between 2005 and 2014. Estimated intraoperative blood loss and transfusion requirement were assessed for different primary tumors including lung, breast, prostate, gastrointestinal, renal, liver, thyroid, myeloma/lymphoma, and others; types of surgical procedure (cervical corpectomy ± stabilization, thoracolumbar posterior decompression ± instrumentation, thoracolumbar corpectomy, minimally invasive surgery); and levels of instrumentation and decompression. Multivariate linear regression was attempted to investigate the factors influencing blood loss and transfusion requirements.
  
  
  
  The mean blood loss was 870 ± 720 ml, and the average blood transfusion was 1.5 ± 1.9 U. The mean blood loss was 1103 ml for patients who received blood transfusion and 597 ml for those who did not. Multivariate analysis showed that the significant factors influencing blood loss were primary tumor, type of surgery, and prolonged operative time. The influencing factors for blood transfusion were primary tumor, type of surgery, preoperative hemoglobin, and prolonged operative time.
  
  
  
  Significant variations in blood loss and transfusion requirement were based on primary tumor of spinal metastases, surgical approaches, and operative time. These findings will help clinicians in preoperative planning to address the problem of blood loss during MSTS.
authors.affiliation: Department of Orthopaedic Surgery, National University Health System, Singapore, Singapore. dosksn@nus.edu.sg.
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Department of Orthopaedic Surgery, National University Health System, Singapore, Singapore.
authors.forename: Aye Sandar
authors.initials: AS
authors.lastname: Zaw
authors.affiliation: Department of Orthopaedic Surgery, National University Health System, Singapore, Singapore.
authors.forename: Hnin Ei
authors.initials: HE
authors.lastname: Khine
authors.affiliation: Department of Orthopaedic Surgery, National University Health System, Singapore, Singapore.
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Maharajan
authors.affiliation: Investigational Medicine Unit, National University Health System, Singapore, Singapore.
authors.forename: Khin Lay
authors.initials: KL
authors.lastname: Wai
authors.affiliation: Department of Orthopaedic Surgery, National University Health System, Singapore, Singapore.
authors.forename: Barry
authors.initials: B
authors.lastname: Tan
authors.affiliation: Department of Orthopaedic Surgery, National University Health System, Singapore, Singapore.
authors.forename: Siti
authors.initials: S
authors.lastname: Mastura
authors.affiliation: Department of Anaesthesia, National University Health System, Singapore, Singapore.
authors.forename: Raymond
authors.initials: R
authors.lastname: Goy
mesh_terms: D016063:Blood Loss, Surgical / Q000706:statistics & numerical data*; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D019299:Decompression, Surgical; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D009362:Neoplasm Metastasis; D011379:Prognosis; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000556:secondary / Q000601:surgery*