Study methods This is a prospective, randomized parallel-group single center study in patients undergoing elective major spine surgery. Patients will be randomized to ROTEM-guided hemostatic therapy algorithm or standard of care hemostatic therapy: arterial blood gas analysis (ABG), normalized index ratio (INR), prothrombin time (PT), thromboplastin time (aPTT), hemoglobin (Hb), platelets, and fibrinogen.