Use of ROTEM for Multi-level Spine Surgery

Inclusion Criteria: * Patients undergoing elective open spine (cervical, thoracic, and/or lumbar) surgery with anticipated blood loss of \> 1 L * Males and females * Age 18 to 100 years of age * ASA physical status 1 to 3 * Arterial line indicated for the intraoperative management of the patient and in place prior to incision * Informed consent obtained Exclusion Criteria: * Known pre-existing hemostatic abnormality * Known clopidogrel use within 10 days prior to surgery * Known warfarin use within 5 days prior to surgery * Known pregnancy * Has physical, mental, or medical conditions which, in the opinion of the Investigator, could compromise the subject's welfare, ability to communicate with the study staff, complete study activities, or would otherwise contraindicate study participation. * Inclusion in another clinical research study * An investigator of this study * Subject's refusal or inability to agree to and sign the Informed Consent form in English