Noninvasive and Continuous Hemoglobin Monitoring for Surgical Blood Management

This is a multi-center cluster-randomized trial with the following Specific Aims: * To evaluate if continuous noninvasive hemoglobin monitoring will reduce the RBC transfusions in patients undergoing surgeries associated with a significant risk of bleeding. * To evaluate if patients monitored with continuous noninvasive hemoglobin experience less frequent complications and shorter hospital stay compared with patients who are not being monitored with continuous noninvasive hemoglobin. Accordingly, the study hypotheses are defined as follows: * The primary null hypothesis is that continuous noninvasive hemoglobin monitoring will not reduce the RBC transfusions in patients undergoing surgeries associated with a significant risk of bleeding. * The secondary hypothesis is that in patients monitored with continuous noninvasive hemoglobin, there will be earlier warning of critical drops in hemoglobin, and thus, there will be less frequent complications compared with patients who are not being monitored with continuous noninvasive hemoglobin.