Noninvasive and Continuous Hemoglobin Monitoring for Surgical Blood Management

This is a matched-pair cluster-randomized controlled trial. At each participating centers,
consenting eligible Anesthesiologists will be grouped into matched pairs based on their
practice characteristics and experience (namely, their main surgical service/procedures and
their years of experience working as a clinician responsible for making transfusion
decisions). From each pair, Anesthesiologists will be randomly allocated to either treat
their patients while having access to data from a continuous noninvasive hemoglobin
monitoring device (total hemoglobin [SpHb] and Pleth Variability Index [PVI]) (SpHb group) or
without access to SpHb/PVI data, under standard of care (control group). Regardless of
randomization, all patients will be monitored with the device but the data will be blinded
and not be available to the Anesthesiologist to be used in the management of the control
group. Only in the SpHb group, the SpHb/PVI data will be provided live to the
Anesthesiologist, to be used during management of the patients.

Inclusion Criteria:

- Adult patients undergoing one of the listed major surgeries associated with
possibility of significant blood loss

- Consenting patients who are primarily managed by the consenting Anesthesiologists
participating in the study (Not applicable at participating centers which have
obtained a waiver of informed consent for the patients from their respective IRB)

- At least one finger available and accessible for performing non-invasive hemoglobin
monitoring (preoperative perfusion index greater than 0.5)

Exclusion Criteria:

- Any patients who do not fit the criteria for use of sensor, specifically, any patient
with nail polish and/or a nail deformity, or obstructed physical access (e.g. due to
bandage) to all fingers that would be used for sensor placement, in a manner that
interferes with satisfactory sensor placement

- Any patients being monitored with motor evoked potential devices

- Any patients with a known hemoglobinopathy

- Any patients undergoing Cardio-Pulmonary Bypass (CPB)

- Any patients who cannot be transfused or has refused consent for a blood transfusion

- Patients who are moribund/salvage cases as determined by the participating
Anesthesiologist in charge of management of the patient in the operating room

- Patients being treated by any artificial oxygen carriers within 30 days of hospital
stay

- Patients who are actively enrolled in or within 30 days of completion of any other
study (except for purely observational studies with no intervention)

- Patients being managed outside of an operating room in the participating centers, or
in operating room with conditions not conducive to perform and complete the study
procedures (including use of the hemoglobin monitoring device)

- Patients younger than 18 years old

- Patients who are pregnant

- Any patients expected to receive transfusion preoperatively