This study will establish the feasibility and preliminary validity of real-time oxygen delivery index (DO₂i) monitoring using noninvasive hemoglobin (SpHb, Masimo) and minimally invasive cardiac output (FloTrac, Edwards) in cardiac surgery patients.
Adults ≥ 18 years undergoing cardiac surgery
Placement of pulmonary artery catheter with continuous cardiac output (CCO) as part of routine clinical care
Placement of arterial line with FloTrac as part of routine clinical care
Availability of ≥ 3 arterial blood gas samples at specified timepoints
Mechanical circulatory support planned or in use (IABP, Impella, ECMO)
Patients without BOTH pulmonary artery catheter with CCO and arterial line with FloTrac
Patients who are Research Opt-Out