Kamal R. Khabbaz

Background: Oxygen delivery during cardiopulmonary bypass reflects the balance between pump flow, hemoglobin concentration, and arterial oxygenation and is a key determinant of tissue oxygen transport. While inadequate oxygen delivery has been linked to postoperative organ dysfunction, its association with mortality remains unclear. Methods: A retrospective cohort study was conducted including 4,358 adult patients undergoing cardiac surgery with cardiopulmonary bypass at a tertiary center between 2018 and 2024. Time-weighted average indexed oxygen delivery (DO _2i ) was calculated from pump flow, arterial oxygen saturation, hemoglobin concentration, and body surface area. The primary outcome was 30-day mortality. Secondary outcomes included postoperative acute kidney injury (AKI), stroke, and intensive care unit and hospital length of stay. Associations were evaluated using multivariable regression models adjusted for demographic, clinical, and procedural factors. Results: Lower intraoperative DO _2i was associated with higher 30-day mortality. Overall, 75 patients (1.7%) died within 30 days. Each 10-ml · min ⁻¹ · m ⁻² decrease in DO _2i was associated with increased odds of mortality (adjusted odds ratio [OR _adj ], 1.16; 95% CI, 1.09 to 1.23; P < 0.001). The adjusted 30-day mortality was 1.69% (95% CI, 1.32 to 2.05%) at the 25th percentile of DO _2i (226.2 ml · min ⁻¹ · m ⁻² ) compared with 0.74% (95% CI 0.41 to 1.07%) at the 75th percentile (295.6 ml · min ⁻¹ · m ⁻² ). Lower DO _2i was also associated with AKI (OR _adj , 1.05; 95% CI, 1.03 to 1.07; P < 0.001) and with longer intensive care unit (adjusted incidence rate ratio, 1.02; 95% CI, 1.01 to 1.03; P < 0.001) and hospital length of stay (adjusted incidence rate ratio, 1.01; 95% CI, 1.01–1.02; P < 0.001) but not with stroke (OR _adj , 1.00; 95% CI, 0.95 to 1.06; P = 0.877). Conclusions: Patients receiving lower intraoperative DO _2i during cardiopulmonary bypass had a higher risk of postoperative mortality, AKI, and prolonged recovery. These findings support the clinical relevance of oxygen delivery during bypass and provide a rationale for future mechanistic and interventional studies.

To quantitatively evaluate and compare the relative efficacy of different chest wall fascial plane blocks in cardiac surgery via median sternotomy. This st

ObjectiveDemonstrate that regional geometric differences exist between regurgitant and non-regurgitant mitral valves (MV's) in patients with coronary artery disease and due to the heterogenous and regional nature of ischemic remodeling in patients with coronary artery disease (CAD), that the available anatomical reserve and likelihood of developing mitral regurgitation (MR) is variable in non-regurgitant MV's in patients with CAD. MethodsIn this retrospective, observational study intraoperative three-dimensional transesophageal echocardiographic data was analyzed in patients undergoing coronary revascularization with MR (IMR group) and without MR (NMR group). Regional geometric differences between both groups were assessed and MV reserve which was defined as the increase in antero-posterior (AP) annular diameter from baseline that would lead to coaptation failure was calculated in three zones of the MV from antero-lateral (zone 1), middle (zone 2), and posteromedial (zone 3). Measurements and Main ResultsThere were 31 patients in the IMR group and 93 patients in the NMR group. Multiple regional geometric differences existed between both groups. Most significantly patients in the NMR group had significantly larger coaptation length and MV reserve than the IMR group in zones 1 (p-value = .005, .049) and 2 (p-value = .00, .00), comparable between the two groups in zone 3 (p-value = .436, .513). Depletion of the MV reserve was associated with posterior displacement of the coaptation point in zones 2 and 3. ConclusionsThere are significant regional geometric differences between regurgitant and non-regurgitant MV's in patients with coronary artery disease. Due to regional variations in available anatomical reserve and the risk of coaptation failure in patients with CAD, absence of MR is not synonymous with normal MV function.