Browsing by Author "Swaminathan, Madhav"
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Item Open Access Assessment of Coronary Blood Flow by Transesophageal Echocardiography.(J Cardiothorac Vasc Anesth, 2016-01) Maxwell, Cory; Cherry, Anne; Daneshmand, Mani; Swaminathan, Madhav; Nicoara, AlinaItem Open Access CASE 7---2015: Perioperative Considerations for a Cardiac Paraganglioma...Not Just Another Cardiac Mass.(J Cardiothorac Vasc Anesth, 2015-08) Gerlach, Rebecca M; Barrus, Adam B; Ramzy, Danny; Hernandez Conte, Antonio; Khoche, Swapnil; McCartney, Sharon L; Swaminathan, MadhavItem Open Access Conventional Ultrafiltration During Elective Cardiac Surgery and Postoperative Acute Kidney Injury.(Journal of cardiothoracic and vascular anesthesia, 2021-05) Manning, Michael W; Li, Yi-Ju; Linder, Dean; Haney, John C; Wu, Yi-Hung; Podgoreanu, Mihai V; Swaminathan, Madhav; Schroder, Jacob N; Milano, Carmelo A; Welsby, Ian J; Stafford-Smith, Mark; Ghadimi, KamrouzObjective
Conventional ultrafiltration (CUF) during cardiopulmonary bypass (CPB) serves to hemoconcentrate blood volume to avoid allogeneic blood transfusions. Previous studies have determined CUF volumes as a continuous variable are associated with postoperative acute kidney injury (AKI) after cardiac surgery, but optimal weight-indexed volumes that predict AKI have not been described.Design
Retrospective cohort.Setting
Single-center university hospital.Participants
A total of 1,641 consecutive patients who underwent elective cardiac surgery between June 2013 and December 2015.Interventions
The CUF volume was removed during CPB in all participants as part of routine practice. The authors investigated the association of dichotomized weight-indexed CUF volume removal with postoperative AKI development to provide pragmatic guidance for clinical practice at the authors' institution.Measurements and main results
Primary outcomes of postoperative AKI were defined by the Kidney Disease: Improving Global Outcomes staging criteria and dichotomized, weight-indexed CUF volumes (mL/kg) were defined by (1) extreme quartiles (Q3) and (2) Youden's criterion that best predicted AKI development. Multivariate logistic regression models were developed to test the association of these dichotomized indices with AKI status. Postoperative AKI occurred in 827 patients (50.4%). Higher CUF volumes were associated with AKI development by quartiles (CUF >Q3 = 32.6 v CUF < Q1 = 10.4 mL/kg; odds ratio [OR] = 1.68, 95% CI: 1.19-2.3) and Youden's criterion (CUF ≥ 32.9 v CUF <32.9 mL/kg; OR = 1.60, 95% CI: 1.21-2.13). Despite similar intraoperative nadir hematocrits among groups (p = 0.8), higher CUF volumes were associated with more allogeneic blood transfusions (p = 0.002) and longer lengths of stay (p < 0.001).Conclusions
Removal of weight-indexed CUF volumes > 32 mL/kg increased the risk for postoperative AKI development. Importantly, CUF volume removal of any amount did not mitigate allogeneic blood transfusion during elective cardiac surgery. Prospective studies are needed to validate these findings.Item Open Access Discordance in Grading Methods of Aortic Stenosis by Pre-Cardiopulmonary Bypass Transesophageal Echocardiography.(Anesth Analg, 2016-04) Whitener, George; McKenzie, Jeff; Akushevich, Igor; White, William D; Dhakal, Ishwori B; Nicoara, Alina; Swaminathan, MadhavBACKGROUND: Current guidelines define severe aortic valve stenosis (AS) as an aortic valve area (AVA) ≤1.0 cm by the continuity equation and mean gradient (ΔPm) ≥ 40 mm Hg. However, these measurements can be discordant when classifying AS severity. Approximately one-third of patients with normal ejection fraction and severe AS by AVA have nonsevere AS by ΔPm when measured by preoperative transthoracic echocardiography (TTE). Given the use of positive pressure ventilation and general anesthesia in the pre-cardiopulmonary bypass (pre-CPB) period, we hypothesized that discordance between ΔPm and AVA during pre-CPB transesophageal echocardiography (TEE) would be higher than previously reported by TTE. METHODS: We retrospectively examined pre-CPB TEE data for patients who had aortic valve replacement, with or without coronary artery bypass grafting, from 2000 to 2012. Patients were excluded if they had ejection fraction <55%, emergency surgery, repeat sternotomy, moderate or severe mitral regurgitation, or severe aortic regurgitation. Only patients with both pre-CPB AVA and ΔPm measurements were included. Patients were grouped according to severity (mild, moderate, and severe) by AVA or ΔPm. Discordance was defined as disagreement between severities based on either parameter. RESULTS: A total of 277 patients met inclusion criteria. There were 227 patients with AVA ≤ 1.0 cm. The proportion of these patients with a ΔPm < 40 mm Hg was 54% (95% confidence interval, 47%-61%). The rate of discordance was significantly higher than the rate (37%; P < 0.001) found in previously reported analyses using TTE. Of the patients with a ΔPm ≥ 40 mm Hg, only 8% (n = 9/113) had a discordant AVA. In contrast, of the patients with ΔPm < 40 mm Hg, 80% (n = 131/164) had a discordant AVA. CONCLUSIONS: We confirmed our hypothesis that grading AS by ΔPm and AVA during pre-CPB TEE exhibits higher discordance than reported for TTE by others. It remains unclear whether these discrepancies reflect the effect of general anesthesia, imaging modality (TTE versus TEE) differences, inaccuracies in AS grading cutoffs when applied to pre-CPB TEE, or selection bias of the surgical population.Item Open Access Grading Aortic Stenosis With Mean Gradient and Aortic Valve Area: A Comparison Between Preoperative Transthoracic and Precardiopulmonary Bypass Transesophageal Echocardiography.(J Cardiothorac Vasc Anesth, 2016-10) Whitener, George; Sivak, Joseph; Akushevich, Igor; Samad, Zainab; Swaminathan, MadhavOBJECTIVE: The authors hypothesized that average precardiopulmonary bypass (pre-CPB) transesophageal echocardiographic (TEE) mean gradient (PGm) and aortic valve area (AVA) values would be significantly different from preoperative transthoracic (TTE) values in the same patients and that these changes would affect pre-CPB TEE grading of aortic stenosis (AS). DESIGN: Retrospective, observational design. SETTING: Single university hospital. PARTICIPANTS: The study comprised 92 patients who underwent aortic valve replacement with or without coronary artery bypass grafting between 2000 and 2012 at Duke University Hospital and who had PGm and AVA values recorded in both pre-CPB TEE and preoperative TTE reporting databases. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: PGm with pre-CPB TEE was lower by 6.6 mmHg (95% confidence interval, -4.0 to -9.3 mmHg; p<0.001), whereas AVA was higher by 0.10 cm(2) (95% confidence interval, 0.04 to 0.15 cm(2); p<0.001), compared with preoperative TTE values. When using PGm, pre-CPB TEE generated an AS severity 1 grade lower 39.1% of the time and revealed no difference 55.4% of the time compared to preoperative TTE. When using AVA by continuity, pre-CPB TEE generated an AS severity 1 grade lower 14.1% of the time and revealed no difference 81.5% of the time compared to preoperative TTE. When using either PGm or AVA, preoperative TTE exhibited moderate or severe AS for all study patients, whereas, pre-CPB TEE demonstrated mild AS in 5.4% (n = 92) of patients. CONCLUSIONS: The authors confirmed their hypothesis that pre-CPB TEE generates different PGm and AVA values compared with preoperative TTE. These differences often underestimate AS severity. Hemodynamic standardizations or adjustments of pre-CPB TEE PGm and AVA values may be necessary in anesthetized patients before assigning an AS grade using these parameters.Item Open Access Integrating tailored approaches in perioperative care strategies for neurodivergent individuals(eClinicalMedicine, 2024-10) Moreno-Duarte, Ingrid; Brandsen, Sam; Dawson, Geraldine; Einhorn, Lisa M; Swaminathan, MadhavItem Open Access Mitral Regurgitation After Orthotopic Lung Transplantation: Natural History and Impact on Outcomes.(J Cardiothorac Vasc Anesth, 2017-06) McCartney, Sharon L; Cooter, Mary; Samad, Zainab; Sivak, Joseph; Castleberry, Anthony; Gregory, Stephen; Haney, John; Hartwig, Matthew; Swaminathan, MadhavOBJECTIVE: Progression of mitral regurgitation (MR) after orthotopic lung transplantation (OLT) may be an underrecognized phenomenon due to the overlapping symptomatology of pulmonary and valvular disease. Literature evaluating the progression of MR after OLT currently is limited to case reports. Therefore, the hypothesis that MR progresses after OLT was tested and the association of preprocedure MR with postoperative mortality was assessed. DESIGN: A retrospective cohort. SETTING: A tertiary-care hospital. PARTICIPANTS: Patients who underwent OLT between January 1, 2003 and February 4, 2012. INTERVENTIONS: After receiving institutional review board approval, a preprocedure transesophageal echocardiogram was compared with a postoperative transthoracic echocardiogram (TTE) to determine the progression of MR. Univariate and multivariate association between preprocedure MR grade and 1- and 5-year mortality was assessed. A p value of<0.05 was considered statistically significant. MEASUREMENTS AND MAIN RESULTS: From 715 patients who underwent OLT, 352 had a postoperative TTE and were included in the evaluation of progression of MR. Five patients had progression of MR postoperatively, and the mean change in MR score of -0.04 was found to be nonsignificant (p = 0.25). Mortality data were available for 634 of the 715 patients. After covariate adjustment, there was no significant association between MR grade and 1-year mortality (p = 0.20) or 5-year mortality (p = 0.46). CONCLUSIONS: This study rejected the hypothesis that primary and secondary MR progresses after OLT and found that preprocedure MR was not associated with increased postoperative mortality. Despite the findings that MR does not progress in all patients, there is a subset of patients for whom MR progression is clinically significant.Item Open Access Pulmonary dysfunction after lung transplantation: the dilemma of coexisting mitral regurgitation.(J Cardiothorac Vasc Anesth, 2014-12) McCartney, Sharon L; Colin, Brian J; Duane Davis, R; Del Rio, J Mauricio; Swaminathan, MadhavA case of MR progression after single-lung transplant as a significant contributor to postoperative respiratory failure is reported. Pre-existing MR may progress due to the decompressive effects of lung transplantation on RV dimension and consequent alteration of MV geometry. This case highlights the importance of intraoperative TEE findings, especially pertaining to valvulopathies in the setting of lung transplantation. Postoperative surveillance of significant findings is imperative when any new symptoms are being investigated.Item Open Access Representation of Female Faculty at US Medical Schools and Success in Obtaining National Institutes of Health Funding, 2008-2018.(JAMA network open, 2021-03) Malinzak, Elizabeth Burney; Weikel, Daniel; Swaminathan, MadhavItem Open Access Use of mobile tablet devices and reduction in time to perioperative transesophageal echocardiography reporting: a historical cohort study(Canadian Journal of Anesthesia, 2015-01-01) Bottiger, Brandi; McCartney, Sharon; Akushevich, Igor; Nicoara, Alina; Yanamadala, Mamata; Swaminathan, Madhav© 2014, Canadian Anesthesiologists' Society.Purpose: Timely communication of intraoperative transesophageal echocardiography (TEE) findings to the postoperative care team is critical to optimizing patient care. We compared the use of a personal computer (PC) system with the use of a mobile tablet device (MTD) system for point-of-care TEE data entry and hypothesized that the MTD-based system would reduce the time to preliminary TEE reporting and decrease the incidence of delinquent reporting by 50%. Methods: In this historical cohort study, we reviewed 508 perioperative TEE reports entered by cardiothoracic anesthesia fellows. Reports were grouped based on whether data were entered on a PC (PC group) or a MTD (MTD group). Time to TEE reporting was defined as the time from the patient leaving the operating room to the time the TEE report was generated. Delinquent reports were defined as those generated >24 hr after the initial exam. Time to TEE reporting and incidence of delinquent reports were compared between the two groups. Results: Mean (SD) time to TEE reporting was significantly improved with MTD data entry vs PC data entry [233 (676) min vs 1,103 (3,830) min, respectively; mean difference 870 min; 95% confidence interval (CI) 293 to 1,448; P = 0.003], and median (IQR) time was also significantly improved [46 (163) min vs 126 (1,000) min, respectively; median difference 80 min; P = 0.0002]. The incidence of report delinquency with MTD data entry vs PC data entry was also significantly reduced [2.1% vs 6.8%, respectively; mean difference 2.2%; 95% CI 0.5 to 9.0; P = 0.02]. Conclusion: Implementation of a MTD system for data entry leads to improved TEE reporting time and reduces TEE reporting delinquency. Further studies are required to determine whether this strategy enhances quality of reporting, optimizes communication between care teams, and improves outcomes without increasing costs.