Effect of geography on the use of ultrafiltration during cardiac surgery with cardiopulmonary bypass.

BACKGROUND: Ultrafiltration (UF) is a common practice during cardiopulmonary bypass (CPB) where it is used as a blood management strategy to reduce red blood cell (RBC) transfusion, minimize adverse effects of hemodilution, and reduce proinflammatory mediators. However, its clinical utilization has been shown to vary throughout the continents. PURPOSE: The purpose of this investigation was to assess the distribution of UF use across the United States. DATA COLLECTION: Data on UF use during cardiac surgery was obtained from a national (United States) perfusion database for adult cardiac procedures performed from January 2016 through December 2018. STUDY SAMPLE: Four geographical regions were established: Northeast (NE), South (SO), Midwest (MW) and West (WE). The primary endpoint was the use of UF with secondary endpoints UF volume, CPB and anesthesia asanguineous volumes, intraoperative allogeneic RBC transfusion, nadir hematocrit and urine output (UO). 92,859 adult cardiac cases from 191 hospitals were reviewed. RESULTS: The NE and the WE had similar usages of UF (59.9% and 59.7% respectively), which were higher than the MW and the SO (38.6% and 34.9%, p < .001). When UF was utilized, the median [IQR] volume removed was highest in the NE (1900 [1200-2800]mL), and similar in all other regions (WE 1500 [850-2400 mL, MW 1500 [900-2300]mL and SO 1500 [950-2200]mL, p < .001. Median total UO was lowest in the NE 400 [210,650]mL vs all other regions (p < .001), and remained so when indexed by patient weight and operative time (NE-0.8 [0.5, 1.3]mL/kg/hour, MW-1.1 [0.7, 1.8] mL/kg/hour, SO-1.3 [0.8, 2.0]mL/kg/hour, WE-1.1 [0.7, 1.3]mL/kg/hour, p < .001. Intraoperative RBC transfusion rate was highest in the SO (21.3%) and WE (20.5%), while similar rates seen in the NE (16.2%) and MW (17.6%), p < .001. CONCLUSIONS: Across the United States there is geographic variation on the use of UF. Further research is warranted to investigate why these practice variations exist and to better understand and determine their reasons for use.

Establishment of a national quality improvement process on oxygen delivery index during cardiopulmonary bypass.

Targeted oxygen delivery during cardiopulmonary bypass (CPB) has received significant attention due to its influence on patient outcomes, especially in mitigating acute kidney injury. While it has gained popularity in select institutions, there remains a gap in establishing it globally across multiple centers. The purpose of this investigation was to describe the development of a quality improvement process of targeted oxygen delivery during CPB across hospitals throughout the United States. A systematic approach to utilize oxygen delivery index (DO2i) as a key performance indicator within hospitals serviced by a national provider of perfusion services. The process included a review of the current literature on DO2i, which yielded a target nadir value (272 mL/min/m2) and an area under the curve (DO2i272AUC) cut off of 632. All data is displayed on a dashboard with results categorized across multiple levels from system-wide to individual clinician performance. From January 2020 through December 2022, DO2i data from 91 hospitals and 11,165 coronary artery bypass graft procedures were collected. During this period the monthly proportion of DO2i measurements above the target nadir DO2i272 ranged from 60.5% to 78.4% with a mean+/-SD of 70.8 +/- 4.2%. Binary logistic regression for the first 7 months following monthly DO2i performance reporting has shown a statistically significant positive linear trend in the probability of achieving the target DO2i272 (p < .001), with a crude increase of approximately 7.8% for DO2i272AUC, and a 73.8% success rate (p < .001). A survey was sent to all individuals measuring oxygen delivery during CPB to assess why a target DO2i272 could not be reached. The two most common responses were an 'inability to improve CPB flow rates' and 'restrictive allogeneic red blood cell transfusion policies'. This study demonstrates that targeting a minimum level of oxygen delivery can serve as a key performance indicator during CPB using a structured quality improvement process.

The assessment of patients undergoing cardiac surgery for Covid-19: Complications occurring during cardiopulmonary bypass.

The outbreak of the novel coronavirus pandemic (COVID-19) has resulted in dramatic changes to the conduct of surgery both from a patient management perspective and in protecting healthcare providers. The current study reports on the status of COVID-19 infections in patients presenting for cardiac surgery with cardiopulmonary bypass (CPB) on circuit complications. A tracking process for monitoring the presence of COVID-19 in adult cardiac surgery patients was integrated into a case documentation system across United States hospitals where out-sourced perfusion services were provided. Assessment included infection status, testing technique employed, surgery status and CPB complications. Records from 5612 adult patients who underwent cardiac surgery between November 1, 2020 and January 18, 2021 from 176 hospitals were reviewed. A sub-cohort of coronary artery bypass graft patients (3283) was compared using a mixed effect binary logistic regression analysis. 4297 patients had negative test results (76.6%) while 49 (0.9%) tested positive for COVID-19, and unknown or no results were reported in 693 (12.4%) and 573 (10.2%) respectively. Coagulation complications were reported at 0.2% in the negative test results group versus 4.1% in the positive test result group (p < 0.001). Oxygenator gas exchange complications were 0.2% in the negative test results group versus 2.0% in the positive test results group (p = 0.088). Coronary artery bypass graft patients with a positive test had significantly higher risk for any CPB complication (p = 0.003) [OR 10.38, CI 2.18-49.53] then negative test patients [OR 0.01, CI 0.00-0.20]. The present study has shown that patients undergoing cardiac surgery with CPB who test positive for COVID-19 have higher CPB complication rate than those who test negative.

Zero-Balance Ultrafiltration during Cardiopulmonary Bypass Is Associated with Decreased Urine Output.

Zero-balance ultrafiltration (ZBUF) during cardiopulmonary bypass (CPB) has been purported to reduce pro-inflammatory mediators during cardiac surgery. However, its clinical benefit is equivocal and its effect on renal function unknown. The purpose of this study was to examine the effect of ZBUF on urine output in adult patients undergoing CPB. Following institutional review board approval, 98,953 records from a national registry of adult patients at 215 U.S. hospitals between January 2016 and September 2019 were reviewed. Groups were stratified according to ZBUF use. Anuric patients were excluded from the study as they were patients with missing data on urine output, ultrafiltration use, or ZBUF volume. The primary endpoint was intraoperative urine output normalized to body weight and procedure duration (total operative time). Final analysis of this endpoint was carried out using a linear mixed-effects regression model adjusting for patient and procedural characteristics, as well as practice patterns associated with surgeons and perfusionists. There was a significant 16.1% reduction in median urine output for ZBUF patients (.94 [.54, 1.47] mL/kg/h) vs. the non-ZBUF group (1.12 [.70,-1.73] mL/kg/h), p < .001. After statistically adjusting for patient and procedural characteristics, each liter of ZBUF volume was associated with an estimated change in intraoperative urine output of -.03 mL/kg/h (95% CI: [-.04 to -.02], p < .001). The median ZBUF volume was 1,550 [1,000, 2,600] mL, and when ZBUF was used, conventional ultrafiltration (CUF) was more likely to be used as well (88.4% vs. 44.8%, p < .001). ZBUF patients had median asanguineous volume and crystalloid cardioplegia nearly two times more than non-ZBUF patients, and had slightly higher red blood cell transfusions (17.6% vs. 16.3%, p < .05). The application of ZBUF during CPB was associated with patients having lower urine output and significantly higher use of CUF. Further research is required to determine if these results are reproducible in prospective clinical studies.

Low-Flow Extracorporeal Carbon Dioxide Removal Using the Hemolung Respiratory Dialysis System® to Facilitate Lung-Protective Mechanical Ventilation in Acute Respiratory Distress Syndrome.

Extracorporeal carbon dioxide removal (ECCO2R) permits reductions in alveolar ventilation requirements that the lungs would otherwise have to provide. This concept was applied to a case of hypercapnia refractory to high-level invasive mechanical ventilator support. We present a case of an 18-year-old man who developed post-pneumonectomy acute respiratory distress syndrome (ARDS) after resection of a mediastinal germ cell tumor involving the left lung hilum. Hypercapnia and hypoxemia persisted despite ventilator support even at traumatic levels. ECCO2R using a miniaturized system was instituted and provided effective carbon dioxide elimination. This facilitated establishment of lung-protective ventilator settings and lung function recovery. Extracorporeal lung support increasingly is being applied to treat ARDS. However, conventional extracorporeal membrane oxygenation (ECMO) generally involves using large cannulae capable of carrying high flow rates. A subset of patients with ARDS has mixed hypercapnia and hypoxemia despite high-level ventilator support. In the absence of profound hypoxemia, ECCO2R may be used to reduce ventilator support requirements to lung-protective levels, while avoiding risks associated with conventional ECMO.

Direct cannulation of the infrahepatic vena cava for emergent cardiopulmonary bypass support.

Cannulation for cardiopulmonary bypass, although seemingly routine, can pose technical challenges. In patients undergoing repeat sternotomy, for example, peripherally established cardiopulmonary bypass may be necessary to ensure safe entry into the chest; however, establishing bypass in this way can sometimes be complicated by patients' body habitus. We describe a technique for direct cannulation of the infrahepatic abdominal vena cava that was required for emergent cardiopulmonary bypass. The patient was a 62-year-old woman who had presented with severely symptomatic left main coronary stenosis 3 months after elective aortic valve replacement. She had gone into cardiogenic shock as general anesthesia was being induced for repeat sternotomy and myocardial revascularization. Emergent establishment of femorofemoral cardiopulmonary bypass was precluded by difficulties in advancing the femoral venous cannula beyond the pelvic brim. Hence, an emergent celiotomy was performed, and the abdominal vena cava was directly cannulated to establish venous drainage for cardiopulmonary bypass. The rest of the operation was uneventful. Our technique for direct cannulation of the infrahepatic abdominal vena cava may be used in exceptional circumstances. Necessary precautions and potential pitfalls are also presented.

Off-pump coronary artery bypass grafting for spontaneous coronary dissection in a 26-year-old patient two weeks post-partum: a case report and review.

Spontaneous coronary artery dissections are an infrequent cause of myocardial infarction and have been reported in late stages of pregnancy and in the puerperium phase. We report a case of a 26-year-old post-partum woman who was diagnosed with a spiral coronary dissection of the left anterior descending artery, with a compromised diagonal branch. She underwent an emergent surgical revascularization without the use of cardiopulmonary bypass. The patient's in-hospital clinical course, prognosis, treatment, and potential etiologies are discussed.

Hemoglobin test result variability and cost analysis of eight different analyzers during open heart surgery.

The purpose of this study was to compare the variation in hemoglobin (Hgb) values among various point-of-care (POC) analyzers available on the market. Eight analyzers (Gem 3000, ABL 720, ABL 77, Rapidpoint 405, IL 682, GemOPL, Hb 201+, and manual/centrifugation) were compared with the Hgb values from the Beckman Coulter LH750. A total of 72 patient samples were analyzed on each test instrument. The samples were obtained after intubation, after heparinization, during cardiopulmonary bypass, and after protamine administration. Four of the samples were excluded from the study because of delayed sample analysis. The calculated mean differences of reference test method Hgb (mean +/- SD) for all samples (n = 68) were Gem 3000 = 1.431 +/- 0.396 g/dL; ABL 720 = -0.224 +/- 0.240 g/dL; ABL 77 = 0.341 +/- 0.578 g/dL; Rapidpoint 405 = 0.001 +/- 0.205 g/dL; IL 682 = -0.137 +/- 0.232 g/dL; GemOPL = 0.774 +/- 0.427 g/dL; Hb 201+ = 0.110 +/- 0.524 g/dL; and manual/ centrifugation = 0.547 +/- 0.499 g/dL. Cumulative results indicated that the bias in Hgb values from the Gem 3000, ABL720, ABL 77, IL 682, GemOPL, and the manual method were statistically significant (p < .05), compared with the Coulter LH750. Additionally, only the Rapidpoint 405 and Hb 201+ most closely matched the values from the Coulter LH750 (p > .05). Some of the methodologies have previously been shown to be affected during hemodilution, hypoproteinemia, and/or after blood transfusion. There is variability among methodologies, which can give rise to statistically different Hgb values, and one should consider the "ideal" instrument based on this and many other factors. Based on our results, the rank order of closest approximation to the Coulter LH750 measurement was Rapidpoint 405, Hb 201+, IL 682, ABL 720, ABL 77, manual/centrifugation, GemOPL, and Gem 3000.