Association Between Extracorporeal Membrane Oxygenation Center Volume and Mortality Among Children With Heart Disease: Propensity and Risk Modeling.

OBJECTIVES: To evaluate the relationship between extracorporeal membrane oxygenation center volume and mortality in children undergoing heart operations using propensity score matching in a multiinstitutional cohort. DESIGN: Post hoc analysis of data from an existing national database, Pediatric Health Information System. Propensity score matching was performed to 1-1-1 match patients in low-volume (0-30 cases per year), medium-volume (31-50 cases per year), and high-volume (> 50 cases per year) categories. We tested the sensitivity of our findings by repeating the primary analyses using traditional statistical techniques (traditional regression-based methods and covariate adjustment using propensity score). SETTING: Forty-two children's hospitals across the Unites States. PATIENTS: Patients 18 years old or younger receiving extracorporeal membrane oxygenation before or after pediatric heart operation at a Pediatric Health Information System participating hospital (2004-2013) were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 3,502 from 42 hospitals qualified for inclusion. Using propensity score matching, 1,962 patients were matched 1-1-1 to compare the three volume categories (654 patients in each category). Overall mortality was 1,493 patients (43%). Before matching and adjustment, low- and medium-volume centers were associated with higher mortality (low versus high volume: unadjusted odds ratio, 1.99; 95% CI, 1.68-2.36; p < 0.001). After matching, there was no significant association between center volume and mortality in unadjusted and adjusted analyses (low versus high volume: unadjusted odds ratio, 1.06; 95% CI, 0.85-1.32; p = 0.62 and adjusted odds ratio, 0.97; 95% CI, 0.63-1.50; p = 0.90). This relationship remained similar for analyses using traditional statistical techniques (regression adjustment, low versus high volume: adjusted odds ratio, 1.23; 95% CI, 0.80-1.89; p = 0.35 and covariate adjustment using propensity score, low versus high volume: adjusted odds ratio, 1.16; 95% CI, 0.77-1.74; p = 0.49). CONCLUSIONS: We demonstrated no relationship between extracorporeal membrane oxygenation center volume and mortality. Further analyses are needed to evaluate this relationship.

Predictors of transfusion of packed red blood cells in coronary artery bypass grafting surgery.

OBJECTIVES: Finding predictors of blood transfusion may facilitate the most efficient approach for the use of blood bank services in coronary artery bypass grafting procedures. The aim of this retrospective study is to identify preoperative and intraoperative patient characteristics predicting the need for blood transfusion during or after CABG in our local cardiac surgical service. METHODS: 435 patients undergoing isolated first-time CABG were reviewed for their preoperative and intraoperative variables and analyzed postoperative data. Patients were 255 males and 180 females, with mean age 62.01 ± 10.13 years. Regression logistic analysis was used for identifying the strongest perioperative predictors of blood transfusion. RESULTS: Blood transfusion was used in 263 patients (60.5%). The mean number of transfused blood products units per patient was 2.27 ± 3.07 (0-23) units. The total number of transfused units of blood products was 983. Univariate analysis identified age >65 years, weight <70 Kg, body mass index <25 Kg/m2, hemoglobin <13mg/dL, hematocrit < 40% and ejection fraction <50%, use of cardiopulmonary bypass (CPB), not using an internal thoracic artery as a bypass, and multiple bypasses as significant predictors. The strongest predictors using multivariate analysis were hematocrit < 40% (OR 2.58; CI 1.62-4.15; P<0.001), CPB use (OR 2.00; CI 1.27-3.17; P=0.003) and multiple bypasses (OR 2.31; CI 1.31-4.08; P=0.036). CONCLUSIONS: The identification of these risk factors leads to better identification of patients with a greater probability of using blood, allocation blood bank resources and cost-effectiveness use of blood products.

Factors associated with failure of weaning from long-term mechanical ventilation after cardiac surgery.

The purpose of this prospective, quantitative, comparative study, conducted at the 55 bed cardiothoracic intensive care unit of the Heart Institute (InCor), University of Sao Paulo Medical School, was to identify factors involved in the weaning of patients who require long-term (> 10 days) mechanical ventilation after cardiac surgery. The subjects included all patients who underwent open-heart surgery with cardiopulmonary bypass during a 10 month period from April 2000 to January 2001 (n = 946). From this group, 52 (5.7%) patients who required a tracheotomy for the management of long-term mechanical ventilation after cardiac surgery with cardiopulmonary bypass were selected. Pre-, intra- and postoperative data from patients who were not successfully weaned after reintubation and who underwent an elective tracheotomy were compared. Parameters of respiratory mechanics such as respiratory complications, oxygenation, and cardiac, renal, and neurological function were evaluated. Weaning success was defined as the ability of a patient to tolerate 48 hours without pressure or flow support from a mechanical ventilator. A patient was considered to have failed weaning if they died or remained under ventilation for more than 8 weeks. Of the 52 patients studied, 25 were successfully weaned, 21 died, and 6 remained ventilated for more than 8 weeks. We found significant statistical differences (P < 0.05) between the groups with respect to success or failure in LVEF (P = 0.0035), the need for vasoactive agents (P = 0.0018), and renal failure (P = 0.002). Parameters of respiratory mechanics and oxygenation (eg, static airway compliance, airway resistance) did not influence the success or failure of weaning. There was a significant difference in relation to the presence of pneumonia (P = 0.0086) between the two groups. Although neurological complications were more frequent in patients in the weaning success group, the failure group had lower GCS scores, which is indicative of worse prognoses. It is concluded that cardiac dysfunction, the need for dialysis, and pneumonia are determinants for weaning failure in patients undergoing long-term mechanical ventilation after cardiac surgery.

Coronary artery bypass grafting without cardiopulmonary bypass through sternotomy and minimally invasive procedure.

Coronary artery bypass grafting without cardiopulmonary bypass (CPB) is now an accepted technique of myocardial revascularization in a special subset of patients. This paper presents our total experience in 1761 cases operated on since September 1981 until April 1997 out of a total of 9164 patients revascularized with the conventional technique during this period of time. Among the 1761 patients, 53 (3%) were operated on by minimally invasive surgery. The overall applicability was 19.2% and the most common grafted arteries were left anterior descending artery (LAD), right coronary artery (RCA), and diagonal. Results indicate that the operation can be performed with an acceptable mortality (2.3%) and that all types of arterial conduits can be used. The incidence of major postoperative complications were significantly lower in this group of patients when compared with our patients receiving conventional myocardial revascularization. Most importantly there was decrease cost when the procedure was used because no extracorporeal circulation cardioplegia sets or other cannulas were used. We conclude based on in this fifteen years experience that the technique of myocardial revascularization in a beating heart is justified, safe and can offer to selected patients the best option of coronary insufficiency surgical treatment.