Kevin W. Lobdell

Effect of body mass index on outcomes after cardiac surgery: is there an obesity paradox?

BACKGROUND Numerous studies have documented an obesity paradox in which overweight and obese people with cardiovascular disease have a better prognosis compared with patients with normal body mass index (BMI). This study sought to quantify the effect of BMI on clinical outcomes after cardiac surgery and investigate the obesity paradox. METHODS A concurrent cohort study of 2,440 consecutive patients undergoing cardiac surgery (coronary artery bypass grafting [CABG], valve, or CABG and valve surgery) from January 2004 to December 2008 was carried out. The patients were divided into three groups on the basis of BMI: normal weight (BMI 18.5 to 24.9; n=556; 23%), overweight (BMI 25.0 to 29.9; n=965; 39%), and obese (BMI≥30; n=919; 38%). Multivariable analyses and propensity score matching were used to compare the early and late clinical outcomes among the different BMI groups. RESULTS Overweight patients had a lower operative mortality (odds ratio, 0.4; 95% confidence interval, 0.2 to 0.9; p=0.031) compared with normal BMI patients. Obese patients had a comparable risk for operative mortality (odds ratio, 0.8; 95% confidence interval, 0.4 to 1.6; p=0.47) compared with normal-weight patients. Actuarial 5-year survival was better for the overweight (hazard ratio, 0.5; 95% confidence interval, 0.4 to 0.8; p=0.002) and comparable for the obese (hazard ratio, 0.9; 95% confidence interval, 0.5 to 1.4; p=0.49) groups compared with the normal-weight patients. CONCLUSIONS Overweight patients have better early hospital outcomes and improved survival after cardiac surgery compared with normal BMI patients, supporting the obesity paradox.

Hospital-Acquired Infections

Health-acquired infection (HAI) is defined as a localized or systemic condition resulting from an adverse reaction to the presence of infectious agents or its toxins. This article focuses on HAIs that are well studied, common, and costly (direct, indirect, and intangible). The HAIs reviewed are catheter-related bloodstream infection, ventilator-associated pneumonia, surgical site infection, and catheter-associated urinary tract infection. This article excludes discussion of Clostridium difficile infections and vancomycin-resistant Enterococcus.

Hypoglycemia with intensive insulin therapy after cardiac surgery: Predisposing factors and association with mortality

BACKGROUND Intensive insulin therapy has become a major therapeutic target in cardiac surgery patients. It has been associated, however, with an increased risk of hypoglycemia compared with conventional insulin therapy. Our study sought to identify the factors predisposing to hypoglycemia with intensive insulin therapy and investigate its effect on early clinical outcomes after cardiac surgery. METHODS A concurrent cohort study of 2,538 consecutive patients undergoing cardiac surgery (coronary artery bypass grafting, valve, or bypass grafting and valve surgery) from January 2005 to March 2010 was carried out. Multivariable logistic regression analysis and propensity score matching were used (1) to identify the risk factors for developing hypoglycemia (blood glucose < 60 mg/dL) after cardiac surgery and (2) to compare major morbidity, operative mortality, and actuarial survival between patients in whom hypoglycemia developed (n = 77) and those in whom it did not (n = 2461). The propensity score-adjusted sample included 61 patients in whom hypoglycemia developed and 305 patients in whom it did not (1 to 5 matching). RESULTS Risk factors for hypoglycemia included female gender (odds ratio [OR] = 2.3, 95% confidence intervals [CI] = 1.4-3.7; P < .001), diabetes (OR = 2.8, CI = 1.7-4.5; P < .001), hemodialysis (OR = 3.0, CI = 1.3-6.8; P = .009), intraoperative blood product transfusion (OR = 2.0, CI = 1.2-3.4; P = .010), and earlier date of surgery (years of surgery, 2005-2007; OR = 2.1, CI = 1.2-3.7; P = .007) . Hypoglycemia increased the risk for operative mortality in univariate (hypoglycemic 10% vs normoglycemic patients 2%; P < .001) but not in propensity score- adjusted analysis (OR= 2.5, 0.9-6.7; P = .11). The propensity score-adjusted analysis demonstrated a significant increase in hemorrhage-related reexploration (P = .048), pneumonia (P < .001), reintubation (P < .001), prolonged ventilatory support (P < .001), hospital length of stay (P < .001), and intensive care unit length of stay (P < .001) for the hypoglycemic compared with normoglycemic patients. Five-year actuarial survival was similar in the compared patient groups (hypoglycemic 75% vs normoglycemic 75%; P = .22). CONCLUSIONS Hypoglycemia with intensive insulin therapy is independently associated with increased risk for respiratory complications and prolonged hospital and intensive care unit lengths of stay after cardiac surgery. In our study, hypoglycemia was not independently associated with increased risk of death.

Quality Improvement Program Increases Early Tracheal Extubation Rate and Decreases Pulmonary Complications and Resource Utilization After Cardiac Surgery

Abstract  Background: Early tracheal extubation is a common goal after cardiac surgery and may improve postoperative outcomes. Our study evaluates the impact of a quality improvement program (QIP) on early extubation, pulmonary complications, and resource utilization after cardiac surgery. Methods: Between 2002 and 2006, 980 patients underwent early tracheal extubation (<6 hours after surgery) and 1231 had conventional extubation (> 6 hours after surgery, conventional group). Outcomes compared between the two groups included: (1) pneumonia, (2) sepsis, (3) intensive care unit (ICU) length of stay, (4) hospital length of stay, (5) ICU readmission, and (6) reintubation. Logistic regression analysis and propensity score adjustment were used to adjust for imbalances in the patients’ preoperative characteristics. Results: Early extubation rates were significantly increased with QIP (QIP 53% vs. Non‐QIP 38%, p = 0.01). Early extubation was associated with a lower rate of (1) pneumonia (odds ratio [OR]= 0.35, 95% confidence intervals [CI]= 0.22–0.55, p <0.001), (2) sepsis (OR = 0.38, CI = 0.20–0.74, p <0.004), (3) prolonged ICU length of stay (OR = 0.42, CI = 0.35–0.50, p <0.001), (4) hospital length of stay (OR = 0.37, CI = 0.29–0.47, p <0.001), (5) ICU readmission (OR = 0.55, CI = 0.39–0.78, p <0.001), and (6) reintubation (OR = 0.53, CI = 0.34–0.81, p <0.003) both in multivariable logistic regression analysis and propensity score adjustment. Conclusions: QIP and early tracheal extubation reduce pulmonary complications and resource utilization after cardiac surgery.

Is advanced age a contraindication for emergent repair of acute type A aortic dissection

With the general increase in human lifespan, cardiac surgeons are faced with treating an increasing number of elderly patients. The aim of our study was to investigate whether advanced age poses an increased risk for major morbidity and mortality with repair of acute type A aortic dissection. Between 2000 and 2008, 119 patients underwent emergency operation for acute type A aortic dissection at two institutions; 90 were younger than 70 years of age and 29 patients were 70 years or older. Major morbidity, operative and 5-year actuarial survival were compared between groups. The operative mortality rates were comparable between the two groups (18.9% in patients <70 years vs. 24.1% for patients >or=70 years, P=0.6). There was no difference in the rates of reoperation for bleeding (<70 years 31.7% vs. 14.3% for >or=70 years, P=0.09), stroke (18.9% for those <70 years vs. 20.7% for those >or=70 years, P=0.79), acute renal failure (22.2% for those <70 years vs. 17.2% for those >or=70 years, P=0.79) or prolonged ventilation (34.4% for those <70 years vs. 24.1% for those >or=70 years, P=0.36) between the two groups. Actuarial 5-year survival rates were 77% for patients <70 years vs. 59% for patients >or=70 years (P=0.07). The mortality for patients who presented with hemodynamic instability was markedly higher (10 out of 14 patients, 71.4%) compared with the mortality of those who presented with stable hemodynamics (21 out of 88 patients, 23.9%, P<0.001), regardless of age group. No significant differences in operative mortality, major morbidity and actuarial 5-year survival were observed between patients >or=70 years and younger patients although there was a trend toward a lower actuarial 5-year survival in older patients. Surgery for type A acute aortic dissection in patients 70 years or older can be performed with acceptable outcomes. Hemodynamic instability portends a poor prognosis, regardless of age.

Does the technique of distal anastomosis influence clinical outcomes in acute type A aortic dissection

The purpose of this study was to evaluate clinical outcomes of two different surgical techniques for the repair of acute type A dissection: open distal anastomosis under deep hypothermic circulatory arrest (DHCA) compared with distal aortic clamping on hypothermic cardiopulmonary bypass (ACPB). Between January 2000 and July 2008, 82 patients underwent DHCA and 42 had ACPB. Major morbidity, operative mortality and five-year actuarial survival were compared between groups. There were no significant differences in the preoperative characteristics. Operative mortality (17% in DHCA vs. 21% in ACPB, P=0.63), reoperation for bleeding (20% in DHCA vs. 34% in ACPB, P=0.16) and stroke rates (16 DHCA vs. 24% in ACPB, P=0.33) were comparable between the two groups. Actuarial five-year survival rates were 74% for DHCA vs. 73% for ACPB, P=0.99. No significant differences in operative mortality, major morbidity and actuarial five-year survival were observed between DHCA and ACPB. There are some practical technical advantages if the distal anastomosis is performed in an open manner. More studies are required to determine the fate of the false lumen between the two techniques.

Failure to Rescue Rates After Coronary Artery Bypass Grafting: An Analysis From The Society of Thoracic Surgeons Adult Cardiac Surgery Database

BACKGROUND Failure to rescue (FTR) is increasingly recognized as an important quality indicator in surgery. The Society of Thoracic Surgeons National Database was used to develop FTR metrics and a predictive FTR model for coronary artery bypass grafting (CABG). METHODS The study included 604,154 patients undergoing isolated CABG at 1,105 centers from January 2010 to January 2014. FTR was defined as death after four complications: stroke, renal failure, reoperation, and prolonged ventilation. FTR was determined for each complication and a composite of the four complications. A statistical model to predict FTR was developed. RESULTS FTR rates were 22.3% for renal failure, 16.4% for stroke, 12.4% for reoperation, 12.1% for prolonged ventilation, and 10.5% for the composite. Mortality increased with multiple complications and with specific combinations of complications. The multivariate risk model for prediction of FTR demonstrated a C index of 0.792 and was well calibrated, with a 1.0% average difference between observed/expected (O/E) FTR rates. With centers grouped into mortality terciles, complication rates increased modestly (11.4% to 15.7%), but FTR rates more than doubled (6.8% to 13.9%) from the lowest to highest terciles. Centers in the lowest complication rate tercile had an FTR O/E of 1.14, whereas centers in the highest complication rate tercile had an FTR O/E of 0.91. CONCLUSIONS CABG mortality rates vary directly with FTR, but complication rates have little relation to death. FTR rates derived from The Society of Thoracic Surgeons data can serve as national benchmarks. Predicted FTR rates may facilitate patient counseling, and FTR O/E ratios have promise as valuable quality metrics.

Original ArticlesBidirectional Cavopulmonary Anastomosis With Intracardiac Repair 1

BACKGROUND Patients with hypoplasia of the right ventricle and tricuspid valve have historically undergone a total cavopulmonary connection or a two-ventricle repair with atrial fenestration. METHODS We reviewed our experience with 9 patients with hypoplasia of the right ventricle and tricuspid valve who underwent a bidirectional cavopulmonary anastomosis with intracardiac repair. Patient diagnoses included pulmonary atresia with intact ventricular septum (n = 3); hypoplastic right ventricle and tricuspid valve with atrial septal defect, ventricular septal defect, and right ventricular outflow tract obstruction (n = 3); unbalanced atrioventricular canal defect (n = 1); inlet ventricular septal defect with coarctation (n = 1); and tricuspid stenosis with atrial septal defect (n = 1). RESULTS The median age at operation was 36 months. There was hypoplasia of the right ventricle and tricuspid valve in all patients. The tricuspid valve measured 56.5% of normal (range, 43.6% to 70.4%) by echocardiography, and the median ratio of the tricuspid valve to the mitral valve was 0.67 (range, 0.54 to 0.82). At operation, the median tricuspid valve annulus diameter was 65.6% of published autopsy normals (range, 57.8% to 78.5%) with a median Z value of -3.8 (range, -6.6 to -2.1). All patients survived operation. At a median follow-up of 16 months, 5 patients are asymptomatic, and 2 have occasional early-morning periorbital edema. Two patients are on a regimen of diuretics, 1 of whom is also taking an unloading agent. The patient with unbalanced atrioventricular canal died suddenly at home 6 months postoperatively. CONCLUSIONS Bidirectional cavopulmonary anastomosis with intracardiac repair may avoid the long-term complications associated with the Fontan modifications and eliminates the need of atrial fenestration in most instances. This operation should be considered for select patients with hypoplasia of the right ventricle and tricuspid valve.

“What's the Risk?” Assessing and Mitigating Risk in Cardiothoracic Surgery

o increase awareness and improve safety, quality, and Tvalue in cardiothoracic surgery, we provide a synopsis of risk, risk assessment methods, and considerations for mitigating modifiable risks associated in the cardiothoracic surgery patient. Definitions of risk include (1) the possibility or danger of injury or loss; (2) a person or thing that creates a hazard; and (3) the chance of financial loss. One way to quantify risk is to sum the product of consequences and probabilities. A common example of risk, in which the potential outcomes and probability are known, would be the flip of a coin. In surgery, however, quantifying risk becomes much more challenging, and all of the possible outcomes and the exact probabilities of each are difficult to forecast for an individual patient. Risk management involves assessing and mitigating risk through avoidance, modification of risk (eg, altering timing or procedure type, cancellation, modifications in host, and other factors), as well as the acceptance of risk. An effective surgical risk management strategy requires an objective comparison of risk exposure to the anticipated value of an operation for each patient. Fundamental characteristics of risk models include calibration, namely, the level of agreement between observed and expected outcomes, and discrimination, which is the ability to distinguish between high-risk and low-risk patients [1]. Additionally, surgical risk scoring systems can be static (eg, a snapshot of a patient’s risk before operative intervention) or dynamic—which factor in the unique pathophysiologic changes associated with the planned procedure through defined phases of care with variation of risk over time [1, 2]. The Society of Thoracic Surgeons (STS) Adult Cardiac Database, established in 1989 and utilized by approximately 1,100 participants in the United States, leads other clinical disciplines in risk assessment and transparency of methodology [3]. Risk algorithms for adult cardiac surgery have been created, are regularly updated with demographic and clinical data, and are currently available for coronary artery bypass grafting (CABG),

Physician Burnout: Are We Treating the Symptoms Instead of the Disease?

Despite increasing recognition of physician burnout, its incidence has only increased in recent years, with nearly half of physicians suffering from symptoms of burnout in the most recent surveys. Unfortunately, most burnout research has focused on its profound prevalence rather than seeking to identify the root cause of the burnout epidemic. Health care organizations throughout the United States are implementing committees and support groups in an attempt to reduce burnout among their physicians, but these efforts are typically focused on increasing resilience and wellness among participants rather than combating problematic changes in how medicine is practiced by physicians in the current era. This report provides a brief review of the current literature on the syndrome of burnout, a summary of several institutional approaches to combating burnout, and a call for a shift in the focus of these efforts toward one proposed root cause of burnout.