Influence of deep sternal wound infection on long-term survival after cardiac surgery

BACKGROUND: This study aimed to investigate the influence of deep sternal wound infection on long-term survival following cardiac surgery. MATERIAL AND METHODS: In our institutional database we retrospectively evaluated medical records of 4732 adult patients who received open-heart surgery from January 1995 through December 2005. The predictive factors for DSWI were determined using logistic regression analysis. Then, each patient with deep sternal wound infection (DSWI) was matched with 2 controls without DSWI, according to the risk factors identified previously. After checking balance resulting from matching, short-term mortality was compared between groups using a paired test, and long-term survival was compared using Kaplan-Meier analysis and a Cox proportional hazard model. RESULTS: Overall, 4732 records were analyzed. The mean age of the investigated population was 69.3±12.8 years. DSWI occurred in 74 (1.56%) patients. Significant independent predictive factors for deep sternal infections were active smoking (OR 2.19, CI95 1.35-3.53, p=0.001), obesity (OR 1.96, CI95 1.20-3.21, p=0.007), and insulin-dependent diabetes mellitus (OR 2.09, CI95 1.05-10.06, p=0.016). Mean follow-up in the matched set was 125 months, IQR 99-162. After matching, in-hospital mortality was higher in the DSWI group (8.1% vs. 2.7% p=0.03), but DSWI was not an independent predictor of long-term survival (adjusted HR 1.5, CI95 0.7-3.2, p=0.33). CONCLUSIONS: The results presented in this report clearly show that post-sternotomy deep wound infection does not influence long-term survival in an adult general cardio-surgical patient population.

Obesity and overweight as a risk factor for pneumonia in polytrauma patients: a retrospective cohort study

BACKGROUND Obesity is a growing problem in western societies. The aim of this retrospective cohort study was to determine the association between the overweight and obese polytrauma patients and pneumonia after injury. METHODS A total of 628 patients with an Injury Severity Score (ISS) of 16 or greater and 16 years or older were included in this retrospective study. The sample was subdivided into three groups as follows: body mass index (BMI) of less than 25 kg/m2; BMI of 25 kg/m2 to 30 kg/m2; and BMI more than 30 kg/m2. The Murray score was assessed at admission and at its maximum during hospitalization to determine pulmonary problems. Pneumonia was defined as bacteriologically positive sputum with appropriate radiologic and laboratory changes (C-reactive protein and interleukin 6). Data are given as mean ± SEM. One-way analysis of variance and the Kruskal-Wallis test were used for the analyses, and the significance level was set at p < 0.05; Bonferroni-Dunn test was performed as post hoc analysis. RESULTS The Abbreviated Injury Scale (AIS) score for the thorax was 3.2 ± 0.1 in the group with a BMI of less than 25 kg/m2, 3.3 ± 0.1 in the group with a BMI of 25 kg/m2 to 30 kg/m2, and 2.8 ± 0.2 in the group with BMI of more than 30 kg/m2 (p = 0.044). The Murray score at admission was elevated with increasing BMI (0.8 ± 0.8 for BMI < 25 kg/m2, 0.9 ± 0.9 for BMI 25–30 kg/m2, and 1.0 ± 0.8 for BMI > 30 kg/m2; p = 0.137); the maximum Murray score during hospitalization revealed significant differences (1.2 ± 0.9 for BMI < 25 kg/m2, 1.6 ± 1.0 for BMI 25–30 kg/m2, and 1.5 ± 0.9 for BMI > 30 kg/m2; p < 0.001). The incidence of pneumonia also increased with increasing BMI (1.6% for BMI < 25 kg/m2, 2.0% for BMI 25–30 kg/m2, and 3.1% for BMI > 30 kg/m2; p = 0.044). CONCLUSION Obesity leads to an increased incidence of pneumonia in a polytrauma situation. LEVEL OF EVIDENCE Prognostic/epidemiologic study, level IV.

Progressive regression of left ventricular hypertrophy two years after bariatric surgery.

BACKGROUND: Obesity is a systemic disorder associated with an increase in left ventricular mass and premature death and disability from cardiovascular disease. Although bariatric surgery reverses many of the hormonal and hemodynamic derangements, the long-term collective effects on body composition and left ventricular mass have not been considered before. We hypothesized that the decrease in fat mass and lean mass after weight loss surgery is associated with a decrease in left ventricular mass. METHODS: Fifteen severely obese women (mean body mass index [BMI]: 46.7+/-1.7 kg/m(2)) with medically controlled hypertension underwent bariatric surgery. Left ventricular mass and plasma markers of systemic metabolism, together with body mass index (BMI), waist and hip circumferences, body composition (fat mass and lean mass), and resting energy expenditure were measured at 0, 3, 9, 12, and 24 months. RESULTS: Left ventricular mass continued to decrease linearly over the entire period of observation, while rates of weight loss, loss of lean mass, loss of fat mass, and resting energy expenditure all plateaued at 9 [corrected] months (P <.001 for all). Parameters of systemic metabolism normalized by 9 months, and showed no further change at 24 months after surgery. CONCLUSIONS: Even though parameters of obesity, including BMI and body composition, plateau, the benefits of bariatric surgery on systemic metabolism and left ventricular mass are sustained. We propose that the progressive decrease of left ventricular mass after weight loss surgery is regulated by neurohumoral factors, and may contribute to improved long-term survival.

Explanations for unsuccessful weight loss among bariatric surgery candidates.

BACKGROUND: Our objective was to analyze subjective explanations for unsuccessful weight loss among bariatric surgery candidates. METHODS: This was a retrospective analysis of 909 bariatric surgery candidates (78.2% female, average body mass index [BMI] 47.3) at a university center from 2001 to April 2007 who answered an open-ended question about why they were unable to lose weight. We generated a coding scheme for answers to the question and established inter-rater reliability of the coding process. Associations with demographic parameters and initial BMI were tested. RESULTS: The most common categories of answers were nonspecific explanations related to diet (25.3%), physical activity (21.0%), or motivation (19.7%), followed by diet-related motivation (12.7%) and medical conditions or medications affecting physical activity (12.7%). Categories related to time, financial cost, social support, physical environment, and knowledge occurred in less than 4% each. Men were more likely than women to cite a medical condition or medication affecting physical activity (19.2% vs 10.8%, P = 0.002, odds ratio [OR] = 1.96, 95% confidence interval [CI] = 1.28-2.99) but less likely to cite diet-related motivation (7.1% vs 14.2%, P = 0.008, OR = 0.46, 95% CI = 0.26-0.82). CONCLUSIONS: Our findings suggest that addressing diet, physical activity, and motivation in a comprehensive approach would meet the stated needs of obese patients. Raising patient awareness of under-recognized barriers to weight loss, such as the physical environment and lack of social support, should also be considered. Lastly, anticipating gender-specific attributions may facilitate tailoring of interventions.

Body weight, insulin resistance, and serum adipokine levels 2 years after 2 types of bariatric surgery.

OBJECTIVE: Bariatric surgery reverses obesity-related comorbidities, including type 2 diabetes mellitus. Several studies have already described differences in anthropometrics and body composition in patients undergoing Roux-en-Y gastric bypass compared with laparoscopic adjustable gastric banding, but the role of adipokines in the outcomes after the different types of surgery is not known. Differences in weight loss and reversal of insulin resistance exist between the 2 groups and correlate with changes in adipokines. METHODS: Fifteen severely obese women (mean body mass index [BMI]: 46.7 kg/m(2)) underwent 2 types of laparoscopic weight loss surgery (Roux-en-Y gastric bypass=10, adjustable gastric banding=5). Weight, waist and hip circumference, body composition, plasma metabolic markers, and lipids were measured at set intervals during a 24-month period after surgery. RESULTS: At 24 months, patients who underwent Roux-en-Y were overweight (BMI 29.7 kg/m(2)), whereas patients who underwent gastric banding remained obese (BMI 36.3 kg/m(2)). Patients who underwent Roux-en-Y lost significantly more fat mass than patients who underwent gastric banding (mean difference 16.8 kg, P<.05). Likewise, leptin levels were lower in the patients who underwent Roux-en-Y (P=.003), and levels correlated with weight loss, loss of fat mass, insulin levels, and Homeostasis Model of Assessment 2. Adiponectin correlated with insulin levels and Homeostasis Model of Assessment 2 (r=-0.653, P=.04 and r=-0.674, P=.032, respectively) in the patients who underwent Roux-en-Y at 24 months. CONCLUSION: After 2 years, weight loss and normalization of metabolic parameters were less pronounced in patients who underwent gastric banding compared with patients who underwent Roux-en-Y gastric bypass. Our findings require confirmation in a prospective randomized trial.

Hepatic steatosis is associated with surgical-site infection after hepatic and colorectal surgery.

BACKGROUND Obesity and increased visceral fat deposits are important risk factors for surgical-site infection (SSI). Interestingly, a potential role of hepatic steatosis on complications after extrahepatic surgery remains unknown. The aim of the present study was to investigate the impact of hepatic steatosis on SSI in patients that underwent open abdominal surgery. METHODS A total of 231 patients that underwent either liver (n = 116) or colorectal (n = 115) resection and received preoperative contrast-enhanced computed tomography scans were retrospectively investigated. Signal attenuation of the liver parenchyma was measured on computed tomography scans to assess hepatic steatosis. RESULTS More SSIs (including types 1, 2, and 3) were found in the group with hepatic steatosis (56/118 [47.5%]) compared with the control group (30/113 [26.6%]; P = .001). Patients with hepatic steatosis showed greater median body mass index than patients without hepatic steatosis (26.6 kg/m(2) [range 16.8-47.0 kg/m(2)] vs 23.2 kg/m(2) [15.9-32.7 kg/m(2)]; P < .001). Patients with hepatic steatosis experienced longer median operation times (297 minutes [52-708 minutes] vs 240 minutes [80-600 minutes]; P = .003). In a multivariate analysis, hepatic steatosis was identified as an independent risk factor for SSI in patients undergoing hepatic (odds ratio 10.33 [95% confidence interval 1.19-89.76]; P = .03) or colorectal (odds ratio 6.67 [95% confidence interval 1.12-39.33]; P = .04) operation. CONCLUSION Hepatic steatosis is associated with SSI after hepatic and colorectal operation.

Effects of bariatric surgery on gastroesophageal reflux

PURPOSE OF REVIEW: Obesity and gastroesophageal reflux disease (GERD) are two prevalent conditions with important impact on health resource utilization around the world. Obesity is a known risk factor in the pathogenesis of GERD. When conservative measures fail, bariatric surgery remains the only option to lose weight and correct obesity-related comorbidities. The influence of bariatric surgery on GERD depends on which bariatric intervention is used. RECENT FINDINGS: Recent studies indicate that laparoscopic gastric banding and laparoscopic sleeve gastrectomy have little influence on preexisting GERD symptoms and findings, but some patients may develop GERD after laparoscopic sleeve gastrectomy. A number of studies have documented that laparoscopic Roux-en-Y gastric bypass improves GERD symptoms and findings, making it the preferred procedure for morbid obese patients with concomitant GERD. SUMMARY: Current findings provide good arguments for searching for and treating GERD in patients scheduled to undergo bariatric surgery. The presence of GERD might represent a relative contraindication for sleeve gastrectomy or gastric banding or both. Gastric bypass might be the procedure of choice in morbid obese patients with GERD symptoms or findings or both.

Telomere length increase after weight loss induced by bariatric surgery: results from a 10 years prospective study

BACKGROUND/OBJECTIVES Obesity contributes to telomere attrition. Studies focusing on short-term effects of weight loss have been unable to identify protection of telomere length. This study investigates long-term effects of pronounced weight loss induced by bariatric surgery on telomere length. SUBJECTS/METHODS One hundred forty-two patients were recruited in a prospective, controlled intervention study, follow-up investigations were done after 10.46±1.48 years. A control group of normal weight participants was recruited and followed from 1995 to 2005 in the Bruneck Study. A total of 110 participants from each study was matched by age and sex to compare changes in telomere length. Quantitative PCR was used to determine telomere length. RESULTS Telomere length increased significantly by 0.024±0.14 (P=0.047) in 142 bariatric patients within 10 years after surgery. The increase was different from telomere attrition in an age- and sex-matched cohort population of the Bruneck Study (-0.057±0.18; β=0.08; P=0.003). Significant changes in telomere length disappeared after adjusting for baseline body mass index (BMI) because of general differences in BMI and telomere length between the two study populations (β=0.07; P=0.06). Age was proportional to telomere length in matched bariatric patients (r=0.188; P=0.049) but inversely correlated with telomere length in participants of the Bruneck Study (r=-0.197; P=0.039). There was no association between percent BMI/excess weight loss and telomere attrition in bariatric patients. Baseline telomere length in bariatric patients was inversely associated with baseline plasma cholesterol and triglyceride concentrations. Telomere shortening was associated with lower high-density lipoprotein cholesterol and higher fasting glucose concentration at baseline in bariatric patients. CONCLUSIONS Increases in relative telomere length were found after bariatric surgery in the long term, presumably due to amelioration of metabolic traits. This may overrule the influence of age and baseline telomere length and facilitate telomere protection in patients experiencing pronounced weight loss.

The effects of obesity in critical illness

Obesity continues to cripple the United States in terms of increasing health care expenditures and its rising rate of prevalence in epidemic proportions. The comorbidities associated with obesity have continued to represent some of the most deadly chronic health diseases. The most vulnerable subpopulation, the critically ill, suffers from not only the comorbid conditions but also the complications encountered within their specialized care. Taking into account the rising prevalence rates of obesity and critical care patients, it has come to the attention of many researchers to measure the trends associated with these two health conditions. Hospital mortality was found to be lower in higher BMI groups whereas there was no difference between BMI groups for ICU mortality. Length of stay and mechanical ventilation were both higher for obese rather than non-obese patients. The most prevalent disease states among the obese critically injured was cardiovascular and pulmonary disease. In conclusion, obesity is not independently associated with increased ICU mortality, but the comorbidities linked to obesity prove a greater threat to vitality.^

Should Texas use public funding for bariatric surgery?

Background. Obesity in America has increased exponentially since the 1970s with no sign of slowing down. It is a major public health problem, and is currently the second leading cause of preventable deaths in America (Flegal et al., 2010). Bariatric surgery is currently the only approved therapy that has shown to have a lasting impact on obese patients. While the initial cost of the surgery remains high, numerous cost-benefit analyses have demonstrated an overall cost saving within two to five years (McEwen et al., 2010). Only three states, including Texas, do not currently fund bariatric surgery through Medicare and Medicaid. ^ Objectives. To determine whether the current data on the cost-benefit analysis of bariatric surgery supports Texas' decision to not publicly fund bariatric surgery through its Medicare and Medicaid programs. ^ Methods. We conducted literature reviews to determine the current cost of obesity in Texas as well as the methods being employed to treat obesity currently. We then analyzed the history of bariatric surgery and its current implementation, looking at safety and the future benefits of bariatric surgery. We then looked at key cost-benefit analyses and meta-analyses to determine the cost effectiveness of bariatric surgery. We then analyzed both direct medical expenditures and indirect benefits of bariatric surgery. ^ Conclusions. If the obesity epidemic continues unabated, it will become one of the leading health expenditures in Texas within decades. Given that surgery is currently the only approved therapy for obesity that has been shown to be effective in the majority of patients, Texas' decision not to publicly fund bariatric surgery is short sighted.^

Is obesity a possible risk factor for Clostridium difficile infection

Aims: Obesity is a state of chronic inflammation characterized by depressed Th2 immune response. Animal studies have shown decreased IgA levels in obese rats and Leptin an adipose cell origin cytokine have been shown to enhance the activity of Clostridium difficile Toxin A. Hence we hypothesized that obesity is a risk factor for C. difficile infection (CDI) ^ Methods: 33 cases of CDI and 131 controls matched by age and HORNS index were identified from an IRB approved observational study at St. Luke's Episcopal Hospital in Houston. Variables like age, gender, height, weight, chronic antibiotic use, proton pump inhibitor use, diabetes mellitus, myocardial infarction, inflammatory bowel disease, diverticulitis, transfer from nursing home, hospital or home, nasogastric tube use and use of hemodialysis were provided in the dataset. Height and weight of the patient were used to calculate the BMI, based on which the study subjects were classified as obese and non-obese. Using STATA these variables were analyzed using test, chi square test followed by conditional logistic regression. ^ Results: On univariate analysis and conditional logistic regression, no significant increase in risk was associated with obesity (OR: 1.24; 95% CI: 0.46 - 3.36; p = 0.67) or BMI (OR: 0.98; CI: 0.92 - 1.04; p = 0.92). Hence, we cannot reject our hypothesis and conclude that "obesity is a risk factor associated with higher incidence of CDI in hospitalized patients. On univariate analysis using hemodialysis, nursing home transfer, home transfer, PPI and chronic antibiotics were found to be significantly different (p<0.05) in the cases and controls. On conditional logistic regression home (OR: 3.4; 95% CI: 1.15 - 9.61) and hemodialysis (OR: 4.1; 95% CI: 1.14 - 15.57) were found to be significantly different (p<0.05) between the case and control groups. ^ Conclusion: Our results show that obesity is not a significant risk factor for CDI. Our sample size was small and hence this may need conformation with a larger study. Patients transferred from home to the hospital and patients on hemodialysis had significantly higher incidence of CDI.^

Challenges in the Management of Geriatric Obesity in High Risk Populations.

The global prevalence of obesity in the older adult population is growing, an increasing concern in both the developed and developing countries of the world. The study of geriatric obesity and its management is a relatively new area of research, especially pertaining to those with elevated health risks. This review characterizes the state of science for this "fat and frail" population and identifies the many gaps in knowledge where future study is urgently needed. In community dwelling older adults, opportunities to improve both body weight and nutritional status are hampered by inadequate programs to identify and treat obesity, but where support programs exist, there are proven benefits. Nutritional status of the hospitalized older adult should be optimized to overcome the stressors of chronic disease, acute illness, and/or surgery. The least restrictive diets tailored to individual preferences while meeting each patient's nutritional needs will facilitate the energy required for mobility, respiratory sufficiency, immunocompentence, and wound healing. Complications of care due to obesity in the nursing home setting, especially in those with advanced physical and mental disabilities, are becoming more ubiquitous; in almost all of these situations, weight stability is advocated, as some evidence links weight loss with increased mortality. High quality interdisciplinary studies in a variety of settings are needed to identify standards of care and effective treatments for the most vulnerable obese older adults.