Infection In Obese Patients Research Articles

Outcomes after elective abdominal aortic aneurysm repair in obese versus nonobese patients

ObjectiveObesity is a worldwide epidemic, particularly in Western society. It predisposes surgical patients to an increased risk of adverse outcomes. The aim of our study was to use a nationally representative vascular database and to compare in-hospital outcomes in obese vs nonobese patients undergoing elective open aortic repair (OAR) and endovascular aneurysm repair (EVAR). MethodsAll patients undergoing elective abdominal aortic aneurysm repair were identified in the Vascular Quality Initiative database (2003-2017). Obesity was defined as body mass index ≥30 kg/m2. Univariable (Student t-test and χ2 test) and multivariable (logistic regression) analyses were implemented to compare in-hospital mortality and any major complications (wound infection, renal failure, and cardiopulmonary failure) in obese vs nonobese patients. ResultsWe identified a total of 33,082 patients undergoing elective OAR (nonobese, n = 4605 [72.4%]; obese, n = 1754 [27.6%]) and EVAR (nonobese, n = 18,338 [68.6%]; obese, n = 8385 [31.4%]). Obese patients undergoing OAR and EVAR were relatively younger compared with nonobese patients (mean age [standard deviation], 67.55 [8.26] years vs 70.27 [8.30] years and 71.06 [8.22] years vs 74.55 [8.55] years), respectively; (both P < .001). Regardless of approach, obese patients had slightly longer operative time (OAR, 259.02 [109.97] minutes vs 239.37 [99.78] minutes; EVAR, 138.27 [70.64] minutes vs 134.34 [69.98] minutes) and higher blood loss (OAR, 2030 [1823] mL vs 1619 [1642] mL; EVAR, 228 [354] mL vs 207 [312] mL; both P < .001). There was no significant difference in mortality between the two groups undergoing OAR and EVAR (OAR, 2.9% vs 3.2% [P = .50]; EVAR, 0.5% vs 0.6% [P = .76]). On multivariable analysis, obese patients undergoing OAR had 33% higher odds of renal failure (adjusted odds ratio [OR], 1.33; 95% confidence interval [CI], 1.09-1.63; P = .006) and 75% higher odds of wound infections (adjusted OR, 1.75; 95% CI, 1.11-2.76; P = .02) compared with nonobese patients. However, in patients undergoing EVAR, no association was seen between obesity and any major complications. A significant interaction was found between obesity and surgical approach in the event of renal failure, in which obese patients undergoing OAR had significantly higher odds of renal failure compared with those in the EVAR group (ORinteraction, 1.36; 95% CI, 1.05-1.75; P = .02). ConclusionsUsing a large nationally representative database, we demonstrated an increased risk of renal failure and wound infections in obese patients undergoing OAR compared with nonobese patients. On the other hand, obesity did not seem to increase the odds of major adverse outcomes in patients undergoing EVAR. Further long-term prospective studies are needed to verify the effects of obesity after abdominal aortic aneurysm repair and the implications of these findings in clinical decision-making.

Prophylactic Negative Pressure Wound Therapy in Obese Patients Following Cesarean Delivery.

Negative pressure therapy (NPT) offers the potential to reduce infection in obese patients. The goal of this study was to explore the association between NPT use and infection after cesarean delivery among obese women. We initiated a hospital protocol wherein women with a body mass index (BMI) of 40 kg/m2 or greater who delivered after January 1, 2011 were to receive NPT following cesarean section. A retrospective comparison of surgical site infection (SSI) in women receiving the intervention to a similar group with a BMI of 40 kg/m2 or greater, a historical control group of women who delivered before January 1, 2011. Incidence of SSI was compared between time periods using logistic regression models. A total of 233 patients in the preintervention (control) group and 234 patients in the intervention group were included in the analysis. In the control group, 23 (9.9%) developed SSI, compared with 13 (5.6%) in the intervention group. After adjustment for potential confounding factors, women in the postintervention period experienced a statistically significant reduction in SSI rates (adjusted odds ratio =0.45, 95% CI = 0.22-0.95); P = .04). Implementation of a hospital protocol of NPT following cesarean delivery in obese women resulted in reduced incidence of postoperative SSI. This study suggests that using NPT after cesarean delivery in women with a BMI ≥40 kg/m2 is an efficacious method to reduce incidence of postoperative wound infections.

Obesity Is Independently Associated With Early Aseptic Loosening in Primary Total Hip Arthroplasty

BackgroundObesity affects millions of patients in the United States and is associated with several complications after total hip arthroplasty (THA). The effect of obesity on the rate and mode of primary THA failure remains poorly understood, especially given other potentially confounding patient characteristics. We hypothesized that, among patients with a failed primary THA, obesity is independently associated with aseptic loosening and a higher rate of early revision. MethodsSix hundred eighty-four consecutive cases with failed THA referred to a single academic center for revision during a 10-year period were retrospectively reviewed. Multivariate logistic regression analysis was used to test the independent association between obesity and the timing as well as cause of THA failure. ResultsThe rate of primary THA failure before 5 years was 48.8% in obese and 37.1% in nonobese patients (odds ratio [OR] = 1.57, P = .010). Primary THA failure before 5 years was more likely with increasing body mass index (BMI) (BMI: 35-40 kg/m2, OR = 2.31, P = .008; BMI >40 kg/m2, OR = 2.51, P = .049). The rate of primary THA failure for aseptic loosening before 5 years was 30% in obese and 18% in nonobese patients (OR = 1.88, P = .023). Obesity was not a risk for revision for infection, whereas an American Society of Anesthesiologists class ≥3 was independently associated with primary THA failure for infection (OR = 2.33, P < .001). ConclusionAmong patients with a failed THA, comorbidities may account for the risk of revision due to infection in obese patients. Obesity is independently associated with early primary THA failure for aseptic loosening.

Association between Pre-Operative Cefazolin Dose and Surgical Site Infection in Obese Patients.

A fixed dose of cefazolin results in serum concentrations that decrease as body mass increases. Current national guidelines suggest a pre-operative cefazolin dose of two grams may be insufficient for patients ≥120 kg; thus a three gram dose is recommended. These recommendations, however, are based on pharmacokinetic rather than outcome data. We evaluate the efficacy of pre-operative cefazolin two gram and three gram doses as measured by the rate of surgical site infection (SSI). We conducted a retrospective review of adult patients ≥100 kg who were prescribed cefazolin as surgical prophylaxis between September 1, 2012 and May 31, 2013 at an academic medical center. Patients were excluded if cefazolin was prescribed but not administered, had a known infection at the site of surgery, or inappropriately received cefazolin prophylaxis based on surgical indication. The SSIs were identified by documentation of SSI in the medical record or findings consistent with the standard Centers for Disease Control and Prevention definition. Inpatient and outpatient records up to 90 days post-operative were reviewed for delayed SSI. Four hundred eighty-three surgical cases were identified in which pre-operative cefazolin was prescribed. Forty-seven patients were excluded leaving a total of 436 patients for final analysis: 152 in the cefazolin two gram group and 284 in the three gram group. Baseline demographics were similar between groups with a mean follow-up duration of 77 days for both groups. Unadjusted SSI rates were 7.2% and 7.4% (odds ratio [OR] 0.98, p = 0.95), for the two gram and three gram groups, respectively. When differences in follow-up between groups were considered and logistic regression was adjusted with propensity score, there remained no difference in SSI rates (OR 0.87, 95% confidence interval 0.36-2.06, p = 0.77). In otherwise similar obese surgical patients weighing ≥100 kg, the administration of a pre-operative cefazolin two gram dose is associated with a similar rate of SSI compared with patients who received a three gram dose.

Severely Obese Patients Have a Higher Risk of Infection After Direct Anterior Approach Total Hip Arthroplasty

BackgroundThe orthopedic literature documents that obesity can place patients at increased risk for complications. This is the first study to document the increased risk of infection in obese patients after direct anterior approach (DAA) primary total hip arthroplasty (THA). MethodsWe retrospectively evaluated 1621 consecutive primary THAs performed with a DAA. Patients were stratified by body mass index <35 kg/m2 (group 1) or ≥35 kg/m2 (group 2). Rates of postoperative infection requiring revision, superficial wound dehiscence, return to the operating room, and total wound complications were compared. There were 1417 cases in group 1 and 204 in group 2. ResultsFive cases in each group had a deep infection, resulting in a significantly higher rate in group 2 (0.35% vs 2.5%, P = .0044, relative risk = 7.1). Superficial wound dehiscence was diagnosed in 13 (0.92%) THA in group 1 and 4 (1.96%) in group 2 (P = .256). The all-cause reoperation rate was 0.92% and 3.43% in each group, respectively (P = .008). The total rate of all studied complications was 1.27% compared to 4.41% (P = .0040, relative risk = 3.5). ConclusionThis is the first study to report on significantly increased rates of postoperative infection requiring revision in patients with body mass index ≥35 kg/m2 after anterior approach hip arthroplasty. We believe it is the combination of immune dysfunction and proximity of the anterior incision to the inguinal crease and genitalia with overlying abdominal pannus that contributes to this risk. Further studies comparing other surgical approaches in obese patients are needed to determine if this complication is truly attributable to the DAA alone.

Effect of Obesity on Outcomes of Forefoot Surgery

Forefoot surgery typically is elective, so it is important to define risk factors to educate patients on potential complications. The purpose of this study was to determine if obesity is an independent risk factor that contributes to increased complication rates after forefoot surgery. Through a retrospective review of records, 633 patients were identified who had forefoot surgery at one institution between 2008 and 2010. All patients who currently smoked or smoked in the past were excluded to eliminate a confounding factor, as smoking is known to increase complication rates, leaving 427 patients for inclusion, 299 nonobese (BMI less than 30) and 128 obese (BMI more than 30). Medical records were reviewed for the occurrence of complications, including nonunion, delayed union, delayed wound healing, infection, and persistent pain. The overall complication rate was 9%, with similar rates between obese (10%) and nonobese patients (9%). The only specific complication approaching significance (P = .13) was a higher rate of infection in obese patients (4 % compared to 1%), which could be attributed to the higher percentage of diabetic patients in the obese group. Diabetic patients, regardless of weight, had significantly higher rates of infection (P = .03), with a trend toward higher rates of overall complications and delayed wound healing (P = .08 and P < .06, respectively). Obesity was not shown to lead to more frequent complications after forefoot surgery. Diabetes was associated with significantly higher rates of infection, regardless of weight. Though not significant, there was a trend toward higher rates of overall complications and delayed wound healing in diabetic patients as well. Level III, retrospective comparative study.

The minimally invasive approach is associated with reduced surgical site infections in obese patients undergoing proctectomy.

While laparoscopic colorectal resection may be underused in technically challenging circumstances, the minimally invasive approach may in fact maximally benefit patients at the greatest risk of complications. Obesity and proctectomy pose particular technical challenges during laparoscopic resection and are also associated with the greatest risks of complications, especially surgical site infections (SSIs). We evaluated the role of laparoscopy in minimizing SSI in such patients. From the American College of Surgeons-National Surgical Quality Improvement Program database, outcomes for obese [body mass index (BMI) ≥ 30 kg/m(2)] and non-obese (BMI < 30 kg/m(2)) patients undergoing colectomy or proctectomy between 2006 and 2011 by the laparoscopic (laparoscopic colectomy, laparoscopic proctectomy) or open (open colectomy, open proctectomy) approaches were compared. A univariate analysis was used to determine the influence of laparoscopic surgery within each group on SSI, and a multivariate analysis evaluated the influence of laparoscopy on SSI for obese patients undergoing proctectomy. OC patients were more likely than OP, LC, and LP, respectively, to undergo emergency operation and have an American Society of Anesthesiologists (ASA) score of 3-5. Overall SSI rates after OC, OP, LC, and LP were 15.2, 17.6, 8.6, and 10.1 %, respectively (p < 0.001), and for obese patients, the rates were 18.7, 22.3, 10.7, and 13.3 % (p < 0.001). On univariate analysis, open surgery, obesity, proctectomy, younger age, race, steroid use, diabetes, chronic obstructive pulmonary disease, prior wound infection, transfusion history, previous operation within 30 days, coronary artery or vascular disease, ASA class 3-5, tobacco use, resident involvement, male gender, albumin <3.5 g/dL, and emergent operation were associated with a higher risk of SSI. Laparoscopy reduced the risk of SSI by at least 35 % across all BMI classes and procedures, an effect that persisted on multivariate analysis even in obese patients undergoing proctectomy. In colorectal surgery, an already high-risk outlier for SSI, obesity and proctectomy are associated with the highest risk of SSI. Despite the particular technical challenges of laparoscopy in these circumstances, the minimally invasive approach attenuates the risk of SSI in these high-risk patients and thus should be strongly considered during treatment planning.

Ceftaroline Fosamil for the Treatment of Acute Bacterial Skin and Skin Structure Infections in Obese Patients

Background: Ceftaroline fosamil is a broad-spectrum antibiotic approved by the US Food and Drug Administration (FDA) for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) and community-acquired bacterial pneumonia. The Clinical Assessment Program and Teflaro Utilization Registry (CAPTURE) is a multicenter registry study of patients treated with ceftaroline fosamil in the United States for ABSSSI or community-acquired bacterial pneumonia. Objective: To describe the clinical effectiveness of ceftaroline fosamil in the treatment of ABSSSI in obese patients [body mass index (BMI) ≥ 30] compared with patients with a normal BMI (18.5 to ≤ 24.9). Methods: Data were collected at US study centers by randomly ordered chart review. Results: Data from 261 patients with a normal BMI and 690 patients with an obese BMI were collected. The percentage of males was higher in the normal BMI than in the obese category (58.2% and 49.0%, respectively). The mean and median ages at baseline were similar. Most patients (91%) were treated on a general hospital ward, and the mean and median lengths of stay were similar between the 2 groups (approximately 11 days and 7 days, respectively). A total of 73.2% of normal BMI patients and 77.5% of obese patients were discharged to home. Rates of diabetes mellitus were 26.4% in the normal BMI group and 55.1% in the obese group. Methicillin-resistant Staphylococcus aureus was isolated from 26.1% of normal BMI patients and 20.5% of obese patients (16.4% morbidly obese subset). Mean treatment duration for all patients was 5.9 days. Of patients with a normal BMI, 57.5% received ceftaroline fosamil as monotherapy as did 63.3% of obese patients. Clinical success was high in both the normal BMI (85.1%) and the obese (89.0%) groups. Conclusion: Ceftaroline fosamil is an effective treatment option for obese patients with ABSSSI with a similar clinical success rate, mean and median length of stay, and discharge destination to home when compared with normal BMI patients.

Thermo-reactive clips do not prevent sternal wound infection in obese patients after cardiac surgery

s / International Journal of Surgery 11 (2013) 589e685 613 ABSTRACTS Conclusion: The results were accessible, useable and reliable, shown by the LIDA tool. The information required a high level of education, shown by the Gunning-Fog Index and Flesch Readability Score. The best three websites for patient self-education about mitral valve replacement are: http://www.drugs.com/cg/mitral-valve-replacementinpatient-care.html, http://www.nhs.uk/conditions/Aorticvalvereplace ment/Pages/Whatisitpage.aspx, http://www.bhf.org.uk/heart-health/ treatments/valve-heart-surgery.aspx 0683: STARTING & EVALUATING A ROBOT-ASSISTED VATS PROGRAMME: PILOT PHASE Sandra Gelvez-Zapata, Maral Rouhani, Rachel Kuo, Priya Sastry, Aman S. Coonar. Papaworth Hospital, Cambridge, UK. Aim: The Freehand TM robot scope holder has been recently released. We sought to assess the feasibility of implementing and using this robotassisted telescope holder in VATS. This is first use in thoracic surgery. Methods: Following dry-lab training of the consultant and theatre team by an experienced trainer we introduced the system into the operating room. Non-lobectomy patients were considered for robot-assisted VATS (RVATS). 27 consecutive VATS patients were selected. 22 procedures were completed by R-VATS. The procedures were 9 wedge resections, 7 pneumothorax, 2 lung volume resections (LVRS), 3 empyema and 1 pleurectomy for mesothelioma. Results: Surgical time (including on table-robot positioning): 50 115 min (mean 82). Total operating room time (including robot set-up/take down): 65 140min (mean 111). R-VATcases by consultant with assistant available but hands-off: 21/22. R-VAT cases by trainee with consultant scrubbed:1/ 22 Conclusions: Dry-lab preparation allowed robot position to be optimized. Implementation was rapid and safe. Consideration of robot placement and port position is critical. The robot gave a stable, non-wandering view. Assistants observed the procedure, but were not required to participate. Since these procedures can be conducted by a single operator there are manpower implications. Operative and theatre times are acceptable. 0801: THERMO-REACTIVE CLIPS DO NOT PREVENT STERNAL WOUND INFECTION IN OBESE PATIENTS AFTER CARDIAC SURGERY Clare Burdett, Simon Kendall, Joel Dunning, Andrew Owens, Andrew Goodwin, Steve Hunter, Jonathan Ferguson, Tracey Smailes, Cheng-Hon Yap, Enoch Akowuah. James Cook University Hospital,

EComment. Prevention of sternal wound infection

We read with great interest the article by Sakic et al. [1] assessing the efficacy of surgical modifications on the incidence of postoperative sternal complications after bilateral internal thoracic arteries (BITA) harvesting. In this single-center retrospective study, the authors demonstrated that using a skeletonized approach in patients receiving bilateral internal thoracic arteries with augmented sternal wires is effective in preventing sternal wound complications. As described by others, this series supports the claim that the risk of sternal infection can be reduced by performing internal thoracic artery harvested in a skeletonized manner. Deo et al. [2] conducted the first systematic review and meta-analysis to address the essential clinical question of whether BITA increases the risk of deep sternal wound infection in patients with diabetes; they concluded that the risk may be minimized using a skeletonized approach. The left internal thoracic artery to left anterior descending artery graft has long been established as the cornerstone of improved early and late outcomes in surgically-treated patients. An overwhelming wealth of evidence, mainly retrospective studies, demonstrated that the use of BITA as bypass grafts provided superior early survival and better event-free survival after coronary artery bypass grafting. The Arterial Revascularization Trial [3] is the only randomized study comparing the outcomes of single internal mammary artery (SITA) vs BITA, with a primary outcome of survival at 10 years, and results should be available in five years. The risk of sternal wound complications may need to be weighed against the long-term benefit of BITA grafts. It is, needless to say, that anterior mediastinitis is a rare but ominous complication after BITA harvesting, carrying a high risk of in-hospital mortality. Many factors have been suggested as responsible for postcardiotomy sternal wound infection, and investigations to prevent this dreaded complication are still considered as a greatly researched topic in cardiac surgery. Recently, Grauhan et al. [4] investigated the efficacy of a new commercially available negative pressure wound therapy system (Prevena Incision Management System; KCI, San Antonio, USA) as a dressing treatment to prevent sternal wound infection in obese patients undergoing cardiac surgery. They showed in a prospective study that the application of a special foam as a wound dressing immediately after skin closure and negative pressure of -125 mmHg for the first 6 to 7 days postoperatively significantly reduces the incidence of sternal infection in this high-risk patient population. The technique of skeletonization during BITA harvest preserves sternal microacirculation [5]; the immediate application of a negative-pressure wound dressing after suturing prevents the breakdown of skin sutures and seepage of bacteria into the deeper layers. These two different methods showed to be effective in reducing the likelihood of sternal wound infection, and should be considered in high-risk patients of sternal complications. Conflict of interest: none declared.

Prevention of poststernotomy wound infections in obese patients by negative pressure wound therapy

Objective: Patients who develop sternal wound infections (SWI) following median sternotomy experience worse clinical outcomes and require longer and more costly care than patients without this complication. The majority of SWI in obese patients are triggered by the breakdown of skin sutures and subsequent seepage of skin flora. The purpose of this study was to evaluate negative pressure wound dressing treatment (NPWT) for the prevention of SWI. We hypothesized that NPWT for 6 – 7 days applied immediately after skin closure reduces the numbers of wound infections by skin flora.

Prevention of poststernotomy wound infections in obese patients by negative pressure wound therapy

The majority of wound infections after median sternotomy in obese patients are triggered by the breakdown of skin sutures and subsequent seepage of skin flora. The purpose of this study was to evaluate negative pressure wound dressing treatment for the prevention of infection. We hypothesized that negative pressure wound dressing treatment for 6 to 7 days applied immediately after skin closure reduces the numbers of wound infections. In a prospective study, 150 consecutive obese patients (body mass index≥30) with cardiac surgery performed via median sternotomy were analyzed. In the negative pressure wound dressing treatment group (n=75), a foam dressing (Prevena, KCI, Wiesbaden, Germany) was placed immediately after skin suturing, and negative pressure of -125 mm Hg was applied for 6 to 7 days. In the control group (n=75), conventional wound dressings were used. The primary end point was wound infection within 90 days. Mann-Whitney U test and Fisher exact test were used. Freedom from infection was estimated by Kaplan-Meier analysis. Three of 75 patients (4%) with continuous negative pressure wound dressing treatment had wound infections compared with 12 of 75 patients (16%) with conventional sterile wound dressing (P=.0266; odds ratio, 4.57; 95% confidence interval, 1.23-16.94). Wound infections with Gram-positive skin flora were found in only 1 patient in the negative pressure wound dressing treatment group compared with 10 patients in the control group (P=.0090; odds ratio, 11.39; 95% confidence interval, 1.42-91.36). Negative pressure wound dressing treatment over clean, closed incisions for the first 6 to 7 postoperative days significantly reduces the incidence of wound infection after median sternotomy in a high-risk group of obese patients.

Obesity and gastric cancer

Obesity is an important public health problem worldwide. It increases the risk of many chronic diseases such as diabetes and cardiovascular diseases. Meanwhile, obesity is a major risk factor for several types of cancer including gastric cancer. Possible mechanisms linking obesity with gastric cancer may include obesity associated gastro-oesophageal reflux, insulin resistance, altered levels of adiponectin, leptin, ghrelin, and an abnormally increased blood level of insulin-like growth factor (IGF). Helicobacter pylori (H. pylori) infection is a well-recognized risk factor for peptic ulcer and gastric cancer. Recent studies have revealed an increased prevalence of H. pylori infection in obese patients, providing another clue for the increased incidence of gastric cancer in obese population. If this connection can be confirmed in animal models and a large cohort of patients, then eradicating H. pylori together with life style modification in obese individuals may help prevent the development of gastric cancer in the increasingly obese population.

Severe respiratory complications as a cause of poor outcome of influenza A (H1N1sw2009) in obese patients

Summary. Thirty three medical records and postmortem examination reports of patients died from influenza A virus (H1N1sw2009) in October and November, 2009, in the Transbaikal Territory were analyzed. The patients were divided into two groups. The first group consisted of 22 patients with obesity and the second group consisted of 11 patients with normal body weight. There was no difference between the groups in age, gender structure, and duration of the disease. Causes of death were pneumonia and progressive respiratory failure. The rate of acute respiratory distress syndrome was similar in both the groups. Thrombosis of various locations was seen more often in obese patients. A tendency was found to a higher rate of rhabdomyolisis, acute canalicular necrosis and intravascular coagulation blood syndrome in obese patients. Additional risk factors in those patients were diabetes mellitus, pancreatitis, and hypertension. Possible reasons of severe course of influenza A virus (H1N1sw2009) infection in obese patients, such as alveolar hypoventilation, production of proinflammatory cytokines by the fat tissue resulting in poor immune response, coagulation and metabolic disorders have been discussed in the article. All these conditions were responsible for complications and exacerbations of concomitant diseases but could not justify high mortality rate in this pandemic influenza A virus infection. The severe course of the infection may be attributable to virus A (H1N1sw2009) ability to damage the mitochondrial protein PB1-F2 and intervene into the fat exchange. Thus, obesity was the most considerable risk factor for death during influenza A virus (H1N1sw2009) outbreak in the Transbaikal Territory due to aggravation of underlying metabolic disorders by specific effects of pandemic influenza virus A strain.

Obesity and Perioperative Morbidity in Total Hip and Total Knee Arthroplasty Patients

The incidence of obesity in 1071 total hip arthroplasty (THA) patients and 1813 total knee arthroplasty (TKA) patients and its effect on perioperative morbidity were evaluated prospectively. Fifty-two percent of TKA and 36% of THA patients were obese (body mass index ≥30). The obese patients were significantly younger, with a higher proportion of obese TKA patients being women. Higher rates of diabetes and hypertension were found in obese patients. Higher postoperative infection rates were observed in patients with body mass index 35 or higher. The odds ratio was 6.7 times higher risk for infection in obese TKA patients and 4.2 times higher for obese THA patients. The increased risk of infection in obese patients undergoing total joint arthroplasty must be realized by both the patient and surgeon.

Arginine and glutamine availability and macrophage functions in the obese insulin-resistant Zucker rat.

Increased susceptibility to infections in obese patients may be related to decreased availability of arginine and glutamine, which may affect immune cell functions. Our aim was to evaluate the in vitro effects of these amino acids on the function of macrophages from obese insulin-resistant Zucker rats. Macrophages, isolated from male Zucker obese or lean rats by peritoneal lavage, were incubated in Dulbecco's modified Eagle medium (DMEM) without arginine or glutamine. Arginine or glutamine was added to the medium at increasing final concentrations (0, 0.25, 0.5, 1 or 2 mM). After stimulation by lipopolysaccharide (LPS) from E. coli (40 microg/ml), productions of tumour necrosis factor alpha (TNFalpha) and of nitric oxide (NO) were measured after 3 or 48 h incubation, respectively. NO production, lower in macrophages from obese rats, decreased in macrophages from lean rats (0 mM: 2,423 +/- 1,174 vs. 2 mM: 198 +/- 31 microM/mg protein/24 h; P < 0.05), but not in those from obese rats, when glutamine was added. TNFalpha production, lower in macrophages from obese rats, was inversely correlated with glutamine concentration. In the presence of arginine, NO production was constantly higher in macrophages from obese rats. It peaked at 0.5 mM arginine and decreased thereafter in both groups. TNFalpha production in macrophages from lean rats was unaffected by arginine, but decreased in macrophages from obese rats (0 mM: 1920 +/- 450 vs. 2 mM: 810 +/- 90 microM/mg protein/3 h; P < 0.05). These results suggest that abnormalities in cell signalling or in arginine and glutamine metabolism in macrophages of obese rats, resulting in decreased TNFalpha production and increased NO release, may contribute to increased susceptibility to infection in insulin-resistant states.

Helicobacter pylori infection in patients undergoing gastric bypass surgery for morbid obesity.

Studies suggest that the incidence of Helicobacter pylori infection in obese patients, including those undergoing gastric reduction surgery, may be increased. We examined the histologic findings at the time of surgery in a series of patients who were undergoing Roux-en-Y gastric bypass (RYGBP) for morbid obesity and compared these results with patients in our institution undergoing endoscopy. Of 60 patients undergoing RYGBP, material for histologic examination was available in 56 cases, and in 40 cases gastric fundic mucosa from the anastomotic site was sampled at the time of surgery. Active chronic gastritis was present in 6 (15%), and chronic gastritis was present in 27 (68%). H. pylori was present in all 6 cases of active chronic gastritis and in 9 cases of chronic gastritis (total 38%). This incidence of H. pylori infection was higher than that found in the series of gastric biopsies (107/500, 21%, p = 0.03) and fundic biopsies (10/80, 13%, p = 0.003), but was not different when compared with age-matched gastric biopsies (44/177, 25%, p = 0.12). The incidence of H. pylori in patients undergoing RYGBP was higher than that found in all patients undergoing endoscopy and biopsy and than those undergoing fundic biopsies, but not higher when age-matched controls were considered.

Modifications of cellotomy techniques to decrease morbidity in obese gynecologic patients

Celiotomy techniques have been modified in an attempt to decrease the wound complication rates at our institution. During a 5-year period, 1044 patients underwent celiotomy and major surgical procedures, usually hysterectomy and bilateral salpingo-oophorectomy. Wound complications were noted in eight of 900 nonobese patients. Of obese patients not operated upon by the protocol, 42.2% had wound complications. Obese patients operated upon according to protocol had a wound complication rate of 3.1%. The difference in wound complication rate in obese, non-protocol operation patients as compared to the obese, protocol operation patients was highly significant (p less than 0.0001). The techniques used minimized wound infections in obese patients.