The risk factors for deep and superficial chest surgical-site infections after coronary artery bypass graft surgery are different

Coronavirus Disease 2019 Pandemic and Reduced Surgical Site Infection After Cardiac Surgery: A Potential Blessing in Disguise

Background: The coronavirus disease 2019 (COVID-19) pandemic has brought about drastic hygienic measures, one upside of which might be the mitigated occurrence of surgical site infection (SSI). This study investigated the association of the pandemic with SSI occurrence after cardiac surgeries. Patients and Methods: From 2014 to 2022, patients undergoing cardiac surgery were included and categorized into pre-pandemic and during-pandemic groups. Surgical site infections were classified into harvest-site, superficial sternal, and complex sternal infection. Multiple logistic regression and inverse probability weighting assessed the association of the pandemic with SSI. Results: Among a total of 26,143 patients, 793 SSIs occurred. The during-pandemic patients were younger (61.87 ± 10.58 vs. 65.64 ± 11.82) with a higher male proportion (70.1% vs. 67.4%) and a higher prevalence of all studied comorbidities/risk factors (expect cigarette smoking). Total SSI rate decreased substantially from 3.3% before COVID-19 to 1.8% afterward (p < 0.001). Inverse probability weights analyses evinced an independent association of the pandemic with a reduced risk of total (adjusted odds ratio [OR]; 0.59; 95% confidence interval [CI], 0.45-0.78), harvest-site (adjusted OR, 0.36; 95% CI, 0.19-0.70), and superficial sternal infection (adjusted OR, 0.60; 95% CI, 0.43-0.81). No significant association was observed with complex sternal site infection (adjusted OR, 1.05; 95% CI, 0.55-2.01). Multivariable regression recapitulated these findings. Conclusions: The COVID-19 pandemic independently pertained to more than a 40% reduction in SSI occurrence, particularly affecting harvest-site and superficial sternal infections. However, there remains the possibility of the implications of other known and unknown confounders on the observed association. To some extent, the decrease in SSIs after the pandemic can be justified by reinforced hygienic precautions, emphasizing the necessity of extending the adherence to these measurements into the post-COVID-19 era to maintain the status quo.

Negative pressure wound therapy in patients with diabetes undergoing left internal thoracic artery harvest: A randomized control trial

BACKGROUND

Patients with diabetes undergoing CABG are at risk of wound infection. Incisional negative pressure wound therapy has been shown to be effective in decreasing incidence of infection in high-risk wounds. Near infrared spectroscopy (NIRS) can be used to assess wound oxygenation and low values can predict infection.

OBJECTIVES

To evaluate utility of NIRS to assess wound oxygenation, to assess effect of sternotomy, left internal thoracic artery harvest, and wound dressing type on wound edge oxygenation.

METHODS

In this blinded randomized control trial, patients with diabetes undergoing isolated coronary artery bypass grafting with a left internal thoracic artery were randomized to receive either incisional negative pressure wound therapy dressing or a standard dressing. NIRS measurements were made on the left upper arm (control), and left and right parasternal regions on day -1 (preoperative), day 5, and week 6 after surgery. Results were analyzed using repeated measures parametric methods.

RESULTS

Eighty patients with diabetes were recruited, 40 to the incisional negative pressure wound therapy group and 40 to the standard dressing group. Adjusted NIRS readings dropped significantly in all patients by day 5 and partially recovered by week 6. In both groups, there was no difference between readings on the left and right. At all time points and on both sides, there was no difference in readings between patients in the 2 groups.

CONCLUSIONS

NIRS can be used to assess oxygenation adjacent to a sternotomy wound. Adjusted tissue oxygen levels change with time after sternotomy and left internal thoracic artery harvest in patients with diabetes. Wound dressing type does not influence day 5 wound edge oxygenation.

Risk factors for sternal wound infection after open-heart operations: A systematic review and meta-analysis

We aimed to quantitatively and systematically elucidate the rationality of the examined variables as independent risk factors for sternal wound infection. We searched databases to screen studies, ascertained the variables to be analysed, extracted the data and applied meta-analysis to each qualified variable. Odds ratios and mean differences were considered to be the effect sizes for binary and continuous variables, respectively. A random-effects model was used for these procedures. The source of heterogeneity was evaluated using a meta-regression. Publication bias was tested by funnel plot and Egger's test, the significant results of which were then calculated using trim and fill analysis. We used a sensitivity analysis and bubble chart to describe their robustness. After screening all variables in the eligible literature, we excluded 55 because only one or no research found them significant after multivariate analysis, leaving 33 variables for synthesis. Two binary variables (age over 65 years, NYHA class >2) and a continuous variable (preoperative stay) were not significant after the meta-analysis. The most robust independent risk factors in our study were diabetes mellitus, obesity, use of bilateral internal thoracic arteries, chronic obstructive pulmonary disease, prolonged surgery time, prolonged ventilation and critical preoperative state, followed by congestive heart failure, atrial fibrillation, renal insufficiency, stroke, peripheral vascular disease and use of an intra-aortic balloon pump. Relatively low-risk factors were emergent/urgent surgery, smoking, myocardial infarction, combined surgery and coronary artery bypass grafting. Sternal wound infection after open-heart surgery is a multifactorial disease. The detected risk factors significantly affected the wound healing process, but some were different in strength. Anything that affects wound healing and antibacterial ability, such as lack of oxygen, local haemodynamic disorders, malnutrition condition and compromised immune system will increase the risk, and this reminds us of comprehensive treatment during the perioperative period.

The impact of COVID-19 prevention measures on surgical wound infection rates post-cardiac surgery

The COVID-19 pandemic had a huge impact on medical services. Several measures have been implemented to reduce the risk of viral transmission. In this paper, we assessed the impact of these measures on surgical wound infection rates in patients post-cardiac surgery. Hypothesis testing was used to compare post-cardiac operation infection rates between the year prior to the COVID-19 pandemic being declared and the first 13 months of the pandemic. The infection rates in 969 patients with operations between 01/03/2019 and 29/02/2020 were compared to those of 925 patients with cardiac surgery between 01/03/2020 and 31/03/2021. Infection rates for various operative urgencies and infection types were analysed. To compare infection rates, a two-tailed pooled z-test using the difference in infection proportions was performed. A 5% significance level was used and only categories with at least 10 patients in both the pre-covid and covid populations were tested. For leg infections, only operations involving coronary artery bypass grafting were included. To ensure that any differences in outcomes were not due to differences in patient demographics resulting in unequal operative risks, Euroscore II values, a measure of cardiac operative risk, were compared between the pre-covid and post-covid cohorts. The Mann-Whitney U-test was used to determine whether the distributions of Euroscore II values were likely to be drawn from the same population. A significance level of 5% was used. A total of 1901 patients (932 during the COVID-19 pandemic) were included in this study. Significant reduction in post-operative infections for all patients undergoing cardiac surgery from 4.3% of patients before COVID to 1.5% during the pandemic. During the pandemic, fewer elective and more urgent operations were performed. This study suggests a significant role of iatrogenic causes in wound infections prior to the pandemic. The implementation of COVID-19 prevention measures in healthcare providers can reduce surgical infection rates. As COVID-19-related restrictions have been eased, we suggest maintaining them in healthcare providers to reduce the incidence of surgical wound infections.

Strategies to prevent surgical site infections in acute-care hospitals: 2022 Update

The intent of this document is to highlight practical recommendations in a concise format designed to assist acute-care hospitals in implementing and prioritizing their surgical-site infection (SSI) prevention efforts. This document updates the Strategies to Prevent Surgical Site Infections in Acute Care Hospitals published in 2014. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA). It is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the Association for Professionals in Infection Control and Epidemiology (APIC), the American Hospital Association (AHA), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise.

Probiotic induced synthesis of microbiota polyamine as a nutraceutical for metabolic syndrome and obesity-related type 2 diabetes

The gut microbiota regulates multiple facets of host metabolism and immunity through the production of signaling metabolites, such as polyamines which are small organic compounds that are essential to host cell growth and lymphocyte activation. Polyamines are most abundant in the intestinal lumen, where their synthesis by the gut microbiota is influenced by microbiome composition and host diet. Disruption of the host gut microbiome in metabolic syndrome and obesity-related type 2 diabetes (obesity/T2D) results in potential dysregulation of polyamine synthesis. A growing body of evidence suggests that restoration of the dysbiotic gut microbiota and polyamine synthesis is effective in ameliorating metabolic syndrome and strengthening the impaired immune responses of obesity/T2D. In this review, we discuss existing studies on gut microbiome determinants of polyamine synthesis, polyamine production in obesity/T2D, and evidence that demonstrates the potential of polyamines as a nutraceutical in obesity/T2D hosts.

Open Chest Duration Following Congenital Cardiac Surgery Increases Risk for Surgical Site Infection

Surgical site infections (SSI) following congenital heart surgery (CHS) remain a significant source of morbidity. Delayed sternal closure (DSC) is often required to minimize the potential for hemodynamic instability. The purpose of this study was to determine the incidence of SSI among patients undergoing DSC versus primary chest closure (PCC) and to define a potential inflection point for increased risk of SSI as a function of open chest duration (OCD).A retrospective review of our institutional Society of Thoracic Surgeons dataset is to identify patients undergoing CHS at our institution between 2015 and 2020. Incidences of SSI were compared between DSC and PCC patients. DSC patients were evaluated to determine the association of OCD and the incidence of SSI.2582 operations were performed at our institution between 2015 and 2020, including 195 DSC and 2387 PCC cases. The incidence of SSI within the cohort was 1.8% (47/2,582). DSC patients had significantly higher incidences of SSI (17/195, 8.7%) than PCC patients (30/2387, 1.3%, p < 0.001). Further, patients with an OCD of four or more days had a significantly higher incidence of SSI (11/62, 17.7%, p = 0.006) than patients with an OCD less than 4 days (6/115, 5.3%).The incidence of SSI following CHS is higher in DSC patients compared to PCC patients. Prolonged OCD of 4 days or more significantly increases the risk of SSI and represents a potentially modifiable risk factor for SSI predisposition. These data support dedicated, daily post-operative assessment of candidacy for chest closure to minimize the risk of SSI.

Evaluation of Postoperative Development of Saphenous Vein Graft Incision Site Infections in Patients Undergoing Isolated Coronary Artery Bypass Graft Surgery: A Single Center Experience

Objective: This study aimed to evaluate surgical site infection patients developing saphenous vein graft incision site infection after isolated coronary artery bypass graft surgery performed in the cardiovascular surgery clinic of our hospital in the last 12 years to reveal the causative microorganisms, risk factors, and clinical characteristics. Material and Methods: A total of 34 surgical site infection patients (23 females, 11 males; mean age 68.0±9.0 years; range 51-86 years) who underwent isolated coronary artery bypass graft surgery in the cardiovascular surgery clinic of our hospital between March 2009 and November 2020 and who postoperatively developed saphenous vein graft incision site infection were included in the study. The patients' demographic data, underlying diseases, and preoperative, intraoperative, and postoperative risk factors were analyzed retrospectively. Results: In all isolated coronary artery bypass graft surgeries performed over a period of about 12 years, the rate of saphenous vein graft incision site surgical site infection was found to be 0.8%. Of these, 23 (67.6%) were evaluated as superficial incisional surgical site infection and 11 (32.4%) as deep incisional surgical site infection. In the patients who developed surgical site infection, the parameters of age, female sex, obesity, diabetes mellitus, smoking, emergency surgery, use of more than 1 saphenous vein graft, prolonged operation, cardiopulmonary bypass, and aortic clamp durations, intraoperative blood transfusion, length of stay in the intensive care unit, use of inotropes, and total length of hospital stay were all found to be significant. The microorganisms in purulent discharge cultures consisted of Gram-negative bacteria in 18 (53%), Gram-positive bacteria in 12 (35.3%), and fungi in 1 (2.9%). No pathogenic microorganism growth was observed in 5 (14.7%) patients. In the patients with surgical site infection, coagulase-negative staphylococci (17.6%) and Escherichia coli (17.6%) were the most frequently isolated agents. Conclusion: Particular attention should be paid to surgical site infection in patients undergoing a cardiovascular surgery intervention. It should be noted that post coronary artery bypass graft surgery surgical site infection can be reduced by determining its risk factors, modifying surgical techniques, and postoperative close monitoring of patients. Follow-up and personal care are crucial after discharge and an empirical treatment approach should be determined when an infection occurs, taking into account that coagulase-negative staphylococci and E. coli were the two leading infectious agents in our hospital.

Addition of benzylpenicillin to antibiotic prophylaxis reduces deep sternal wound infection after cardiac surgery

Objectives

In Sweden, cloxacillin is recommended as the sole antibiotic prophylaxis for prevention of surgical site infections after cardiac surgery. Cutibacterium acnes, formerly Propionibacterium acnes, has been shown to be present in the surgical wound. Formerly an overlooked pathogen, there are increasing reports that C acnes can cause surgical site infections, including sternal wound infections. Cloxacillin may not be optimal for prevention of C acnes infection, therefore benzylpenicillin was added to our routine intraoperative prophylaxis in 2015. The aim of this study was to investigate the effect of benzylpenicillin on incidence of sternal wound infection.

Methods

We included 3920 consecutive patients that underwent cardiac surgery via median sternotomy at our centre from 2009 thru 2018. All patients were followed up two months postoperatively. The rate of sternal wound infection before and after 2015 were compared. Logistic multivariable analysis was used to adjust for potential confounders.

Results

The mean incidence of sternal wound infection that required surgical revision decreased from 4.7% to 1.7% after addition of benzylpenicillin (p < 0.001). Significant decrease was seen in sternal wound infections caused by Coagulase negative staphylococci, either alone (p<0.001) or concomitant with C acnes (p=0.008). Addition of benzylpenicillin remained independently associated with the reduction of sternal wound infections in the multivariable analysis (OR=0.36 CI=0.23–0.56, p<0.001).

Conclusions

Addition of benzylpenicillin was associated with a reduction in surgically treated infections and might be effective against infection caused by CoNS with and without co-infection by C acnes, although the exact underlying mechanism is unknown.

Single-use negative pressure wound therapy reduces costs in closed surgical incisions: UK and US economic evaluation

OBJECTIVE

Single-use negative pressure wound therapy (sNPWT) following closed surgical incisions has a demonstrable effect in reducing surgical site complications (SSC). However, there is little health economic evidence to support its widespread use. We sought to evaluate the cost-effectiveness of sNPWT compared with standard care in reducing SSCs following closed surgical incisions.

METHOD

A decision analytic model was developed to explore the total costs and health outcomes associated with the use of the interventions in patients following vascular, colorectal, cardiothoracic, orthopaedic, C-section and breast surgery from the UK National Health Service (NHS) and US payer perspective over a 12-week time horizon. We modelled complications avoided (surgical site infection (SSI) and dehiscence) using data from a recently published meta-analysis. Cost data were sourced from published literature, NHS reference costs and Centers for Medicare and Medicaid Services. We conducted subgroup analysis of patients with diabetes, an American Society of Anesthesiologists (ASA) score ≥3 and body mass index (BMI) ≥30kg/m². A sensitivity analysis was also conducted.

RESULTS

sNPWT resulted in better clinical outcomes and overall savings of £105 per patient from the UK perspective and $637 per patient from the US perspective. There were more savings when higher-risk patients with diabetes, or a BMI ≥30kg/m² or an ASA≥3 were considered. We conducted both one-way and probabilistic sensitivity analysis, and the results suggested that this conclusion is robust.

CONCLUSION

Our findings suggest that the use of sNPWT following closed surgical incisions saves cost when compared with standard care because of reduced incidence of SSC. Patients at higher risk should be targeted first as they benefit more from sNPWT. This analysis is underpinned by strong and robust clinical evidence from both randomised and observational studies.

Postimplantation pocket hematoma increases risk of cardiac implantable electronic device infection: A meta-analysis

INTRODUCTION

 Several studies have shown an inconsistent relationship between postimplantation pocket hematoma and cardiac implantable electronic device (CIED) infection. In this study, we performed a systematic review and meta-analysis to explore the effect of postimplantation hematoma and the risk of CIED infection.

METHODS

 We searched the databases of MEDLINE and EMBASE from inception to March 2020. Included studies were cohort studies, case-control studies, cross-sectional studies, and randomized controlled trials that reported incidence of postimplantation pocket hematoma and CIED infection during the follow-up period. CIED infection was defined as either a device-related local or systemic infection. Data from each study were combined using the random effects, generic inverse variance method of Der Simonian and Laird to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Fourteen studies were included in final analysis, involving a total of 28 319 participants. In random-effect model, we found that postimplantation pocket hematoma significantly increases the risk of overall CIED infection (OR = 6.30, 95% CI: 3.87-10.24, I 2 = 49.3%). There was no publication bias observed in the funnel plot as well as no small-study effect observed in Egger's test.

CONCLUSIONS

Our meta-analysis demonstrated that postimplantation pocket hematoma significantly increases the risk of CIED infection. Precaution should be taken during device implantation to reduce postimplantation hematoma and subsequent CIED infection.

[Surgical site infections-Prevention and treatment strategies]

Surgical site infections (SSI) are the most frequent nosocomial infection in Germany. They are defined as an infection of the surgical site that occurs within 30 days after a surgical procedure. The diagnostic criteria include localized pain or tenderness, localized swelling, erythema, excess warmth, purulent drainage from the incision and cultural detection of pathogens in an aseptically obtained specimen from the incision. Wound infections are differentiated into superficial incisional (grade 1), deep incisional (grade 2) and infections of organs and body cavities in the region of the operation (grade 3). Risk factors for SSI include anemia, immunosuppression, diabetes mellitus, obesity, smoking and malnutrition. The crucial preoperative preventive measures are antisepsis of the surgical area and antibiotic prophylaxis. Intraoperative subcutaneous wound irrigation with an antiseptic solution reduces SSI in visceral surgery. The primary treatment encompasses the liberal debridement of the wound.

Comparison of pedicled versus free flaps for reconstruction of extensive deep sternal wound defects following cardiac surgery: A retrospective study

BACKGROUND

Myocutaneous pedicled flaps are the method of choice for sternal reconstruction after deep sternal wound infection (DSWI) following cardiac surgery. We set out to investigate whether free flaps provide a superior alternative for particularly extended sternal defects.

METHODS

Between October 2008 and February 2020, 86 patients with DSWI underwent sternal reconstruction with myocutaneous flaps at our institution. Patients were retrospectively grouped into pedicled (A; n = 42) and free flaps (B, n = 44). The objective was to compare operative details, outcome variables, surgical as well as medical complication rates between both groups, retrospectively. Binary logistic regression analysis was applied to determine the effect of increasing defect size on flap necrosis.

RESULTS

Rates of partial flap necrosis (>5% of the skin island) were significant higher in pedicled flaps (n = 14), when compared to free flaps (n = 4) (OR: 5.0; 33 vs. 9%; p = .008). Increasing defect size was a significant risk factor for the incidence of partial flap necrosis of pedicled flaps (p = .012), resulting in a significant higher rate of additional surgeries (p = .036). Binary regression model revealed that the relative likelihood of pedicled flap necrosis increased by 2.7% with every extra square-centimeter of defect size.

CONCLUSION

To avoid an increased risk of partial flap necrosis, free flaps expand the limits of extensive sternal defect reconstruction with encouragingly low complication rates and proved to be a superior alternative to pedicled flaps in selected patients.

Monitoring the Impact of Aggressive Glycemic Intervention during Critical Care after Cardiac Surgery with a Glycemic Expert System for Nurse-Implemented Euglycemia: The MAGIC GENIE Project

A novel, multi-dimensional protocol named GENIE has been in use for intensive insulin therapy (IIT, target glucose <140 mg/dL) in the surgical intensive care unit (SICU) after open heart surgery (OHS) at VA Pittsburgh since 2005. Despite concerns over increased mortality from IIT after the publication of the NICE-SUGAR Trial, it remains in use, with ongoing monitoring under the MAGIC GENIE Project showing that GENIE performance over 12 years (2005-2016) aligns with the current consensus that IIT with target blood glucose (BG) <140 mg/dL is advisable only if it does not provoke severe hypoglycemia (SH). Two studies have been conducted to monitor glucometrics and outcomes during GENIE use in the SICU. One compares GENIE (n = 382) with a traditional IIT protocol (FORMULA, n = 289) during four years of contemporaneous use (2005-2008). The other compares GENIE's impact overall (n = 1404) with a cohort of patients who maintained euglycemia after OHS (euglycemic no-insulin [ENo-I], n = 111) extending across 12 years (2005-2016). GENIE performed significantly better than FORMULA during contemporaneous use, maintaining lower time-averaged glucose, provoking less frequent, severe, prolonged, or repetitive hypoglycemia, and achieving 50% lower one-year mortality, with no deaths from mediastinitis (0 of 8 cases vs 4 of 9 on FORMULA). Those benefits were sustained over the subsequent eight years of exclusive use in OHS patients, with an overall one-year mortality rate (4.2%) equivalent to the ENo-I cohort (4.5%). The results of the MAGIC GENIE Project show that GENIE can maintain tight glycemic control without provoking SH in patients undergoing OHS, and may be associated with a durable survival benefit. The results, however, await confirmation in a randomized control trial.

Higher Surgery and Recovery Room Air Pressures Associated with Reduced Surgical Site Infection Risk

BACKGROUND

Incisional surgical site infections (SSIs) following coronary artery bypass grafting (CABG) prolong hospital stays, elevate healthcare costs and increase likelihood of further complications. High air pressure deactivates bacteria and is utilized for commercial food preservation, assuring microbiologically safe pharmaceuticals and sanitizing instruments. However, research on utilizing air pressure deactivation thresholds in surgical and postoperative rooms to reduce rates of SSIs is lacking.

METHODS

A case-control study of 801 CABG patients, 128 SSI cases and 673 controls was conducted from January 1, 2006 through March 31, 2009 in Yerevan, Armenia. Patient and surgery characteristics, air pressure measurements and seasons were selected as independent variables with SSI rates as the outcome. The novel threshold regression analysis was used to determine potential air pressure bacterial deactivation thresholds. A final multivariate logistic regression model adjusted for confounders.

RESULTS

Overall, bacterial deactivation air pressure threshold was 694.2 mmHg, with the presence of infection for higher air pressure values not statistically significant from zero. Individual deactivation thresholds for Staphylococcus epidermidis (threshold = 694.2 mmHg) and Escherichia coli (threshold = 689.2) showed similar patterns. Multivariate logistic regression showed air pressure above the deactivation threshold was highly protective against SSIs with adjOR = 0.27 (p-value = 0.009, 95%CI: 0.10-0.72). Other SSI risk factors included female sex, adjOR = 2.12 (p-value = 0.006, 95%CI: 1.24-3.62), diabetes, adjOR = 2.61 (p-value < 0.001, 95%CI: 1.72-3.96) and longer time on ventilator, adjOdds = 1.01 (p-value = 0.012, 95%CI: 1.00-1.02).

CONCLUSION

Maintaining air pressures in operating and postoperative rooms exceeding bacterial-deactivation thresholds might substantially reduce SSI rates following surgery. Further research should identify specific bacterial-deactivation air pressure thresholds in surgical and postoperative rooms to reduce SSI rates, especially for drug-resistant bacteria.

Sternal wound infections during the COVID-19 pandemic: an unexpected benefit

BACKGROUND

The novel coronavirus, now termed SARS-CoV-2, has had a significant impact on cardiac surgical services globally. Although drastically reduced, our institution has maintained a significant level of cardiac surgical activity during the pandemic. Rigorous COVID-19 guidelines have been instituted to mitigate the risk of viral transmission. We observed a reduction in sternal wound infections since the institution of new perioperative surgical guidelines.

METHODS

We performed a retrospective analysis of all patients who underwent cardiac surgery at our institution since a national lockdown was declared in March 2020. A retrospective analysis of all patients who underwent cardiac surgery in the 12 months preceding the national lockdown, as a baseline cohort group, was also performed.

RESULTS

A total of 2600 patients (493 during the COVID-19 pandemic) were included in this study. Urgent/emergency procedures accounted for more than 60% of procedures performed during the lockdown compared to 39% previously. During the COVID-19 pandemic, there were 4 sternal wound infections with an overall incidence of 0.8%. In comparison, the incidence of sternal wound infections was significantly higher at 3.0% in the 12-month period prior to lockdown with 63 sternal wound infections (p = 0.006).

CONCLUSION

This report suggests a significant role of iatrogenic causes in sternal wound infections prior to the pandemic. The strict implementation of guidelines in the perioperative period suggests that sternal wound infections can be prevented. We propose that the now widespread COVID-19 guidelines to reduce transmission risk be adapted to help reduce the incidence of sternal wound infections.

Determinants of surgeons' adherence to preventive intraoperative measures of surgical site infection in Gaza Strip hospitals: a multi-centre cross-sectional study

Background

Surgical site infection (SSI) is one of the most common hospital-acquired infections and is associated with serious impact on the rates of morbidity, mortality as well as healthcare costs. This study examined factors influencing the application of several intraoperative preventive measures of SSI by surgeons and surgical residents in the Gaza Strip.

Methods

A cross-sectional study was conducted from December 2016 to February 2017 at the operation rooms of the three major hospitals located in the Gaza-Strip, Palestine. Inclusion criteria for patients were being adult (aged ≥18 years), no history of wound infection at time of operation and surgical procedure under general anaesthesia with endotracheal intubation. The association between different patient- and procedure-related SSI risk factors and adherence to several intraoperative SSI preventive measures was tested.

Results

In total, 281 operations were observed. The mean patient age ± standard deviation (SD) was 38.4 ± 14.6 years and the mean duration of surgery ± SD was 58.2 ± 32.1 minutes. A hundred-thirty-two patients (47.0%) were male. Location and time of the operation were found to have significant associations with adherence to all SSI preventive measures except for antibiotic prophylaxis. Type of operation had a significant association with performing all measures except changing surgical instruments. Patient age did not have a statistically significant association with adherence to any measure.

Conclusion

The results suggest that the surgeon could be a major factor that can lead to a better outcome of surgical procedures by reducing postoperative complications of SSI. Operating department professionals would benefit from clinical guidance and continuous training, highlighting the importance of persistent implementation of SSI preventive measures in everyday practice to improve the quality of care provided to surgical patients.

Negative-pressure sternal wound closure with interrupted subcuticular suturing and a subcutaneous drain tube reduces the incidence of poststernotomy wound infection after coronary artery bypass grafting surgery

PURPOSES

To retrospectively evaluate the effect of negative-pressure sternal wound closure (NPSWC) with a subcutaneous closed drain tube on the sternal surgical site infection (SSI) incidence.

METHODS

After propensity score matching of 231 patients undergoing coronary artery bypass grafting (CABG), we compared 104 pairs in the NPSWC and historical control groups. In the molecular analysis, the interleukin-6 (IL-6), basic fibroblast growth factor (b-FGF), and transforming growth factor β1 (TGF-β1) levels in the wound fluid were measured using two different reservoir types at postoperative days 2 and 7.

RESULTS

NPSWC significantly reduced the SSI incidence from 10.6 to 2.9%. No mediastinitis occurred in the NPSWC group. A multivariate logistic regression analysis identified female sex (p = 0.0040) and no NPSWC (p = 0.0084) as significant risk factors for sternal SSI development. The Negative-pressure value was 49.4 ± 4.1 and 115.5 ± 15.2 mmHg in the standard-type (SSR) and bulb-type suction reservoirs (BSR), respectively. Given that growth factors were affected by the difference in negative pressure, the IL-6, b-FGF, and TGF-β1 levels were significantly higher in the BSR than in the SSR.

CONCLUSIONS

NPSWC using a subcutaneous closed drain tube was effective in preventing sternal SSI after CABG and may accelerate wound healing even when both internal thoracic arteries are harvested.

CLINICAL REGISTRATION NUMBER

University Hospital Medical Information Network Clinical Trials Registry, registration number: UMIN000037060.

Risk Factors of Secondary Lumbar Discectomy of a Herniated Lumbar Disc after Lumbar Discectomy

Objective

To study risk factors of secondary lumbar discectomy (LD) for recurrent herniated lumbar disc (HLD) and identify methods to lower the rate of recurrence.

Methods

Data from 160 patients who underwent primary LD were collected retrospectively. Demographic features, radiologic findings including Pfirrmann disc degeneration, and surgical information were analyzed to compare risks between revision and non-revision patients.

Results

The revision rate was 15% (24 patients), and the mean follow-up was 28.3 months. HLD recurrence was not related to any demographic characteristics. Primary and secondary LD were most common at the L4–5 level, but the level of operation was not significantly associated with revision. Primary LD most commonly had a Pfirrmann disc degeneration grade of 3, followed by 4. For recurrent HLD, Pfirrmann grade 4 was most common and was statistically significant (p<0.05). A body mass index (BMI) over 30 was considered obese and was significantly related with HLD revision (p<0.05).

Conclusion

Patients with high BMI or severe disc degeneration should be informed of HLD revision.

Total arterial myocardial revascularization using bilateral internal mammary arteries and the role of postoperative sternal stabilization to reduce wound infections in a large cohort study

OBJECTIVES

Total arterial myocardial revascularization using bilateral internal mammary arteries shows improved results for mortality, long-term survival and superior graft patency. It has become the standard technique according to recent guidelines. However, these patients may have an increased risk of developing sternal wound infections, especially obese patients or those with diabetes. One reason for the wound complications may be early sternum instability. This situation could be avoided by using a thorax support vest (e.g. Posthorax® vest). This retrospective study compared the wound complications after bilateral internal mammary artery grafting including the use of a Posthorax vest.

METHODS

Between April 2015 and May 2017, 1613 patients received total arterial myocardial revascularization using bilateral internal mammary artery via a median sternotomy. The Posthorax support vest was used from the second postoperative day. We compared those patients with 1667 patients operated on via the same access in the preceding 26 months. The end points were the incidence of wound infections, when the wound infection occurred and how many wound revisions were needed until wound closure.

RESULTS

The demographic data of both groups were similar. A significant advantage for the use of a thorax support vest could be seen regarding the incidence of wound infections (P = 0.036) and the length of hospital stay when a wound complication did occur (P = 0.018).

CONCLUSIONS

As seen in this retrospective study, the early perioperative use of a thorax stabilization vest, such as the Posthorax vest, can reduce the incidence of sternal wound complications significantly. Furthermore, when a wound infection occurred, and the patient returned to the hospital for wound revision, patients who were given the Posthorax vest postoperatively had a significantly shorter length of stay until wound closure.

Mediastinitis in open heart surgery: a systematic review and meta-analysis of risk factors

Objective. We aimed to summarize the evidence from observational studies examining the risk factors of the incidence of mediastinitis in open heart surgery. Design. The study was a systematic review and meta-analysis of cohorts and case-control studies. Material and methods. We searched the literature and 74 studies with at least one risk factor were identified. Both fixed and random effects models were used. Heterogeneity between studies was examined by subgroup and meta-regression analysis. Publication bias or small study effects were evaluated and corrected by limit meta-analysis. Results. When correcting for small study effect, presence of obesity as estimated from 43 studies had Odds Ratio OR = 2.26. (95% CI: 2.17-2.36). This risk was increasing with decreasing latitude of study place. Presence of diabetes mellitus from 63 studies carried an OR = 1.90 (95% CI: 1.59-2.27). Presence of Chronic Obstructive Pulmonary Disease (COPD) from 30 studies had an OR = 2.59 (95% CI: 2.22-2.85). Presence of bilateral intramammary graft (BIMA) from 23 studies carried an OR = 2.54 (95% CI: 2.07-3.13). This risk was increasing with increasing frequency of female patients in the study population. Conclusion. Evidence from this study showed the robustness of the risk factors in the pathogenesis of mediastinitis. Preventive measures can be implemented for reducing obesity, especially in lower latitude countries. Furthermore, it is mandatory to monitor perioperative hyperglycemias with continuous insulin infusion. Use of skeletonized BIMA carries higher risk of mediastinitis especially in female patients without evidence of beneficial effect on survival for the time being.

Impact of blood transfusion on major infection after isolated coronary artery bypass surgery: Incidence and risk factors

Background/aim

Cardiac surgery is considered one of the conditions that require a transfusion of blood and blood products in large amount. Infections are one of the most common complications after cardiac surgery. The aim of this study is to assess the impact of blood transfusion on major infections after isolated coronary artery bypass surgery (CABG).

Methods

A retrospective cohort study was conducted at King Abdulaziz Cardiac Center. Eligible adult patients, aged >18 years, who underwent an isolated CABG from 2015 to 2016, were included. Patient demographic information, as well as pre-, intra-, and postoperative data were collected from the electronic hospital information system charts and perfusion records. For data analysis, categorical pre- and postoperative variables were summarized by frequencies and percentages, whereas for continuous variables, means and standard deviation or median and interquartile ranges were used.

Results

The sample size was 459 patients. Red blood cells (RBCs) were transfused in 60.1% of the patients, and the median number of units transfused per patient was 2. The mean hemoglobin threshold for transfusion was 8.2 (standard deviation ± 3.6) g/dL. The mean EuroSCORE of RBC recipients was 3.8 ± 5.9% and that of non-RBC recipients was 2.0 ± 2.0%. In both groups (RBC recipients and non-RBC recipients), the most frequent infections after CABG were pneumonia (12% and 8.7%, respectively), deep surgical site infection (3.6% and 0.5%, respectively), and superficial sternal infection (6.9% and 3.8%, respectively), with a statistically significant difference (all p < 0.05). Patients receiving a blood transfusion at any stage during the intraoperative or postoperative period were 2.6 times more likely to develop an infection compared with those who did not receive a blood transfusion. The recipients of a blood transfusion experienced a longer hospital stay compared with the non-recipients at 11.5 ± 9.8 days versus 8.7 ± 3.4 days, respectively.

Conclusions

Blood transfusion appears to increase the risk of infection post-CABG. However, increased understanding of the role of other potential clinical confounding variables that may impact the infection rate is required. We recommend management strategies that limit RBC transfusion.

History of Depression and Increased Risk of Sternal Wound Infection After Cardiothoracic Surgery: A Novel and Potentially Modifiable Risk Factor

Background

Sternal wound infection (SWI) is a leading cause of postoperative disease and death; the risk factors for SWI remain incompletely understood. The goal of the current study was to investigate the relationship between a preoperative history of depression and the risk of SWI after cardiothoracic surgery.

Methods

Among patients undergoing cardiothoracic surgery in a major academic medical center between 2007 and 2012, those in whom SWI developed (n = 129) were matched, by date of surgery, with those in whom it did not (n = 258). Multivariable logistic regression was used to examine the strength of relationships between risk factors and development of infection. History of depression was defined as a composite variable to increase the sensitivity of detection.

Results

History of depression as defined by our composite variable was associated with increased risk of SWI (adjusted odds ratio, 2.4; 95% confidence interval, 1.2–4.7; P = .01). Staphylococcus aureus was the most common organism isolated.

Conclusions

History of depression was associated with increased risk of SWI. Future prospective studies are warranted to further investigate this relationship. Depression is highly treatable, and increased efforts to identify and treat depression preoperatively may be a critical step toward preventing infection-related disease and death.

Comparing Negative Pressure Wound Therapy with Instillation and Conventional Dressings for Sternal Wound Reconstructions

Background:

Muscle flap reconstruction has become a mainstay of therapy following treatment of sternal wound complications; however, success depends on removing wound exudate and infectious material from the wound before reconstruction and closure. Importantly, time to closure is a key factor affecting morbidity/mortality and cost-to-treat for this wound type.

Methods:

A retrospective analysis of 30 patients who were treated for sternal wound complications between June 2015 and October 2017 was performed. After surgical debridement, group 1 patients (n = 15) received negative pressure wound therapy (NPWT) with instillation and dwell time (NPWTi-d), instilling 1/8-strength Dakin’s solution with a 20-minute dwell time followed by 2 hours of NPWT (-125 mm Hg); group 2 patients (n = 15) were treated with wet-to-moist dressings soaked in 1/8-strength Dakin’s solution. After muscle flap reconstruction and closure with sutures, group 1 patients received closed incision negative pressure therapy, and group 2 patients received Benzoin and wound closure strips. Data collected included time to closure, therapy duration, number of debridements/dressing changes, drain duration, and complications.

Results:

There was a significantly shorter time to closure (P < 0.0001) for group 1 when compared with group 2. In addition, there were fewer therapy days (P = 0.0041), fewer debridements/dressing changes (P = 0.0011), and shorter drain duration (P = 0.0001) for group 1 when compared with group 2.

Conclusions:

We describe a novel regimen consisting of adjunctive NPWTi-d, along with debridement and systemic antibiotics, followed by closed incision negative pressure therapy after muscle flap reconstruction and closure, to help manage preexisting sternal wounds that had failed to close following a previous cardiac procedure.

Myocardial revascularization: the evolution of the STS database and quality measurement for improvement

The Society of Thoracic Surgeons (STS) is a not-for-profit organization dedicated to helping clinicians and researchers provide optimal outcomes for patients undergoing heart, lung, and esophageal surgery. The organization was founded in 1964 and has grown to now include over 7300 members in over 90 countries. The STS created a national database that collects detailed clinical information on patients undergoing adult cardiac, pediatric and congenital cardiac, and general thoracic operations. The data collected are used to produce risk-adjusted, nationally benchmarked performance assessments and feedback; facilitate voluntary public reporting; support quality initiatives; develop evidence-based guidelines; monitor long-term clinical outcomes; track device performance; and promote high-quality research collaboratives.

Preoperative cigarette smoking and short-term morbidity and mortality after cardiac surgery: a meta-analysis

Currently, the choice of whether or not to electively operate on current smokers is varied among cardiothoracic surgeons. This meta-analysis aims to determine whether preoperative current versus ex-smoking status is related to short-term postoperative morbidity and mortality in cardiac surgical patients. Systematic literature searches of the PubMed, MEDLINE and Cochrane databases were carried out to identify all studies in cardiac surgery that investigated the relationship between smoking status and postoperative outcomes. Extracted data were analysed by random effects models. Primary outcomes included 30-day or in-hospital all-cause mortality and pulmonary morbidity. Overall, 13 relevant studies were identified, with 34 230 patients in current or ex-smoking subgroups. There was no difference in mortality (p=0.93). Current smokers had significantly higher risk of overall pulmonary complications (OR 1.44; 95% CI 1.27 to 1.64; p<0.001) and postoperative pneumonia (OR 1.62; 95%  CI 1.27 to 2.06; p<0.001) as well as lower risk of postoperative renal complications (OR 0.82; 95%  CI 0.70 to 0.96; p=0.01) compared with ex-smokers. There was a trend towards an increased risk of postoperative MI (OR 1.29; 95%  CI 0.95 to 1.75; p=0.10). No difference in postoperative neurological complications (p=0.15), postoperative sternal surgical site infections (p=0.20) or postoperative length of intensive care unit stay (p=0.86) was seen. Cardiac surgical patients who are current smokers at the time of operation do not have an increased 30-day mortality risk compared with ex-smokers, although they are at significantly increased risk of postoperative pulmonary complications.

Cost-effectiveness analysis of single use negative pressure wound therapy dressings (sNPWT) compared to standard of care in reducing surgical site complications (SSC) in patients undergoing coronary artery bypass grafting surgery

Background

There is a growing interest in using negative pressure wound therapy in closed surgical incision to prevent wound complications which continue to persist following surgery despite advances in infection measures.

Objectives

To estimate the cost-effectiveness of single use negative pressure wound therapy (sNPWT) compared to standard of care in patients following coronary artery bypass grafting surgery (CABG) procedure to reduce surgical site complications (SSC) defined as dehiscence and sternotomy infections.

Method

A decision analytic model was developed from the Germany Statutory Health Insurance payer’s perspective over a 12-week time horizon. Baseline data on SSC, revision operations, length of stay, and readmissions were obtained from a prospective observational study of 2621 CABG patients in Germany. Effectiveness data for sNPWT was taken from a randomised open label trial conducted in Poland which randomised 80 patients to treatment with either sNPWT or standard care. Cost data (in Euros) were taken from the relevant diagnostic related groups and published literature.

Results

The clinical study reported an increase in wounds that healed without complications 37/40 (92.5%) in the sNPWT compared to 30/40 (75%) patients in the SC group p = 0.03. The model estimated sNPWT resulted in 0.989 complications avoided compared to 0.952 and the estimated quality adjusted life years were 0.8904 and 0.8593 per patient compared to standard care. The estimated mean cost per patient was €19,986 for sNPWT compared to €20,572 for SC resulting in cost-saving of €586. The findings were robust to a range of sensitivity analyses.

Conclusion

The sNPWT can be considered a cost saving intervention that reduces surgical site complications following CABG surgery compared to standard care. We however recommend that additional economic studies should be conducted as new evidence on the use of sNPWT in CABG patients becomes available to validate the results of this economic analysis.

Risk factor analysis and management strategies of operating room-related infections after coronary artery bypass grafting

Background

To investigate and analyze the risk factors of operating room-related infections after coronary artery bypass grafting (CABG), to propose corresponding infection control management strategies, and to verify and evaluate the effectiveness of the strategy implementation.

Methods

Patients with coronary heart disease who underwent CABG in a hospital from January 2015 to December 2016 were selected for inclusion in this study. The following patient variables were documented: demographics, history of underlying diseases (hypertension and diabetes), preoperative American Society of Anesthesiologists (ASA) score, skin preparation method, perioperative use of antibiotics, operation duration, intraoperative hypothermia, intraoperative blood loss, intraoperative blood transfusion, presence of visitors in the operating room, consecutive use of the same operating room, qualification of the surgeon, and surgical site infection. The infection diagnosis was confirmed using the Diagnostic Criteria for Nosocomial Infections (Trial) issued by the Ministry of Health in 2001. Univariate chi-square tests and multivariate logistic regression analysis were used to analyze the risk factors for infection in patients undergoing CABG, and infection control management strategies were proposed. The proposed infection control strategies were applied to patients who underwent CABG in the hospital in 2017. The effectiveness of the strategy implementation was evaluated.

Results

We analyzed in 139 patients (417 coronary artery bypass grafts from January 2015 to December 2016) and identified 4 surgical site infections. The incidence of infection was 2.88%. According to the univariate analysis, the following factors were related to the high incidence of surgical site infections: advanced age, history of underlying diseases (hypertension and diabetes), obesity, ASA score (class II or above), conventional skin preparation method, irrational perioperative antibiotic use, operation duration >4 hours, presence of visitors in the operating room, and consecutive use of the same operating room (P<0.05 for all variables). Multivariate logistic regression analysis showed that advanced age, history of underlying diseases (hypertension and diabetes), irrational perioperative antibiotic use, operation duration >4 hours, and presence of visitors in the operating room were high risk factors for surgical site infection after CABG. From January 2017 to December 2017, after applying the proposed infection control measures to patients undergoing CABG, the surgical site infection rate was 1.13% (3/266), which was significantly different from that of the previous period (P<0.05).

Conclusions

The following are high risk factors for surgical site infection after CABG: advanced age, history of underlying diseases (hypertension and diabetes), irrational antibiotic use during the perioperative period, operation duration >4 hours, and presence of visitors in the operating room. Medical providers should fully understand these risk factors and optimize the adjustable factors during the perioperative period to minimize the incidence of infections after CABG.

Bilateral Internal Mammary Artery Bypass Grafting: Sternal Wound Infection in High-Risk Population. Should Sternal Infection Scare Us?

Background

Bilateral internal mammary arteries (BIMAs) remain underused in coronary artery bypass grafting (CABG), especially in elderly, diabetic, and obese patients. This study investigated incidence of sternal wound infection (SWI), sternal instability (SI), and reintervention for bleeding (RIB) in this high-risk population.

Methods

A single-center retrospective observational study was performed in "Grand Hôpital de Charleroi, Gilly, Belgium." A total of 319 patients undergoing CABG from December 2011 to December 2015 were included. Three main outcome measures (SWI, SI, and RIB) were investigated in obese vs nonobese, diabetic vs nondiabetic, and elderly vs younger patients.

Results

In all, 14 SWI, 11 SI, and 6 RIB were discounted. Death rate was as follows: SWI: 2/14 vs 17/305 (P = .178), SI: 2/11 vs 17/308 (P = .081), and RIB: 2/6 vs 17/313 (P = .004). In obese (n = 113) vs nonobese (n = 206) patients, there was no difference for SWI (P = .263), SI (P = .565), and RIB (P = .332). In diabetic (n = 118) vs nondiabetic (n = 201) patients, there was no difference for SWI (P = .642), SI (P = .497), and RIB (P = .298). In elderly (n = 62) vs younger (n = 257) patients, there was no difference for SWI (P = .619), SI (P = .915), and RIB (P = .385).

Conclusions

Obesity, age, and diabetes treated by insulin (or not) do not seem to be risk factors for developing SWI, SI, or RIB in patients receiving a CABG using BIMA. Nevertheless, mortality was higher in RIB group.

Thoracic Surgery Considerations in Obese Patients

The obesity epidemic in the United States has increased greatly over the past several decades, and thoracic surgeons are likely to see obese patients routinely in their practices. Obesity has direct deleterious health effects such as metabolic disorder and cardiovascular disease, and is associated with many cancers. Obese patients who need thoracic surgery pose practical challenges to many of the routine elements in perioperative management. Preoperative assessment of obesity-related comorbid conditions and risk stratification for surgery, thorough intraoperative planning for anesthesia and surgery, and postoperative strategies to optimize pulmonary hygiene and mobility minimize the risk of adverse outcomes.

Bacteriuria is not associated with surgical site infection in patients undergoing cardiovascular surgery

BACKGROUND

Despite absence of evidence, in practice, asymptomatic bacteriuria is perceived as a risk factor for surgical site infection (SSI) among patients with cardiac surgery. We aimed to identify whether an association exists between the preoperative presence of asymptomatic bacteriuria or urinary tract infection and SSI in patients undergoing cardiovascular surgery.

METHODS

This is an analytical study with a retrospective cohort of patients undergoing coronary revascularization or valve replacement surgery. We identified cases of bacteriuria, urinary tract infection, and cardiovascular SSI and adjusted the results according to exposure to antibiotics and known risk factors for SSI using a multivariate logistic regression analysis.

RESULTS

A total of 840 patients were included in the study, of whom 33 (3.9%) had asymptomatic bacteriuria and 13 (1.5%) had urinary tract infections. The incidence of SSI was 9.5% (80 patients), with 2.3% of cases having mediastinitis. In the multivariate analysis, asymptomatic bacteriuria (relative risk, 0.83; 95% confidence interval, 0.26-2.56; P = .74) and urinary tract infection (relative risk, 2.54; 95% confidence interval, 0.60-10.69; P = .20) were not risk factors for SSI. Traditional risk factors were found to increase the risk of SSI.

CONCLUSIONS

The presence of bacteriuria is not a risk factor for presenting SSI in cardiovascular surgery. Screening with urinalysis or urine culture would not be recommended for patients undergoing cardiac surgery.

Prevalence of depression and its associated factors in patients post-coronary artery bypass graft surgery

This research aimed to determine the depression level and its correlation experienced by post-coronary artery bypass graft patients after being discharged from cardiac intensive care units. A cross-sectional design was employed for assessing variables. The Self-rating Depression Scale, as proposed by Zung, was used by the researchers on a convenience sample of Jordanian patients (N = 143) who were approached soon after their discharge from the targeted units. The results suggested that the level of depression among Jordanian patients was relatively high (M = 62.7, SD = 5.6). Moreover, depression was significantly higher among female, unmarried and unemployed patients. Patients who received their information about coronary artery bypass graft surgery from nurses had a lower level of depression. Age, length of stay in the cardiac intensive care unit and hospital type significantly predicted the level of depression. The research concluded that the post-coronary artery bypass graft patients who experienced an early onset depression required more attention to highlight the importance of supportive interventions.

Predictors of surgical site infection after open lower extremity revascularization

OBJECTIVE

Surgical site infection (SSI) after open lower extremity bypass (LEB) is a serious complication leading to an increased rate of graft failure, hospital readmission, and health care costs. This study sought to identify predictors of SSI after LEB for arterial occlusive disease and also potential modifiable factors to improve outcomes.

METHODS

Data from a statewide cardiovascular consortium of 35 hospitals were used to obtain demographic, procedural, and hospital risk factors for patients undergoing elective or urgent open LEB between January 2012 and June 2015. Bivariate comparisons and targeted maximum likelihood estimation were used to identify independent risk factors of SSI. Adjusted odds ratios (ORs) were calculated for patient demographics, comorbidities, operative details, and hospital-level factors.

RESULTS

Our study population included 3033 patients who underwent 703 femoral-femoral bypasses, 1431 femoral-popliteal bypasses, and 899 femoral-distal vessel bypasses. An SSI was diagnosed in 320 patients (10.6%) ≤30 days after the index operation. Adjusted patient and procedural predictors of SSI included renal failure currently requiring dialysis (OR, 4.35; 95% confidence interval [CI], 3.45-5.47; P < .001), hypertension (OR, 4.29; 95% CI, 2.74-6.72; P < .001), body mass index ≥25 kg/m² (OR, 1.78; 95% CI, 1.23-2.57; P = .002), procedural time >240 minutes (OR, 2.95; 95% CI, 1.89-4.62; P < .001), and iodine-only skin preparation (OR, 1.73; 95% CI, 1.02-2.91; P = .04). Hospital factors associated with increased SSI included hospital size <500 beds (OR, 2.22; 95% CI, 1.09-4.55; P = .028) and major teaching hospital (OR, 1.66; 95% CI, 1.07-2.58; P = .024). SSI resulted in increased risk of major amputation and surgical reoperation (P < .01), but did not affect 30-day mortality.

CONCLUSIONS

SSI after LEB is associated with an increase in rate of amputation and reoperation. Several patient, operative, and hospital-related risk factors that predict postoperative SSI were identified, suggesting that targeted improvements in perioperative care may decrease complications and improve vascular patient outcomes.

Case-Control Study of Risk Factors for Mediastinitis After Cardiovascular Surgery

We report results of a case-control study in which we evaluated 41 risk factors potentially associated with the development of post-surgical mediastinitis. There were 163 case patients and 326 control patients. Independent risk factors kept in the final multivariate logistic regression model were obesity (defined as a body mass index of greater than 30), diabetes mellitus, chronic obstructive pulmonary disease, preoperative stay longer than 1 week, pulmonary hypertension, perioperative myocardial infarction, and reoperation.

Delayed aortic rupture resulting from postoperative superficial sternal wound infection

While deep sternal wound infection (DSWI) after cardiac surgery is a significant contributor to patient morbidity and mortality, superficial sternal wound infection (SSWI) mostly has a benign course. We report a mortality case of aortic rupture resulting from SSWI after cardiac surgery. A 50-year-old male underwent an aortic valve replacement (AVR). Three months after the valve operation, he presented with severe dyspnea, which had never before been observed, and chest computed tomography revealed an ascending aortic rupture with large hematoma compressing the main pulmonary artery. We performed an emergent operation for aortic rupture that possibly originated from the SSWI. Postoperatively, the patient died of hypovolemic shock due to recurrent aortic rupture despite efforts to resuscitate him.

Nosocomial Infections and Balloon Counterpulsation: Risk Factors and Outcome

Between February and September 2003, 136 (5.3%) of 2,558 patients undergoing cardiac surgery were supported with intra-aortic balloon counterpulsation. There were 71 infected (group 1) and 65 noninfected (group 2) patients. Risk factors for nosocomial infections were identified by univariate and multivariate analysis. On univariate analysis, significant risk factors were operation time, balloon pump duration, ventilation hours, duration of central venous catheter placement, amount of blood transfused, left ventricular ejection fraction < 30%, intra- and/or postoperative intra-aortic balloon counterpulsation, surgery under cardiopulmonary bypass, combined procedures, re-exploration, and Acute Physiology And Chronic Health Evaluation (APACHE) II score. On multivariate analysis, ventilation hours and amount of blood transfused were independently associated with group 1. Respiratory tract infections were common in the balloon counterpulsation population (41.1%). Mortality was significantly higher in patients needing balloon pump support (19.9%) compared to controls (1.1%), but it was similar in groups 1 and 2. Recognition of risk factors for postoperative infection in patients undergoing cardiovascular surgical procedures with intra-aortic balloon counterpulsation may help to improve their prognosis and allow more organized surveillance.

Surgical Site Infection During Hospitalization and After Discharge in Patients Who Have Undergone Cardiac Surgery

During a 13-month period, 513 patients who were scheduled to undergo cardiac surgery were prospectively observed for surgical site infection during hospitalization after surgery and for 1 month after hospital discharge. Fifty-three patients showed evidence of surgical site infection (during hospitalization for 31 patients and after discharge for 22). Multivariate analysis identified that risk factors for surgical site infection differed between infections that occurred during hospitalization and those that occurred after discharge.

Case-Control Study of Risk Factors for Mediastinitis After Cardiovascular Surgery

We report results of a case-control study in which we evaluated 41 risk factors potentially associated with the development of post-surgical mediastinitis. There were 163 case patients and 326 control patients. Independent risk factors kept in the final multivariate logistic regression model were obesity (defined as a body mass index of greater than 30), diabetes mellitus, chronic obstructive pulmonary disease, preoperative stay longer than 1 week, pulmonary hypertension, perioperative myocardial infarction, and reoperation.

Focus on the prophylaxis, epidemiology and therapy of methicillin-resistant Staphylococcus aureus surgical site infections and a position paper on associated risk factors: the perspective of an Italian group of surgeons

BACKGROUND

The aim of this research was to study the epidemiology, microbiology, prophylaxis, and antibiotic therapy of surgical site infections (SSIs), especially those caused by methicillin-resistant Staphylococcus aureus (MRSA), and identify the risk factors for these infections. In Italy SSIs occur in about 5 % of all surgical procedures. They are predominantly caused by staphylococci, and 30 % of them are diagnosed after discharge. In every surgical specialty there are specific procedures more associated with SSIs.

METHODS

The authors conducted a systematic review of the literature on SSIs, especially MRSA infections, and used the Delphi method to identify risk factors for these resistant infections.

RESULTS

Risk factors associated with MRSA SSIs identified by the Delphi method were: patients from long-term care facilities, recent hospitalization (within the preceding 30 days), Charlson score > 5 points, chronic obstructive pulmonary disease and thoracic surgery, antibiotic therapy with beta-lactams (especially cephalosporins and carbapenem) and/or quinolones in the preceding 30 days, age 75 years or older, current duration of hospitalization >16 days, and surgery with prothesis implantation. Protective factors were adequate antibiotic prophylaxis, laparoscopic surgery and the presence of an active, in-hospital surveillance program for the control of infections. MRSA therapy, especially with agents that enable the patient's rapid discharge from hospital is described.

CONCLUSION

The prevention, identification and treatment of SSIs, especially those caused by MRSA, should be implemented in surgical units in order to improve clinical and economic outcomes.

Latitude of the study place and age of the patient are associated with incidence of mediastinitis and microbiology in open-heart surgery: a systematic review and meta-analysis

Objective

We aimed to summarize the pooled frequency of mediastinitis following open-heart surgery caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and Gram-negative bacteria.

Design

This study was a systematic review and a meta-analysis of prospective and retrospective cohort studies.

Materials and methods

We searched the literature, and a total of 97 cohort studies were identified. Random-effect model was used to synthesize the results. Heterogeneity between studies was examined by subgroup and meta-regression analyses, considering study and patient-level variables. Small-study effect was evaluated.

Results

Substantial heterogeneity was present. The estimated incidence of mediastinitis evaluated from 97 studies was 1.58% (95% confidence intervals [CI] 1.42, 1.75) and that of Gram-positive bacteria, Gram-negative bacteria, and MRSA bacteria evaluated from 63 studies was 0.90% (95% CI 0.81, 1.21), 0.24% (95% CI 0.18, 0.32), and 0.08% (95% CI 0.05, 0.12), respectively. A meta-regression pinpointed negative association between the frequency of mediastinitis and latitude of study place and positive association between the frequency of mediastinitis and the age of the patient at operation. Multivariate meta-regression showed that prospective cohort design and age of the patients and latitude of study place together or in combination accounted for 17% of heterogeneity for end point frequency of mediastinitis, 16.3% for Gram-positive bacteria, 14.7% for Gram-negative bacteria, and 23.3% for MRSA bacteria.

Conclusion

Evidence from this study suggests the importance of latitude of study place and advanced age as risk factors of mediastinitis. Latitude is a marker of thermally regulated bacterial virulence and other local surgical practice. There is concern of increasing risk of mediastinitis and of MRSA in elderly patients undergoing sternotomy.

Strategies to Prevent Surgical Site Infections in Acute Care Hospitals: 2014 Update

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their surgical site infection (SSI) prevention efforts. This document updates “Strategies to Prevent Surgical Site Infections in Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

Diabetes and Risk of Surgical Site Infection: A Systematic Review and Meta-analysis

OBJECTIVE To determine the independent association between diabetes and surgical site infection (SSI) across multiple surgical procedures. DESIGN Systematic review and meta-analysis. METHODS Studies indexed in PubMed published between December 1985 and through July 2015 were identified through the search terms "risk factors" or "glucose" and "surgical site infection." A total of 3,631 abstracts were identified through the initial search terms. Full texts were reviewed for 522 articles. Of these, 94 articles met the criteria for inclusion. Standardized data collection forms were used to extract study-specific estimates for diabetes, blood glucose levels, and body mass index (BMI). A random-effects meta-analysis was used to generate pooled estimates, and meta-regression was used to evaluate specific hypothesized sources of heterogeneity. RESULTS The primary outcome was SSI, as defined by the Centers for Disease Control and Prevention surveillance criteria. The overall effect size for the association between diabetes and SSI was odds ratio (OR)=1.53 (95% predictive interval [PI], 1.11-2.12; I2, 57.2%). SSI class, study design, or patient BMI did not significantly impact study results in a meta-regression model. The association was higher for cardiac surgery 2.03 (95% PI, 1.13-4.05) compared with surgeries of other types (P=.001). CONCLUSIONS These results support the consideration of diabetes as an independent risk factor for SSIs for multiple surgical procedure types. Continued efforts are needed to improve surgical outcomes for diabetic patients. Infect. Control Hosp. Epidemiol. 2015;37(1):88-99.

Cardiac Implantable Electronic Device Infection: From an Infection Prevention Perspective

A cardiac implantable electronic device (CIED) is indicated for patients with severely reduced ejection fraction or with life-threatening cardiac arrhythmias. Infection related to a CIED is one of the most feared complications of this life-saving device. The rate of CIED infection has been estimated to be between 2 and 25; though evidence shows that this rate continues to rise with increasing expenditure to the patient as well as healthcare systems. Multiple risk factors have been attributed to the increased rates of CIED infection and host comorbidities as well as procedure related risks. Infection prevention efforts are being developed as defined bundles in numerous hospitals around the country given the increased morbidity and mortality from CIED related infections. This paper aims at reviewing the various infection prevention measures employed at hospitals and also highlights the areas that have relatively less established evidence for efficacy.