Drainage days-an independent risk factor for serious sternal wound infections after cardiac surgery: a case control study

Identifying potential predictors of the risk of surgical site infection following cardiac surgery: a scoping review

OBJECTIVES

This scoping review was undertaken to identify risk prediction models and pre-operative predictors of surgical site infection (SSI) in adult cardiac surgery. A particular focus was on the identification of novel predictors that could underpin the future development of a risk prediction model to identify individuals at high risk of SSI, and therefore guide a national SSI prevention strategy.

METHODS

A scoping review to systematically identify and map out existing research evidence on pre-operative predictors of SSI was conducted in two stages. Stage 1 reviewed prediction modelling studies of SSI in cardiac surgery. Stage 2 identified primary studies and systematic reviews of novel cardiac SSI predictors.

RESULTS

The search identified 7887 unique reports; 7154 were excluded at abstract screening and 733 were selected for full-text assessment. Twenty-nine studies (across 30 reports) were included in Stage 1 and reported the development (N=14), validation (N=13), or both development and validation (N=2) of 52 SSI risk prediction models including 67 different pre-operative predictors. The remaining 703 reports were re-assessed in Stage 2; 49 studies met the inclusion criteria, and 56 novel pre-operative predictors that have not been assessed previously in models were identified.

CONCLUSIONS

This review identified 123 pre-operative predictors of the risk of SSI following cardiac surgery, 56 of which have not been included previously in the development of cardiac SSI risk prediction models. These candidate predictors will be a valuable resource in the future development of risk prediction scores, and may be relevant to prediction of the risk of SSI in other surgical specialities.

Management of Pathologic Hip Fracture Secondary to Musculoskeletal Echinococcosis: A Case Report

A 50-year-old female from Uzbekistan presented to our emergency department with severe right hip pain and loss of ambulation. Her history included multiple hepatic echinococcal cyst resections. After a fall, she underwent a proximal femur open reduction and internal fixation (ORIF) and revision in Uzbekistan, which revealed broken screws and cystic lesions. Subsequent treatment included hardware removal, proximal femur replacement, and antiparasitic therapy, leading to significant improvement. This case highlights the need for considering rare pathologies in atypical orthopedic presentations and demonstrates the effectiveness of integrating detailed history, careful diagnostics, and coordinated care to manage challenging conditions.

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.

Reduction of drainage-associated complications in cardiac surgery with a digital drainage system: a randomized controlled trial

Background

Thoracic chest drains are placed after cardiac surgery allowing for the clearance of blood, fluid, and air to prevent post-operative complications. Despite its importance, there is little data on the application of digital chest drainage systems in cardiac surgery. Therefore, the differences between an analog and a digital chest drainage system in cardiac surgery patients were investigated in a randomized controlled trial.

Methods

A total of 354 elective cardiac surgery patients were preoperatively randomized 1:1 between September 2016 and September 2017 to either an analog (Ocean) or a digital (Thopaz⁺) chest drainage system aiming to compare drainage-associated postoperative outcome parameters.

Results

A total of 340 patients were included in the analysis (analog: 188; digital: 152) with no significant differences in preoperative baseline parameters. Incidence of X-rays to detect air leaks was significantly lower in the digital group (analog: 20.2%; digital: 8.6%; P<0.01). Patients treated with the digital system showed a 3.3% reduction of re-thoracotomies, however, not statistically significant (analog: 5.3%; digital: 2.0%; P=0.19). Median total fluid amount did not significantly differ between study groups [median (P25; P75); analog: 705 (400; 1,333) mL; digital: 686 (404; 1,229) mL; P=0.83]; however, the use of the digital drainage system resulted in a quicker removal with a reduced median drainage duration of 16 hours (analog: 65 hours; digital: 49 hours; P≤0.01).

Conclusions

The study provides evidence that digital drainage systems can be safely applied in cardiac surgery patients. The use of the digital management system led to a decreased incidence of drainage-associated complications as well as to shortened chest tube duration. Findings require confirmation by additional studies.

Are systematic drain tip or drainage fluid cultures predictive of surgical site infections?

Systematic cultures of drain tips or drainage fluids for the early detection of surgical site infections (SSIs) are controversial. To examine the association between the results of systematic drain tip or drainage fluid cultures and the occurrence of SSIs in clean or clean-contaminated surgery. Searches were performed in the PubMed, and Cat.inist databases for observational studies published before 31st March 2017. Studies reporting results of drain tip or drainage fluid systematic cultures and SSIs after clean or clean-contaminated surgeries were included, and meta-analyses were performed. Seventeen studies, including 4390 patients for drain tip cultures and 1288 for drainage fluid cultures, were selected. The pooled negative predictive values were high (99%, 95% confidence interval (CI) 98-100 for drain tip cultures and 98%, 95% CI 94-100 for drainage fluid cultures). The positive predictive values were low (11%, 95% CI 2-24 for drain tip cultures and 12%, 95% CI 3-24 for drainage fluid cultures). The sensitivities were low (41%, 95% CI 12-73 for drain tip cultures and 37%, 95% CI 16-60 for drainage fluid cultures). The specificities were high (93%, 95% CI 88-96) for drain tip cultures and moderate (77%, 95% CI 54-94) for drainage fluid cultures. Systematic cultures of drain tips or drainage fluids appear not to be relevant, because their positive predictive values were low in the prediction of SSIs.

A Prospective Multi-Institutional Cohort Study of Mediastinal Infections After Cardiac Operations

BACKGROUND

Mediastinal infections are a potentially devastating complication of cardiac operations. This study analyzed the frequency, risk factors, and perioperative outcomes of mediastinal infections after cardiac operations.

METHODS

In 2010, 5,158 patients enrolled in a prospective study evaluating infections after cardiac operations and their effect on readmissions and mortality for up to 65 days after the procedure. Clinical and demographic characteristics, operative variables, management practices, and outcomes were compared for patients with and without mediastinal infections, defined as deep sternal wound infection, myocarditis, pericarditis, or mediastinitis.

RESULTS

There were 43 mediastinal infections in 41 patients (cumulative incidence, 0.79%; 95% confidence interval [CI] 0.60% to 1.06%). Median time to infection was 20.0 days, with 65% of infections occurring after the index hospitalization discharge. Higher body mass index (hazard ratio [HR] 1.06; 95% CI, 1.01 to 1.10), higher creatinine (HR, 1.25; 95% CI, 1.13 to 1.38), peripheral vascular disease (HR, 2.47; 95% CI, 1.21 to 5.05), preoperative corticosteroid use (HR, 3.33; 95% CI, 1.27 to 8.76), and ventricular assist device or transplant surgery (HR, 5.81; 95% CI, 2.36 to 14.33) were associated with increased risk of mediastinal infection. Postoperative hyperglycemia (HR, 3.15; 95% CI, 1.32 to 7.51) was associated with increased risk of infection in nondiabetic patients. Additional length of stay attributable to mediastinal infection was 11.5 days (bootstrap 95% CI, 1.88 to 21.11). Readmission rates and mortality were five times higher in patients with mediastinal infection than in patients without mediastinal infection.

CONCLUSIONS

Mediastinal infection after a cardiac operation is associated with substantial increases in length of stay, readmissions, and death. Reducing these infections remains a high priority, and improving post-operative glycemic management may reduce their risk in patients without diabetes.