Incidence, types and outcomes of sternal wound infections after cardiac surgery in Saudi Arabia. A retrospective medical chart review

Mortality Associated with Surgical Site Infections Following Cardiac Surgery: Insights from the International ID-IRI Study

Objectives

Surgical site infections (SSIs) after cardiac surgery increase morbidity and mortality rates. This multicenter study aimed to identify mortality risk factors associated with SSIs after heart surgery.

Methods

Conducted from January to March 2023, this prospective study included 167 patients aged >16 years with post-heart surgery SSIs. The primary focus was the 30-day mortality. Univariate analysis and multivariate logistic regression utilizing the backward elimination method were used to establish the final model.

Results

Several factors significantly correlated with mortality. These included urinary catheterization (odds ratio [OR] 14.197; 90% confidence interval [CI] 12.198-91.721]), emergent surgery (OR 8.470 [90% CI 2.028-35.379]), valvular replacement (OR 4.487 [90% CI 1.001-20.627]), higher quick Sequential Organ Failure Assessment scores (OR 3.147 [90% CI 1.450-6.827]), advanced age (OR 1.075 [90% CI 1.020-1.132]), and postoperative re-interventions within 30 days after SSI (OR 14.832 [90% CI 2.684-81.972]). No pathogens were isolated from the wound cultures of 53 (31.7%) patients. A total of 43.1% of SSIs (n = 72) were due to gram-positive microorganisms, whereas 27.5% of cases (n = 46) involved gram-negatives. Among the gram-positive bacteria, Staphylococci (n = 30, 17.9%) were the predominant microorganisms, whereas Klebsiella (n = 16, 9.6%), Escherichia coli (n = 9, 5.4%), and Pseudomonas aeruginosa (n = 7, 4.2%) were the most prevalent.

Conclusions

To mitigate mortality after heart surgery, stringent infection control measures and effective surgical antisepsis are crucial, particularly, in the elderly. The clinical progression of the disease is reflected by the quick Sequential Organ Failure Assessment score and patient re-intervention, and effective treatment is another essential component of SSI management.

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.

Factors associated with surgical site infection in myocardial revascularization: a retrospective longitudinal study

OBJECTIVES

to analyze the influence of sociodemographic and clinical variables, as well as the surgical checklist adherence score, on the occurrence of surgical site infection among patients undergoing myocardial revascularization.

METHODS

an observational, longitudinal, retrospective study was conducted at a university hospital, involving 266 medical records of patients who underwent myocardial revascularization surgery. Instruments containing sociodemographic, clinical, and infection-related variables were used, along with the Perioperative Surgical Safety Checklist. Descriptive, bivariate, and logistic regression analyses were employed.

RESULTS

surgical site infection occurred in 89 (33.5%) patients. There was a statistically significant association between body temperature outside the range of 36 degrees Celsius to 36.5 degrees Celsius (p=0.01), the presence of invasive devices (p=0.05), surgical procedures with the anticipation of critical events (p<0.001), and the occurrence of infection.

CONCLUSIONS

body temperature, the presence of invasive devices, and surgical procedures with the anticipation of critical events were significant factors contributing to an increased risk of infection.

Predictors of sternal wound infection post cardiac surgery in a Saudi Centre: a case control study

BACKGROUND

Sternal wound infection (SWI) post cardiac surgery remains an important cause of extra morbidity, mortality and cost. The objective was to identify risk factors for SWI in a cardiac centre in Eastern Saudi Arabia as part of the investigation into Surveillance variance in the local rates of SWI.

METHODS

We included cases and controls from a cross section of patients who underwent major cardiac surgery between 2017 and 2020 matched for age, sex and time of surgery. An explanatory logistic regression model was fitted to estimate the risk factors.

RESULTS

N = 204 (51 cases and 153 controls matching ratio 1:3, from a source population of 985 patients). factors significantly associated with SWI in the final multivariate model: hospital stay OR (1.05, Cl 1.01-1.10), Graft Conduit BIMA versus No Graft OR (10.94, Cl 1.60-74.63), transfusion of both packed cells plus other blood products versus no transfusion OR (3.53, Cl 93-13.44), HbA1c OR (1.09 Cl 0.84-1.41), BMI OR (1.25, Cl 1.04-1.50), perioperative blood glucose OR (1.02, Cl 1.004-1.03), surgery time OR (1.19, Cl 1.00-1.58).

CONCLUSIONS

The diverse aetiology, cross-disciplinary nature of SWI prevention, and despite improved prevention and control practices, including related care bundles with their proven value, SWI remain a serious challenge in cardiac surgery. Multidisciplinary consensus guidelines are well overdue.

Impact of Pre-operative Hemoglobin A1C Level and Microbiological Pattern on Surgical Site Infection After Cardiac Surgery

Background Surgical site infection (SSI) after cardiac surgery is a major concern. A limited number of studies have addressed the relationship of preoperative glycemic control on the risk of developing SSI after cardiac surgery. We aim to determine the incidence, microbiological pattern, and impact of preoperative hemoglobin A1C (Hgb A1C) on the development of SSI after cardiac surgery. Methods This is a single-center retrospective chart review that was performed on adult patients undergoing cardiac surgery from January 2017 to December 2018. Results Two hundred and twenty-nine patients underwent 233 procedures. The median age was 60 years; 71% males, 64% were diabetic, and 67% had a Hb A1C above 7% preoperatively. Around 7% of patients developed deep SSI. For patients that developed SSI, 63% had gram-negative bacteria. Hb A1C >7% was not found to be associated with an increased incidence of SSI. Conclusion Our results show that there is no apparent relationship between pre-operative Hgb A1C levels and SSI after cardiac surgery. Although we follow a comprehensive SSI perioperative bundle based on international guidelines that advocates using antibiotics to cover gram-positive organisms, it is interesting that the rate of gram-negative organisms in our patients' cohort is unexpectedly high. We believe that adjusting the perioperative antibiotic regimen based on local microbiological patterns seems to be a reasonable and easily achievable target to decrease the incidence of SSI.