A retrospective analysis of factors affecting surgical site infection in orthopaedic patients

The surgical interval between robot-assisted SEEG and epilepsy resection surgery is an influencing factor of SSI

BACKGROUND

In recent years, the development of robotic neurosurgery has brought many benefits to patients, but there are few studies on the occurrence of surgical site infection (SSI) after robot-assisted stereoelectroencephalography (SEEG). The purpose of this study was to collect relevant data from robot-assisted SEEG over the past ten years and to analyze the influencing factors and economic burden of surgical site infection.

METHODS

Basic and surgical information was collected for all patients who underwent robot-assisted SEEG from January 2014 to December 2023. Logistic regression was used to analyze the factors influencing SSI according to different subgroups (radiofrequency thermocoagulation or epilepsy resection surgery).

RESULTS

A total of 242 subjects were included in this study. The risk of SSI in the epilepsy resection surgery group (18.1%) was 3.5 times greater than that in the radiofrequency thermocoagulation group (5.1%) (OR 3.49, 95% CI 1.39 to 9.05); this difference was statistically significant. SSI rates in the epilepsy resection surgery group were associated with shorter surgical intervals (≤ 9 days) and higher BMI (≥ 23 kg/m2) (6.1 and 5.2 times greater than those in the control group, respectively). Hypertension and admission to the intensive care unit (ICU) were risk factors for SSI in the radiofrequency thermocoagulation group. Patients with SSIs had $21,231 more total hospital costs, a 7-day longer hospital stay, and an 8-day longer postoperative hospital stay than patients without SSI.

CONCLUSIONS

The incidence of SSI in patients undergoing epilepsy resection after stereoelectroencephalography was higher than that in patients undergoing radiofrequency thermocoagulation. For patients undergoing epilepsy resection surgery, prolonging the interval between stereoelectroencephalography and epilepsy resection surgery can reduce the risk of SSI; At the same time, for patients receiving radiofrequency thermocoagulation treatment, it is not recommended to enter the ICU for short-term observation if the condition permits.

-A machine learning model to predict surgical site infection after surgery of lower extremity fractures

PURPOSE

This study aimed to develop machine learning algorithms for identifying predictive factors associated with the risk of postoperative surgical site infection in patients with lower extremity fractures.

METHODS

A machine learning analysis was conducted on a dataset comprising 1,579 patients who underwent surgical fixation for lower extremity fractures to create a predictive model for risk stratification of postoperative surgical site infection. We evaluated different clinical and demographic variables to train four machine learning models (neural networks, boosted generalised linear model, naïve bayes, and penalised discriminant analysis). Performance was measured by the area under the curve score, Youdon's index and Brier score. A multivariate adaptive regression splines (MARS) was used to optimise predictor selection.

RESULTS

The final model consisted of five predictors. (1) Operating room time, (2) ankle region, (3) open injury, (4) body mass index, and (5) age. The best-performing machine learning algorithm demonstrated a promising predictive performance, with an area under the ROC curve, Youdon's index, and Brier score of 77.8%, 62.5%, and 5.1%-5.6%, respectively.

CONCLUSION

The proposed predictive model not only assists surgeons in determining high-risk factors for surgical site infections but also empowers patients to closely monitor these factors and take proactive measures to prevent complications. Furthermore, by considering the identified predictors, this model can serve as a reference for implementing preventive measures and reducing postoperative complications, ultimately enhancing patient outcomes. However, further investigations involving larger datasets and external validations are required to confirm the reliability and applicability of our model.

The incidence of surgical site infections in China

Surgical site infections (SSIs) are a common type of healthcare-associated infection. We performed a literature review to demonstrate the incidence of SSIs in mainland China based on studies since 2010. We included 231 eligible studies with ≥30 postoperative patients, comprising 14 providing overall SSI data regardless of surgical sites and 217 reporting SSIs for a specific site. We found that the overall SSI incidence was 2.91% (median; interquartile range: 1.05%, 4.57%) or 3.18% (pooled; 95% confidence interval: 1.85%, 4.51%) and the SSI incidence varied remarkably according to the surgical site between the lowest (median, 1.00%; pooled, 1.69%) in thyroid surgeries and the highest (median, 14.89%; pooled, 12.54%) in colorectal procedures. We uncovered that Enterobacterales and staphylococci were the most common types of micro-organisms associated with SSIs after various abdominal surgeries and cardiac or neurological procedures, respectively. We identified two, nine, and five studies addressing the impact of SSIs on mortality, the length of stay (LOS) in hospital, and additional healthcare-related economic burden, respectively, all of which demonstrated increased mortality, prolonged LOS, and elevated medical costs associated with SSIs among affected patients. Our findings illustrate that SSIs remain a relatively common, serious threat to patient safety in China, requiring more action. To tackle SSIs, we propose to establish a nationwide network for SSI surveillance using unified criteria with the aid of informatic techniques and to tailor and implement countermeasures based on local data and observation. We highlight that the impact of SSIs in China warrants further study.

Prevalence of surgical site infection and risk factors in patients after knee surgery: A systematic review and meta-analysis

The present systematic review and meta-analysis aimed to determine the prevalence of surgical site infection (SSI) and risk factors in patients after knee surgery. A comprehensive and systematic search was carried out across various international electronic databases, including Scopus, PubMed and Web of Science, as well as Persian electronic databases like Iranmedex and the Scientific Information Database (SID). This search involved the utilization of keywords derived from Medical Subject Headings, such as 'Prevalence', 'Surgical wound infection', 'Surgical site infection' and 'Orthopaedics', spanning from the earliest records up to 1 October 2023. To assess the quality of the included studies, the Appraisal tool for Cross-Sectional Studies (AXIS tool) was utilized. The study encompassed a combined participant pool of 11 028 individuals who underwent knee surgery across seven selected studies. The collective prevalence of SSI in patients who underwent knee surgery, as reported in the seven included studies, was determined to be 3.0% (95% CI: 1.2% to 7.5%; I2  = 96.612%; p < 0.001). The combined prevalence of SSI in patients with DM, as reported in six studies, was 5.1% (95% CI: 1.7% to 14.5%; I2  = 79.054%; p < 0.001). Similarly, the pooled prevalence of SSI in patients with HTN, drawn from four studies, was 1.8% (95% CI: 0.7% to 4.5%; I2  = 63.996%; p = 0.040). Additionally, the collective prevalence of SSI in patients with a history of tobacco use, based on findings from six studies, was 4.8% (95% CI: 1.4% to 15.2%; I2  = 93.358%; p < 0.001). Subgroup analysis was conducted within six studies, categorizing them by two countries, namely China and the USA. These analyses revealed that the prevalence of SSI following knee surgery was 3.0% in China and 2.0% in the USA. It is noteworthy that variations in SSI prevalence across different studies may be attributed to a multitude of factors, particularly varying risk factors among patient populations. To address this issue and mitigate the impact of SSI on knee surgery patients, it is advisable to develop tailored interventions.

Comorbidities directly extracted from the hospital database for adjusting SSI risk in the new national semiautomated surveillance system in France: The SPICMI network

OBJECTIVE

To evaluate the performance of a comorbidity-based risk-adjustment model for surgical-site infection (SSI) reporting and benchmarking using a panel of variables extracted from the hospital discharge database (HDD), including comorbidities, compared to other models that use variables from different data sources.

METHODS

The French national surveillance program for SSI (SPICMI) has collected data from voluntary hospitals in the first 6 months of 2020 and 2021, for 16 selected surgery procedures, using a semiautomated algorithm for detection. Four risk-adjustment models were selected with logistic regression analysis, combining the different patterns of variables: National Nosocomial Infections Surveillance System (NNIS) risk-index components, individual operative data, and 6 individual comorbidities according to International Classification of Disease, Tenth Revision (ICD-10) diagnosis: obesity, diabetes, malnutrition, hypertension, cancer, or immunosuppression. Areas under the curve (AUCs) were calculated and compared.

RESULTS

Overall, 294 SSI were detected among 11,975 procedures included. All 6 comorbidities were related to SSI in the univariate analysis. The AUC of the selected model including comorbidities (0.675; 95% confidence interval [CI], 0.642-0.707), was significantly higher than the AUC of the model without comorbidities (0.641; 95% CI, 0.609-0.672; P = .016) or the AUC using the NNIS-index components (0.598; 95% CI, 0.564-0.630; P < .001). The HDD-based model AUC (0.659; 95% CI, 0.625-0.692) did not differ significantly from the selected model without comorbidities (P = .23).

CONCLUSION

Including HDD-based comorbidities as patient case-mix variables instead of NNIS risk index factors could be an effective approach for risk-adjustment of automated SSI surveillance more widely accessible to hospitals.

A clinical prediction model for predicting the surgical site infection after an open reduction and internal fixation procedure considering the NHSN/SIR risk model: a multicenter case-control study

Introduction

Surgical site infection (SSI) is one of the most common surgical-related complications worldwide, particularly in developing countries. SSI is responsible for mortality, long hospitalization period, and a high economic burden.

Method

This hospital-based case-control study was conducted in six educational hospitals in Tehran, Iran. A total of 244 patients at the age of 18-85 years who had undergone open reduction and internal fixation (ORIF) surgery were included in this study. Among the 244 patients, 122 patients who developed SSIs were selected to be compared with 122 non-infected patients used as controls. At the second stage, all patients (n = 350) who underwent ORIF surgery in a hospital were selected for an estimation of the standardized infection ratio (SIR). A logistic regression model was used for predicting the most important factors associated with the occurrence of SSIs. Finally, the performance of the ORIF prediction model was evaluated using discrimination and calibration indices. Data were analyzed using R.3.6.2 and STATA.14 software.

Results

Klebsiella (14.75%) was the most frequently detected bacterium in SSIs following ORIF surgery. The results revealed that the most important factors associated with SSI following an ORIF procedure were found to be elder age, elective surgery, prolonged operation time, American Society of Anesthesiologists score of ≥2, class 3 and 4 wound, and preoperative blood glucose levels of >200 mg/dl; while preoperative higher hemoglobin level (g/dl) was found to be a protective factor. The evidence for the interaction effect between age and gender, body mass index and gender, and age and elective surgery were also observed. After assessing the internal validity of the model, the overall performance of the models was found to be good with an area under the curve of 95%. The SIR of SSI for ORIF surgery in the selected hospital was 0.66 among the patients aged 18-85 years old.

Conclusion

New risk prediction models can help in detecting high-risk patients and monitoring the infection rate in hospitals based on their infection prevention and control programs. Physicians using prediction models can identify high-risk patients with these factors prior to ORIF procedure.

Age as a risk factor for surgical site infections: German surveillance data on total hip replacement and total knee replacement procedures 2009 to 2018

BackgroundOlder age is frequently cited as a risk factor for healthcare-associated infections in general, and surgical site infections (SSIs) specifically.AimWe aimed to investigate the correlation between age and SSI occurrence.MethodsData on total hip replacement (THR) and total knee replacement (TKR) surgeries and resulting SSIs documented in the German national surveillance network from a 10-year period from 2009 to 2018 were selected for analysis. SSI rates and adjusted odds ratios (AOR) were calculated and a multivariable analysis to determine risk factors for SSI occurrence was conducted.ResultsA total of 418,312 THR procedures resulting in 3,231 SSIs, and 286,074 TKR procedures with 1,288 SSIs were included in the analyses. For THR, SSI rates were higher in older age groups when compared with the reference age group of 61-65 years. A significantly higher risk was observed in the 76-80 years age group (AOR: 1.21, 95% CI: 1.05-1.4). An age of ≤ 50 years was associated with a significantly lower SSI risk (AOR: 0.64, 95% CI: 0.52-0.8). For TKR, a similar correlation was observed, with the exception of the youngest age group (≤ 52 years), which was shown to have an SSI risk equal to that of the knee prosthesis reference age group (78-82 years).ConclusionA strong correlation between increasing age and SSI occurrence was observed for both procedure types. The results of our analyses provide a basis to consider future targeted SSI prevention measures for different age groups.

Predictors of 30-Day Readmission Following Cervical Laminoplasty in 3,085 Patients: An American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Database Study

Background Cervical laminoplasty is a surgical alternative to laminectomy and fusion for treating multi-level cervical spondylotic myelopathy. There is limited evidence evaluating readmission incidence and risk factors following cervical laminoplasty. Here, we provide a retrospective review evaluating preoperative risk for 30-day readmission following cervical laminoplasty. Methodology The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients undergoing laminoplasty as defined by Current Procedural Terminology codes 63050 and 63051. Patients were then categorized based on whether 30-day readmission occurred, and preoperative risk factors were examined. Continuous and categorical variables were analyzed using Student's t-test or Fisher's exact test. Multivariate regression analysis was performed for each variable, with p-values of <0.05 considered significant. Results In total, 3,085 patients were identified as undergoing posterior cervical laminoplasty. Of these, 2,938 patients did not require readmission, and 147 patients were readmitted, representing a 4.77% 30-day readmission rate. For all patients, sepsis (odds ratio (OR) = 5.58, p = 0.03), dialysis (OR = 3.46, p = 0.01), American Society of Anesthesiologists class >2 (OR = 1.69, p = 0.011), and hypertension (OR = 1.51, p = 0.04) were predictive of readmission. A subgroup analysis was performed for all geriatric patients (aged >65). In total, 1,353 patients were identified, of whom 76 were readmitted, demonstrating a readmission rate of 5.62%. For the elderly patients, hypertension (OR = 1.98, confidence interval (CI) = 1.04-3.75, p = 0.04) and independent status (OR = 0.39, CI = 0.21-0.74, p = 0.004) were predictive of readmission. Conclusions Assessment of predictors for readmission is important for patient education and setting appropriate clinical expectations for surgeons and providers. Preoperative hypertension, dialysis, and sepsis were risk factors for 30-day readmission following cervical laminoplasty, with functional status being a unique risk factor for elderly patients.

Arthroscopic rotator cuff repair without antibiotic prophylaxis does not increase the infection rate

PURPOSE

Rotator cuff repair is a commonly performed shoulder procedure. In the past 20 years, there has been a shift from mini-open towards arthroscopic repair, and many units exclusively use arthroscopic techniques for rotator cuff surgery. The aim of this study was to find out whether withholding antibiotics had any effect on the infection rate in patients undergoing arthroscopic rotator cuff repair.

METHODS

A retrospective analysis of 336 consecutive patients with an arthroscopic rotator cuff repair (RCR) and a minimum 2-year follow-up was performed. The control group received prophylactic antibiotics (controls) and the cases of interest did not receive perioperative antibiotics. A power analysis was performed according to literature regarding infection proportions. The primary outcome was an infection (superficial or deep) in the operated shoulder.

RESULTS

There were 336 patients who underwent a RCR. Two-hundred-and-twelve in the control group and 124 in the non-antibiotic group. Average ages were 57.3 ± 12.5 and 56.8 ± 13.2 years in each group, respectively. The follow-up times ranged from 24 to 76 months. Equipment used and surgical techniques were identical, only operating times were statistically different between the groups (control 77.2 ± 41.3 min versus no antibiotic cases 52.9 ± 16.7 min) (p = 0.000009). There was no recorded infection in either group.

CONCLUSION

Infection following arthroscopic surgery is uncommon. Small incisions, constant lavage with saline, minimal hardware insertion and short operating times all combine to minimise the risks. Current results point towards no detriment in withholding prophylactic antibiotics in low-risk patients undergoing routine rotator cuff repair surgery. Therefore, judicious use of prophylactic antibiotics in patients undergoing this procedure is advocated to prevent potential harm to those it is administered to.

LEVEL OF EVIDENCE

Level III.

A Retrospective Study of Bacteriology and Antibiotic Sensitivity Pattern of Post Operative Surgical Site Infections in Orthopedics

Surgical Site infection (SSI) is one of the most common post-operative complications and causes significant post-operative morbidity and mortality. The global estimates of SSI have varied from 0.5% to 15%, studies in India have consistently shown higher rates ranging from 23% to 38%1. The aim of the study was to know the etiological bacterial agents causing SSI and their antimicrobial susceptibility pattern. This retrospective study included 69 patients who developed Post-operative wound infections (SSI) during the 1-year period from April 2019 to March 2020. An analysis of SSI occurrence, the organisms isolated and antibiotic sensitivity pattern results was made. In overall surgeries conducted during the study period in orthopedics department at our institute, 69 cases were clinically diagnosed of having SSIs, including 51 males and 18 females with the mean age of 39.2 years. Out of the total 69 samples, 6 (8.69%) yielded no bacterial growth and among the rest 63 samples, Staphylococcus aureus 21 (30.43%) was the most common organism isolated. The other organisms isolated were Klebsiella pneumonia 13 (18.84%), Pseudomonas 11 (15.94%), Escherichia coli 5 (7.24%), Proteus species 3 (4.34%) and Acinetobacter species 3 (4.34%). Mixed isolates were obtained in 2 (11.9%) specimens. Bacteriological and antibiotic susceptibility study is an important tool to treat infection timely and effectively in-turn minimizing untoward long term sequelae of surgical site infections.

Infection prevention plan to decrease surgical site infections in bariatric surgery patients

BACKGROUND

Surgical site infections (SSI) are one of the most common complications of bariatric surgery. The Metabolic and Bariatric Surgery Accreditation and Quality Improvement (QI) Program (MBSAQIP) allows accredited programs to develop processes for quality improvement based on data collection. The objective of this study was to decrease SSI rates in patients undergoing bariatric surgery at an accredited MBSAQIP center.

METHODS

Using the MBSAQIP semiannual report, SSI rates were retrospectively reviewed. Baseline SSI rates were collected from 01/01/2014-12/31/2015. On 01/01/2016, the first infection prevention protocol (IPP-1) was created that included 4% chlorhexidine gluconate (CHG) showers, CHG wipes immediately prior to surgery, and routine cultures of SSIs. An updated IPP (IPP-2) was implemented on 09/01/2016, which discontinued routine surgical drain placement and broadened antibiotic coverage for penicillin allergic patients.

RESULTS

During baseline data collection, SSI rates were 5.1%. After the implementation of IPP-1, SSI rates trended down to 2.5%. After implementation of IPP-2, SSI rates decreased significantly to 1.5%, a 66% relative risk reduction in SSIs from baseline. On multivariate regression analysis, the perioperative factors associated with an increased risk for SSIs included diabetes mellitus, intraoperative surgical drain placement, the number of hypertension medications prior to bariatric surgery, and an open approach.

CONCLUSIONS

Our study demonstrates that the implementation of a specific protocol for reducing SSIs is safe and feasible in patients undergoing bariatric surgery. We also identified that the success of the IPP is likely centered on the elimination of routine drain placement during primary bariatric procedures.