First Results of the Swiss National Surgical Site Infection Surveillance Program: Who Seeks Shall Find

Povidone Iodine vs Chlorhexidine Gluconate in Alcohol for Preoperative Skin Antisepsis: A Randomized Clinical Trial

Importance

Preoperative skin antisepsis is an established procedure to prevent surgical site infections (SSIs). The choice of antiseptic agent, povidone iodine or chlorhexidine gluconate, remains debated.

Objective

To determine whether povidone iodine in alcohol is noninferior to chlorhexidine gluconate in alcohol to prevent SSIs after cardiac or abdominal surgery.

Design, Setting, and Participants

Multicenter, cluster-randomized, investigator-masked, crossover, noninferiority trial; 4403 patients undergoing cardiac or abdominal surgery in 3 tertiary care hospitals in Switzerland between September 2018 and March 2020 were assessed and 3360 patients were enrolled (cardiac, n = 2187 [65%]; abdominal, n = 1173 [35%]). The last follow-up was on July 1, 2020.

Interventions

Over 18 consecutive months, study sites were randomly assigned each month to either use povidone iodine or chlorhexidine gluconate, each formulated in alcohol. Disinfectants and skin application processes were standardized and followed published protocols.

Main Outcomes and Measures

Primary outcome was SSI within 30 days after abdominal surgery and within 1 year after cardiac surgery, using definitions from the US Centers for Disease Control and Prevention's National Healthcare Safety Network. A noninferiority margin of 2.5% was used. Secondary outcomes included SSIs stratified by depth of infection and type of surgery.

Results

A total of 1598 patients (26 cluster periods) were randomly assigned to receive povidone iodine vs 1762 patients (26 cluster periods) to chlorhexidine gluconate. Mean (SD) age of patients was 65.0 years (39.0-79.0) in the povidone iodine group and 65.0 years (41.0-78.0) in the chlorhexidine gluconate group. Patients were 32.7% and 33.9% female in the povidone iodine and chlorhexidine gluconate groups, respectively. SSIs were identified in 80 patients (5.1%) in the povidone iodine group vs 97 (5.5%) in the chlorhexidine gluconate group, a difference of 0.4% (95% CI, -1.1% to 2.0%) with the lower limit of the CI not exceeding the predefined noninferiority margin of -2.5%; results were similar when corrected for clustering. The unadjusted relative risk for povidone iodine vs chlorhexidine gluconate was 0.92 (95% CI, 0.69-1.23). Nonsignificant differences were observed following stratification by type of surgical procedure. In cardiac surgery, SSIs were present in 4.2% of patients with povidone iodine vs 3.3% with chlorhexidine gluconate (relative risk, 1.26 [95% CI, 0.82-1.94]); in abdominal surgery, SSIs were present in 6.8% with povidone iodine vs 9.9% with chlorhexidine gluconate (relative risk, 0.69 [95% CI, 0.46-1.02]).

Conclusions and Relevance

Povidone iodine in alcohol as preoperative skin antisepsis was noninferior to chlorhexidine gluconate in alcohol in preventing SSIs after cardiac or abdominal surgery.

Trial Registration

ClinicalTrials.gov Identifier: NCT03685604.

A novel web-based risk calculator for predicting surgical site infection in HIV-positive facture patients: a multicenter cohort study in China

Background

Surgical site infection (SSI) is a common complication in HIV-positive fracture patients undergoing surgery, leading to increased morbidity, mortality, and healthcare costs. Accurate prediction of SSI risk can help guide clinical decision-making and improve patient outcomes. However, there is a lack of user-friendly, Web-based calculator for predicting SSI risk in this patient population.

Objective

This study aimed to develop and validate a novel web-based risk calculator for predicting SSI in HIV-positive fracture patients undergoing surgery in China.

Method

A multicenter retrospective cohort study was conducted using data from HIV-positive fracture patients who underwent surgery in three tertiary hospitals in China between May 2011 and September 2023. We used patients from Beijing Ditan Hospital as the training cohort and patients from Chengdu Public Health and Changsha First Hospital as the external validation cohort. Univariate, multivariate logistic regression analyses and SVM-RFE were performed to identify independent risk factors for SSIs. A web-based calculator was developed using the identified risk factors and validated using an external validation cohort. The performance of the nomogram was evaluated using the area under the receiver operating characteristic (AUC) curves, calibration plots, and decision curve analysis (DCA).

Results

A total of 338 HIV-positive patients were included in the study, with 216 patients in the training cohort and 122 patients in the validation cohort. The overall SSI incidence was 10.7%. The web-based risk calculator (https://sydtliubo.shinyapps.io/DynNom_for_SSI/) incorporated six risk factors: HBV/HCV co-infection, HIV RNA load, CD4+ T-cell count, Neu and Lym level. The nomogram demonstrated good discrimination, with an AUC of 0.890 in the training cohort and 0.853 in the validation cohort. The calibration plot showed good agreement between predicted and observed SSI probabilities. The DCA indicated that the nomogram had clinical utility across a wide range of threshold probabilities.

Conclusion

Our study developed and validated a novel web-based risk calculator for predicting SSI risk in HIV-positive fracture patients undergoing surgery in China. The nomogram demonstrated good discrimination, calibration, and clinical utility, and can serve as a valuable tool for risk stratification and clinical decision-making in this patient population. Future studies should focus on integrating this nomogram into hospital information systems for real-time risk assessment and management.

Current Approaches to Following Up Women and Newborns After Discharge From Childbirth Facilities: A Scoping Review

INTRODUCTION

The postpartum period is critical for the health and well-being of women and newborns, but there is limited research on the most effective methods of post-childbirth follow-up. This scoping review synthesizes evidence from high-, middle-, and low-income countries on approaches to following up individuals after discharge from childbirth facilities.

METHODS

Using a systematic search in Ovid MEDLINE, we identified quantitative studies describing post-discharge follow-up methods deployed up to 12 months postpartum. We searched for English-language, peer-reviewed articles published between January 1, 2007 and November 2, 2022, with search terms covering 2 broad areas: "postpartum/postnatal period" and "surveillance." We single-screened titles and abstracts and double-extracted all included articles, recording study design and location, population, health outcome, method, timing and frequency of data collection, and percentage of study participants reached.

RESULTS

We identified 1,654 records, of which 31 studies were included. Eight studies used in-person visits to follow up participants, 10 used telephone calls, 7 used self-administered questionnaires, and 6 used multiple methods. Across studies, the minimum length of follow-up was 1 week after delivery, and up to 4 contacts were made within the first year after delivery. Follow-up (response) rates ranged from 23% to100%. Postpartum infection was the most common outcome investigated. Other outcomes included maternal (ill-)health, neonatal (ill-)health and growth, maternal mental health and well-being, care-giving/-seeking behaviors, and knowledge and intentions.

CONCLUSION

Our scoping review identified multiple follow-up methods after discharge, ranging from home visits to self-administered electronic questionnaires, which could be implemented with high response rates. The studies demonstrated that post-discharge follow-up of women and newborns was feasible, well received, and important for identifying postpartum illness or complications that would otherwise be missed. Therefore, the identified methods have the potential to become an important component of fostering a continuum of care and measuring and addressing postpartum morbidity.

Development of machine learning models for the surveillance of colon surgical site infections

BACKGROUND

Conventional surgical site infection (SSI) surveillance is labour-intensive. We aimed to develop machine learning (ML) models for the surveillance of SSIs for colon surgery and to assess whether the ML could improve surveillance process efficiency.

METHODS

This study included cases who underwent colon surgery at a tertiary center between 2013 and 2014. Logistic regression and four ML algorithms including random forest (RF), gradient boosting (GB), and neural networks (NNs) with or without recursive feature elimination (RFE) were first trained on the entire cohort, and then re-trained on cases selected based on a previous rule-based algorithm. We assessed model performance based on the area under the curve (AUC), sensitivity, and positive predictive value (PPV). The estimated proportion of reduction in workload for chart review based on the ML models was evaluated and compared with the conventional method.

RESULTS

At a sensitivity of 95%, the NN with RFE using 29 variables had the best performance with an AUC of 0.963 and PPV of 21.1%. When combining both the rule-based algorithm and ML algorithms, the NN with RFE using 19 variables had a higher PPV (28.9%) than with the ML algorithm alone, which could decrease the number of cases requiring chart review by 83.9% compared with the conventional method.

CONCLUSION

We demonstrated that ML can improve the efficiency of SSI surveillance for colon surgery by decreasing the burden of chart review while providing high sensitivity. In particular, the hybrid approach of ML with a rule-based algorithm showed the best performance in terms of PPV.

Addressing an increase in surgical site infections during the COVID-19 pandemic-Identifying opportunities during a chaotic time

BACKGROUND

Health care systems saw increases in device-associated infections and decreases in surgical site infections (SSI) during the COVID-19 pandemic. However, following an increase in SSIs, an acute care hospital assessed the risk and preventative factors of SSIs among patients.

METHODS

A retrospective cohort study on surgeries performed between January 2020 and September 2021 analyzed associations of SSI with risk and preventive factors utilizing χ2, t-tests, and odds ratios. A secondary analysis was utilized to determine the association of case urgency and prevention practice performance.

RESULTS

There was a significant difference in the administration of correct perioperative antibiotic selection between SSI (78.1%) and non-SSI (86.2%) along with 2.9 greater odds of developing an SSI with incorrect perioperative antibiotics. Patients who had urgent cases were significantly less likely than elective to receive preoperative chlorhexidine gluconate wipes (81.6%, 61.5%, respectively), correct antibiotic selection and timing (93.2%, 70.8%, respectively) and chlorhexidine and alcohol skin preparation (81.6%, 67.5%, respectively).

DISCUSSION

Disruption of perioperative workflow during the COVID-19 pandemic likely resulted in an increase in SSI. Numerous opportunities were identified for focused prevention efforts.

CONCLUSIONS

The next steps include implementing strategies to improve SSI prevention and establish a culture that can withstand workflow disruptions to maintain a safe environment during significant changes.

The incidence and cost implications of surgical site infection following lymph node surgery for skin malignancy

BACKGROUND

Lymph node surgery is commonly performed in the staging and treatment of metastatic skin cancer. Previous studies have demonstrated sentinel lymph node biopsy (SLNB) and, particularly, lymph node dissection (LND) to be plagued by high rates of wound complications, including surgical site infection (SSI) and seroma formation. This study evaluated the incidence of wound complications following lymph node surgery and provided the first published cost estimate of SSI associated with lymph node surgery in the UK.

PATIENTS AND METHODS

A retrospective cohort study of 169 patients with a histological diagnosis of primary skin malignancy who underwent SLNB or LND of the axilla and/or inguinal region at a single tertiary centre over a 2 year period was conducted. Demographic, patient risk factor, and operation characteristics data were collected and effect on SSI and seroma formation was analysed. Cost-per-infection was estimated using National Health Service (NHS) reference and antibiotic costs.

RESULTS

A total of 146 patients underwent SLNB with a SSI rate of 4.1% and a seroma incidence of 12.3%. Twenty-three patients underwent LND with a SSI rate of 39.1% and a seroma incidence of 39.1%. Seroma formation was strongly associated with the development of SSI in both the SLNB (odds ratio (OR) = 18.0, p < 0.001) and LND (OR = 21.0, p = 0.007) group. The median additional cost of care events and treatment of SSI in the SLNB and LND groups was £199.46 and £5187.04, respectively.

CONCLUSION

SSI remains a troublesome and costly event following SLNB and LND. Further research into perioperative care protocols and methods of reducing lymph node surgery morbidity is required and could result in significant cost savings to the NHS.

Association between the introduction of a national targeted intervention program and the incidence of surgical site infections in Swiss acute care hospitals

BACKGROUND

In Switzerland, the national surgical site infection (SSI) surveillance program showed a modest decrease in SSI rates for different procedures over the last decade. The study aimed to determine whether a multimodal, targeted intervention program in addition to existing SSI surveillance is associated with decreased SSI rates in the participating hospitals.

METHODS

Prospective multicenter pre- and postintervention study conducted in eight Swiss acute care hospitals between 2013 and 2020. All consecutive patients > 18 years undergoing cardiac, colon, or hip/knee replacement surgery were included. The follow-up period was 30 days and one year for implant-related surgery. Patients with at least one follow-up were included. The intervention was to optimize three elements of preoperative management: (i) hair removal; (ii) skin disinfection; and (iii) perioperative antimicrobial prophylaxis. We compared SSI incidence rates (main outcome measure) pre- and postintervention (three years each) adjusted for potential confounders. Poisson generalized linear mixed models fitted to quarter-yearly confirmed SSIs and adjusted for baseline differences between hospitals and procedures. Adherence was routinely monitored through on-site visits.

RESULTS

A total of 10 151 patients were included, with a similar median age pre- and postintervention (69.6 and IQR 60.9, 76.8 years, vs 69.5 and IQR 60.4, 76.8 years, respectively; P = 0.55) and similar proportions of females (44.8% vs. 46.1%, respectively; P = 0.227). Preintervention, 309 SSIs occurred in 5 489 patients (5.6%), compared to 226 infections in 4 662 cases (4.8%, P = 0.09) postintervention. The adjusted incidence rate ratio (aIRR) for overall SSI after intervention implementation was 0.81 (95% CI, 0.68 to 0.96, P = 0.02). For cardiac surgery (n = 2 927), the aIRR of SSI was 0.48 (95% CI, 0.32 to 0.72, P < 0.001). For hip/knee replacement surgery (n = 4 522), the aIRR was 0.88 (95% CI, 0.52 to 1.48, P = 0.63), and for colon surgery (n = 2 702), the aIRR was 0.92 (95% CI, 0.75 to 1.14, P = 0.49).

CONCLUSIONS

The SSI intervention bundle was associated with a statistically significant decrease in SSI cases. A significant association was observed for cardiac surgery. Adding a specific intervention program can add value compared to routine surveillance only. Further prevention modules might be necessary for colon and orthopedic surgery.

Association between perioperative prophylaxis with cefuroxime plus metronidazole or amoxicillin/clavulanic acid and surgical site infections in paediatric uncomplicated appendectomy: a Swiss retrospective cohort study

OBJECTIVE

We aimed to evaluate the association between post-appendectomy SSI rates and the two most commonly used regimens for perioperative antimicrobial prophylaxis in Swiss children.

METHODS

We conducted a retrospective cohort study, analysing data from the Swiss national SSI surveillance database with a study period from 2014 to 2018. All hospitals undertaking paediatric appendectomies in Switzerland participate in the surveillance. We compared the cumulative incidence and odds of post-appendectomy SSI within 30 days of surgery in children ≤ 16 years of age undergoing appendectomy for uncomplicated appendicitis and receiving perioperative antimicrobial prophylaxis with cefuroxime plus metronidazole or with amoxicillin/clavulanic acid using multivariable adjusted logistic regression and propensity-score matching.

RESULTS

A total of 6207 cases were recorded in the study time frame. Overall SSI cumulative incidence was 1.9% (n = 119). 4256 children (54.9% male, median (IQR) age 12 [10, 14] years) received either cefuroxime plus metronidazole (n = 2348, 53.8% male) or amoxicillin/clavulanic acid (n = 1491, 57.0% male). SSI cumulative incidence was 1.1% (25/2348) among children receiving cefuroxime plus metronidazole and 2.8% (42/1491, p < 0.001) when receiving amoxicillin/clavulanic acid. The administration of cefuroxime plus metronidazole was associated with statistically significantly lower SSI odds compared to amoxicillin/clavulanic acid (aOR 0.35, 95%CI [0.20, 0.61], p < 0.001), and this was confirmed upon propensity-score matching.

CONCLUSION

We found lower odds of post-appendectomy SSI in children receiving cefuroxime plus metronidazole compared to amoxicillin/clavulanic acid. Treating amoxicillin/clavulanic acid as the baseline, only 55 children need to receive cefuroxime plus metronidazole perioperative prophylaxis to avert one SSI. Existing guidelines recommending amoxicillin/clavulanic acid may need to be revised. Trial registration ISRCTN47727811, registered retrospectively.

Association of antimicrobial perioperative prophylaxis with cefuroxime plus metronidazole or amoxicillin/clavulanic acid and surgical site infections in colorectal surgery

OBJECTIVE

To compare intravenous (IV) amoxicillin/clavulanic acid (A/CA) to IV cefuroxime plus metronidazole (C + M) for preventing surgical site infections (SSI) in colorectal surgery.

BACKGROUND

Given their spectra that include most Enterobacterales and anaerobes, C + M is commonly recommended as prophylaxis of SSI in colorectal surgery. A/CA offers good coverage of Enterobacterales and anaerobes as well, but, in contrast to C + M, it also includes Enterococcus faecalis which is also isolated from patients with SSI and could trigger anastomotic leakage.

METHODS

Data from a Swiss SSI surveillance program were used to compare SSI rates after class II (clean contaminated) colorectal surgery between patients who received C + M and those who received A/CA. We employed multivariable logistic regression to adjust for potential confounders, along with propensity score matching to adjust for group imbalance.

RESULTS

From 2009 to 2018, 27,922 patients from 127 hospitals were included. SSI was diagnosed in 3132 (11.2%): 278/1835 (15.1%) in those who received A/CA and 2854/26,087 (10.9%) in those who received C + M (p < 0.001). The crude OR for SSI in the A/CA group as compared to C + M was 1.45 [CI 95% 1.21-1.75]. The adjusted OR was 1.49 [1.24-1.78]. This finding persisted in a 1:1 propensity score matched cohort of 1835 patients pairs with an OR of 1.60 [1.28-2.00]. Other factors independently associated with SSI were an ASA score > 2, a longer duration of operation, and a reoperation for a non-infectious complication. Protective factors were female sex, older age, antibiotic prophylaxis received 60 to 30 min before surgery, elective operation, and endoscopic approach.

CONCLUSIONS

Despite its activity against enterococci, A/CA was less effective than C + M for preventing SSI, suggesting that it should not be a first choice antibiotic prophylaxis for colorectal surgery.

Timing of Cefuroxime Surgical Antimicrobial Prophylaxis and Its Association With Surgical Site Infections

Importance

World Health Organization guidelines recommend administering surgical antimicrobial prophylaxis (SAP), including cefuroxime, within 120 minutes prior to incision. However, data from clinical settings supporting this long interval is limited.

Objective

To assess whether earlier vs later timing of administration of cefuroxime SAP is associated with the occurrence of surgical site infections (SSI).

Design, Setting, and Participants

This cohort study included adult patients who underwent 1 of 11 major surgical procedures with cefuroxime SAP, documented by the Swissnoso SSI surveillance system between January 2009 and December 2020 at 158 Swiss hospitals. Data were analyzed from January 2021 to April 2023.

Exposures

Timing of cefuroxime SAP administration before incision was divided into 3 groups: 61 to 120 minutes before incision, 31 to 60 minutes before incision, and 0 to 30 minutes before incision. In addition, a subgroup analysis was performed with time windows of 30 to 55 minutes and 10 to 25 minutes as a surrogate marker for administration in the preoperating room vs in the operating room, respectively. The timing of SAP administration was defined as the start of the infusion obtained from the anesthesia protocol.

Main Outcomes and Measures

Occurrence of SSI according to Centers for Disease Control and Prevention definitions. Mixed-effects logistic regression models adjusted for institutional, patient, and perioperative variables were applied.

Results

Of 538 967 surveilled patients, 222 439 (104 047 men [46.8%]; median [IQR] age, 65.7 [53.9-74.2] years), fulfilled inclusion criteria. SSI was identified in 5355 patients (2.4%). Cefuroxime SAP was administered 61 to 120 minutes prior to incision in 27 207 patients (12.2%), 31 to 60 minutes prior to incision in 118 004 patients (53.1%), and 0 to 30 minutes prior to incision in 77 228 patients (34.7%). SAP administration at 0 to 30 minutes was significantly associated with a lower SSI rate (adjusted odds ratio [aOR], 0.85; 95% CI, 0.78-0.93; P < .001), as was SAP administration 31 to 60 minutes prior to incision (aOR, 0.91; 95% CI, 0.84-0.98; P = .01) compared with administration 61 to 120 minutes prior to incision. Administration 10 to 25 minutes prior to incision in 45 448 patients (20.4%) was significantly associated with a lower SSI rate (aOR, 0.89; 95% CI, 0.82-0.97; P = .009) vs administration within 30 to 55 minutes prior to incision in 117 348 patients (52.8%).

Conclusions and Relevance

In this cohort study, administration of cefuroxime SAP closer to the incision time was associated with significantly lower odds of SSI, suggesting that cefuroxime SAP should be administrated within 60 minutes prior to incision, and ideally within 10 to 25 minutes.

Influence of environmental temperature and heatwaves on surgical site infection after hip and knee arthroplasty: a nationwide study

BACKGROUND

Previous studies reported higher incidence of surgical site infection (SSI) after procedures performed in summer or with high temperatures. However, no study used detailed climate data to assess this risk after hip and knee arthroplasty, and no study specifically investigated the role of heatwaves.

AIM

To assess the impact of higher environmental temperatures and heatwaves on SSI rates after hip and knee arthroplasty.

METHODS

Data on hip and knee arthroplasty procedures performed between 01/2013 - 09/2019 in hospitals participating in the Swiss SSI surveillance were linked to climate data extracted from weather stations located in their vicinity. The association between temperature, heatwaves and SSI was studied using mixed effects logistic regression models fitted at the patient level. Poisson mixed models were fitted for both calendar year and month of the year to investigate the SSI incidence trajectory over time.

RESULTS

We included 116,981 procedures performed in 122 hospitals. Significantly higher SSI rates were observed for procedures performed in the summertime (incidence rate ratio 1.39, 95% CI [1.20-1.60], p<0.001; reference: autumn) or in calendar months in which the mean temperature was above 20°C (reference 05-10°C; odds ratio 1.59, 95% CI [1.27, 1.98] p<0.001). We observed a slight but non-significant increase in the rate of SSI during heatwaves (1.44% versus 1.01%, p=0.2).

CONCLUSION

SSI rates after hip and knee replacement appear to increase with higher environmental temperature. To establish if, and to what extent, heatwaves increase the risk of SSI, studies involving geographical areas with larger variability in temperature are needed.

Better Operating Room Ventilation as Determined by a Novel Ventilation Index is Associated With Lower Rates of Surgical Site Infections

OBJECTIVE

The aim was to assess the impact of operating room (OR) ventilation quality on surgical site infections (SSIs) using a novel ventilation index.

BACKGROUND

Previous studies compared laminar air flow with conventional ventilation, thereby ignoring many parameters that influence air flow properties.

METHODS

In this cohort study, we surveyed hospitals participating in the Swiss SSI surveillance and calculated a ventilation index for their ORs, with higher values reflecting less turbulent air displacement. For procedures captured between January 2017 and December 2019, we studied the association between ventilation index and SSI rates using linear regression (hospital-level analysis) and with the individual SSI risk using generalized linear mixed-effects models (patient-level analysis).

RESULTS

We included 47 hospitals (182 ORs). Among the 163,740 included procedures, 6791 SSIs were identified. In hospital-level analyses, a 5-unit increase in the ventilation index was associated with lower SSI rates for knee and hip arthroplasty (-0.41 infections per 100 procedures, 95% confidence interval: -0.69 to -0.13), cardiac (-0.89, -1.91 to 0.12), and spine surgeries (-1.15, -2.56 to 0.26). Similarly, patient-level analyses showed a lower SSI risk with each 5-unit increase in ventilation index (adjusted odds ratio 0.71, confidence interval: 0.58-0.87 for knee and hip; 0.72, 0.49-1.06 for spine; 0.82, 0.69-0.98 for cardiac surgery). Higher index values were mainly associated with a lower risk for superficial and deep incisional SSIs.

CONCLUSIONS

Better ventilation properties, assessed with our ventilation index, are associated with lower rates of superficial and deep incisional SSIs in orthopedic and cardiac procedures. OR ventilation quality appeared to be less relevant for other surgery types.

Implementing a surgical site infection prevention bundle for emergency appendectomy: Worth the effort or waste of time?

BACKGROUND

The aim of this study was to evaluate feasibility and impact of an intraoperative surgical site infection prevention bundle for emergency appendectomy.

METHODS

Consecutive adult patients undergoing emergency appendectomy were prospectively included during a 10-year study period (2011-2020). The care bundle was implemented as of November 1, 2018, and focused on 4 intraoperative items (disinfection, antibiotic prophylaxis, induction temperature control >36.5°C, and intracavity lavage). The primary outcome was the compliance to bundle items. Thirty-day surgical site infections were assessed by the independent Swiss National SSI Surveillance Program (2011 to October 2018) and by an institutional audit (November 2018-2020). Independent risk factors for surgical site infection were identified through multinominal logistic regression analysis.

RESULTS

Of 1,901 patients, 449 (23.6%) were included after bundle implementation. Overall surgical site infection rate was 111 (5.8%). In 42 patients with surgical site infection (37.8%), antibiotic treatment alone was done, and additional surgical management was necessary in 31 patients (27.9%), computed tomography-guided drainage in 30 patients (27%), and bedside wound opening in 9 cases (8.1%). Overall compliance to the bundle was 79.9%. Overall surgical site infection rates were decreased after bundle implementation (17/449 [3.8%] vs 94/1,452 [6.5%], P = .038), mainly due to a decrease in superficial incisional infections (P = .014). Independent risk factors for surgical site infection were surgical duration ≥60 minutes (odds ratio: 1.66, P = .018), contamination class IV (odds ratio: 2.64, P < .001), and open or converted approach (odds ratio: 4.0, P < .001), and the bundle was an independent protective factor (odds ratio: 0.58, P = .048).

CONCLUSION

Implementation of an intraoperative surgical site infection prevention bundle was feasible and might have a beneficial impact on surgical site infection rates after emergency appendectomy.

Semiautomated surveillance of deep surgical site infections after colorectal surgeries: A multicenter external validation of two surveillance algorithms

Objective:

Automated surveillance methods increasingly replace or support conventional (manual) surveillance; the latter is labor intensive and vulnerable to subjective interpretation. We sought to validate 2 previously developed semiautomated surveillance algorithms to identify deep surgical site infections (SSIs) in patients undergoing colorectal surgeries in Dutch hospitals.

Design:

Multicenter retrospective cohort study.

Methods:

From 4 hospitals, we selected colorectal surgery patients between 2018 and 2019 based on procedure codes, and we extracted routine care data from electronic health records. Per hospital, a classification model and a regression model were applied independently to classify patients into low- or high probability of having developed deep SSI. High-probability patients need manual SSI confirmation; low-probability records are classified as no deep SSI. Sensitivity, positive predictive value (PPV), and workload reduction were calculated compared to conventional surveillance.

Results:

In total, 672 colorectal surgery patients were included, of whom 28 (4.1%) developed deep SSI. Both surveillance models achieved good performance. After adaptation to clinical practice, the classification model had 100% sensitivity and PPV ranged from 11.1% to 45.8% between hospitals. The regression model had 100% sensitivity and 9.0%–14.9% PPV. With both models, <25% of records needed review to confirm SSI. The regression model requires more complex data management skills, partly due to incomplete data.

Conclusions:

In this independent external validation, both surveillance models performed well. The classification model is preferred above the regression model because of source-data availability and less complex data-management requirements. The next step is implementation in infection prevention practices and workflow processes.

Changes in the gut bacterial communities in colon cancer surgery patients: an observational study

Background

Colon surgery has been shown to modulate the intestinal microbiota. Our objective was to characterize these changes using state-of-the-art next generation sequencing techniques.

Methods

We performed a single-centre prospective observational cohort study to evaluate the changes in the gut microbiota, i.e., taxon distribution, before and after elective oncologic colon surgery in adult patients with different antimicrobial prophylaxis regimens (standard prophylaxis with cefuroxime/metronidazole versus carbapenems for extended-spectrum beta-lactamase-producing Enterobacterales [ESBL-E] carriers). We obtained rectal samples on the day of surgery, intraoperative luminal samples, and rectal or stoma samples 3 days after surgery. We performed metataxonomic analysis based on sequencing of the bacterial 16S rRNA gene marker. Similarities and differences between bacterial communities were assessed using Bray–Curtis similarity, visualised using principal coordinates analysis and statistically tested by PERMANOVA. Comparison of taxa relative abundance was performed using ANCOM.

Results

We included 27 patients between March 27, 2019 and September 17, 2019. The median age was 63.6 years (IQR 56.4–76.3) and 44% were females. Most (81%) patients received standard perioperative prophylaxis as they were not ESBL carriers. There was no significant association between ESBL carriage and differences in gut microbiome. We observed large and significant increases in the genus Enterococcus between the preoperative/intraoperative samples and the postoperative sample, mainly driven by Enterococcus faecalis. There were significant differences in the postoperative microbiome between patients who received standard prophylaxis and carbapenems, specifically in the family Erysipelotrichaceae.

Conclusion

This hypothesis-generating study showed rapid changes in the rectal microbiota following colon cancer surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13099-021-00477-7.

Similar periprosthetic joint infection rates after and before a national infection control program: a study of 45,438 primary total knee arthroplasties

Background and purpose - Strenuous efforts to minimize postoperative infection rates have been made, including the Swedish nationwide initiative Prosthesis Related Infections Shall be Stopped (PRISS). This study calculated the incidence rate of periprosthetic joint infection (PJI) following primary total knee arthroplasty (TKA) before and after PRISS. Patients and methods - All 45,438 primary TKAs registered in the Swedish Knee Arthroplasty Register (SKAR) during 2007-2008 and 2012-2013 were included. Matched data on antibiotic prescriptions were obtained from the Swedish Prescribed Drug Register (SPDR). All patients with ≥ 28 days of continuous antibiotic treatment within 2 years of primary surgery had their medical charts reviewed to identify cases of PJI. The incidence rate was calculated by dividing the number of PJIs by the total time at risk during each time period and presented as percentages with 95% confidence interval (CI). Results - 644 PJIs were identified, equaling a 2-year incidence rate of 1.45% (CI 1.34-1.57). The incidence rate was 1.44% (CI 1.27-1.61) before PRISS and 1.46% (CI 1.31-1.61) after. Diagnosis was made within 30 days of primary TKA in 52%, and within 90 days in 73% of cases. 603 cases were reoperated on or revised. Median time from operation to diagnosis was 29 days (1-716), for both time periods. Debridement with exchange of the insert was performed in 32% and 63% of cases before and after PRISS, respectively. Interpretation - We found similar incidence rates before and after the PRISS initiative without any statistically significant difference. Time to diagnosis was similar during both time periods. The project may have contributed to increased compliance with treatment protocols.

Association Between Antimicrobial Prophylaxis With Double-Dose Cefuroxime and Surgical Site Infections in Patients Weighing 80 kg or More

IMPORTANCE

Many guidelines recommend a weight-adopted dose increase of cefuroxime for surgical antimicrobial prophylaxis (SAP). However, the evidence that this approach is associated with lower rates of surgical site infection (SSI) is limited.

OBJECTIVE

To assess whether double-dose cefuroxime SAP was associated with a decreased SSI rate in patients weighing at least 80 kg.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included adult patients (>18 years) weighing at least 80 kg who underwent 9 major surgical procedures with a cefuroxime SAP administration from the Swissnoso SSI surveillance system between January 2015 and December 2019 at 142 Swiss hospitals. The follow-up was 30 days for all surgical procedures and 1 year for implant-related operations.

EXPOSURES

Cefuroxime SAP dose (1.5 vs 3.0 g).

MAIN OUTCOMES AND MEASURES

Overall SSI. A mixed-effects logistic regression adjusted for institutional, epidemiological, and perioperative variables was applied. Results were stratified by weight categories as well as by wound contamination classes.

RESULTS

Of 41 076 eligible patients, 37 640 were included, with 22 625 (60.1%) men and a median (IQR) age of 61.9 (49.9-71.1) years. The outcome SSI was met by 1203 patients (3.2%). Double-dose cefuroxime was administered to 13 246 patients (35.2%) and was not significantly associated with a lower SSI rate (adjusted odds ratio [aOR], 0.89; 95% CI, 0.78-1.02; P = .10). After stratification by weight category, double-dose SAP vs single-dose SAP was associated with lower SSI rates among 16 605 patients weighing at least 80 to less than 90 kg (aOR, 0.76; 95% CI, 0.61-0.97; P = .02) but not in the other weight categories (≥90 to <100 kg, 10 342 patients: aOR, 1.12; 95% CI, 0.87-1.47; P = .37; ≥100 to <120 kg, 8099 patients: aOR, 0.99; 95% CI, 0.76-1.30; P = .96; ≥120 kg, 2594 patients: aOR, 0.65; 95% CI, 0.42-1.04; P = .06). After stratification by contamination class, double-dose SAP was associated with lower SSI rates among 1946 patients with contaminated wounds (aOR, 0.49; 95% CI, 0.30-0.84; P = .008) but not those with clean wounds (25 680 patients; aOR, 0.92; 95% CI, 0.76-1.12; P = .44) or clean-contaminated wounds (10 014 patients; aOR, 0.90; 95% CI, 0.73-1.12; P = .37) compared with a single dose.

CONCLUSIONS AND RELEVANCE

In this study, double-dose SAP with cefuroxime for patients weighing at least 80 kg was not consistently associated with a lower SSI rate.

Worldwide incidence of surgical site infections in general surgical patients: A systematic review and meta-analysis of 488,594 patients

BACKGROUND

Establishing worldwide incidence of general surgical site infections (SSI) is imperative to understand the extent of the condition to assist decision-makers to improve the planning and delivery of surgical care. This systematic review and meta-analysis aimed to estimate the worldwide incidence of SSI and identify associated factors in adult general surgical patients.

MATERIALS AND METHODS

A systematic review was undertaken using MEDLINE (Ovid), CINAHL (EBSCO), EMBASE (Elsevier) and the Cochrane Library to identify cross-sectional, cohort and observational studies reporting SSI incidence or prevalence. Studies of less than 50 participants were excluded. Data extraction and quality appraisal were undertaken independently by two review authors. The primary outcome was cumulative incidence of SSI occurring up to 30 days postoperative. The secondary outcome was the severity/depth of SSI. The I² statistic was used to explore heterogeneity. Random effects models were used in the presence of substantial heterogeneity. Subgroup, meta-regression sensitivity analyses were used to explore the sources of heterogeneity. Publication bias was assessed using Hunter's plots and Egger's regression test.

RESULTS

Of 2091 publications retrieved, 62 studies were included. Of these, 57 were included in the meta-analysis across six anatomical locations with 488,594 patients. The pooled 30-day cumulative incidence of SSI was 11% (95% CI 10%-13%). No prevalence data were identified. SSI rates varied across anatomical location, surgical approach, and priority (i.e., planned, emergency). Multivariable meta-regression showed SSI is significantly associated with duration of surgery (estimate 1.01, 95% CI 1.00-1.02, P = .014).

CONCLUSIONS

and Relevance: 11 out of 100 general surgical patients are likely to develop an infection 30 days after surgery. Given the imperative to reduce the burden of harm caused by SSI, high-quality studies are warranted to better understand the patient and related risk factors associated with SSI.

Beyond the operating room: do hospital characteristics have an impact on surgical site infections after colorectal surgery? A systematic review

Background

Hospital characteristics have been recognized as potential risk factors for surgical site infection for over 20 years. However, most research has focused on patient and procedural risk factors. Understanding how structural and process variables influence infection is vital to identify targets for effective interventions and to optimize healthcare services. The aim of this study was to systematically review the association between hospital characteristics and surgical site infection in colorectal surgery.

Main body

A systematic literature search was conducted using PubMed, Scopus and Web of Science databases until the 31st of May, 2021. The search strategy followed the Participants, Exposure/Intervention, Comparison, Outcomes and Study design. The primary outcome of interest was surgical site infection rate after colorectal surgery. Studies were grouped into nine risk factor typologies: hospital size, ownership affiliation, being an oncological hospital, safety-net burden, hospital volume, surgeon caseload, discharge destination and time since implementation of surveillance. The STROBE statement was used for evaluating the methodological quality.

A total of 4703 records were identified, of which 172 were reviewed and 16 were included. Studies were published between 2008 and 2021, and referred to data collected between 1996 and 2016. Surgical site infection incidence ranged from 3.2 to 27.6%. Two out of five studies evaluating hospital size adjusted the analysis to patient and procedure-related risk factors, and showed that larger hospitals were either positively associated or had no association with SSI. Public hospitals did not present significantly different infection rates than private or non-profit ones. Medical school affiliation and higher safety-net burden were associated with higher surgical site infection (crude estimates), while oncological hospitals were associated with higher incidence independently of other variables. Hospital caseload showed mixed results, while surgeon caseload and surveillance time since implementation appear to be associated with fewer infections.

Conclusions

Although there are few studies addressing hospital-level factors on surgical site infection, surgeon experience and the implementation of a surveillance system appear to be associated with better outcomes. For hospitals and services to be efficiently optimized, more studies addressing these variables are needed that take into account the confounding effect of patient case mix.

Clinical data for paediatric research: the Swiss approach : Proceedings of the National Symposium in Bern, Switzerland, Dec 5-6, 2019

BACKGROUND AND PURPOSE

Continuous improvement of health and healthcare system is hampered by inefficient processes of generating new evidence, particularly in the case of rare diseases and paediatrics. Currently, most evidence is generated through specific research projects, which typically require extra encounters with patients, are costly and entail long delays between the recognition of specific needs in healthcare and the generation of necessary evidence to address those needs. The Swiss Personalised Health Network (SPHN) aims to improve the use of data obtained during routine healthcare encounters by harmonizing data across Switzerland and facilitating accessibility for research. The project "Harmonising the collection of health-related data and biospecimens in paediatric hospitals throughout Switzerland (SwissPedData)" was an infrastructure development project funded by the SPHN, which aimed to identify and describe available data on child health in Switzerland and to agree on a standardised core dataset for electronic health records across all paediatric teaching hospitals. Here, we describe the results of a two-day symposium that aimed to summarise what had been achieved in the SwissPedData project, to put it in an international context, and to discuss the next steps for a sustainable future. The target audience included clinicians and researchers who produce and use health-related data on children in Switzerland.

KEY HIGHLIGHTS

The symposium consisted of state-of-the-art lectures from national and international keynote speakers, workshops and plenary discussions. This manuscript summarises the talks and discussions in four sections: (I) a description of the Swiss Personalized Health Network and the results of the SwissPedData project; (II) examples of similar initiatives from other countries; (III) an overview of existing health-related datasets and projects in Switzerland; and (IV) a summary of the lessons learned and future prospective from workshops and plenary discussions.

IMPLICATIONS

Streamlined processes linking initial collection of information during routine healthcare encounters, standardised recording of this information in electronic health records and fast accessibility for research are essential to accelerate research in child health and make it affordable. Ongoing projects prove that this is feasible in Switzerland and elsewhere. International collaboration is vital to success. The next steps include the implementation of the SwissPedData core dataset in the clinical information systems of Swiss hospitals, the use of this data to address priority research questions, and the acquisition of sustainable funding to support a slim central infrastructure and local support in each hospital. This will lay the foundation for a national paediatric learning health system in Switzerland.

Surgical site infection in a Greek general surgery department: who is at most risk?

OBJECTIVE

Surgical site infections (SSIs) are associated with protracted hospitalisation, antibiotics administration, and increased morbidity and mortality. This work investigated the incidence rate of SSIs in the Department of General Surgery at the University Hospital of Ioannina, Greece, the associated risk factors and pathogens responsible.

METHOD

In this prospective cohort study, patients who underwent elective procedures under general anaesthesia were enrolled. Risk factors monitored included age, sex, body mass index, smoking, alcohol consumption, preoperative length of stay, chemoprophylaxis, intensive care unit (ICU) stay, American Society of Anesthesiology (ASA) score, and the National Nosocomial Infections Surveillance System (NNIS) basic SSI risk index.

RESULTS

Of the 1058 enrolled patients, 80 (7.6%) developed SSIs. Of the total cohort, 62.5% of patients received chemoprophylaxis for >24 hours. A total of 20 different pathogens, each with multiple strains (n=108 in total), were identified, 53 (49.5%) Gram-negative rods, 46 (42%) Gram-positive cocci, and nine (8.4%) fungi (Candida spp.). Escherichia coli was the prevalent microorganism (24.3%). SSI-related risk factors, as defined by univariate analysis, included: ICU stay, ASA score >2 (p<0.001), NNIS score >0, and wound classes II, III, and IV. Also, serum albumin levels <3.5g/dl were associated with increased rate of SSIs. The multivariate model identified an NNIS score of >0 and wound classes II, III, and IV as independent SSI-related risk factors.

CONCLUSION

This study showed high SSI rates. Several factors were associated with increased SSI rates, as well as overuse of prophylactic antibiotics. The results of the present study could be a starting point for the introduction of a system for recording and actively monitoring SSIs in Greek hospitals, and implementation of specific guidelines according to risk factors.

Surveillance quality correlates with surgical site infection rates in knee and hip arthroplasty and colorectal surgeries: A call to action to adjust reporting of SSI rates

OBJECTIVE

The incidence of surgical site infections may be underreported if the data are not routinely validated for accuracy. Our goal was to investigate the communicated SSI rate from a large network of Swiss hospitals compared with the results from on-site surveillance quality audits.

DESIGN

Retrospective cohort study.

PATIENTS

In total, 81,957 knee and hip prosthetic arthroplasties from 125 hospitals and 33,315 colorectal surgeries from 110 hospitals were included in the study.

METHODS

Hospitals had at least 2 external audits to assess the surveillance quality. The 50-point standardized score per audit summarizes quantitative and qualitative information from both structured interviews and a random selection of patient records. We calculated the mean National Healthcare Safety Network (NHSN) risk index adjusted infection rates in both surgery groups.

RESULTS

The median NHSN adjusted infection rate per hospital was 1.0% (interquartile range [IQR], 0.6%-1.5%) with median audit score of 37 (IQR, 33-42) for knee and hip arthroplasty, and 12.7% (IQR, 9.0%-16.6%), with median audit score 38 (IQR, 35-42) for colorectal surgeries. We observed a wide range of SSI rates and surveillance quality, with discernible clustering for public and private hospitals, and both lower infection rates and audit scores for private hospitals. Infection rates increased with audit scores for knee and hip arthroplasty (P value for the slope = .002), and this was also the case for planned (P = .002), and unplanned (P = .02) colorectal surgeries.

CONCLUSIONS

Surveillance systems without routine evaluation of validity may underestimate the true incidence of SSIs. Audit quality should be taken into account when interpreting SSI rates, perhaps by adjusting infection rates for those hospitals with lower audit scores.

Antimicrobial prophylaxis administration after umbilical cord clamping in cesarean section and the risk of surgical site infection: a cohort study with 55,901 patients

Background

The World Health Organization (WHO) recommends administration of surgical antimicrobial prophylaxis (SAP) in cesarean section prior to incision to prevent surgical site infections (SSI). This study aimed to determine whether SAP administration following cord clamping confers an increased SSI risk to the mother.

Methods

Study design: Cohort. Setting: 75 participating Swiss hospitals, from 2009 to 2018. Participants: A total of 55,901 patients were analyzed. Main outcome measures: We assessed the association between SAP administration relative to incision and clamping and the SSI rate, using generalized linear multilevel models, adjusted for patient characteristics, procedural variables, and health-care system factors.

Results

SAP was administered before incision in 26′405 patients (47.2%) and after clamping in 29,496 patients (52.8%). Overall 846 SSIs were documented, of which 379 (1.6% [95% CI, 1.4–1.8%]) occurred before incision and 449 (1.7% [1.5–1.9%]) after clamping (p = 0.759). The adjusted odds ratio for SAP administration after clamping was not significantly associated with an increased SSI rate (1.14, 95% CI 0.96–1.36; p = 0.144) when compared to before incision. Supplementary and subgroup analyses supported these main results.

Conclusions

This study did not confirm an increased SSI risk for the mother in cesarean section if SAP is given after umbilical cord clamping compared to before incision.

Antimicrobial prophylaxis and the prevention of surgical site infection in cardiac surgery: an analysis of 21 007 patients in Switzerland†

OBJECTIVES

Our goal was to determine the optimal timing and choice of surgical antimicrobial prophylaxis (SAP) in patients having cardiac surgery.

METHODS

The setting was the Swiss surgical site infection (SSI) national surveillance system with a follow-up rate of >94%. Participants were patients from 14 hospitals who had cardiac surgery from 2009 to 2017 with clean wounds, SAP with cefuroxime, cefazolin or a vancomycin/cefuroxime combination and timing of SAP within 120 min before the incision. Exposures were SAP timing and agents; the main outcome was the incidence of SSI. We fitted generalized additive and mixed-effects generalized linear models to describe effects predicting SSIs.

RESULTS

A total of 21 007 patients were enrolled with an SSI incidence of 5.5%. Administration of SAP within 30 min before the incision was significantly associated with decreased deep/organ space SSI [adjusted odds ratio (OR) 0.73, 95% confidence interval (CI) 0.54-0.98; P = 0.035] compared to administration of SAP 60-120 min before the incision. Cefazolin (adjusted OR 0.64, 95% CI 0.49-0.84; P = 0.001) but not vancomycin/cefuroxime combination (adjusted OR 1.05, 95% CI 0.82-1.34; P = 0.689) was significantly associated with a lower risk of overall SSI compared to cefuroxime alone. Nevertheless, there were no statistically significant differences between the SAP agents and the risk of deep/organ space SSI.

CONCLUSIONS

The results from this large prospective study provide substantial arguments that administration of SAP close to the time of the incision is more effective than earlier administration before cardiac surgery, making compliance with SAP administration easier. The choice of SAP appears to play a significant role in the prevention of all SSIs, even after adjusting for confounding variables.

Are three antiseptic paints needed for safe preparation of the surgical field? A prospective cohort study with 239 patients

Background

Preoperative skin antisepsis is an essential component of safe surgery. However, it is unclear how many antiseptic paints are needed to eliminate bacteria prior to incision. This study compared microbial skin counts after two and three antiseptic paints.

Methods

We conducted a prospective cohort study in non-emergency patients receiving a cardiac/abdominal surgery with standardized, preoperative skin antisepsis consisting of an alcoholic compound and either povidone iodine (PI) or chlorhexidine (CHX). We obtained three skin swabs from the participant’s thorax/abdomen using a sterile template with a 25 cm² window: After collection of the first swab prior to skin antisepsis, and once the second and third application of PI/CHX had dried out, we obtained a second and third swab, respectively. Our primary outcome was the reduction in microbial skin counts after two and three paints of PI/CHX.

Results

Among the 239 enrolled patients, there was no significant difference in the reduction of mean square root-transformed microbial skin counts with three versus two paints (P = 0.2). But distributions of colony forming units (CFUs) decreased from paint 2 to 3 in a predefined analysis (P = 0.002). There was strong evidence of an increased proportion of patients with zero CFU after paint 3 versus paint 2 (P = 0.003). We did not identify risk factors for insufficient reduction of microbial skin counts after two paints, defined as the detection of > 5 CFUs and/or ≥ 1 pathogens.

Conclusions

In non-emergency surgical patients, three antiseptic paints may be superior to two paints in reducing microbial skin colonization prior to surgery.

Frequent Door Openings During Cardiac Surgery Are Associated With Increased Risk for Surgical Site Infection: A Prospective Observational Study

BACKGROUND

Preliminary studies that analyzed surrogate markers have suggested that operating room (OR) door openings may be a risk factor for surgical site infection (SSI). We therefore aimed to estimate the effect of OR door openings on SSI risk in patients undergoing cardiac surgery.

METHODS

This prospective, observational study involved consecutive patients undergoing cardiac surgery in 2 prespecified ORs equipped with automatic door-counting devices from June 2016 to October 2017. Occurrence of an SSI within 30 days after cardiac surgery was our primary outcome measure. Respective outcome data were obtained from a national SSI surveillance cohort. We analyzed the relationship between mean OR door opening frequencies and SSI risk by use of uni- and multivariable Cox regression models.

RESULTS

A total of 301 594 OR door openings were recorded during the study period, with 87 676 eligible door openings being logged between incision and skin closure. There were 688 patients included in the study, of whom 24 (3.5%) developed an SSI within 30 days after surgery. In uni- and multivariable analysis, an increased mean door opening frequency during cardiac surgery was associated with higher risk for consecutive SSI (adjusted hazard ratio per 5-unit increment, 1.49; 95% confidence interval, 1.11-2.00; P = .008). The observed effect was driven by internal OR door openings toward the clean instrument preparation room.

CONCLUSIONS

Frequent door openings during cardiac surgery were independently associated with an increased risk for SSI. This finding warrants further study to establish a potentially causal relationship between OR door openings and the occurrence of SSI.

Surgical Site Infection after Digestive Surgery: Diagnosis and Treatment in a Context of Limited Resources

Background: Surgical site infections (SSIs) are responsible for substantial morbidity in patients who undergo digestive surgery. However, very little is known about the aspects of SSIs in sub-Saharan Africa. Methods: The purpose of this study was to assess the prevalence and identify the risk factors of SSI in patients who were treated in the Department of Digestive Surgery of Tenkodogo Hospital in Burkina Faso. We performed a prospective study from January 1, 2016 to December 31, 2016. All patients who underwent digestive tract surgery during this period were included and followed. Patients whose post-operative surgical sites were complicated by infection were identified. Surgical site infection was diagnosed according to the U.S. Centers for Disease Control and Prevention (CDC) definition. Bacteriologic sampling was performed in all included patients. Results: A total 964 patients underwent surgery during the study period and were included in the study. Seven hundred thirty-seven were females (76.4%), and 227 were males. The mean age of the included patients was 47.5 years (standard deviation [SD] = 9 years). One hundred fourteen patients presented with SSI, the incidence of which was 11.8%. The incidence of SSI was substantially higher in females than in males (63.2 vs. 36.8%, p < 0.05). The incidence was also higher in patients living below the poverty line (71.1 vs. 28.9%, p < 0.05). Clinically, the incidence of SSI was higher in emergency surgery than in scheduled surgery (84.2 vs. 15.8%, p < 0.05). Contaminated or dirty surgery was more risky than clean surgery (p < 0.05). With respect to bacteria, the most commonly isolated microbes were Escherichia coli (66.7%) and Staphylococcus aureus (15%). Treatment mainly consisted of appropriate antibiotic therapy and local care. Three deaths were recorded for a mortality rate of 2.6%. Conclusions: Surgical site infections are frequent in sub-Saharan environments. The risk factors seem to be clinical and social.

Association of Dysplastic Coronoid Process with Long-Face Morphology

Vertical malocclusion is a developmental condition, resulting from complex interactions among multiple etiological factors during the growth period. As a tricky dentofacial deformity clinically, long-face (LF) morphology is characterized by excessive vertical facial growth with severe disarrangement of jaws and teeth. Since the improvement of LF patients on facial profile and occlusion is often difficult and lacks long-term stability, it becomes important to unravel the etiology of LF pattern formation for early prevention and treatment. In the current studies, we identified a transgenic mouse model that exhibited a dysplastic coronoid process and LF morphology. Although the mutant mice exhibited jaw structures and occlusion comparable to controls at birth, they all acquired typical LF morphology with anterior open bite during postnatal growth, resembling clinical features of the selected skeletal class III patients. Since the coronoid process provides an insertion site for the temporalis attachment, we examined the initial development and differentiation of the temporalis and found identical results in both control and mutant mice before E17.5 when the temporal muscle makes attachment to the coronoid process. However, thereafter, we observed altered orientation and reduced size of the cross-sectional area of the temporalis in mutant mice, which persisted to the weaning stage. Biomechanical analysis and simulation modeling further support the idea that altered morphology of the coronoid process may impair the efficiency of the vertical temporalis contraction and appears to correlate with LF formation. Consistently, we present evidence that a dysplastic mandibular coronoid process was also seen in some human patients with skeletal III LF morphology. Taken together, the results presented in this study establish an association of the craniofacial bony structures with vertical patterning, which will have implications in earlier prediction for clinical precaution and intervention.

Air quality in the operating room: Surgical site infections, HVAC systems and discipline - position paper of the German Society of Hospital Hygiene (DGKH)

In recent years, there has been an ongoing discussion about the value of laminar airflow (LAF=low turbulence displacement ventilation) in the operating room for prevention of surgical site infections (SSI). Some publications, e.g., from the WHO, issued the demand to no longer build LAF ceilings in operating rooms. The present statement deals critically with this position and justifies the use of LAF ceilings in different ways: Many of the papers cited by the WHO and others for the case against LAF do not provide reliable data.The remaining studies which might be used for answering the question give quite different results, also in favor of LAF.The size of the LAF ceiling in many studies is not given or mostly too small in comparison to actual technical requirements.LAF in different countries can mean quite different techniques (e.g., the US in comparison to Germany) so that the results of studies that do not take this into account may not be comparable.LAF has positive effects in terms of reducing particulate and bacterial load, associated with increased airflow in the surgical working area. A reduction of carcinogenic substances in the air may also be assumed, which would increase workers' safety. Thus, this paper recommends building LAF ceilings in the future as well, depending on the operations intended. Further, this paper gives an overview of possible reasons for surgical site infections and highlights the importance of discipline in the operating theatre.

Association of Cutibacterium avidum Colonization in the Groin With Obesity: A Potential Risk Factor for Hip Periprosthetic Joint Infection

Background

An increase in the incidence of hip periprosthetic joint infections caused by Cutibacterium avidum has recently been detected after hip arthroplasty with an anterior surgical approach. We raised the question of whether skin colonization with C. avidum differs between the anterior and the lateral thigh as areas of surgical incision fields.

Methods

Between February and June 2017, we analyzed skin scrapings from the groin and the anterior and lateral thigh in patients undergoing a primary hip arthroplasty. We anaerobically cultured plated swab samples for Cutibacterium spp. for ≥7 days. Univariate logistic regression analysis was used to explore associations between body mass index (BMI) and colonization rate at different sites.

Results

Twenty-one of 65 patients (32.3%) were colonized with C. avidum at any site, mainly at the groin (n = 16; 24.6%), which was significantly higher at the anterior (n = 5; 7.7%; P = .009) or lateral (n = 6; 9.2%; P = .02) thigh. Patients colonized with C. avidum did not differ from noncolonized patients in age or sex, but their BMIs were significantly higher (30.1 vs 25.6 kg/m2, respectively; P = .02). Furthermore, increased BMI was associated with colonization at the groin (odds ratio per unit BMI increase, 1.15; 95% confidence interval; 1.03-1.29; P = .01).

Conclusions

The groin, rather than the anterior thigh, showed colonization for C. avidum in obese patients. Further studies are needed to evaluate current skin disinfection and draping protocols for hip arthroplasty, particularly in obese patients.

Incidence and risk factors of surgical site infection after total knee arthroplasty: Results of a retrospective cohort study

Knee arthroplasty is commonly performed in the case of advanced osteoarthritis, and deep joint infections represent a severe complication following surgery. A 4-year retrospective cohort study was conducted to determine the incidence and risk factors for such surgical site infections. Of the 2439 patients included in the study, 84 of them (3.4%) developed infections. Postoperative bleeding, Ahlbäck's disease, obesity, smoking, and male gender were independent risk factors that should be considered when caring for those patients.

Implementation of an infection prevention bundle is associated with reduced surgical site infections in cranial neurosurgery

OBJECTIVE

The objective of this study was to quantify surgical site infection (SSI) rates after cranial neurosurgery in a tertiary care hospital, identify risk factors for SSI, and evaluate the impact of standardized surveillance and an infection prevention bundle (IPB).

METHODS

The authors compared SSI rates during 7 months before and after the intervention. The IPB included standardized patient preparation, perioperative antibiotic/antiseptic use, barrier precautions, coaching of surgeons, and the implementation of a specialized technical operation assistant team.

RESULTS

Three hundred twenty-two unselected consecutive patients were evaluated before the IPB, and 296 were evaluated after implementation. Infection rates after 1 year decreased from 7.8% (25/322) to 3.7% (11/296, p = 0.03) with similar mortality rates (14.7% vs 13.8%, p = 0.8). The isolated bacteria included Staphylococcus aureus (42%), Cutibacterium acnes (22%), and coagulase-negative staphylococci (14%). Organ/space infections dominated with 67%, and mostly consisted of subdural empyema and meningitis/ventriculitis. Among the 36 SSIs, 13 (36%) occurred during hospitalization, and 29 (81%) within the first 3 months of follow-up. In multivariable analysis including established risk factors described in the literature, non-CNS neoplasia (odds ratio [OR] 3.82, 95% confidence interval [CI] 1.39–10.53), postoperative bleeding (OR 4.09, 1.44–11.62), operations performed by or under supervision of a senior faculty surgeon (OR 0.38, 0.17–0.84), and operations performed after the implementation of standardized surveillance and an IPB (OR 0.38, 0.17–0.85) significantly influenced the infection rate.

CONCLUSIONS

The introduction of an IPB combined with routine surveillance and personal feedback was associated with a 53% reduced infection rate. The lower infection rates of senior faculty and the strong association between postoperative bleeding and infection underline the importance of both surgical experience as well as thorough supervision and coaching of younger surgeons.

Impact of health insurance status on surgical site infection incidence: A prospective cohort study

Health insurance status may affect the risk for surgical site infection (SSI). A large prospective cohort study in a Swiss tertiary-care hospital did not find evidence of a difference in SSI risk in individuals with basic versus semiprivate or private insurance in a setting with universal health insurance coverage.

Performance of surgical site infection risk prediction models in colorectal surgery: external validity assessment from three European national surveillance networks

OBJECTIVE

To assess the validity of multivariable models for predicting risk of surgical site infection (SSI) after colorectal surgery based on routinely collected data in national surveillance networks.

DESIGN

Retrospective analysis performed on 3 validation cohorts.

PATIENTS

Colorectal surgery patients in Switzerland, France, and England, 2007-2017.

METHODS

We determined calibration and discrimination (ie, area under the curve, AUC) of the COLA (contamination class, obesity, laparoscopy, American Society of Anesthesiologists [ASA]) multivariable risk model and the National Healthcare Safety Network (NHSN) multivariable risk model in each cohort. A new score was constructed based on multivariable analysis of the Swiss cohort following colorectal surgery, then based on colon and rectal surgery separately.

RESULTS

We included 40,813 patients who had undergone elective or emergency colorectal surgery to validate the COLA score, 45,216 patients to validate the NHSN colon and rectal surgery risk models, and 46,320 patients in the construction of a new predictive model. The COLA score's predictive ability was poor, with AUC values of 0.64 (95% confidence interval [CI], 0.63-0.65), 0.62 (95% CI, 0.58-0.67), 0.60 (95% CI, 0.58-0.61) in the Swiss, French, and English cohorts, respectively. The NHSN colon-specific model (AUC, 0.61; 95% CI, 0.61-0.62) and the rectal surgery-specific model (AUC, 0.57; 95% CI, 0.53-0.61) showed limited predictive ability. The new predictive score showed poor predictive accuracy for colorectal surgery overall (AUC, 0.65; 95% CI, 0.64-0.66), for colon surgery (AUC, 0.65; 95% CI, 0.65-0.66), and for rectal surgery (AUC, 0.63; 95% CI, 0.60-0.66).

CONCLUSION

Models based on routinely collected data in SSI surveillance networks poorly predict individual risk of SSI following colorectal surgery. Further models that include other more predictive variables could be developed and validated.

Cardiovascular daytime varying effect in cardiac surgery on surgical site infections and 1-year mortality: A prospective cohort study with 22,305 patients

Afternoon aortic valve replacement surgery may provide perioperative myocardial protection and improve patient outcomes compared with morning surgery. The results of our large observational study based on Swiss cardiac surgical site infection surveillance data suggest that the current evidence is insufficient to generally promote afternoon cardiac surgeries.

Can surgical site infections be controlled through microbiological surveillance? A three-year laboratory-based surveillance at an orthopaedic unit, retrospective observatory study

OBJECTIVE

The aims of the study were to analyse the surgical site infections (SSIs) in patients operated at an orthopaedic ward and to describe the drug-resistance of the aetiology of those infections. Also, analyse the possibility of SSI control through microbiological surveillance. Additionally, we have studied the information inferred by aggregating cumulative antibiograms for the SSIs of the studied orthopaedic unit.

DESIGN

Cross-sectional studies carried out in 2013-2015.

SETTING AND PATIENTS

Orthopaedic and Trauma Surgery Unit in Sosnowiec, Poland; 5995 patients, 5239 operations.

METHODS

Retrospective laboratory-based data collection study of surgical site infections.

RESULTS

SSI incidence rate was 6.6%, in the implantations-hip prosthesis 5.8% and knee prosthesis 5.4%, about 6 times higher compared with European HAI-Net. SSIs were usually caused by Gram-positive bacteria (56%). The prevalence of MDR microorganisms was 22.6%, and mainly concerned the Gram-negative bacilli: 97.6% of Acinetobacter baumannii and 50.0% of Klebsiella pneumoniae were multidrug-resistant. On the basis of what the Formula for Rational Empiric Antimicrobial Therapy analysis has shown, the use of amikacin, imipenem and ciprofloxacin has been recommended as the most efficient in the empirical therapy of SSIs.

CONCLUSIONS

The infection control was a significant problem at the studied orthopaedic unit, as evidenced by the SSI incidence rate significantly higher than expected. We suggest implementing the infection control and prevention based on evidence-based medicine, and a unit-based surveillance. A cumulative unit-based antibiogram reflects the drug-susceptibility pattern for the strains from the infections acquired at the unit.

Impact of participation in a surgical site infection surveillance network: results from a large international cohort study

BACKGROUND

Surveillance of surgical site infections (SSIs) is a core component of effective infection control practices, though its impact has not been quantified on a large scale.

AIM

To determine the time-trend of SSI rates in surveillance networks.

METHODS

SSI surveillance networks provided procedure-specific data on numbers of SSIs and operations, stratified by hospitals' year of participation in the surveillance, to capture length of participation as an exposure. Pooled and procedure-specific random-effects Poisson regression was performed to obtain yearly rate ratios (RRs) with 95% confidence intervals (CIs), and including surveillance network as random intercept.

FINDINGS

Of 36 invited networks, 17 networks from 15 high-income countries across Asia, Australia and Europe participated in the study. Aggregated data on 17 surgical procedures (cardiovascular, digestive, gynaecological-obstetrical, neurosurgical, and orthopaedic) were collected, resulting in data concerning 5,831,737 operations and 113,166 SSIs. There was a significant decrease in overall SSI rates over surveillance time, resulting in a 35% reduction at the ninth (final) included year of surveillance (RR: 0.65; 95% CI: 0.63-0.67). There were large variations across procedure-specific trends, but strong consistent decreases were observed for colorectal surgery, herniorrhaphy, caesarean section, hip prosthesis, and knee prosthesis.

CONCLUSION

In this large, international cohort study, pooled SSI rates were associated with a stable and sustainable decrease after joining an SSI surveillance network; a causal relationship is possible, although unproven. There was heterogeneity in procedure-specific trends. These findings support the pivotal role of surveillance in reducing infection rates and call for widespread implementation of hospital-based SSI surveillance in high-income countries.

Costs versus earnings in colon surgery and coronary artery bypass grafting under a prospective payment system: Sufficient financial incentives to reduce surgical site infections?

Based on a surgical site infection (SSI) cohort at an academic center, we showed a median potentially preventable loss per non-SSI case of $17,916 in colon surgery and of $34,741 in coronary artery bypass grafting.

Different Types of Heater-Cooler Units and Their Risk of Transmission of Mycobacterium chimaera During Open-Heart Surgery: Clues From Device Design

OBJECTIVEWorldwide, Mycobacterium chimaera infections have been linked to contaminated aerosols from heater-cooler units (HCUs) during open-heart surgery. These infections have mainly been associated with the 3T HCU (LivaNova, formerly Sorin). The reasons for this and the risk of transmission from other HCUs have not been systematically assessed.DESIGNProspective observational study.SETTINGUniversity Hospital Basel, Switzerland.METHODSContinuous microbiological surveillance of 3 types of HCUs in use (3T from LivaNova/Sorin and HCU30 and HCU40 from Maquet) was initiated in June 2014, coupled with an epidemiologic workup. Monthly water and air samples were taken. Construction design was analyzed, and exhausted airflow was measured.RESULTS Mycobacterium chimaera grew in 8 of 12 water samples (66%) and 22 of 24 air samples (91%) of initial 3T HCUs in use, and in 2 of 83 water samples (2%) and 0 of 41 (0%) air samples of new replacement 3T HCUs. Moreover, 7 of 12 water samples (58%) and 0 of 4 (0%) air samples from the HCU30 were positive, and 0 of 64 (0%) water samples and 0 of 50 (0%) air samples from the HCU40 were positive. We identified 4 relevant differences in HCU design compared to the 3T: air flow direction, location of cooling ventilators, continuous cooling of the water tank at 4°C, and an electronic alarm in the HCU40 reminding the user of the next disinfection cycle.CONCLUSIONSAll infected patients were associated with a 3T HCU. The individual HCU design may explain the different risk of disseminating M. chimaera into the air of the operating room. These observations can help the construction of improved devices to ensure patient safety during cardiac surgery.Infect Control Hosp Epidemiol 2018;834-840.

Surgical site infection surveillance following total knee arthroplasty: Tertiary care hospital experience

Introduction

Surgical Site Infection (SSI) after knee arthroplasty is a major cause of morbidity and mortality that increases the hospital stay, financial burden and mental anguish of the patient. Infection Control Unit at Aga Khan University Hospital (AKUH) incorporated total knee arthroplasty in its surgical care surveillance program and started collecting data in June 2012. The purpose of this study is to review Surgical Site Infection (SSI) rates in patients undergoing primary total knee replacement (TKR) surgery.

Patients and methodology

All patients from June 2012 to December 2013 undergoing knee arthroplasty at our hospital were included. Data was acquired from the hospital SSI database for knee arthroplasty surgery. Data was collected by SSI nurses for inpatients a well as post-discharge monitoring in clinics till 90 days post-op follow-up. The work has been reported in line with the PROCESS criteria.

Results

During this time period a total of 164 patients had primary TKR at AKUH. Out of these, 85 patients (52%) had bilateral TKR while 79 (48%) had unilateral TKR. The overall SSI was in 2 patients (1.2%).

Conclusion

Identifying SSIs is multidimensional. Since our 2 infected cases after TKR occurred after discharge, this highlights the importance of post-discharge surveillance and not limiting the surveillance for inpatients only. Furthermore, the SSI program may be effective in controlling postoperative wound infections.

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Surgical Site Infection (SSI) after knee arthroplasty is a major cause of morbidity and mortality.

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It increases the hospital stay, financial burden and mental anguish of the patient.

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The purpose of this study is to review SSI rates in patients undergoing primary total knee replacement.

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Identifying SSIs is multidimensional.

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The importance of post-discharge surveillance and not limiting the surveillance for inpatients only is highlighted here.

Temporal trends and epidemiology of Staphylococcus aureus surgical site infection in the Swiss surveillance network: a cohort study

BACKGROUND

Staphylococcus aureus is the leading pathogen in surgical site infections (SSI).

AIM

To explore trends and risk factors associated with S. aureus SSI.

METHODS

Risk factors for monomicrobial S. aureus SSI were identified from the Swiss multi-centre SSI surveillance system using multi-variate logistic regression. Both in-hospital and postdischarge SSI were identified using standardized definitions.

FINDINGS

Over a six-year period, data were collected on 229,765 surgical patients, of whom 499 (0.22%) developed monomicrobial S. aureus SSI; 459 (92.0%) and 40 (8.0%) were due to meticillin-susceptible S. aureus (MSSA) and meticillin-resistant S. aureus (MRSA), respectively. There was a significant decrease in the rate of MSSA SSI (P = 0.007), but not in the rate of MRSA SSI (P = 0.70). Independent protective factors for S. aureus SSI were older age [≥75 years vs <50 years: odds ratio (OR) 0.60, 95% confidence interval (CI) 0.44-0.83], laparoscopy/minimally invasive surgery (OR 0.68, 95% CI 0.50-0.92), non-clean surgery [OR 0.78 (per increase in wound contamination class), 95% CI 0.64-0.94] and correct timing of pre-operative antibiotic prophylaxis (OR 0.80, 95% CI 0.65-0.98). Independent risk factors were male sex (OR 1.38, 95% CI 1.14-1.66), higher American Society of Anesthesiologists' score (per one-point increment: OR 1.30, 95% CI 1.13-1.51), re-operation for non-infectious reasons (OR 4.59, 95% CI 3.59-5.87) and procedure type: cardiac surgery, laminectomy, and hip or knee arthroplasty had two-to nine-fold increased odds of S. aureus SSI compared with other procedures.

CONCLUSIONS

SSI due to S. aureus are decreasing and becoming rare events in Switzerland. High-risk procedures that may benefit from specific preventive measures were identified. Unfortunately, many of the independent risk factors are not easily modifiable.

Structure, Process, and Outcome Quality of Surgical Site Infection Surveillance in Switzerland

OBJECTIVE

To assess the structure and quality of surveillance activities and to validate outcome detection in the Swiss national surgical site infection (SSI) surveillance program.

DESIGN

Countrywide survey of SSI surveillance quality.

SETTING

147 hospitals or hospital units with surgical activities in Switzerland.

METHODS

Site visits were conducted with on-site structured interviews and review of a random sample of 15 patient records per hospital: 10 from the entire data set and 5 from a subset of patients with originally reported infection. Process and structure were rated in 9 domains with a weighted overall validation score, and sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the identification of SSI.

RESULTS

Of 50 possible points, the median validation score was 35.5 (range, 16.25–48.5). Public hospitals (P<.001), hospitals in the Italian-speaking region of Switzerland (P=.021), and hospitals with longer participation in the surveillance (P=.018) had higher scores than others. Domains that contributed most to lower scores were quality of chart review and quality of data extraction. Of 49 infections, 15 (30.6%) had been overlooked in a random sample of 1,110 patient records, accounting for a sensitivity of 69.4% (95% confidence interval [CI], 54.6%–81.7%), a specificity of 99.9% (95% CI, 99.5%–100%), a positive predictive value of 97.1% (95% CI, 85.1%–99.9%), and a negative predictive value of 98.6% (95% CI, 97.7%–99.2%).

CONCLUSIONS

Irrespective of a well-defined surveillance methodology, there is a wide variation of SSI surveillance quality. The quality of chart review and the accuracy of data collection are the main areas for improvement.

Infect Control Hosp Epidemiol 2017;38:1172–1181