Surgical site infection in patients submitted to digestive surgery: risk prediction and the NNIS risk index

Prognostic models for surgical-site infection in gastrointestinal surgery: systematic review

BACKGROUND

Identification of patients at high risk of surgical-site infection may allow clinicians to target interventions and monitoring to minimize associated morbidity. The aim of this systematic review was to identify and evaluate prognostic tools for the prediction of surgical-site infection in gastrointestinal surgery.

METHODS

This systematic review sought to identify original studies describing the development and validation of prognostic models for 30-day SSI after gastrointestinal surgery (PROSPERO: CRD42022311019). MEDLINE, Embase, Global Health, and IEEE Xplore were searched from 1 January 2000 to 24 February 2022. Studies were excluded if prognostic models included postoperative parameters or were procedure specific. A narrative synthesis was performed, with sample-size sufficiency, discriminative ability (area under the receiver operating characteristic curve), and prognostic accuracy compared.

RESULTS

Of 2249 records reviewed, 23 eligible prognostic models were identified. A total of 13 (57 per cent) reported no internal validation and only 4 (17 per cent) had undergone external validation. Most identified operative contamination (57 per cent, 13 of 23) and duration (52 per cent, 12 of 23) as important predictors; however, there remained substantial heterogeneity in other predictors identified (range 2-28). All models demonstrated a high risk of bias due to the analytic approach, with overall low applicability to an undifferentiated gastrointestinal surgical population. Model discrimination was reported in most studies (83 per cent, 19 of 23); however, calibration (22 per cent, 5 of 23) and prognostic accuracy (17 per cent, 4 of 23) were infrequently assessed. Of externally validated models (of which there were four), none displayed 'good' discrimination (area under the receiver operating characteristic curve greater than or equal to 0.7).

CONCLUSION

The risk of surgical-site infection after gastrointestinal surgery is insufficiently described by existing risk-prediction tools, which are not suitable for routine use. Novel risk-stratification tools are required to target perioperative interventions and mitigate modifiable risk factors.

Clinical prediction models and risk tools for early detection of patients at risk of surgical site infection and surgical wound dehiscence: a scoping review

OBJECTIVE

Despite advances in surgical techniques, intraoperative practice and a plethora of advanced wound therapies, surgical wound complications (SWCs), such as surgical site infection (SSI) and surgical wound dehiscence (SWD), continue to pose a considerable burden to the patient and healthcare setting. Predicting those patients at risk of a SWC may give patients and healthcare providers the opportunity to implement a tailored prevention plan or potentially ameliorate known risk factors to improve patient postoperative outcomes.

METHOD

A scoping review of the literature for studies which reported predictive power and internal/external validity of risk tools for clinical use in predicting patients at risk of SWCs after surgery was conducted. An electronic search of three databases and two registries was carried out with date restrictions. The search terms included 'prediction surgical site infection' and 'prediction surgical wound dehiscence'.

RESULTS

A total of 73 records were identified from the database search, of which six studies met the inclusion criteria. Of these, the majority of validated risk tools were predominantly within the cardiothoracic domain, and targeted morbidity and mortality outcomes. There were four risk tools specifically targeting SWCs following surgery.

CONCLUSION

The findings of this review have highlighted an absence of well-developed risk tools specifically for SSI and/or SWD in most surgical populations. This review suggests that further research is required for the development and clinical implementation of rigorously validated and fit-for-purpose risk tools for predicting patients at risk of SWCs following surgery. The ability to predict such patients enables the implementation of preventive strategies, such as the use of prophylactic antibiotics, delayed timing of surgery, or advanced wound therapies following a procedure.

Surgical Site Infections in Gastroenterological Surgery

Surgical site infections (SSIs) remain one of the most common serious surgical complications and are the second most frequent healthcare-associated infection. Patients with SSIs have a significantly increased postoperative length of hospital stay, hospital expenses, and mortality risk compared with patients without SSIs. The prevention of SSI requires the integration of a range of perioperative measures, and approximately 50% of SSIs are preventable through the implementation of evidence-based preventative strategies. Several international guidelines for SSI prevention are currently available worldwide. However, there is an urgent need for SSI prevention guidelines specific to Japan because of the differences in the healthcare systems of Japan versus western countries. In 2018, the Japan Society for Surgical Infection published SSI prevention guidelines for gastroenterological surgery. Although evidence-based SSI prevention guidelines are now available, it is important to consider the appropriateness of these guidelines depending on the actual conditions in each facility. A systemic inflammatory host response is a hallmark of bacterial infection, including SSI. Therefore, blood inflammatory markers are potentially useful in SSI diagnosis, outcome prediction, and termination of therapeutic intervention. In this review, we describe the current guideline-based perioperative management strategies for SSI prevention, focusing on gastroenterological surgery and the supplemental utility of blood inflammatory markers.

Comparison of laparoscopic and open inguinal hernia repair in adults: A retrospective cohort study using a medical claims database

INTRODUCTION

This study aimed to investigate and compare the surgical complications following laparoscopic inguinal hernia repair (LIHR) with those following open inguinal hernia repair (OIHR).

METHODS

This was a retrospective cohort study based on nationwide claims data. We extracted the data of patients aged ≥20 years who underwent inguinal hernia repair (IHR) between 2009 and 2020. The primary outcome was postoperative complications of IHR, and the secondary outcomes were recurrence of hernia and length of hospital stay. Patient characteristics were adjusted with propensity score (PS) matching, the annual proportions of LIHR versus OIHR were summarized, and the surgical outcomes of each IHR were analyzed.

RESULTS

Of the 15 728 eligible patients, 6512 underwent LIHR. The proportion of LIHR increased from 14.7% to 52.8% annually during the study period. From the analysis of 6060 pairs created by PS matching, the risk of surgical site infection (odds ratio [OR] 0.70; 95% confidence interval [CI] 0.56-0.86; P = .0007), and acute postoperative pain (OR 0.69; 95% CI 0.60-0.79; P < .0001), and chronic postoperative pain (OR 0.83; 95% CI 0.70-0.98; P = .0291) were significantly lower with LIHR than with OIHR. The recurrent rate was not significantly different between the LIHR and OIHR groups (OR, 0.68; 95% CI 0.45-1.01; P = .0558). Furthermore, no significant difference was found in the length of hospital stay between the LIHR and OIHR groups (2.91 ± 1.94 days vs 2.97 ± 2.61 days, difference ± SE: 0.06 ± 0.04, P = .1307).

CONCLUSION

LIHR might be superior to OIHR in terms of fewer surgical complications and might be preferred over OIHR in the future.

Awareness and wound assesment decrease surgical site infections

Objective: Various surveillance methods have been described for surveillance of surgical site infections (SSI). The aim of this study was to examine prac- ticality of SSI risk assessment methods (SENIC and NNIS) with a postoperative wound monitoring scale (ASEPSIS) as an outcome assessment measure and evaluation of the contribution of wound assesment to the reduction of wound infection.

Material and Methods: Patients were followed with a prospective data chart through four year. Correlation of SENIC and NNIS together with ASEPSIS were performed.

Results: During the study period, 275 SSI occurred. SSIs were determined within the 21 days-period after operations. Correlation between SENIC with ASEPSIS (rs= 0.41, p< 0.001) was found better than that for NNIS with ASEPSIS (rs= 0.37, p< 0.001). Type of operation (emergency vs. elective), body mass index, operation class and American Society of Anesthesiologists scores were found independently predictive factors for SSI. The forth year SSI rate was found to be significantly lower than the other years (p< 0.001).

Conclusion: This study indicates weak but significant correlation between preoperative risk assessment methods for SSI and ASEPSIS method. In addi- tion, surgical wound assesment and awarness of the wound infection rates, have decreased the SSI rates over the years.

Initial Outcomes of a Novel Irrigating Wound Protector for Reducing the Risk of Surgical Site Infection in Elective Colectomies

BACKGROUND

Surgical site infection (SSI) rates in elective colorectal surgery remain high due to intraoperative exposure of colonic bacteria at the surgical site. We aimed to evaluate 30-day SSI outcomes of a novel wound retractor that combines barrier protection with continuous wound irrigation in elective colorectal resection.

MATERIALS AND METHODS

A retrospective single-center cohort-matched analysis included all patients undergoing elective colorectal resection utilizing the novel irrigating wound protector (IWP) from April 2015 to July 2019. A control cohort of patients who underwent the same procedures with a standard wound protector over the same time period were also identified. Patients from both groups were matched for procedure type, procedure approach, pathology requiring operation, age, sex, race, body mass index, diabetes, smoker status, hypertension, presence of disseminated cancer, current steroid or immunosuppressant use, wound classification, and American Society of Anesthesiologist classification. SSI frequency, SSI subtype (superficial, deep, or organ space), hospital length of stay (LOS) and associated procedure were tabulated through 30 postoperative days. Fisher's exact test and number needed to treat (NNT) were used to compare SSI rates and estimate cost between both groups.

RESULTS

The IWP group had 41 patients. The control group had 82 patients. Control-matched variables were similar for both groups. 30-day SSI rates were significantly lower in the IWP group (P=0.0298). length of stay was significantly shorter in the IWP group (P=0.0150). The NNT for the IWP to prevent one episode of SSI was 8.2 patients.

CONCLUSIONS

The novel IWP device shows promise to reducing the risk of SSI in elective colorectal surgery.

Intraoperative core temperature and infectious complications after colorectal surgery: A registry analysis

STUDY OBJECTIVE

Moderate hypothermia (e.g., 34.5 °C) causes surgical site infections, but it remains unknown whether mild hypothermia (34.6 °C-35.9 °C) causes infection. Therefore, the objective of this study was to evaluate the relationship between intraoperative time-weighted average core temperature and a composite of serious wound and systemic infections in adults having colorectal surgery over a range of near-normal temperatures.

DESIGN

Retrospective, single center study.

SETTING

The operating rooms of the Cleveland Clinic Foundation from January 2005 to December 2014.

PATIENTS

Adult patients having colorectal surgery at least 1 h in length who received both general anesthesia and esophageal core temperature monitoring.

INTERVENTION(S)

Time weighted average intraoperative core temperature.

MEASUREMENTS

Our primary outcome was a composite of serious infections obtained from a surgical registry and billing codes. Average intraoperative esophageal temperatures and the composite of serious 30-day complications were assessed with logistic regression, adjusted for potential confounding factors.

MAIN RESULTS

A total of 7908 patients were included in the analysis. A 0.5 °C decrease in time-weighted average intraoperative core temperature ≤ 35.4 °C was associated with an increased odds of serious infection (OR = 1.38, P = .045); that is, hypothermia below 35.4 °C progressively worsened infection risk. Additionally, at higher core temperatures, the odds of serious infection increased slightly with each 0.5 °C increase in average temperature (OR = 1.10, P = .047).

CONCLUSIONS

Below 35.5 °C, hypothermia was associated with increased risk of serious infectious complications. Why composite complications increased at higher temperatures remains unclear, but the highest temperatures may reflect febrile patients who had pre-existing infections. Avoiding time-weighted average core temperatures <35.5 °C appears prudent from an infection perspective, but higher temperatures may be needed to prevent other hypothermia-related complications.

Surgical site infection following abdominal surgery: a prospective cohort study

Background

Surgical site infection (SSI) is one of the most common complications of abdominal surgery and is associated with substantial discomfort, morbidity and cost. The goal of this study was to describe the incidence, bacteriology and risk factors associated with SSI in patients undergoing abdominal surgery.

Methods

In this prospective cohort study, all patients aged 14 years or more undergoing abdominal surgery between Feb. 1 and July 31, 2016, at a single large academic hospital were included. Patients undergoing vascular, gynecological, urological or plastic procedures were excluded. Patients were followed prospectively for 30 days. Wound assessment was done with the Centers for Disease Control and Prevention definition of SSI. We performed multivariate analysis to identify factors associated with SSI.

Results

A total of 337 patients were included. The overall incidence of SSI was 16.3% (55/337); 5 patients (9%) had deep infections, and 25 (45%) had combined superficial and deep infections. The incidence of SSI in open versus laparoscopic operations was 35% versus 4% (p < 0.001). The bacteria most commonly isolated were extended-spectrum β-lactamase-producing Escherichia coli, followed by Enterococcus species. Only 23% of cultured bacteria were sensitive to the prophylactic antibiotic given preoperatively. The independent predictors of SSI were open surgical approach, emergency operation, longed operation duration and male sex.

Conclusion

Potentially modifiable independent risk factors for SSI after abdominal surgery including open surgical approach, contaminated wound class and emergency surgery should be addressed systematically. We recommend tailoring the antibiotic prophylactic regimen to target the commonly isolated organisms in patients at higher risk for SSI.

The Double-Lumen Irrigation-Suction Tube in The Management of Incisional Surgical Site Infection After Enterocutaneous Fistula Excisions: An Observational Study

BACKGROUND

This study aimed to investigate the effect of double-lumen irrigation-suction tube (DLIST) in the management of surgical site infections (SSIs) after enterocutaneous fistula (ECF) excisions.

METHOD

From January 2016 to December 2017 medical records of patients with ECF excisions were reviewed. Patients with primary superficial SSI were divided into group a (treated with DLIST) and b (treated with delayed primary closures). Patients with primary deep SSI were divided into group A (treated with DLIST) and B (treated with vacuum-assisted closure [VAC]). The effect of the DLIST was evaluated.

RESULTS

There were 32 in group a and 27 in group b. The therapeutic time and cost in group a were lower (13.13 ± 2.37 d vs. 24.89 ± 7.44 d; p < .001; $1456 ± 302 vs.$2784 ± 583; p < .001). There were 21 in group A and 23 in group B. While the therapeutic time of group A was longer, the cost was lower ($1717 ± 404 vs. $2636 ± 592; p < .001).

CONCLUSIONS

Placing DLIST is an effective and cheap method to treat superficial SSI after ECF excisions. The cost of DLIST in treatment of deep SSI is lower, while the effect of VAC is better.

Compliance with preoperative care measures reduces surgical site infection after colorectal operation

BACKGROUND

Surgical site infections (SSIs) are a major cause of morbidity complicating colorectal operations. Several evidence-based preoperative strategies are associated with decreased SSI rates. We hypothesize that compliance with multiple strategies is associated with lower incidence of SSI after the elective colorectal operation.

METHODS

Preoperative care measure compliance before colorectal operations were assessed. Measures included antiseptic wash the night before and day of operation, oral antibiotic, and mechanical bowel preparation, antibiotic prophylaxis, Chloraprep skin preparation, and hair clipping. Rates of SSI after colectomy and other pertinent outcomes were stratified by full and partial compliance with preoperative measures. Exclusion criteria included bowel perforation, ischemia, complete obstruction, intra-abdominal abscess, and no intraoperative skin closure.

RESULTS

Eight hundred twenty-six subjects underwent colectomy between 2010 and 2016; 469 met inclusion criteria. Compliance with all measures occurred in 214 (46%) and was independently associated with lower postoperative infection rates (odds ratio [OR], 0.37; confidence interval [CI], 0.16-0.85; P = 0.02). SSI occurred in 51 (11%): was superficial in 35 (7%); deep in 5 (1%); and organ space in 11 (2%). SSI rates were reduced from 16% (partial or no compliance group) to 5% (full compliance group). No stand-alone intervention was independently associated with decreased SSI rate. Multivariate analysis found the following factors associated with a lower risk of SSI: full compliance with all five process measures, lower BMI, nonsmoker, and minimally invasive operation.

DISCUSSION AND CONCLUSION

Compliance with preoperative care strategies reduces rates of SSI after colectomy with a cumulative effect more pronounced than any single intervention reinforcing the need for protocol-driven and evidence-based care for patients undergoing colorectal operations.

Clinical prediction score for superficial surgical site infection after appendectomy in adults with complicated appendicitis

Background

Superficial surgical site infection (SSI) is common after appendectomy. This study aims to determine a clinical prediction score for SSI after appendectomy in complicated appendicitis.

Methods

Data from randomized controlled trial of delayed versus primary wound closures in complicated appendicitis was used. Nineteen patient- and operative-related predictors were selected in the logit model. Clinical prediction score was then constructed using coefficients of significant predictors. Risk stratification was done by receiver operating characteristic (ROC) curve analysis. Bootstrap technique was used to internal validate the score.

Results

Among 607 patients, the SSI incidence was 8.7% (95% CI 6.4, 11.2). Four predictors were significantly associated with SSI, i.e., presence of diabetes, incisional length > 7 cm, fecal contamination, and operative time > 75 min with the odds ratio of 2.6 (95% CI 1.2, 5.9), 2.8 (1.5, 5.4), 3.6 (1.9, 6.8), and 3.4 (1.8, 6.5), respectively. Clinical prediction score ranged from 0 to 4.5 with its discrimination concordance (C) statistic of 0.74 (95% CI 0.66, 0.81). Risk stratification classified patients into very low, low, moderate, and high risk groups for SSI when none, one, two, and more than two risk factors were presented with positive likelihood ratio of 1.00, 1.45, 3.32, and 9.28, respectively. A bootstrap demonstrated well calibration and thus good internal validation.

Conclusions

Diabetes, incisional length, fecal contamination, and operative time could be used to predict SSI with acceptable discrimination. This clinical risk prediction should be useful in prediction of SSI. However, external validation should be performed.

Trial registration

ClinicalTrials.gov (ID NCT01659983), registered August 8, 2012

Electronic supplementary material

The online version of this article (10.1186/s13017-018-0186-1) contains supplementary material, which is available to authorized users.

Mechanical and Oral Antibiotic Bowel Preparation in the Era of Minimally Invasive Surgery and Enhanced Recovery

INTRODUCTION

In the modern era of minimally invasive colorectal surgery and enhanced recovery pathways, the value of preoperative bowel preparation remains debated. In this review, we evaluate evidence regarding the use of mechanical bowel preparation (MBP) and oral antibiotic bowel preparation to make recommendations for their application in contemporary practice.

METHODS

We searched the PubMed database through December 2017 for relevant randomized controlled trials, Cochrane Reviews, American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database studies, and other reviews pertaining to MBP and oral antibiotic bowel preparation in elective colorectal surgery and conducted a narrative review.

RESULTS

The combination of MBP and oral antibiotics reduces the incidence of surgical site infection, anastomotic leak, and postoperative sepsis. MBP improves laparoscopic surgical viewing and facilitates intraoperative manipulation of the bowel in minimally invasive surgery.

CONCLUSION

Based on existing data, we recommend that preoperative care includes MBP and oral antibiotics in elective minimally invasive colorectal surgery.

Outcomes are Local: Patient, Disease, and Procedure-Specific Risk Factors for Colorectal Surgical Site Infections from a Single Institution

BACKGROUND

Colorectal surgical site infections (SSIs) contribute to postoperative morbidity, mortality, and resource utilization. Risk factors associated with colorectal SSI are well-documented. However, quality improvement efforts are informed by national data, which may not identify institution-specific risk factors.

METHOD

Retrospective cohort study of colorectal surgery patients uses institutional ACS-NSQIP data from 2006 through 2014. ACS-NSQIP data were enhanced with additional variables from medical records. Multivariable logistic regression identified factors associated with SSI development.

RESULTS

Of 2376 patients, 213 (9.0%) developed at least one SSI (superficial 4.8%, deep 1.1%, organ space 3.5%). Age < 40, BMI > 30, ASA3+, steroid use, smoking, diabetes, pre-operative sepsis, higher wound class, elevated WBC or serum glutamic-oxalocetic transaminase, low hematocrit or albumin, Crohn's disease, and prolonged incision-to-closure time were associated with increased SSI rate (all P < 0.01). After adjustment, BMI > 30, steroids, diabetes, and wound contamination were associated with SSI. Patients with Crohn's had greater odds of SSI than other indications.

CONCLUSION

Institutional modeling of SSI suggests that many previously suggested risk factors established on a national level do not contribute to SSIs at our institution. Identification of institution-specific predictors of SSI, rather than relying upon conclusions derived from external data, is a critical endeavor in facilitating quality improvement and maximizing value of quality investments.

Reducing Surgical Site Infection with Negative-Pressure Wound Therapy After Open Abdominal Surgery: A Prospective Randomized Controlled Study

BACKGROUND AND AIMS

Surgical site infection, in particular superficial incision infection, is a common type of complication following abdominal surgery. Negative-pressure wound therapy has been confirmed to reduce the incidence of surgical site infection in various surgeries, but there are few prospective randomized studies into its application to abdominal surgery.

MATERIAL AND METHODS

A prospective randomized controlled study was conducted in which patients with abdominal surgery and open surgery were randomly divided into a negative-pressure wound therapy experimental group and a gauze-covering control group. Information about demographic data, type of surgery, surgical sites, incision treatment outcomes, surgical site infection factors, and follow-up was recorded.

RESULTS

From May 2015 to December 2015, 71 patients were enrolled in this study, including 33 in the experimental group and 38 in the control group. There were 10 cases of incision complications, all superficial infections, with an incidence of 14.1%. The surgical site infection incidence was statistically different between the experimental and control groups (3.0% vs 23.7%, p = 0.031). Multivariate logistic regression analysis showed that incision length ⩾20 cm increased the surgical site infection incidence (odds ratio value of 15.576, p = 0.004) and that the application of negative-pressure wound therapy reduced the surgical site infection incidence (odds ratio value of 0.073, p = 0.029).

CONCLUSION

Negative-pressure wound therapy can reduce the incidence of surgical site infection in open abdominal surgery.

Is obesity a predisposing factor for free flap failure and complications? Comparison between breast and nonbreast reconstruction: Systematic review and meta-analysis

Obesity is a risk factor for postoperative morbidity in breast reconstruction. Although existing studies about nonbreast reconstruction are limited, previous research has demonstrated that obesity is not an important factor in poor outcomes in nonbreast reconstruction. Our study evaluates the effects of obesity on postoperative morbidity in nonbreast reconstruction in comparison to breast reconstruction. A systematic literature review and meta-analysis was performed using Medline, EMBASE, and Cochrane databases. Obesity was extracted for predictor variables and partial, total loss of flap, and complication were extracted for outcome variables. Subgroup analyses were performed according to reconstruction site. The Newcastle-Ottawa scale (NOS) was used to assess the quality of the studies, and the Cochrane risk of bias tool was used. Publication bias was evaluated using funnel plots. The search strategy identified 944 publications. After screening, 19 articles were selected for review. Partial flap loss, total flap loss, and complications in breast reconstruction occurred significantly more often in obese patients in comparison to nonobese patients (OR = 2.479, P = 0.021 for partial loss, OR = 3.083, P = 0.002 for total loss, OR = 2.666, P = 0.001 for complications). In contrast, partial flap loss, total flap loss, and complications in nonbreast reconstruction were not significantly different in obese patients in comparison to nonobese patients (OR = 0.786, P = 0.629 for partial loss, OR = 0.960, P = 0.961 for total loss, and OR = 1.009, P = 0.536 for complications). In contrast to the relationship between obesity and poor outcomes in breast reconstruction, our study suggests the obesity is not a predisposing factor for poor outcomes in nonbreast reconstruction. Long-term studies are needed to confirm these findings.

An Economic Model: Value of Antimicrobial-Coated Sutures to Society, Hospitals, and Third-Party Payers in Preventing Abdominal Surgical Site Infections

Background

While the persistence of high surgical site infection (SSI) rates has prompted the advent of more expensive sutures that are coated with antimicrobial agents to prevent SSIs, the economic value of such sutures has yet to be determined.

Methods

Using TreeAge Pro, we developed a decision analytic model to determine the cost-effectiveness of using antimicrobial sutures in abdominal incisions from the hospital, third-party payer, and societal perspectives. Sensitivity analyses systematically varied the risk of developing an SSI (range, 5%–20%), the cost of triclosan-coated sutures (range, $5–$25/inch), and triclosan-coated suture efficacy in preventing infection (range, 5%–50%) to highlight the range of costs associated with using such sutures.

Results

Triclosan-coated sutures saved $4,109–$13,975 (hospital perspective), $4,133–$14,297 (third-party payer perspective), and $40,127–$53,244 (societal perspective) per SSI prevented, when a surgery had a 15% SSI risk, depending on their efficacy. If the SSI risk was no more than 5% and the efficacy in preventing SSIs was no more than 10%, triclosan-coated sutures resulted in extra expenditure for hospitals and third-party payers (resulting in extra costs of $1,626 and $1,071 per SSI prevented for hospitals and third-party payers, respectively; SSI risk, 5%; efficacy, 10%).

Conclusions

Our results suggest that switching to triclosan-coated sutures from the uncoated sutures can both prevent SSIs and save substantial costs for hospitals, third-party payers, and society, as long as efficacy in preventing SSIs is at least 10% and SSI risk is at least 10%.

Factors Associated with Surgical Site Infection in Colorectal Surgery: The Japan Nosocomial Infections Surveillance

Objective.

Surgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs). This study aims to assess factors associated with SSI after colorectal surgery in Japan, using a Japanese national database for HAIs.

Design.

A retrospective nationwide surveillance-based study.

Setting.

Japanese healthcare facilities.

Methods.

Data on colon and rectal surgeries performed from 2008 through 2010 were extracted from a national monitoring system for healthcare-associated infections, the Japan Nosocomial Infections Surveillance (JANIS). Factors associated with SSI after colon and rectal surgery were assessed using multivariate logistic regression.

Results.

The cumulative incidence of SSI for colon and rectal surgery was 15.0% (6,691 of 44,751) and 17.8% (3,230 of 18,187), respectively. Traditional risk factors included in the National Nosocomial Infections Surveillance (NNIS) modified risk index were significant in predicting SSI in the final model for both colon and rectal surgery. Among the additional variables routinely collected in JANIS were factors independently associated with the development of SSI, such as male sex (adjusted odds ratio [aOR], 1.20 [95% confidence interval (CI), 1.14–1.27]), ileostomy or colostomy placement (aOR, 1.13 [95% CI, 1.04–1.21]), emergency operation (aOR, 1.40 [95% CI, 1.29–1.52]), and multiple procedures (aOR, 1.22 [95% CI, 1.13–1.33]) for colon surgery as well as male sex (aOR, 1.43 [95% CI, 1.31–1.55]), ileostomy or colostomy placement (aOR, 1,63 [95% CI, 1.51–1.79]), and emergency operation (aOR, 1.43 [95% CI, 1.20–1.72]) for rectal surgery.

Conclusions.

For colorectal operations, inclusion of additional variables routinely collected in JANIS can more accurately predict SSI risk than can the NNIS risk index alone.

Infect Control Hosp Epidemiol 2014;35(6):660–666

Malignancy is a risk factor for postoperative infectious complications after elective colorectal resection

PURPOSE

Patient and technical factors influencing the postoperative infectious complications (ICs) after elective colorectal resections are satisfactorily described. However, the underlying disease-related factors have not been extensively evaluated. This study aimed to measure the effect of malignancy on postoperative surgical site and extra surgical site infections after elective colorectal resection.

METHODS

This study is a bicentric retrospective matched pair study of prospectively gathered data. Between 2004 and 2013, 1104 consecutive patients underwent colorectal resection in two centers. Patients undergoing elective resection with supraperitoneal anastomosis for benign diseases (excluding inflammatory bowel disease) (group B, n = 305) were matched to randomly selected patients with malignancy (group M, n = 305). The matching variables were age, gender, American Society of Anesthesiologists (ASA) score, malnutrition, type of resection, and surgical approach. We compared the 30-day IC rates between patients with benign diseases (group B) and malignancy (group M). Multivariate logistic regression analysis was performed to identify the risk factors for ICs.

RESULTS

Group M had a higher overall rate of IC (25.6 vs 16.1 %, P = 0.004) as well as a higher risk of extra surgical site infections (P = 0.007) and anastomotic leakage (P = 0.039). The independent risk factors for ICs were malignancy (odds ratio (OR) = 2.02; P = 0.002), age ≥70 years (OR = 1.73, P = 0.018), tobacco history (OR = 1.87; P = 0.030), and obesity (OR = 1.68; P = 0.039).

CONCLUSION

Malignancy, age, tobacco history, and obesity increase the risk of ICs after colorectal resection. Improvement of the modifiable risk factors, increased compliance with an enhanced recovery after surgery (ERAS) program in the overall population, and optimization of immune function in patients with malignancy should be considered.

Factors affecting surgical site infection rate after elective gastric cancer surgery

OBJECTIVE

Surgical site infection (SSI) is a common complication after surgery and is an indicator of quality of care. Risk factors for SSI are studied thoroughly for most types of gastrointestinal surgeries and especially colorectal surgeries, but accumulated data is still lacking for gastric surgeries. We studied the parameters affecting SSI rate after gastric cancer surgery.

MATERIAL AND METHODS

Consecutive patients, who underwent elective gastric cancer surgery between June and December 2013, were included. Descriptive parameters, laboratory values and past medical histories were recorded prospectively. All patients were followed for 1 month. Recorded parameters were compared between the SSI (+) and SSI (-) groups.

RESULTS

Fifty-two patients (mean age: 58.87±9.25 [31-80]; 67% male) were included. SSI incidence was 19%. ASA score ≥3 (p<0.001), postoperative weight gain (p<0.001), smoking (p=0.014) and body mass index (BMI) ≥30 (p=0.025) were related with a higher SSI incidence. Also patients in the SSI (+) group had a higher preoperative serum C-reactive protein level (p=0.014).

CONCLUSION

We assume that decreasing BMI to <30, stopping smoking at least 3 weeks before the operation, and preventing postoperative weight gain by avoiding excessive intravenous hydration will all help decrease SSI rate after gastric surgery.

Surgical site infections after abdominal surgery: incidence and risk factors. A prospective cohort study

BACKGROUND

Abdominal surgeries have high rates of surgical site infections (SSIs), contributing to increased morbidity and mortality and costs for hospitalization. The aim of this study was to determine the SSI incidence rates and risk factors after abdominal surgeries.

METHODS

This prospective cohort study included all patients undergoing abdominal surgeries between 2005 and 2007 in the Western Galilee Medical Center in Nahariya, Israel. SSI incidence rates were calculated per 100 operations. Odds ratios (ORs) were estimated for each risk factor using univariate and multivariate analyses by logistic regression models.

RESULTS

Among 302 patients in the study cohort, the total SSI incidence rate was 22.2%. The univariate analysis defined 13 variables significantly associated with SSI: age > 60 years, lower functional status, diabetes mellitus, congestive heart failure, immunocompromising underlying disease, treatment with chemotherapy and other immunosuppressive medications, impaired immune system open cholecystectomy, laparotomy, an American Society of Anesthesiologists (ASA) score > 2, drain insertion, and 'dirty wound' classification. In multivariate regression analysis, treatment with immunosuppressive medications (OR = 2.5, 95% confidence interval (CI) = 1.099-143.443), open cholecystectomy (OR = 2.25, 95% CI = 2.242-40.109), and dirty wound classification (OR = 2.179, 95% CI = 3.80-20.551) were significantly associated with SSI.

CONCLUSIONS

The significant risk factors defined should be addressed preoperatively to decrease the risk for SSI. Wound surveillance in the post-discharge period is necessary for correct estimation of SSI rates.

Surgical site infection risk factors identified for patients undergoing colon procedures, New York State 2009-2010

BACKGROUND

Since 2007, New York State (NYS) hospitals have been required to report surgical site infections (SSIs) following colon procedures to the NYS Department of Health, using the National Healthcare Safety Network (NHSN). The purpose of this study was to identify risk factors for the development of SSIs in patients undergoing colon procedures.

METHODS

NYS has been conducting validation studies at hospitals to assess the accuracy of the surveillance data reported by the participating hospitals. A sample of patients undergoing colon procedures in NYS hospitals were included in hospital-acquired infection program validation studies in 2009 and 2010. Medical chart reviews and on-site visits were performed to verify patient information reported and to evaluate additional risk factors for SSI. Bivariable and multivariable logistic regressions were performed.

RESULTS

A total of 2,656 colon procedures were included in this analysis, including 698 SSI cases. Multivariable analysis indicated that SSI following colon procedure was associated with body mass index greater than 30 (odds ratio [OR], 1.48 [95% confidence interval (CI), 1.21-1.80]), male sex (OR, 1.34 [95% CI, 1.10-1.64]), American Society of Anesthesiologists physical classification score greater than 3 (OR, 1.33 [95% CI, 1.08-1.64]), procedure duration, transfusion (OR, 1.32 [95% CI, 1.05-1.66]), left-side colon surgical procedures, other gastroenterologic procedures, irrigation, hospital bed size greater than 500, and medical school affiliation.

CONCLUSIONS

Male sex, obesity, transfusion, type of procedure, and prolonged duration were significant factors associated with overall infection risk after adjusting other factors. Additional factors not collected in the NHSN slightly improved prediction of SSIs.

Predictors and costs of surgical site infections in patients with endometrial cancer

OBJECTIVE

Technological advances in surgical management of endometrial cancer (EC) may allow for novel risk modification in surgical site infection (SSI).

METHODS

Perioperative variables were abstracted from EC cases surgically staged between January 1, 1999, and December 31, 2008. Primary outcome was SSI, as defined by American College of Surgeons National Surgical Quality Improvement Program. Counseling and global models were built to assess perioperative predictors of superficial incisional SSI and organ/space SSI. Thirty-day cost of SSI was calculated.

RESULTS

Among 1369 EC patients, 136 (9.9%) had SSI. In the counseling model, significant predictors of superficial incisional SSI were obesity, American Society of Anesthesiologists (ASA) score >2, preoperative anemia (hematocrit <36%), and laparotomy. In the global model, significant predictors of superficial incisional SSI were obesity, ASA score >2, smoking, laparotomy, and intraoperative transfusion. Counseling model predictors of organ/space SSI were older age, smoking, preoperative glucose >110 mg/dL, and prior methicillin-resistant Staphylococcus aureus (MRSA) infection. Global predictors of organ/space SSI were older age, smoking, vascular disease, prior MRSA infection, greater estimated blood loss, and lymphadenectomy or bowel resection. SSI resulted in a $5447 median increase in 30-day cost.

CONCLUSIONS

Our findings are useful to individualize preoperative risk counseling. Hyperglycemia and smoking are modifiable, and minimally invasive surgical approaches should be the preferred surgical route because they decrease SSI events. Judicious use of lymphadenectomy may decrease SSI. Thirty-day postoperative costs are considerably increased when SSI occurs.

MRSA infections following colorectal surgery in an enhanced recovery programme

AIM

The aim of this study was to evaluate the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections in a cohort of patients undergoing elective colorectal resections within an enhanced recovery programme.

METHOD

A prospective database of all patients undergoing colorectal resections by a single surgical team over a 3.5-year period was reviewed. Demographics including age, gender, body mass index, American Society of Anesthesiologists classification, type of surgery (abdominal or pelvic) and whether or not the procedure was laparoscopic or open were analysed. All patients were screened preoperatively and postoperatively and on discharge for MRSA. Patients found preoperatively to be MRSA positive were excluded from the study.

RESULTS

In all, 186 patients underwent colorectal resection over the time reviewed. There were 113 laparoscopic resections, 70 open resections and three laparoscopic converted to open resections. Five patients (2.7%) were found to be MRSA positive postoperatively. All of these had open rather than laparoscopic surgery (P < 0.01). Length of stay for patients that had MRSA infections was significantly longer than those remaining MRSA free (P < 0.05).

CONCLUSION

These results suggest that patients who successfully undergo laparoscopic colorectal resections within an enhanced recovery programme have a lower incidence of postoperative MRSA infections.

The impact of MRSA colonization on surgical site infection following major gastrointestinal surgery

PURPOSE

The purpose of this study is to determine whether methicillin-resistant Staphylococcus aureus (MRSA) colonization affects surgical site infections (SSI) after major gastrointestinal (GI) operations.

METHODS

We retrospectively reviewed the charts of all patients undergoing major GI surgery from December 2007 to August 2009. All patients were tested for MRSA colonization and grouped according to results (MRSA+, methicillin-sensitive S. aureus [MSSA]+, and negative). Data analyzed included demographics, incidence of SSI, and wound culture results.

RESULTS

A total of 1,137 patients were identified; 78.9 % negative, 14.7 % MSSA+, and 6.4 % MRSA+. The mean age was 59.5 years, 44.5 % of the patients were men, and 47.9 % of the patients underwent colorectal operation. SSI was identified in 101 (8.9 %) patients and was higher in the MRSA+ group than the negative and MSSA+ groups (13.7 vs. 9.4 vs. 4.2 %; p < 0.05). Although MRSA colonization had an odds ratio of 1.43 for developing an SSI, it was not a significant independent risk factor. However, the MRSA+ group was strongly associated with MRSA cultured from the wound when SSI was present (70 vs. 8.5 %; p < 0.0001).

CONCLUSIONS

MRSA colonization is not an independent risk factor for SSI following major GI operations; however, it is strongly predictive of MRSA-associated SSI in these patients. Preoperative MRSA nasal swab test with decolonization may reduce the incidence of MRSA-associated SSI after major GI surgery.

Development and validation of a novel stratification tool for identifying cancer patients at increased risk of surgical site infection

OBJECTIVE

To identify cancer-specific predictors of postoperative surgical site infection (SSI), and to develop a risk-stratification prognostic tool and compare its performance with traditional measures.

BACKGROUND

The incidence and risk factors for SSI in cancer patients are unknown; current risk-stratification tools are not cancer-specific.

METHODS

A prospective cohort study of patients undergoing elective operations (n = 503) at a tertiary cancer center was conducted. SSI was assessed using postdischarge active surveillance. Multivariate logistic regression analyses were performed to identify predictors of SSI, and β-coefficients were used to create a scoring system. The sum of these was used to create a Risk of Surgical Site Infection in Cancer (RSSIC) score. The RSSIC was validated using bootstrapping techniques, and its discrimination was compared with the National Nosocomial Infection Surveillance (NNIS) risk index.

RESULTS

The 30-day SSI incidence was 24%. Significant predictors of SSI included preoperative chemotherapy (OR = 1.94 [95% CI, 1.16-3.25]), clean-contaminated wounds (OR = 2.1 [95% CI, 1.24-3.55]), operative time ≥2 hours (OR = 1.75 [95% CI, 1.01-3.04]) and ≥4 hours (OR = 2.24 [95% CI, 1.22-4.1]), and surgical site: groin (OR = 4.65 [95% CI, 1.69-12.83]), and head/neck (OR = 0.12 [95% CI, 0.02-0.89]). The RSSIC score stratified patients into 4 risk strata for SSI. The performance of this score exceeded that of the NNIS score (AUC = 0.70 vs. 0.63, respectively; P = 0.01).

CONCLUSION

SSIs are common following cancer surgery. Preoperative chemotherapy, in addition to other common risk factors, was identified as a significant predictor for SSI in cancer patients. The RSSIC improves risk-stratification of cancer patients and identifies those that may benefit from more aggressive or novel preventive strategies.

Impact of obesity on surgical site infection in colon and rectal surgery

Obesity affects over 30% of the United States population. Over the past 10 years, there has been increased recognition of the prevalence of obesity and its contribution to worse outcomes among medical and surgical patients. In particular, obesity has been validated as a risk factor for surgical site infection (SSI) among patients undergoing major abdominal surgery with some reports demonstrating an increased risk of SSI as high as sixty percent (60%) among obese patients. For patients undergoing elective colon and rectal surgery, a higher incidence of SSI (up to 45%) has been reported in comparison to outcomes of other surgical procedures. Obesity, as well as numerous other variables, have been implicated as a potential source for this increased incidence. Although the pathophysiology of obesity-related SSI has been suggested (decreased wound oxygen tension, impaired tissue antibiotic penetration, altered immune function, etc.), the true effect of obesity has not been clearly described. The purpose of this review is to examine the growing epidemic of obesity and its specific impact on SSI for both general and colorectal surgical patients. The proposed mechanisms for why obesity increases the risk of SSI will be briefly discussed, as well.

The effects of group 1 versus group 2 carbapenems on imipenem-resistant Pseudomonas aeruginosa: an ecological study

Use of the group 2 carbapenems, imipenem and meropenem, may lead to emergence of Pseudomonas aeruginosa resistance. The group 1 carbapenem ertapenem has limited activity against P. aeruginosa and is not associated with imipenem-resistant P. aeruginosa (IMP-R PA) in vitro. This retrospective, group-level, longitudinal study collected patient, antibiotic use, and resistance data from 2001 to 2005 using a hospital database containing information on 9 medical wards. A longitudinal data time series analysis was done to evaluate the association between carbapenem use (defined daily doses, or DDDs) and IMP-R PA. A total of 139 185 patient admissions were included, with 541 150 antibiotics DDDs prescribed: 4637 DDDs of group 2 carbapenems and 2130 DDDs of ertapenem. A total of 779 IMP-R PA were isolated (5.6 cases/1000 admissions). Univariate analysis found a higher incidence of IMP-R PA with group 2 carbapenems (P < 0.001), aminoglycosides (P = 0.034), and penicillins (P = 0.05), but not with ertapenem. Multivariate analysis showed a yearly increase in incidence of IMP-R-PA (3.8%, P < 0.001). Group 2 carbapenem use was highly associated with IMP-R PA, with a 20% increase in incidence (P = 0.0014) for each 100 DDDs. Group 2 carbapenem use tended to be associated with an increased proportion of IMP-R PA (P = 0.0625) in multivariate analysis. Ertapenem was not associated with IMP-R PA. These data would support preferentially prescribing ertapenem rather than group 2 carbapenems where clinically appropriate.

Surgical site infection in patients submitted to orthopedic surgery: the NNIS risk index and risk prediction

The applicability of the risk index for surgical site infection of the National Nosocomial Infection Surveillance (NNIS) has been evaluated for its performance in different surgeries. In some procedures, it is necessary to include other variables to predict. Objective: to evaluate the applicability of the NNIS index for prediction of surgical site infection in orthopedic surgeries and to propose an alternative index. The study involved a historical cohort of 8236 patients who had been submitted to orthopaedic surgery. Statistical analysis was performed using multivariate logistic regression to fit the model. The incidence of infection was 1.41%. Prediction models were evaluated and compared to the NNIS index. The proposed model was not considered a good predictor of infection, despite moderately stratified orthopedic surgical patients in at least three of the four scores. The alternative model scored higher than the NNIS models in the prediction of infection.

Burden of endemic health-care-associated infection in developing countries: systematic review and meta-analysis

BACKGROUND

Health-care-associated infection is the most frequent result of unsafe patient care worldwide, but few data are available from the developing world. We aimed to assess the epidemiology of endemic health-care-associated infection in developing countries.

METHODS

We searched electronic databases and reference lists of relevant papers for articles published 1995-2008. Studies containing full or partial data from developing countries related to infection prevalence or incidence-including overall health-care-associated infection and major infection sites, and their microbiological cause-were selected. We classified studies as low-quality or high-quality according to predefined criteria. Data were pooled for analysis.

FINDINGS

Of 271 selected articles, 220 were included in the final analysis. Limited data were retrieved from some regions and many countries were not represented. 118 (54%) studies were low quality. In general, infection frequencies reported in high-quality studies were greater than those from low-quality studies. Prevalence of health-care-associated infection (pooled prevalence in high-quality studies, 15·5 per 100 patients [95% CI 12·6-18·9]) was much higher than proportions reported from Europe and the USA. Pooled overall health-care-associated infection density in adult intensive-care units was 47·9 per 1000 patient-days (95% CI 36·7-59·1), at least three times as high as densities reported from the USA. Surgical-site infection was the leading infection in hospitals (pooled cumulative incidence 5·6 per 100 surgical procedures), strikingly higher than proportions recorded in developed countries. Gram-negative bacilli represented the most common nosocomial isolates. Apart from meticillin resistance, noted in 158 of 290 (54%) Staphylococcus aureus isolates (in eight studies), very few articles reported antimicrobial resistance.

INTERPRETATION

The burden of health-care-associated infection in developing countries is high. Our findings indicate a need to improve surveillance and infection-control practices.

FUNDING

World Health Organization.

Changes of inflammatory mediators in obese patients after laparoscopic cholecystectomy

BACKGROUND

Obesity is associated with the impairment of immunological functions. The aim of this study was to analyze some inflammatory mediators in obese subjects who underwent laparoscopic cholecystectomy.

METHODS

Seventeen consecutive female patients with a BMI ranging from 35 to 45 kg/m(2) (obese) and 17 consecutive female patients with BMI ranging from 20 to 25 kg/m(2) (nonobese) were included in the study. All patients were affected by symptomatic gallbladder stone disease and underwent laparoscopic cholecystectomy. Changes in levels of leukocytes, neutrophils, IL-6, IL-10, leptin, and adiponectin were evaluated.

RESULTS

We observed a significant increase in leukocyte and neutrophil levels in the obese subjects compared to the nonobese subjects. The serum levels of leptin and IL-6 were higher in the postoperative period (compared to the baseline values in both groups), and always higher in the obese. Both adiponectin and IL-10 increased in the postoperative period in nonobese subjects and was always higher than in the obese.

CONCLUSIONS

Obese patients have a stronger acute inflammatory response than do nonobese subjects in reaction to surgical stress.

Surgical site infections in adults patients undergoing of clean and contaminated surgeries at a university Brazilian hospital

CONTEXT: Surgical site infections are a risk inherent to surgical procedures, especially after digestive surgeries. They occur up to 30 days after surgery, or up to a year later if a prosthesis is implanted. The Surgical-site Infection Risk Index (SIRI), NISS (National Nosocomial Infection Surveillance) methodology, is a method to evaluate the risk of surgical site infections, which takes into account the potential contamination of the surgery, the patient's health status and surgery duration. OBJECTIVES: To evaluate the correlation between the surgical-site infection risk index score on the 1st day postoperatively, and the development of surgical site infection up to 30 days postoperatively. METHODS: The postoperative surgical site infections (NNIS) was evaluated by following-up in hospital and as an outpatient. The patients followed prospectively were those submitted to elective surgeries, clean (hernioplasties) or contaminated (colorretal), performed by conventional approach at a university hospital, during the period from June 2007 to August 2008. The mean age of the patients was 55.5 years, 133 (65.5%) male; 120 (59.1%) submitted to clean surgeries and 83 (40.9%) contaminated. RESULTS: The global index of surgical site infections was 10.3%; 10 (8.3%) in clean procedures and 111(3.2%) in contaminated ones. Four (19.1%) of the surgical site infections were diagnosed at the time of hospitalization and 17 (80.9%) at post-discharge follow-up. Twelve (57.1%) of the surgical site infections were superficial, 2 (9.5%) deep and 7 (33.3%) at a specific site. Of these, 5 (6.6%) were in patients classified as SIRI 0 (76); 9 (15%) for SIRI 1 (60); 5 (9.1%) for SIRI 2 (55) and 2 (16.7%) for SIRI 3. CONCLUSION: The global index of surgical site infections and its incidence among contaminated procedures are within the expected limits. On the other hand according to SIRI, the surgical site infection indexes are above the expected standards both for the clean and for the contaminated procedures.

A simple risk score for predicting surgical site infections in inflammatory bowel disease

PURPOSE

Patients with inflammatory bowel disease are often at highest risk for surgical site infections. We sought to define the predictors of surgical site infections and to develop a risk score for predicting those at highest risk.

METHODS

Patients undergoing a bowel resection for Crohn's disease or ulcerative colitis were identified from National Surgical Quality Improvement Program 2008. Univariate and multivariate analyses were conducted to identify predictors of surgical site infections. Clinically relevant prediction categories were developed and the predictive behavior of the model was validated by use of National Surgical Quality Improvement Program 2007. An integer-based scoring system risk score was created proportional to the logistic regression coefficients, grouping patients into categories of similar risk.

RESULTS

We identified 271,368 patients; 3981 of these patients underwent an operation for Crohn's disease (n = 2895) or ulcerative colitis (n = 1086). Nine hundred (22.6%) patients developed surgical site infections. Predictors included weight loss, smoking, emergent surgery, wound class, operative time (minutes), and an ASA score >2. A risk score was developed by stratifying patients into low (0-5), 15.6%; medium (6-8), 25.2%; and high (>8), 36.1% risk.

CONCLUSIONS

Patients with inflammatory bowel disease are at high risk for surgical site infections. Preoperative factors including weight loss, smoking, emergent surgery and an ASA score >2 are strong predictors of surgical site infections. Operative time and wound class are important intraoperative predictors. A risk score, based on pre- and intraoperative variables, can be used to identify patients at highest risk of developing surgical site infections. This may allow for appropriate process measures to be implemented to prevent and lessen the impact of surgical site infections in this high-risk population.