Nosocomial Infection Surveillance Risk Index Research Articles

Using the National Nosocomial Infections Surveillance risk index to determine risk factors associated with surgical site infections following gynecologic surgeries.

We used the National Nosocomial Infections Surveillance (NNIS) risk index to determine risk factors associated with surgical site infections (SSIs) following gynecologic surgeries. A retrospective study was conducted based on the medical records of 185 patients with SSIs, following gynecologic surgeries at a Grade A tertiary gynecologic and obstetric hospital in southwest China during September 2013-June 2021. Suspected risk factors associated with SSIs were: length of hospital stay, age, whether the patient had cancer, whether the patient had chemotherapy or high-dose antibiotic therapy before surgery, duration of surgery, amount of blood loss, and whether a blood transfusion was done. It was found that SSIs were more likely to occur in cancer patients with an NNIS risk index score of 1 and in patients with preoperative chemotherapy and an NNIS risk index score of 2. Among the patients with an NNIS risk index score of 2, the older the patient, the higher incidence of SSIs. Gynecologic surgery teams should pay more attention to the independent risk factors associated with SSIs determined by the NNIS risk index score to prevent SSIs following gynecologic surgeries, thus ensuring patient safety.

Intraoperative techniques to prevent deep incisional or organ-space surgical site infection after emergency surgery for nonappendiceal perforation peritonitis: a prospective two-center observational study.

The rate of surgical site infection (SSI) after surgery for secondary peritonitis is very high. This study investigated the relationship between intraoperative procedures of emergency surgery for nonappendiceal perforation peritonitis and deep incisional or organ-space SSI. This prospective, two-center observational study included patients aged ≥ 20years who underwent emergency surgery for perforation peritonitis between April 2017 and March 2020. We compared patients with deep incisional or organ-space SSI (Group S) to patients without SSIs or with superficial incisional SSIs (Group C). Thereafter, we evaluated the association between intraoperative technical variables and deep incisional or organ-space SSI using a multivariate logistic regression model. All multivariate analyses were adjusted for potentially relevant risk factors (e.g., age, body mass index, diabetes, smoking habit, and National Nosocomial Infection Surveillance risk index). Of the 75 participants, 14 were in Group S and 61 were in Group C. The use of a wound protector device was significantly associated with decreased odds of deep incisional or organ-space SSI (adjusted odds ratios [AOR], 0.017; 95% confidence intervals [CI] 0.0014-0.19, p = 0.0011). A 1000ml increase in intra-abdominal lavage with normal saline was significantly associated with increased odds of deep incisional or organ-space SSI (AOR: 1.28, 95% CI 1.02-1.61, p = 0.033). Wound protector devices should be used in emergency surgery for nonappendiceal perforation peritonitis. Excessive intra-abdominal lavage with normal saline for peritonitis may have unsatisfactory benefits and increases the incidence of deep incisional or organ-space SSI.

Surgical site infections in thyroid and parathyroid surgery in Japan: An analysis of the Japan Nosocomial Infections Surveillance database from 2013 to 2020.

Surgical site infections (SSIs) after thyroid surgery are rare complications, with incidence rates of 0.3%-1.6%. Using a Japanese database, we conducted exploratory analyses on the incidence of SSIs, investigated the incidence of SSIs by the National Nosocomial Infections Surveillance risk index, and identified the causative bacteria of SSIs. SSIs occurred in 50 (0.7%) of 7388 thyroid surgery cases. Risk index-0 patients had the lowest incidence rate of SSIs (0.41%). The incidence of SSIs in risk index-1 patients was 3.05 times the incidence of SSIs in risk index-0 patients. The rate of SSI occurrence for risk index-2 patients was 4.22 times the rate of SSI occurrence for risk index-0 patients. Thirty-one bacterial species were identified as the cause of SSIs in thyroid surgery cases, of which 12 (38.7%) SSIs were caused by Staphylococcus aureus and Staphylococcus epidermidis. Of the nine SSIs caused by Staphylococcus aureus, 55.6% (five cases) were attributed to methicillin-resistant Staphylococcus aureus. Therefore, routine prophylactic antibiotic administration should be avoided, while the target for administration should be narrowed, according to the SSI risk. Administration of prophylactic antibiotics, such as 2 g piperacillin or 1 g cefazolin, is considered appropriate.

NNIS risk score or COLA score: which predicts better the risk of surgical site infection among patients undergoing colorectal resection in a tertiary care hospital setting?

Background: By using predictive scores to identify and quantify risk of Surgical site infections (SSI), preventive measures can be directed effectively to improve patient outcome post operatively. This study was undertaken to compare the National Nosocomial Infections Surveillance (NNIS) risk index and COLA (contamination, obesity, laparotomy and ASA grade) scores to predict risk of SSI among patients undergoing colorectal resection.Methods: A total of 77 patients who underwent colorectal resection at a tertiary care hospital were enrolled in this study. Wound surveillance was performed in all patients during the hospital stay and follow-up information for 30 days postoperatively was collected. Data analysis was done in SPSS version 20.0 for windows. Descriptive analysis was used to exhibit the clinical parameters. Differences between groups were tested by Pearson chi-square and fisher’s exact test. ROC curves were utilized. All the statistical tests were examined with 5% (p≤0.05) level of significance.Results: Incidence of overall SSI was 28.6%. Superficial SSI was more common (14.3%). Serious organ/deep space infection occurred only in 9.1%. Area under the curve (AUC) for NNIS score was 0.645 (95% CI: 0.510-0.781, p<0.05) and 0.611 for the COLA score. (95% CI: 0.472-0.750, p>0.05). Therefore, both these scores have less than acceptable accuracy in this data set to predict SSI.Conclusions: The risk prediction models (NNIS, COLA) although simple, did not accurately predict the risk of SSI in the given study population.

Risk Factors for Surgical Site Infection After Orthopedic Trauma Surgery: A Two-Year Prospective Multicenter Analysis

Background: Trauma is defined by the NHSN as “blunt or penetrating traumatic injury.” Therefore, if the surgery was performed because of a recent fall, for example, then it is a trauma surgery. Here, we investigated which preoperative and operative parameters are associated with surgical site infection (SSI) after orthopedic trauma surgery. Objective: We aimed to answer 3 main questions: What is the risk of wound infection for patients undergoing trauma surgery? What are the main etiologic agents of SSI after trauma surgery? And what are the risk factors associated with SSI after trauma surgery? Methods: This prospective multicenter cohort study included 2,035 patients undergoing trauma surgery between July 2016 and June 2018 in 4 hospitals in Belo Horizonte, Brazil. Outcome variables were SSI, hospital mortality, and length of hospital stay. The following preoperative and operative parameters were evaluated: age, length of hospital stay before surgery, duration of surgery, number of professionals at surgery, number of hospital admissions, surgical wound classification, American Society of Anesthesiologists (ASA) preoperative assessment score, type of surgery (elective, emergency), general anesthesia (yes, no), trauma surgery (yes, no), and the 3-point prediction Nosocomial Infections Surveillance (NNIS) risk index. Results: The overall estimated SSI risk was 2.8% (95% CI, 2.0%–3.6%). Hospital mortality risk after trauma surgery was 3.4% (95% CI, 2.8%–4.4%). Hospital length of stay parameters in noninfected patients were as follows: mean, 8 days; median, 3 days; SD, 12 days. Hospital length of stay parameters in infected patients were mean, 30 days; median, 23 days; with SD, 31 days. The parameters for hospital stay in infected patients were mean, 10 days; median, 3 days, and SD, 15.9 (P < .001). Trauma orthopedic surgery lasting >2 hours was associated with approximately twice the risk (RR, 2.2) of developing an SSI compared to ≤2 hours of surgery: 27 of 739 (3.7%) versus 21 of 1,290 (1.6%), respectively, (P = .005) (Fig. 1). The NNIS risk index predicts the risk of SSI after trauma surgery (P = .003): 13 of 737 SSIs (1.8%) had an NNIS risk index of 0; 20 of 736 SSIs (2.7%) had an NNIS risk index of 1; 8 of 211 SSIs (3.8%) had an NNIS risk index of 2; and 2 of 11 SSIs (18.2%) had an NNIS risk index of 3 (Fig. 2). Conclusions: We identified intrinsic risk factors for SSI after orthopedic trauma surgery. The identification of the actual SSI incidence after trauma surgery in developing country hospitals and associated risk factors may support actions to minimize the complications caused by SSI.Funding: NoneDisclosures: None

Artificial Intelligence-Based Multimodal Risk Assessment Model for Surgical Site Infection (AMRAMS): Development and Validation Study.

BackgroundSurgical site infection (SSI) is one of the most common types of health care–associated infections. It increases mortality, prolongs hospital length of stay, and raises health care costs. Many institutions developed risk assessment models for SSI to help surgeons preoperatively identify high-risk patients and guide clinical intervention. However, most of these models had low accuracies.ObjectiveWe aimed to provide a solution in the form of an Artificial intelligence–based Multimodal Risk Assessment Model for Surgical site infection (AMRAMS) for inpatients undergoing operations, using routinely collected clinical data. We internally and externally validated the discriminations of the models, which combined various machine learning and natural language processing techniques, and compared them with the National Nosocomial Infections Surveillance (NNIS) risk index.MethodsWe retrieved inpatient records between January 1, 2014, and June 30, 2019, from the electronic medical record (EMR) system of Rui Jin Hospital, Luwan Branch, Shanghai, China. We used data from before July 1, 2018, as the development set for internal validation and the remaining data as the test set for external validation. We included patient demographics, preoperative lab results, and free-text preoperative notes as our features. We used word-embedding techniques to encode text information, and we trained the LASSO (least absolute shrinkage and selection operator) model, random forest model, gradient boosting decision tree (GBDT) model, convolutional neural network (CNN) model, and self-attention network model using the combined data. Surgeons manually scored the NNIS risk index values.ResultsFor internal bootstrapping validation, CNN yielded the highest mean area under the receiver operating characteristic curve (AUROC) of 0.889 (95% CI 0.886-0.892), and the paired-sample t test revealed statistically significant advantages as compared with other models (P<.001). The self-attention network yielded the second-highest mean AUROC of 0.882 (95% CI 0.878-0.886), but the AUROC was only numerically higher than the AUROC of the third-best model, GBDT with text embeddings (mean AUROC 0.881, 95% CI 0.878-0.884, P=.47). The AUROCs of LASSO, random forest, and GBDT models using text embeddings were statistically higher than the AUROCs of models not using text embeddings (P<.001). For external validation, the self-attention network yielded the highest AUROC of 0.879. CNN was the second-best model (AUROC 0.878), and GBDT with text embeddings was the third-best model (AUROC 0.872). The NNIS risk index scored by surgeons had an AUROC of 0.651.ConclusionsOur AMRAMS based on EMR data and deep learning methods—CNN and self-attention network—had significant advantages in terms of accuracy compared with other conventional machine learning methods and the NNIS risk index. Moreover, the semantic embeddings of preoperative notes improved the model performance further. Our models could replace the NNIS risk index to provide personalized guidance for the preoperative intervention of SSIs. Through this case, we offered an easy-to-implement solution for building multimodal RAMs for other similar scenarios.

Surgical Site Infection After Gastrointestinal Surgery in China: A Multicenter Prospective Study

BackgroundThere is no nationwide database of information on surgical site infection (SSI) after gastrointestinal surgery in China. This study aimed to determine the incidence of SSI after gastrointestinal surgery in China and evaluate the related risk factors. Materials and methodsThe multicenter, prospective, observational study enrolled adult patients who underwent gastrointestinal surgery from May 1, 2018 to June 30, 2018 in 30 hospitals in China. The demographic and perioperative characteristics were collected, and the primary outcome was 30-d SSI. Predictors of SSI were determined by multivariable logistic regressions. Subgroup analysis was performed to determine the predictors of SSI in different surgeries. ResultsA total of 1290 patients were enrolled and SSI occurred in 68 patients (5.2%). Multivariate analysis with adjustments revealed that normal body mass index, normal blood glucose level, low national nosocomial infection surveillance risk index score, noncolon surgery, laparoscopic or robotic surgery, and use of mechanical bowel preparation were associated with reduced SSI in gastrointestinal surgery. Subgroup analysis revealed diverse predictors of SSI in diverse surgeries. National nosocomial infection surveillance risk index score of 2 and a high blood glucose level increased the incidence of SSI in colorectal and noncolorectal surgery, respectively. Besides, mechanical bowel preparation and laparoscopic or robotic surgery were protective factors for SSI in colorectal and noncolorectal surgery, respectively. ConclusionsThis study provides the newest data of SSI after gastrointestinal surgery in China and revealed some predictors of SSI in diverse surgeries, which can be a tool to look for areas to target quality improvement initiatives.

A New Surgical Site Infection Risk Score: Infection Risk Index in Cardiac Surgery.

Various scoring systems attempt to predict the risk of surgical site infection (SSI) after cardiac surgery, but their discrimination is limited. Our aim was to analyze all SSI risk factors in both coronary artery bypass graft (CABG) and valve replacement patients in order to create a new SSI risk score for such individuals. A priori prospective collected data on patients that underwent cardiac surgery (n = 2020) were analyzed following recommendations from the Reporting of studies Conducted using Observational Routinely collected health Data (RECORD) group. Study participants were divided into two periods: the training sample for defining the new tool (2010–2014, n = 1298), and the test sample for its validation (2015–2017, n = 722). In logistic regression, two preoperative variables were significantly associated with SSI (odds ratio (OR) and 95% confidence interval (CI)): diabetes, 3.3/2–5.7; and obesity, 4.5/2.2–9.3. The new score was constructed using a summation system for punctuation using integer numbers, that is, by assigning one point to the presence of either diabetes or obesity. The tool performed better in terms of assessing SSI risk in the test sample (area under the Receiver-Operating Characteristic curve (aROC) and 95% CI, 0.67/055–0.76) compared to the National Nosocomial Infections Surveillance (NNIS) risk index (0.61/0.50–0.71) and the Australian Clinical Risk Index (ACRI) (0.61/0.50–0.72). A new two-variable score to preoperative SSI risk stratification of cardiac surgery patients, named Infection Risk Index in Cardiac surgery (IRIC), which outperforms other classical scores, is now available to surgeons. Personalization of treatment for cardiac surgery patients is needed.

Incidence Risk Level and Severity of Orthopedic Surgical Site Infection in Jordan

Background Orthopedic surgical site infections are higher in developing countries compared with developed countries. Purpose This study aimed to determine the following: incidence rate of infection, levels of risk of infection, the severity of orthopedic infection, and the relationship between risk level of and severity level of orthopedic infection. Methods The study used a prospective approach to collect data about orthopedic surgery patients through assessing their health status and reviewing their medical records and monitoring for the occurrence of surgical site infection within 90 days after the operation. A total of 286 patients met the eligibility criteria from 18 hospitals. The severity of wound infection was assessed using the Additional treatment, Serous discharge, Erythema, Purulent exudate, Separation of deep tissues, isolation of bacteria, and duration of inpatient Stay wound scoring scale, and the levels of risk were assessed using the National Nosocomial Infection Surveillance risk index score. Results The incidence rate of orthopedic surgical site infection was (n = 8; 2.8%). Five patients (62.5%) had a moderate-risk level of infection, and 2 patients (25%) had a high-risk level. Most patients (n = 278; 97.2%) had satisfactory healing level. Both risk levels and severity levels of orthopedic surgical site infection were significantly correlated with each other. Conclusion Appropriate risk level and severity level assessment tools should be used to aid in the assessment of orthopedic surgical site infection.

Preoperative oral antibiotic prophylaxis reduces Pseudomonas aeruginosa surgical site infections after elective colorectal surgery: a multicenter prospective cohort study

BackgroundHealthcare-associated infections caused by Pseudomonas aeruginosa are associated with poor outcomes. However, the role of P. aeruginosa in surgical site infections after colorectal surgery has not been evaluated. The aim of this study was to determine the predictive factors and outcomes of surgical site infections caused by P. aeruginosa after colorectal surgery, with special emphasis on the role of preoperative oral antibiotic prophylaxis.MethodsWe conducted an observational, multicenter, prospective cohort study of all patients undergoing elective colorectal surgery at 10 Spanish hospitals (2011–2014). A logistic regression model was used to identify predictive factors for P. aeruginosa surgical site infections.ResultsOut of 3701 patients, 669 (18.1%) developed surgical site infections, and 62 (9.3%) of these were due to P. aeruginosa. The following factors were found to differentiate between P. aeruginosa surgical site infections and those caused by other microorganisms: American Society of Anesthesiologists’ score III–IV (67.7% vs 45.5%, p = 0.001, odds ratio (OR) 2.5, 95% confidence interval (95% CI) 1.44–4.39), National Nosocomial Infections Surveillance risk index 1–2 (74.2% vs 44.2%, p < 0.001, OR 3.6, 95% CI 2.01–6.56), duration of surgery ≥75thpercentile (61.3% vs 41.4%, p = 0.003, OR 2.2, 95% CI 1.31–3.83) and oral antibiotic prophylaxis (17.7% vs 33.6%, p = 0.01, OR 0.4, 95% CI 0.21–0.83). Patients with P. aeruginosa surgical site infections were administered antibiotic treatment for a longer duration (median 17 days [interquartile range (IQR) 10–24] vs 13d [IQR 8–20], p = 0.015, OR 1.1, 95% CI 1.00–1.12), had a higher treatment failure rate (30.6% vs 20.8%, p = 0.07, OR 1.7, 95% CI 0.96–2.99), and longer hospitalization (median 22 days [IQR 15–42] vs 19d [IQR 12–28], p = 0.02, OR 1.1, 95% CI 1.00–1.17) than those with surgical site infections due to other microorganisms. Independent predictive factors associated with P. aeruginosa surgical site infections were the National Nosocomial Infections Surveillance risk index 1–2 (OR 2.3, 95% CI 1.03–5.40) and the use of oral antibiotic prophylaxis (OR 0.4, 95% CI 0.23–0.90).ConclusionsWe observed that surgical site infections due to P. aeruginosa are associated with a higher National Nosocomial Infections Surveillance risk index, poor outcomes, and lack of preoperative oral antibiotic prophylaxis. These findings can aid in establishing specific preventive measures and appropriate empirical antibiotic treatment.

Exploring an optimal risk adjustment model for public reporting of cesarean section surgical site infections.

Public report of surgical site infections (SSI) rates has been an important component of SSI reduction strategies, and risk adjustment is needed before SSI rates are publicly reported. Improving the risk adjustment model facilitates meaningful comparison in the public reporting of SSIs. This research aimed to explore an optimal risk adjustment model for the public reporting of cesarean section (CS) SSI. Information on 2506 cases of CS performed at T hospital, a tertiary general hospital located in the W City of H Province in China, from 01 January 2013 to 31 December 2014 was collected. The data were used to construct the multivariate risk adjustment models of CS SSI through logistic and Poisson stepwise regression. The c-index was used to compare the predictive power between the new logistic regression and the National Nosocomial Infections Surveillance (NNIS) risk index model. Pearson goodness-of-fit was determined to compare the goodness-of-fit between the new Poisson regression and the NNIS risk index model. The two new regression models were also compared. The logistic and Poisson regression models included two patient-related risk factors, namely, BMI (OR=1.085, P=0.006; RR=1.081, P=0.006) and ASA score (OR=1.522, P=0.044; RR=1.501, P=0.047). The c-index of the logistic regression model (0.628) was higher than that of the NNIS risk index model (0.600). The goodness-of-fit of the Poisson regression model (0.946) was better than that of the NNIS risk index model (0.851). The logistic and Poisson regression risk models are better than the NNIS risk index model, implying that a multifactorial risk adjustment model is needed for the public reporting of CS SSI. The advantage of logistic regression model is that the predictive power of model can be evaluated by c-index, however, Poisson regression may offer more advantages on model accuracy than logistic regression does when the infection rate decreases.

A prospective study of surgical site infection of orthopedic implant surgeries

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Surgical-site infection accounts for approximately 10% of all hospital-acquired infections, which are estimated to double the cost of care and result in an additional mean of 6.5 days of hospital stay. We did prospective study of surgical site infection of orthopaedic implant surgeries.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The aim of the study is to assess the clinical and microbiological outcome of 125 patients who had open reduction and internal fixation with implants and prosthesis at Southern Railway Hospital from January 2006 to January 2007, and its strength of association with major risk factors using univariate analysis. In our study, Patients were allocated in to three groups as NINS risk index group 0, 1 and 2 with risk factors as duration of surgery &amp;gt;2 hours and ASA class ≥3. Post-operative wound infection was diagnosed based on the criteria of Center of Disease Control and assessed for the period of 6 weeks using National Nosocomial Infections Surveillance Risk Index.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; There were 87 male and 38 females in the study. From 125 Patients, 13 patients had post-operative superficial surgical site infection and presented within 21 days of operation. The infection rate was 10.4%. Two Patients developed deep infection after 6 weeks of study. All the cases with superficial infection were followed at regular intervals, 11 cases resolved with regular dressing and antibiotics but 2 cases continued to discharge sinus up to 3 months.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; The study showed that the risk of infection rate increased significantly with ASA score, duration of surgery, obesity and NINS risk index. There was no significant association of infection rate with age, diabetes and smoking. &lt;/p&gt;

Epidemiology and Risk Factors Associated with Surgical Site Infection Following Thoracic Aortic Surgery

BackgroundSurgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs). SSI following surgery on thoracic aorta, such as mediastinis and infection of reconstructed vessel, is often critical, but its epidemiology has not been well described. This study aims to describe the epidemiology and assess risk factors associated with SSI following thoracic aortic surgery (TAS) in Japan, using a Japanese national database for HAIs.MethodsData on TAS performed between 2012 and 2014 were extracted from a national surveillance system for healthcare-associated infections, Japan Nosocomial Infections Surveillance (JANIS). Risk factors associated with SSI following TAS were assessed using multivariate logistic regression analysis.ResultsThe overall incidence of SSI following TAS was 4.1% (146/3,538). The proportion of incisional SSI and organ/space SSI was similar (71 and 75, respectively). Staphylococci were the major causative pathogens. Among the three traditional risk factors included in the National Nosocomial Infections Surveillance (NNIS) risk index, American Society of Anesthesiologists (ASA) score and wound class were insignificant in predicting SSI, leaving duration of operation the sole significant risk factor. Additional risk factors were identified, including emergency and male gender.ConclusionIncidence of SSI following TAS was substantial. Risk factors associated with SSI following TAS were identified. In order to accurately compare hospital performance regarding SSI following TAS, emergency and gender should be incorporated into risk adjustment model.Disclosures All authors: No reported disclosures.

Five-year decreased incidence of surgical site infections following gastrectomy and prosthetic joint replacement surgery through active surveillance by the Korean Nosocomial Infection Surveillance System

Surveillance of healthcare-associated infection has been associated with a reduction in surgical site infection (SSI). To evaluate the Korean Nosocomial Infection Surveillance System (KONIS) in order to assess its effects on SSI since it was introduced. SSI data after gastrectomy, total hip arthroplasty (THA), and total knee arthroplasty (TKA) between 2008 and 2012 were analysed. The pooled incidence of SSI was calculated for each year; the same analyses were also conducted from hospitals that had participated in KONIS for at least three consecutive years. Standardized SSI rates for each year were calculated by adjusting for SSI risk factors. SSI trends were analysed using the Cochran-Armitage test. The SSI rate following gastrectomy was 3.12% (522/16,918). There was a significant trend of decreased crude SSI rates over five years. This trend was also evident in analysis of hospitals that had participated for more than three years. The SSI rate for THA was 2.05% (157/7656), which decreased significantly from 2008 to 2012. The risk factors for SSI after THA included the National Nosocomial Infections Surveillance risk index, trauma, reoperation, and age (60-69 years). The SSI rate for TKA was 1.90% (152/7648), which also decreased significantly during a period of five years. However, the risk-adjusted analysis of SSI did not show a significant decrease for all surgical procedures. The SSI incidence of gastrectomy and prosthetic joint replacement declined over five years as a result of active surveillance by KONIS.

Risk Factors for Surgical Site Infection after Hip Arthroplasty: A Multicentric Study

The objective of this study is to answer three main questions: What is the risk of wound infection for patients undergoing hip arthroplasty? What are the main etiologicagents of surgical site infection (SSI)? What are the risk factors most associated with surgical site infection? Method: This was a multicentric, retrospective cohort study which analyzed data collected in five general hospitals in Belo Horizonte, Brazil, between the period of January 2009 and December 2013. The continuous parameters studied were age, length of hospital stay before surgery, duration of surgery, number of professionals at surgery and number of hospital admissions. Categorical variables were surgical wound classification (clean, clean contaminated, contaminated, dirty/infected), American Society of Anesthesiologists (ASA) score (I, II, III, IV, V), type of surgery (elective, emergency), general anesthesia (yes, no), prophylactic antibiotic (yes, no), trauma surgery (yes, no) and Nosocomial Infections Surveillance (NNIS) risk index (IRIC = 0, 1, 2, 3). Results: Estimated SSI risk was 3.2% (95% C.I. = 2.6% to 4.1%) and risk of osteomyelitis was 0.6% (95% C.I. = 0.4% to 1.1%). ASA score > 2, general anesthesia, length of hospital stay before surgery higher than four days, more than two professionals at surgical field and duration of surgery higher than five hours were risk factors for SSI after hip prosthesis (p p > 0.100). Each modified NNIS risk category increased the chance of a patient being infected by almost three times, when compared with the previous category (OR = 2.82; p = 0.011).

Surgical site infection surveillance in orthopedic patients in the Military Medical Academy, Belgrade.

Active surveillance is an important component of surgical site infection (SSI) reduction strategy. The aim of this study was to analyze and compare SSI surveillance data in orthopedic patients in the Military Medical Academy (MMA), Belgrade. A 4-year prospective cohort study was performed to identify the incidence rate and risk factors for SSI in orthopedic patients in the MMA, Belgrade. We collected data regarding patients characteristics, health care and micro-organisms isolated in SSI. The National Nosocomial Infection Surveillance (NNIS) risk index was subsequently calculated for each patient. The Centers for Disease Control and Prevention criteria were used for the diagnosis of SSI. Assessment of 3,867 patients after different orthopedic operations revealed SSI in 109 patients. The overall incidence rate of SSI was 2.8% with the decrease from 4.6% in 2007 to 1.6% in 2010. Using NNIS risk index for surgical procedures there were: 53.7% (2,077) patients with risk 0--the incidence rate of 1.4%; 38.9% (1,506) patients with risk 1--the incidence rate of 3.1%; 7.3% (281) patients with risk 2--the incidence rate of 11.7%; 0.1% (3) patients with risk 3--without infection within the risk. Multivariate logistic regression analysis identified 6 independent risk factors associated with SSI: contaninated or dirty wounds, smoking, preoperative infection, NNIS risk index, body mass index and the length of hospital stay. The results of our study are valuable confirmation of relations between risk factors and SSI in orthopedic patients. A decreasing incidence rate of SSI (from 4.6% to 1.6%) during a 4-year active surveillance approved its implementation as an important component of SSI reduction strategy.

Surgical Site Infection Rates and Risk Factors in Orthopedic Pediatric Patients in Madrid, Spain

The objective of the study is to study surgical site infection (SSI) rates and risk factors in a pediatric population. We conducted a prospective cohort study to estimate the SSI rate at a national pediatric referral center, covering all patients managed at the Orthopedic Surgery Department of the Niño Jesús Children's University Teaching Hospital from January 2010 through December 2012. Risk factors and antibiotic prophylaxis were monitored. A comparison between Spanish and US data was performed, with a breakdown by National Nosocomial Infection Surveillance risk indices. We also conducted a comparative study of SSI rates from 2010 to 2012 to assess the impact of the epidemiologic surveillance system. The study population of 1079 patients had a SSI rate of 2.8%. SSI rates were calculated for spinal fusion and other musculoskeletal procedures according to the National Nosocomial Infection Surveillance risk index. In the case of other musculoskeletal procedures, our SSI rates were 0.8 times lower than the overall Spanish rate, but higher than US rates for all risk categories. For spinal fusion procedures, our SSI rates were 1.2 times higher than the Spanish rates and 3.5 times higher than National Nosocomial Infection Surveillance rates. This latter finding should be interpreted with caution because it was based on a small sample. The multivariate analysis indicated that the only predictive factors of SSI were American Society of Anesthesiologists score and age. The surveillance program showed that for clean procedures, SSI incidence decreased from 4% in 2010 to 3.2% in 2011 and to 2.4% in 2012.

Development and Validation of a Risk-Stratification Score for Surgical Site Occurrence and Surgical Site Infection after Open Ventral Hernia Repair

Current risk-assessment tools for surgical site occurrence (SSO) and surgical site infection (SSI) are based on expert opinion or are not specific to open ventral hernia repairs. We aimed to develop a risk-assessment tool for SSO and SSI and compare its performance against existing risk-assessment tools in patients with open ventral hernia repair. A retrospective study of patients undergoing open ventral hernia repair (n = 888) was conducted at a single institution from 2000 through 2010. Rates of SSO and SSI were determined by chart review. Stepwise regression models were built to identify predictors of SSO and SSI and internally validated using bootstrapping. Odds ratios were converted to a point system and summed to create the Ventral Hernia Risk Score (VHRS) for SSO and SSI, respectively. Area under the receiver operating characteristic curve was used to compare the accuracy of the VHRS models against the National Nosocomial Infection Surveillance Risk Index, Ventral Hernia Working Group (VHWG) grade, and VHWG score. The rates of SSO and SSI were 33% and 22%, respectively. Factors associated with SSO included mesh implant, concomitant hernia repair, dissection of skin flaps, and wound class 4. Predictors of SSI included concomitant repair, dissection of skin flaps, American Society of Anesthesiologists class ≥ 3, wound class 4, and body mass index ≥ 40. The accuracy of the VHRS in predicting SSO and SSI exceeded National Nosocomial Infection Surveillance and VHWG grade, but was not better than VHWG score. The VHRS identified patients at increased risk for SSO/SSI more accurately than the National Nosocomial Infection Surveillance scores and VHWG grade, and can be used to guide clinical decisions and patient counseling.

Program and AbstractsThirty-third Annual Meeting of the Surgical Infection SocietyLas Vegas, NevadaApril 12–15, 2013

Program and AbstractsThirty-third Annual Meeting of the Surgical Infection SocietyLas Vegas, NevadaApril 12–15, 2013

Preliminary data from a surveillance study on surgical site infections and assessment of risk factors in a university hospital

Surgical site infections (SSIs) lead to substantial mortality, morbidity, and socioeconomic loss. To explore the rate of infections and risk factors for the development of infection in surgical units. Materials and methods: All patients (n = 1397) who underwent a surgical intervention and were hospitalized for >48 h in surgical units (except the ophthalmology unit) of Gaziantep University Medical Faculty Hospital between 17 March 2008 and 15 July 2008 were included in the study. The Center for Disease Control and Prevention criteria were used for identifying and diagnosing SSIs. Rate of SSI was calculated as the number of SSIs observed after every 100 surgical procedures. Potential risk factors for SSIs were evaluated by multivariate logistic regression model. Results: SSIs occurred in 131 (9.4%) of the 1397 patients during this period. SSIs extended length of stay by 12.8 days. In the multivariate logistic regression analysis, diabetes mellitus (OR: 2.660, CI: 1.389-5.093), use of surgical drains (OR: 3.706, CI: 1.910-7.191), perioperative transfusion (OR: 1.787, CI: 1.077-2.965), trauma (OR: 2.244, CI: 1032-4.880), reoperation (OR: 7.408, CI: 3.315-16.555), contaminated (OR: 3.291, CI: 1.433-7.556) or dirty-infected (OR: 3.451, CI: 1.888-6.310) wound types, and each point increase in the National Nosocomial Infection Surveillance (NNIS) risk index (OR: 7.499, CI: 4.336-12.967) were detected as independent risk factors for developing SSIs. Conclusion: In an effort to decrease SSI rate, risk factors should be determined and essential measures should be implemented regarding preventable factors. In this context, the excess transfusion of blood and blood products and unnecessary use of surgical drains should be avoided, and surgical drains should be removed as soon as possible. In addition, traditional wound classification and NNIS risk index may be used in the prediction of SSIs.