Surgical site infection (SSI) is the second most common infectious complication after urinary tract infection following a delivery by caesarean section (CS). At Bugando Medical Centre there has no study documenting the epidemiology of SSI after CS despite the large number of CSs performed and the relatively common occurrence of SSIs.
This was a prospective cohort study involving pregnant women who underwent a CS between October 2011 and February 2012 at Bugando Medical Centre. A total of 345 pregnant women were enrolled. Preoperative, intraoperative and postoperative data were collected using a standardized questionnaire. Wound specimens were collected and processed as per standard operative procedures; and susceptibility testing was carried out using a disc diffusion technique. Data was analyzed using STATA version 11.
The overall cumulative incidence of SSI was 10.9% with an incidence rate of 37.5 per 10,000 people/day (95% CI, 26.8-52.4). The median time from CS to the development of SSI was 7 days (interquartile range [IQR] = 6–9 days). Six independent risk factors for post caesarean SSI as identified in this study by multivariate analysis are: hypertensive disorders of pregnancy (HR: 2.5; 95% CI, 1.1-5.6; P = 0.021), severe anaemia (HR: 3.8; 95% CI, 1.2-12.4, P = 0.028), surgical wound class III (HR: 2.4; 95% CI, 1.1-5.0; P = 0.021), multiple vaginal examinations (HR: 2.5; 95% CI, 1.2-5.1; P = 0.011), prolonged duration of operation (HR: 2.6; 95% CI, 1.2-5.5; P = 0.015) and an operation performed by an intern or junior doctor (HR: 4.0; 95% CI, 1.7-9.2; P = 0.001). Staphylococcus aureus was the most common organism (27.3%), followed by Klebsiella pneumoniae (22.7%). Patients with a SSI had a longer average hospital stay than those without a SSI (12.7 ± 6.9 vs. 4 ± 1.7; P < 0.0001) and the case fatality rate among patients with a SSI was 2.9%.
SSIs are common among women undergoing CSs at Bugando Medical Centre. SSIs were commonly associated with multiple factors. Strategies to control these factors are urgently needed to control SSIs post CS at Bugando Medical Centre and other centres in developing countries.
Surgical site infections (SSIs), the second most common healthcare-associated infections, increase hospital stay and healthcare costs significantly. Traditional surveillance of SSIs is labor-intensive. Mandatory reporting and new non-payment policies for some SSIs increase the need for efficient and standardized surveillance methods. Computer algorithms using administrative, clinical, and laboratory data collected routinely have shown promise for complementing traditional surveillance.
Two computer algorithms were created to identify SSIs in inpatient admissions to an urban, academic tertiary-care hospital in 2007 using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes (Rule A) and laboratory culture data (Rule B). We calculated the number of SSIs identified by each rule and both rules combined and the percent agreement between the rules. In a subset analysis, the results of the rules were compared with those of traditional surveillance in patients who had undergone coronary artery bypass graft surgery (CABG).
Of the 28,956 index hospital admissions, 5,918 patients (20.4%) had at least one major surgical procedure. Among those and readmissions within 30 days, the ICD-9-CM-only rule identified 235 SSIs, the culture-only rule identified 287 SSIs; combined, the rules identified 426 SSIs, of which 96 were identified by both rules. Positive and negative agreement between the rules was 36.8% and 97.1%, respectively, with a kappa of 0.34 (95% confidence interval [CI] 0.27–0.41). In the subset analysis of patients who underwent CABG, of the 22 SSIs identified by traditional surveillance, Rule A identified 19 (86.4%) and Rule B identified 13 (59.1%) cases. Positive and negative agreement between Rules A and B within these “positive controls” was 81.3% and 50.0% with a kappa of 0.37 (95% CI 0.04–0.70).
Differences in the rates of SSI identified by computer algorithms depend on sources and inherent biases in electronic data. Different algorithms may be appropriate, depending on the purpose of case identification. Further research on the reliability and validity of these algorithms and the impact of changes in reimbursement on clinician practices and electronic reporting is suggested.
Surgical site infections (SSI) are a significant cause of post-surgical morbidity and mortality and can be an indicator of surgical quality. The objectives of this study were to measure post-operative SSI after cesarean section (CS) at four sites in three sub-Saharan African countries and to describe the associated risk factors in order to improved quality of care in low and middle income surgical programs.
This study included data from four emergency obstetric programs supported by Medecins sans Frontieres, from Burundi, the Democratic Republic of Congo (DRC), and Sierra Leone. Women undergoing from August 1 2010 to January 31 2011 were included. CS post-operative SSI data were prospectively collected. Logistic regression was used to model SSI risk factors.
In total, 1,276 women underwent CS. The incidence of SSI was 7.3 % (range 1.7–10.4 %). 93 % of SSI were superficial. The median length of stay of women without SSI was 7 days (range 3–63 days) compared to 21 days (range 5–51 days) in those with SSI (p < 0.001). In multivariate analysis, younger age, premature rupture of the membranes, and neonatal death were associated with an increased risk of SSI, while antenatal hemorrhage and the Lubutu, DRC project site were associated with a lower risk of developing an SSI.
This study demonstrates that surgery can be performed with a low incidence of SSI, a proxy for surgical safety, in sub-Saharan Africa. Protocols such as perioperative antibiotics and basic infrastructure such as clean water and sterilization can be achieved. Simple data collection tools will assist policymakers with monitoring and evaluation as well as quality control assurance of surgical programs in low and middle income countries.
Surgical site infections (SSI’s) are associated with severe morbidity, mortality and increased health care costs in vascular surgery.
To implement a bundle of care in vascular surgery and measure the effects on the overall and deep-SSI’s rates.
Prospective, quasi-experimental, cohort study.
A prospective surveillance for SSI’s after vascular surgery was performed in the Amphia hospital in Breda, from 2009 through 2011. A bundle developed by the Dutch hospital patient safety program (DHPSP) was introduced in 2009. The elements of the bundle were (1) perioperative normothermia, (2) hair removal before surgery, (3) the use of perioperative antibiotic prophylaxis and (4) discipline in the operating room. Bundle compliance was measured every 3 months in a random sample of surgical procedures and this was used for feedback.
Bundle compliance improved significantly from an average of 10% in 2009 to 60% in 2011. In total, 720 vascular procedures were performed during the study period and 75 (10.4%) SSI were observed. Deep SSI occurred in 25 (3.5%) patients. Patients with SSI’s (28,5±29.3 vs 10.8±11.3, p<0.001) and deep-SSI’s (48.3±39.4 vs 11.4±11.8, p<0.001) had a significantly longer length of hospital stay after surgery than patients without an infection. A significantly higher mortality was observed in patients who developed a deep SSI (Adjusted OR: 2.96, 95% confidence interval 1.32–6.63). Multivariate analysis showed a significant and independent decrease of the SSI-rate over time that paralleled the introduction of the bundle. The SSI-rate was 51% lower in 2011 compared to 2009.
The implementation of the bundle was associated with improved compliance over time and a 51% reduction of the SSI-rate in vascular procedures. The bundle did not require expensive or potentially harmful interventions and is therefore an important tool to improve patient safety and reduce SSI’s in patients undergoing vascular surgery.
Surgical site infections following breast surgery result in increased length of hospital stay, antibiotic utilization, and morbidity. Understanding SSI risk factors is essential to develop infection prevention strategies and improve surgical outcomes.
A retrospective case-control design was used to determine independent risk factors for surgical site infection in subjects selected from a cohort of patients who had mastectomy, breast reconstruction or reduction surgery between January 1998 and June 2002 at a tertiary-care university affiliated hospital. SSI cases within 1 year after surgery were identified using ICD-9-CM diagnosis codes for wound infection or complication and/or positive wound cultures. The medical records of 57 case patients with breast SSI and 268 randomly selected uninfected control patients were reviewed. Multivariate logistic regression was used to identify independent risk factors for SSI.
During the 4.5-year study period, 57 patients developed SSIs involving a breast incision and 10 patients developed SSIs involving a donor site incision. Significant independent risk factors for SSI involving the breast incision included insertion of a breast implant or tissue expander (odds ratio (OR) 5.3, 95% confidence interval (CI):2.5–11.1), suboptimal prophylactic antibiotic dosing (OR 5.1, 95% CI: 2.5–0.2 ), transfusion (OR 3.4, 95% CI: 1.3–9.0), mastectomy (OR 3.3, 95% CI: 1.4–7.7), previous chest irradiation (OR 2.8, 95% CI: 1.2–6.5), and current or recent smoking (OR 2.1, 95% CI: 0.9–4.9). Local infiltration of an anesthetic agent was associated with significantly reduced risk of SSI (OR 0.4, 95% CI: 0.1–0.9).
Suboptimal prophylactic antibiotic dosing is a potentially modifiable risk factor for SSI following breast surgery. Risk of SSI was increased in patients undergoing mastectomy and in patients who had an implant or tissue expander placed during surgery. Knowledge of these risk factors can be used to develop a specific risk stratification index to predict SSI in breast surgery and infection preventive strategies tailored for breast surgery patients.
To conduct a systematic literature review of the epidemiological and economic burden of surgical site infection (SSI) in Korea.
A search of the EMBASE, Medline and KoreaMed databases for English and Korean language publications was conducted. Searches for epidemiological and economic studies were conducted separately and limited to 1995 to 2010 to ensure the pertinence of the data.
Twenty-six studies were included. The overall incidence of SSI in Korea was 2.0 to 9.7%. The National Nosocomial Infections Surveillance risk index was positively correlated with the risk of developing an SSI. Specific risk factors for SSI, identified through multivariate analyses included; diabetes, antibiotic prophylaxis and wound classification. SSIs were associated with increased hospitalisation cost, with each episode of SSI estimated to cost about an additional ₩2,000,000. A substantial portion of the increased cost was attributed to hospital room costs and the need for additional medication. Studies also found that post-operative stays for patients with SSIs were 5 to 20 days longer, while two studies reported that following cardiac surgery, patients with SSIs spent an additional 5 to 11 days in the intensive care unit, compared to patients without SSIs.
Data from the included studies demonstrate that SSI represents a significant clinical and economic burden in Korea. Consequently, the identification of high-risk patient populations and the development of strategies aimed at reducing SSI may lead to cost-savings for the healthcare system.
Surgical site infection; Epidemiology; Cost
Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of invasive surgical site infection (SSI) in the USA. Antimicrobial prophylaxis for SSI typically includes a cephalosporin. Vancomycin is used to provide MRSA coverage, but administration timing is challenging. Linezolid is an attractive agent for SSI prophylaxis, particularly for the prevention of SSI due to MRSA.
We developed a decision-analytic model to evaluate linezolid use for cardiothoracic SSI prophylaxis. A theoretical cohort of 10,000 cardiothoracic surgery patients was followed through 2 stages: 1) occurrence of SSI, and 2) mortality after SSI. All patients were administered cefuroxime, vancomycin, or linezolid between 1–180 minutes prior to surgical incision. SSIs were categorized into three pathogen categories: 1) methicillin-susceptible Gram-positive, 2) methicillin-resistant Gram-positive, and 3) other organisms. The most effective strategy resulted in the fewest SSIs. Assumptions for antibiotic effectiveness, impact of administration time, and pathogens were based on the published literature.
Compared with cefuroxime, there was a 1% increase in the total number of SSIs in the linezolid group (mean SSI increase = 7), while there was a 12% increase in the vancomycin group (mean SSI increase = 86). Linezolid prophylaxis resulted in fewer SSIs due to methicillin-resistant Gram-positive infections (n=108) compared with cefuroxime (n = 200, 46% reduction in the linezolid group) and vancomycin (n = 119, 9% reduction in the linezolid group).
This simulation indicates that linezolid may offer benefits for SSI prophylaxis over existing prophylactic agents, particularly for the prevention of SSI due to Gram-positive methicillin-resistant pathogens.
Surgical site infection; prophylaxis; decision-analytic model; linezolid; vancomycin
Information regarding antimicrobial prophylaxis (AMP) for gastric cancer surgery is limited. The present study investigated the efficacy of single-dose AMP for the prevention of surgical site infection (SSI) in patients undergoing gastrectomy for gastric carcinoma.
Materials and Methods
Between 2011 and 2013, 1,330 gastric carcinoma surgery patients were divided into two AMP administration groups depending on the duration of treatment. Postoperative outcomes including morbidity and SSI were compared between the two groups overall and in matched patients. Risk factors for SSI were analyzed.
The extended group (n=1,129) received AMP until postoperative day 1 and the single-dose group (n=201) received singledose AMP only during an operation. Postoperatively, there were no significant differences between the two groups with respect to overall morbidity, mortality, or length of hospital stay. The SSI rate of the single-dose group was not significantly different from that of the extended group overall (4.5% vs. 5.5%, respectively, P=0.556) or in matched patients (4.5% vs. 4.0%, respectively, P=0.801). There was no increase in the SSI rate of the single-dose group compared to the extended group in subgroups based on different clinicopathological and operative factors. Univariate and multivariate analyses revealed male gender, open surgery, and operating time (≥180 minutes) as independent risk factors for SSI.
Single-dose AMP showed no increase in the postoperative SSI rate compared to postoperative extended use in patients undergoing gastrectomy for gastric carcinoma. The efficacy of single-dose AMP requires further investigation in randomized clinical trials specific to gastric cancer surgery.
Antibiotic prophylaxis; Surgical wound infection; Stomach neoplasms
Surgical site infections (SSI) remain a major clinical problem in terms of morbidity, mortality, and hospital costs. Nearly 60% of SSI diagnosis occur in the postdischarge period. However, literature provides little information on risk factors associated to in-hospital and postdischarge SSI occurrence. A national prospective multicenter study was conducted with the aim of assessing the incidence of both in-hospital and postdisharge SSI, and the associated risk factors.
In 2002, a one-month, prospective national multicenter surveillance study was conducted in General and Gynecological units of 48 Italian hospitals. Case ascertainment of SSI was carried out using standardized surveillance methodology. To assess potential risk factors for SSI we used a conditional logistic regression model. We also reported the odds ratios of in-hospital and postdischarge SSI.
SSI occurred in 241 (5.2%) of 4,665 patients, of which 148 (61.4%) during in-hospital, and 93 (38.6%) during postdischarge period. Of 93 postdischarge SSI, sixty-two (66.7%) and 31 (33.3%) were detected through telephone interview and questionnaire survey, respectively. Higher SSI incidence rates were observed in colon surgery (18.9%), gastric surgery (13.6%), and appendectomy (8.6%). If considering risk factors for SSI, at multivariate analysis we found that emergency interventions, NNIS risk score, pre-operative hospital stay, and use of drains were significantly associated with SSI occurrence. Moreover, risk factors for total SSI were also associated to in-hospital SSI. Additionally, only NNIS, pre-operative hospital stay, use of drains, and antibiotic prophylaxis were associated with postdischarge SSI.
Our study provided information on risk factors for SSI in a large population in general surgery setting in Italy. Standardized postdischarge surveillance detected 38.6% of all SSI. We also compared risk factors for in-hospital and postdischarge SSI, thus providing additional information to that of the current available literature. Finally, a large amount of postdischarge SSI were detected through telephone interview. The evaluation of the cost-effectiveness of the telephone interview as a postdischarge surveillance method could be an issue for further research.
Background: The present study was conducted to establish the patterns and risk factors of surgical site infections in our institution between 2006 and 2011.
Methods: This was a retrospective cross-sectional study. The surgical site infection (SSI) was identified based on the presence of ICD-10-CM diagnostic code in hospital discharge records. By using a standardized data collection form predictor variables including patient characteristics, preoperative, intra-operative and postoperative data were obtained.
Results: Ninety five patients fulfilled the inclusion criteria. The patients were admitted for various procedures including both elective (62.1%) and emergency (37.9%) operations. Colectomy (13.7%) was the leading procedure followed by umbilical herniation (12.6) and appendix perforation (12.6%). The mean age was 47.13 years with standard deviation of 19.60 years. Twenty percent were addicted to opium. Midline incision above and below the umbilicus (40%) had the highest prevalence of infection. Most patients (46.3%) had cleancontaminated
wounds and 30.5% had contaminated one. The quantitative variables which were also measured include duration of surgery, pre-operative and post-operative hospital stay with the mean of 2.9±1.45 hours,
1.02±1.42 and 7.75±6.75 days respectively. The most antibiotics prescribed post-operatively were the combination of ceftriaxone and metronidazole (51.6%).
Conclusion: The contaminated and clean-contaminated wounds are associated with higher rate of SSIs. Also, there was a converse relation between length of surgical incision and rate of SSIs. In overall, we found type of surgery as the main risk factor in developing the SSIs.
Risk factor; Surgical Wound Infection; Contamination; International Classification of Diseases
Diabetes mellitus (DM) is known as an important risk factor for surgical site infection (SSI) in spine surgery. It is still unclear however which DM-related parameters have stronger influence on SSI. The purpose of this study is to determine predisposing factors for SSI following spinal instrumentation surgery for patients with DM.
110 DM patients (66 males and 44 females) who underwent spinal instrumentation surgery in one institute were enrolled in this study. For each patient, various preoperative or intraoperative parameters were reviewed from medical records. Patients were divided into two groups (SSI or non-SSI) based on the postoperative course. Each parameter between these two groups was compared. Univariate and multivariate analyses were performed to determine predisposing factor for SSI.
The SSI group consisted of 11 patients (10 %), and the non-SSI group of 99 patients (90 %). Univariate analysis revealed that preoperative proteinuria (p = 0.01), operation time (p = 0.04) and estimated blood loss (p = 0.02) were significantly higher in the SSI group compared to the non-SSI group. Multivariate logistic regression identified preoperative proteinuria as a statistically significant predictor of SSI (OR 6.28, 95 % CI 1.58–25.0, p = 0.009).
Proteinuria is a significant predisposing factor for SSI in spinal instrumentation surgery for DM patients. DM patients with proteinuria who are likely to suffer latent nephropathy have a potential risk for SSI. For them less invasive surgery is recommended for spinal instrumentation. In this retrospective study, there was no significant difference of preoperative condition in glycemic control between the two groups.
Spinal instrumentation surgery; Surgical site infection; Diabetes mellitus; Proteinuria; Microvascular disease; Diabetic nephropathy
Surgical site infection (SSI) surveillance is a key factor in the elaboration of strategies to reduce SSI occurrence and in providing surgeons with appropriate data feedback (risk indicators, clinical prediction rule).
To improve the predictive performance of an individual-based SSI risk model by considering a multilevel hierarchical structure.
Patients and Methods
Data were collected anonymously by the French SSI active surveillance system in 2011. An SSI diagnosis was made by the surgical teams and infection control practitioners following standardized criteria. A random 20% sample comprising 151 hospitals, 502 wards and 62280 patients was used. Three-level (patient, ward, hospital) hierarchical logistic regression models were initially performed. Parameters were estimated using the simulation-based Markov Chain Monte Carlo procedure.
A total of 623 SSI were diagnosed (1%). The hospital level was discarded from the analysis as it did not contribute to variability of SSI occurrence (p = 0.32). Established individual risk factors (patient history, surgical procedure and hospitalization characteristics) were identified. A significant heterogeneity in SSI occurrence between wards was found (median odds ratio [MOR] 3.59, 95% credibility interval [CI] 3.03 to 4.33) after adjusting for patient-level variables. The effects of the follow-up duration varied between wards (p<10−9), with an increased heterogeneity when follow-up was <15 days (MOR 6.92, 95% CI 5.31 to 9.07]). The final two-level model significantly improved the discriminative accuracy compared to the single level reference model (p<10−9), with an area under the ROC curve of 0.84.
This study sheds new light on the respective contribution of patient-, ward- and hospital-levels to SSI occurrence and demonstrates the significant impact of the ward level over and above risk factors present at patient level (i.e., independently from patient case-mix).
To describe the epidemiology of surgical-site infections (SSIs) in community hospitals and to explore the impact of depth of SSI, healthcare location at the time of diagnosis, and variations in surveillance practices on the overall rate of SSI.
Retrospective cohort study.
Thirty-seven community hospitals in the southeastern United States.
Consecutive sample of patients undergoing surgical procedures between July 1, 2007, and December 31, 2008.
ANOVA was used to compare rates of SSIs, and the F test was used to compare the distribution of rates of SSIs. Wilcoxon rank-sum was used to test for differences in performance rankings of hospitals.
Following 177,706 surgical procedures, 1,919 SSIs were identified (incidence, 1.08 per 100 procedures). Sixty-four percent (1,223 of 1,919) of these were identified as complex SSIs; 87% of the complex SSIs were diagnosed in inpatient settings. The median proportion of superficial-incisional SSIs was 37% (interquartile range, 29.6%–49.5%). Postdischarge SSI surveillance was variable, with 58% of responding hospitals using surgeon letters. As reporting focus was narrowed from all SSIs to complex SSIs (incidence, 0.69 per 100 procedures) and, finally, to complex SSIs diagnosed in the inpatient setting (incidence, 0.51 per 100 procedures), variance in rates changed significantly (P =.02). Performance ranking of individual hospitals, based on rates of SSIs, differed significantly, depending on the reporting method utilized (P =.0006).
Inconsistent reporting methods focused on variable depths of infection and healthcare location at time of diagnosis significantly impact rates of SSI, distribution of rates of SSI, and hospital comparative-performance rankings. We believe that public reporting of SSI rates should be limited to complex SSIs diagnosed in the inpatient setting.
The aim of this study was to determine the incidence of surgical site infections (SSI) in patients undergoing a Caesarean section (CS) and to identify risk factors, common bacterial pathogens and antibiotic sensitivity. SSI significantly affect the patient’s quality of life by increasing morbidity and extending hospital stays.
A retrospective cross-sectional study was conducted in Nizwa Hospital, Oman, to determine the incidence of post-Caesarean (PCS) SSI from 2001 to 2012. This was followed by a case-control study of 211 PCS cases with SSI. Controls (220) were randomly selected cases, at the same hospital in the same time period, who had undergone CS without any SSI. Data was collected on CS type, risk factors, demographic profile, type of organism, drug sensitivity and date of infection.
The total number of PCS wound infections was 211 (2.66%). There was a four-fold higher incidence of premature rupture of the membranes (37, 17.53%) and a three-fold higher incidence of diabetes (32, 15.16%) in the PCS cases compared with controls. The most common organisms responsible for SSI were Staphylococcus aureus (66, 31.27%) and the Gram-negative Escherichia coli group (40, 18.95%). The most sensitive antibiotics were aminoglycoside and cephalosporin. Polymicrobial infections were noted in 42 (19.90%), while 47 (22.27%) yielded no growth. A high incidence of associated risk factors like obesity, hypertension, anaemia and wound haematoma was noted.
Measures are recommended to reduce the incidence of SSI, including the implementation of infection prevention practices and the administration of antibiotic prophylaxis with rigorous surgical techniques.
Caesarean Section; Surgical Wound Infections; Wounds and Injuries; Antibiotics; Risk Factors; Nosocomial Infections; Oman
Surgical site infection (SSI) complicates 2-5% of surgeries in the United States. Severity of SSI ranges from superficial skin infection to life-threatening conditions such as severe sepsis, and SSIs are responsible for increased morbidity, mortality, and economic burden associated with surgery. Staphylococcus aureus (S. aureus) is a commonly-isolated organism for SSI, and methicillin-resistant S. aureus SSI incidence is increasing globally.
The objective of this systematic review was to characterize risk factors for SSI within observational studies describing incidence of SSI in a real-world setting.
An initial search identified 328 titles published in 2002-2012; 57 were identified as relevant for data extraction. Extracted information included study design and methodology, reported cumulative incidence and post-surgical time until onset of SSI, and odds ratios and associated variability for all factors considered in univariate and/or multivariable analyses.
Median SSI incidence was 3.7%, ranging from 0.1% to 50.4%. Incidence of overall SSI and S. aureus SSI were both highest in tumor-related and transplant surgeries. Median time until SSI onset was 17.0 days, with longer time-to-onset for orthopedic and transplant surgeries. Risk factors consistently identified as associated with SSI included co-morbidities, advanced age, risk indices, patient frailty, and surgery complexity. Thirteen studies considered diabetes as a risk factor in multivariable analysis; 85% found a significant association with SSI, with odds ratios ranging from 1.5-24.3. Longer surgeries were associated with increased SSI risk, with a median odds ratio of 2.3 across 11 studies reporting significant results.
Conclusions and Relevance
In a broad review of published literature, risk factors for SSI were characterized as describing reduced fitness, patient frailty, surgery duration, and complexity. Recognition of risk factors frequently associated with SSI allows for identification of such patients with the greatest need for optimal preventive measures to be identified and pre-treatment prior to surgery.
Methicillin-resistant Staphylococcus aureus (MRSA) has become a common surgical site infection (SSI) pathogen, particularly in older adults. Risk factors for MRSA SSI in elderly patients have not been described.
A nested case–control study was conducted. Patients were enrolled from seven study hospitals (one medical center and six community hospitals) between January 1, 1998, and April 1, 2003. Risk factors for MRSA SSI were identified by comparing cases with two reference groups: uninfected surgical patients and patients with SSI due to methicillin-susceptible S. aureus (MSSA). Two separate multivariate models were created using logistic regression and then compared and contrasted.
Eighty-six patients with MRSA and 64 with MSSA SSI were identified. One hundred sixty-seven uninfected surgical patients were selected. In multivariate analysis using uninfected surgical patients as controls, requiring assistance in three or more activities of daily living (ADLs) was an independent risk factor for MRSA SSI (odds ratio (OR) = 2.73, 95% confidence interval (CI) = 1.16–6.46). Using patients with MSSA SSIs as a reference group, requiring assistance in three or more ADLs was also a significant predictor for MRSA SSI (OR = 3.78, 95% CI = 1.43–9.98) in multivariate analysis. Other independent predictors included Charlson score, wound class, and surgical duration. Lack of independence in ADLs was an independent risk factor for MRSA SSI in elderly patients in both models.
Poor functional status (requiring assistance in ≥3 ADLs) was specifically associated with MRSA SSI. Functional status is an objective, readily available variable that can be used to stratify patients at risk for MRSA SSI.
MRSA; surgical site infection; elderly
Surgical site infection (SSI) can be a challenging complication after posterior spinal fusion and instrumentation (PSFI). An increasing rate of SSI by gram-negative bacteria (GNB) has been observed. Current guideline recommendations have not been effective for preventing infection by these microorganisms.
Retrospective cohort study comparing two consecutive groups of patients undergoing PSFI at a single institution. Cohort A includes 236 patients, operated between January 2006 and March 2007, receiving standard preoperative antibiotic prophylaxis with cefazolin (clindamycin in allergic patients). Cohort B includes 223 patients operated between January and December 2009, receiving individualized antibiotic prophylaxis and treatment based on preoperative urine culture. Cultures were done 3–5 days before surgery in patients meeting one of the following risk criteria for urinary tract colonization: hospitalization longer than 7 days, indwelling catheter, neurogenic bladder, history of urinary incontinence, or history of recurrent urinary tract infection.
Twenty-two (9.3%) patients in cohort A developed SSI, 68.2% due to GNB. 38 (17%) patients in cohort B were considered at risk for GNB colonization; preoperative urine culture was positive in 14 (36%). After adjusted antibiotic prophylaxis, 15 (6.27%) patients in cohort B developed SSI, 33.4% due to GNB. A statistically significant reduction in GNB SSI was seen in cohort B (Fisher’s exact test, p = 0.039).
Higher preoperative GNB colonization rates were found in patients with neurogenic bladder or indwelling catheters. Preoperative bacteriological screening, treatment for bacteriuria, and individualized antibiotic prophylaxis were effective for reducing GNB SSI.
Antibiotic prophylaxis; Surgical site infection; Gram-negative bacteria; Urinary tract infection; Spine surgery
To evaluate the association between stress-induced hyperglycemia and infectious complications in non-diabetic orthopaedic trauma patients admitted to the Intensive Care Unit (ICU).
Academic Level-1 Trauma Center.
One hundred and eighty-seven consecutive trauma patients with isolated orthopaedic injuries.
Blood glucose values during initial hospitalization were evaluated. The admission blood glucose (BG) and Hyperglycemic Index (HGI) were determined for each patient.
Main Outcome Measures
Perioperative infectious complications: pneumonia, urinary tract infection (UTI), surgical-site infection (SSI), sepsis.
An average of 21.5 BG values was obtained for each patient. Mean ICU and hospital length of stay was 4.0±4.9 and 10.0±8.1 days, respectively. Infections were recorded in 43/187 patients (23.0%) and SSI’s specifically documented in 16 patients (8.6%). Open fractures were not associated with SSI (8/83, 9.6% vs. 8/104, 7.7%). There was no difference in admission BG or HGI and infection. However, there was a significant difference in HGI when considering SSI alone (2.1±1.7 vs. 1.2±1.1). Patients with an SSI received a greater amount of blood transfusions (14.9±12.1 vs. 4.9±7.6). No patient was diagnosed with a separate infection (i.e. pneumonia, UTI, bacteremia) prior to SSI. There was no significant difference in Injury Severity Score among patients with an SSI (11.1±4.0 vs. 9.6±3.0). Multivariable regression testing with HGI as a continuous variable demonstrated a significant relationship (OR: 1.8, 95% CI: 1.3–2.5) with SSI after adjusting for blood transfusions (OR: 1.1, 95% CI: 1.1–1.2).
Stress-induced hyperglycemia demonstrated a significant independent association with SSI’s in non-diabetic orthopaedic trauma patients who were admitted to the ICU.
hyperglycemia; orthopaedic trauma; surgical site infection; non-diabetic; intensive care unit
Analyses of risk factors associated with surgical site infections (SSIs) after laparoscopic appendectomy (LA) have been limited. Especially, the association of an underweight body mass index (BMI) with SSIs has not been clearly defined. This study aimed to identify the impact of underweight BMI in predicting SSIs after LA.
Materials and Methods
The records of a total of 101 consecutive patients aged ≥16 years who underwent LA by a single surgeon between March 2011 and December 2012 were retrieved from a prospectively collected database. The rate of SSIs was compared among the underweight, normal and overweight and obese groups. Also, univariate and multivariate analyses were performed to identify the factors associated with SSIs.
The overall rate of SSIs was 12.8%. The superficial incisional SSI rate was highest in the underweight group (44.4% in the underweight group, 11.0% in the normal group, and 0% in the overweight and obese group, p=0.006). In univariate analysis, open conversion and being underweight were determined to be risk factors for SSIs. Underweight BMI was also found to be a significant predictor for SSIs in multivariate analysis (odds ratio, 10.0; 95% confidence interval, 2.0-49.5; p=0.005).
This study demonstrated underweight BMI as being associated with SSIs after LA. Surgeons should be more cautious to prevent SSIs in patients that are underweight when performing LA.
Appendicitis; laparoscopic appendectomy; surgical site infection; body mass index; morbidity
Wound infections are a common complication of surgery that add significantly to the morbidity of patients and costs of treatment. The global trend towards reducing length of hospital stay post-surgery and the increase in day case surgery means that surgical site infections (SSI) will increasingly occur after hospital discharge. Surveillance of SSIs is important because rates of SSI are viewed as a measure of hospital performance, however accurate detection of SSIs post-hospital discharge is not straightforward.
We conducted a systematic review of methods of post discharge surveillance for surgical wound infection and undertook a national audit of methods of post-discharge surveillance for surgical site infection currently used within United Kingdom NHS Trusts.
Seven reports of six comparative studies which examined the validity of post-discharge surveillance methods were located; these involved different comparisons and some had methodological limitations, making it difficult to identify an optimal method. Several studies evaluated automated screening of electronic records and found this to be a useful strategy for the identification of SSIs that occurred post discharge. The audit identified a wide range of relevant post-discharge surveillance programmes in England, Scotland and Wales and Northern Ireland; however, these programmes used varying approaches for which there is little supporting evidence of validity and/or reliability.
In order to establish robust methods of surveillance for those surgical site infections that occur post discharge, there is a need to develop a method of case ascertainment that is valid and reliable post discharge. Existing research has not identified a valid and reliable method. A standardised definition of wound infection (e.g. that of the Centres for Disease Control) should be used as a basis for developing a feasible, valid and reliable approach to defining post discharge SSI. At a local level, the method used to ascertain post discharge SSI will depend upon the purpose of the surveillance, the nature of available routine data and the resources available.
Surgical site infections (SSIs) are associated with significant morbidity, mortality, and resource utilization and are potentially preventable. Peri-operative hyperglycaemia has been associated with increased SSIs and previous recommendations have been to treat glucose levels above 200 mg/dL. However, recent studies have questioned the optimal glycaemic control regimen to prevent SSIs. Whether the benefits of strict or intensive glycaemic control with insulin infusion as compared to conventional management outweigh the risks remains controversial.
To summarise the evidence for the impact of glycaemic control in the peri-operative period on the incidence of surgical site infections, hypoglycaemia, level of glycaemic control, all-cause and infection-related mortality, and hospital length of stay and to investigate for differences of effect between different levels of glycaemic control.
A search strategy was developed to search the following databases: Cochrane Wounds Group Specialised Register (searched 25 March 2009), The Cochrane Central Register of Controlled Trials, The Cochrane Library 2009, Issue 1; Ovid MEDLINE (1950 to March Week 2 2009); Ovid EMBASE (1980 to 2009 Week 12) and EBSCO CINAHL (1982 to March Week 3 2009). The search was not limited by language or publication status.
Randomised controlled trials (RCTs) were eligible for inclusion if they evaluated two (or more) glycaemic control regimens in the peri-operative period (within one week pre-, intra-, and/or post-operative) and reported surgical site infections as an outcome.
Data collection and analysis
The standard method for conducting a systematic review in accordance with the Cochrane Wounds Group was used. Two review authors independently reviewed the results from the database searches and identified relevant studies. Two review authors extracted study data and outcomes from each study and reviewed each study for methodological quality. Any disagreement was resolved by discussion or by referral to a third review author.
Five RCTs met the pre-specified inclusion criteria for this review. No trials evaluated strict glycaemic control in the immediate pre-operative period or outside the intensive care unit. Due to heterogeneity in patient populations, peri-operative period, glycaemic target, route of insulin administration, and definitions of outcome measures, combination of the results of the five included trials into a meta-analysis was not appropriate. The methodological quality of the trials was variable. In terms of outcomes, only one trial demonstrated a significant reduction in SSIs with strict glycaemic control, but the quality of this trial was difficult to assess as a result of poor reporting; furthermore the baseline rate of SSIs was high (30%). The other trials were either underpowered to detect a difference in SSIs, due to a low baseline rate (less than or equal to 5%), or did not report SSIs as a single outcome but as part of a composite. Of the three trials reporting hypoglycaemia (which was not consistently defined) all had a higher rate in the strict glycaemic control group but none attributed significant morbidity to the hypoglycaemia. Adequacy of glucose control between groups was measured differently among studies. Studies could not be compared due to differences in target ranges, and were susceptible to measurement bias due to differences in frequency of measurement and lack of blinding by the providers following the glycaemic protocols. Infection-related mortality was not reported in any of the trials, and no trials demonstrated a significant difference in all-cause mortality. Length of hospital stay was significantly reduced in the strict glycaemic control groups in only one trial.
Hyperglycemia [complications; *prevention & control]; Hypoglycemic Agents [therapeutic use]; Insulin [therapeutic use]; Intraoperative Complications [prevention & control]; Perioperative Care; Postoperative Complications [prevention & control]; Randomized Controlled Trials as Topic; Surgical Wound Infection [etiology; *prevention & control]; Adult; Humans
The genetics of microbial pathogens have been extensively studied, but there has been little work on human genetic susceptibility to surgical site infection (SSI). We analyzed a large genealogical population database to study the familial contribution to SSI.
We analyzed 651 individuals with ICD-9 codes indicating presence of SSI. Matched hospital controls were randomly selected from the database based on birth year, sex and birthplace. The average relatedness of all possible pairs of cases, and separately of controls (x1000 sets) was compared empirically. The relative risk for SSI was estimated by comparing the number of observed affected individuals among the relatives of cases to the number of affected individuals observed among relatives of matched hospital controls. The Genealogical Index of Familiality test for patients with SSI showed significant excess relatedness (p< 0.010); this excess was still observed when close relationships were ignored (p=0.019). The RR for third-degree relatives of cases was significantly elevated (1.62, p = 0.029). The significant excess relatedness and the significantly elevated RR to distant relatives support a genetic predisposition to acquiring SSI.
surgical site infection; genetics; familiality; population database
Surgical site infection (SSI) are the third most frequently reported nosocomial infection, and the most common on surgical wards. HIV-infected patients may increase the possibility of developing SSI after surgery. There are few reported date on incidence and the preventive measures of SSI in HIV-infected patients. This study was to determine the incidence and the associated risk factors for SSI in HIV-infected patients. And we also explored the preventive measures.
A retrospective study of SSI was conducted in 242 HIV-infected patients including 17 patients who combined with hemophilia from October 2008 to September 2011 in Shanghai Public Health Clinical Center. SSI were classified according to Centers for Disease Control and Prevention (CDC) criteria and identified by bedside surveillance and post-discharge follow-up. Data were analyzed using SPSS 16.0 statistical software (SPSS Inc., Chicago, IL).
The SSI incidence rate was 47.5% (115 of 242); 38.4% incisional SSIs, 5.4% deep incisional SSIs and 3.7% organ/space SSIs. The SSI incidence rate was 37.9% in HIV-infected patients undergoing abdominal operation. Patients undergoing abdominal surgery with lower preoperative CD4 counts were more likely to develop SSIs. The incidence increased from 2.6% in clean wounds to 100% in dirty wounds. In the HIV-infected patients combined with hemophilia, the mean preoperative albumin and postoperative hemoglobin were found significantly lower than those in no-SSIs group (P<0.05).
SSI is frequent in HIV-infected patients. And suitable perioperative management may decrease the SSIs incidence rate of HIV-infected patients.
The optimal treatment of hyperglycemia in general surgical patients with type 2 diabetes mellitus is not known.
RESEARCH DESIGN AND METHODS
This randomized multicenter trial compared the safety and efficacy of a basal-bolus insulin regimen with glargine once daily and glulisine before meals (n = 104) to sliding scale regular insulin (SSI) four times daily (n = 107) in patients with type 2 diabetes mellitus undergoing general surgery. Outcomes included differences in daily blood glucose (BG) and a composite of postoperative complications including wound infection, pneumonia, bacteremia, and respiratory and acute renal failure.
The mean daily glucose concentration after the 1st day of basal-bolus insulin and SSI was 145 ± 32 mg/dL and 172 ± 47 mg/dL, respectively (P < 0.01). Glucose readings <140 mg/dL were recorded in 55% of patients in basal-bolus and 31% in the SSI group (P < 0.001). There were reductions with basal-bolus as compared with SSI in the composite outcome [24.3 and 8.6%; odds ratio 3.39 (95% CI 1.50–7.65); P = 0.003]. Glucose <70 mg/dL was reported in 23.1% of patients in the basal-bolus group and 4.7% in the SSI group (P < 0.001), but there were no significant differences in the frequency of BG <40 mg/dL between groups (P = 0.057).
Basal-bolus treatment with glargine once daily plus glulisine before meals improved glycemic control and reduced hospital complications compared with SSI in general surgery patients. Our study indicates that a basal-bolus insulin regimen is preferred over SSI in the hospital management of general surgery patients with type 2 diabetes.
Surveillance of surgical site infections (SSI) provides data upon which interventions to improve patient safety can be based. In Thailand, however, SSI surveillance has not yet been standardized.
To develop a standardized SSI surveillance system and to monitor SSI rates after introduction of such a system.
We conducted a prospective study among 17,752 patients who underwent surgery in ten hospitals in Thailand from April 2004 to May 2005. The SSI rates were computed and benchmarked with the US rates, reported in terms of standardized infection ratio (SIR). We estimated the incidence rate ratio of surgical site infections by comparing the incidence in the last study period with the incidence in the first study period.
The study included 17,869 operations and identified 248 SSIs, yielding an SSI rate of 1.4 infections/100 operations and a corresponding SIR of 0.6 (95% confidence interval [CI] = 0.5–0.7). During the study period the overall SSI rate decreased from 1.8 infections/100 operations to 1.2 infections/100 operations, yielding an incidence rate ratio of 0.65 (95% CI = 0.47–0.89).
Our study highlighted that a standardized SSI surveillance in a developing country can be initiated through a network and may be followed by a decrease in SSI rates.
surgical site infection; surveillance; network; Thailand