Microbiologic prediction of abdominal surgical wound infection

We compared two methods of estimating parietal bacterial contamination during abdominal operations. Duplicate swabs were taken from the subcutaneous tissues at the end of 817 operations; one was transported to the Department of Microbiology in Stuart's thioglycollate medium and the other immediately incubated in Robertson's cooked meat broth in the operating room suite and subsequently subcultured. The broth cultures revealed significantly more isolations of potentially pathogenic bacteria and more accurately predicted the likelihood of wound infection. In particular, when visceral cultures were positive, broth culture of wound swabs predicted a major wound infection rate of 0% when sterile, 4.8% when a single pathogenic species was cultured, and 10.1% when two or more were cultured. The corresponding figures for thioglycollate-transported swabs were 1.0%, 10.5%, and 12.9%. We conclude that broth cultures of parietal swabs allow accurate identification of patients at risk of infection from bacterial contamination of the wound during operation.     

Predictors of surgical site infection in dirty urological surgery

Objectives:   Risk factors for surgical site infection (SSI) following urologic dirty operations have not been clearly identified. This study was conducted to describe incidence, potential risk factors and common causative pathogens of the SSI in such operations.
Methods:   Medical records of patients who had undergone simple nephrectomy or lumbotomy for suppurative renal infection at our institutions from 1999 to 2006 were retrospectively evaluated. The following data were retrieved: presence of SSI, demographic data, laboratory findings, comorbidities, microbiological data, type of renal suppuration, type of urological surgery and antibiotic regimen. Risk factors for SSI were evaluated using the multiple logistic regression model.
Results:   Sixty-five patients (mean age 55.6 ± 13.1 years) were eligible for data analysis. In 20 of them (30.8%) a SSI was identified. The most common isolated pathogens were gram-negative bacteria. At univariate logistic regression analysis risk factors significantly associated with SSI included: presence of emphysematous infection, hypoalbuminemia, number of predisposing conditions, emergency operations, isolation of Enterobacteriaceae, positive pus culture. The use of trimethoprim/sulfamethoxazole was associated with a decreased risk for SSI. Multiple logistic model identified only the emergency operations and isolated Enterobacteriaceae as independent predictors of SSI (odds ratio [OR] = 11.1) (95% confidence interval [CI] = 3.0–40.8) and OR = 3.9 (1.0–14.8), respectively.
Conclusions:   Patients with suppurative renal infections are submitted to life-saving emergency surgery. Urological surgeons should keep in mind that this carries a high risk for subsequent SSI. Effective preventive measures in these circumstance cannot be identified. Further research in this area is necessary to clarify this issue.     

Absence of prophylactic antibiotics in minimum incision endoscopic urological surgery (MEUS) of adrenal and renal tumors

OBJECTIVE: Recently, some studies suggested that antimicrobial prophylactics (AMP) are not needed to prevent surgical site infection (SSI) for clean operations despite worldwide acceptance of AMP. However, appropriate use of AMP in urological surgery has not been fully studied. Herein, we report an attempt of gradual decrease of AMP to non-use of AMP in minimum incision endoscopic urological surgery (MEUS) of adrenal and renal tumors. MATERIALS AND METHODS: We investigated 95 consecutive patients who underwent 16 MEUS adrenalectomy and 79 MEUS radical and partial nephrectomy in our hospital. Patients were classified into the following three groups by means of prevention of SSI: the first step group received ampicillin sodium/sulbactam sodium 1.5 g i.v. 30 min before the operation; the second step group received a single 300 mg of levofloxacin orally 60 min before the operation; and the third step group received no AMP. Clinical backgrounds and incidences of SSI were compared among these three groups. RESULTS: The first, second and third step groups consisted of 31, 36 and 28 patients, respectively. There was no statistically significant difference among these groups in terms of clinical backgrounds including age, sex, body mass index, American Society of Anesthesiologists classification, National Nosocomial Infections Surveillance risk index, and type and length of operation. The first step group had one superficial SSI that healed without any non-specific treatment. None of the second and third step groups had superficial SSI. There was no case of deep surgical site or distant infection. CONCLUSION: AMP could be discarded in clean MEUS of adrenal and renal tumors without increasing the incidence of SSI.     

Impact of Perioperative Urinary Tract Infection on Surgical Site Infection in Patients Undergoing Primary Hip and Knee Arthroplasty

BackgroundThe literature lacks clear consensus regarding the association between postoperative urinary tract infection (UTI) and surgical site infection (SSI). Additionally, in contrast to preoperative asymptomatic bacteriuria, SSI risk in patients with preoperative UTI has been incompletely studied. Therefore, our goal was to determine the effect of perioperative UTI on SSI in patients undergoing primary hip and knee arthroplasty.MethodsUsing the National Surgical Quality Improvement Program database, all patients undergoing primary hip and knee arthroplasty were identified. Univariate and multivariate regressions, as well as propensity matching, were used to determine the independent risk of preoperative and postoperative UTI on SSI, reported as odds ratios (ORs) with 95% confidence intervals (CIs).ResultsPostoperative UTI significantly increased the risk for superficial wound infection (OR 2.147, 95% CI 1.622-2.842), deep periprosthetic joint infection (PJI) (OR 2.288, 95% CI 1.579-3.316), and all SSIs (superficial and deep) (OR 2.193, 95% CI 1.741-2.763) (all P < .001). Preoperative UTI was not associated with a significantly increased risk of superficial infection (P = .636), PJI (P = .330), or all SSIs (P = .284). Further analysis of UTI present at the time of surgery using propensity matching showed no increased risk of superficial infection (P = 1.000), PJI (P = .624), or SSI (P = .546).ConclusionPostoperative UTI was associated with SSI, reinforcing the need to minimize factors which predispose patients to the risk of UTI after surgery. The lack of association between preoperative UTI and SSI suggests that hip and knee arthroplasty can proceed without delay, although initiating antibiotic treatment is prudent and future prospective investigations are warranted.     

Clinical study of surgical site infection following portless endoscopic urological surgery (PLES)

We investigated the clinical risk factors and bacteriological examination for surgical site infection (SSI) in 144 portless endoscopic surgeries consisting of 66 clean and 78 clean-contaminated surgeries in urological diseases from April 2000 to December 2001. There were no cases of SSI in the clean surgeries. SSI occurred in 5 cases (3.5%) of clean-contaminated surgeries including total cystectomy and ileal conduit in 4 cases and total prostatectomy in 1 case. Multivariate statistical studies revealed that usage of ileum during operation and preoperative hypo-albuminemia were significant risk factors for SSI. Gram-negative rods and anaerobic bacteria were isolated from the operative wound in the total cystectomy and ileal conduit, suggesting that SSI in the operation with usage of the ileum was partially derived from contamination with endogenous bacteria, while, normal flora of the skin in the wound did not cause any post-operative SSI.     

Routine throat swabs in artificially ventilated patients: meaningful bacteriologic monitoring or a needless procedure?

Organisms colonizing the oropharynx of patients in the intensive care unit (ICU) play an important role in the development of nosocomial infection. Thus, routine throat swab specimens of ICU patients are recommended to screen for potential pathogens [20]. This investigation was designed to clarify the value of throat swabs taken in addition to tracheal aspirates, urine cultures, and wound swabs with regard to antibiotic therapy in patients with pneumonia and other infections. MATERIALS AND METHODS. A total 627 intubated patients were examined in a surgical ICU during a 12 month period. Pharyngeal swabs, tracheal aspirates, urine cultures, and-if necessary-swabs from wounds and drains were taken immediately after admission to the ICU and routinely thereafter three times each week. Definitions: Early onset pneumonia: pneumonia occurring within 4 days; late onset pneumonia: pneumonia occurring after the 4th day. Intra-abdominal infection: diffuse or localized peritonitis or abdominal abscess. Wound infection: soft-tissue or bone infection. Corresponding organisms: the same species of bacteria with the same sensitivity pattern (Table 1). RESULTS. Sixty-eight of the patients developed pneumonia. 37 had early onset pneumonia. In 22 of these patients, throat and tracheal specimens had been obtained 2-3 days before the pneumonia was diagnosed. In these specimens, the causative organisms for the subsequent pneumonia were isolated in the throat in 60% of cases and in tracheal secretions in 40% (Table 3). In 35 patients with late onset pneumonia, the causative bacteria were found in 66% of the cases in the throat swabs obtained 2-3 days before the diagnosis was made, in tracheal aspirates in 74% (Table 4). Throat swabs obtained at admission to the ICU from already infected patients or from patients who developed an infection were significantly more colonized with potentially pathogenic micro-organisms (Fig. 1). In 4 patients with early onset pneumonia the results of the throat swab cultures influenced antibiotic therapy, but none of the throat culture results influenced the therapy of the patients with late onset pneumonia or other infections (intra-abdominal infection, wound infection, urinary tract infection). CONCLUSIONS. The throat swab taken at admission may indicate patients at risk for infection. However, throat cultures taken routinely thereafter, parallel with tracheal aspirate cultures, do not provide additional information that is diagnostically or therapeutically helpful. Therefore, throat swab cultures are not necessary for routine bacteriological monitoring. For the prevention of colonization by local administration of antimicrobial agents, regular throat cultures are mandatory.     

Risk factors of surgical wound infection

Surgical Site Infection (SSI) continues to be a major source of morbidity following operative procedures. The aging of the population means that not only will the number of operations likely increase, but the National Nosocomial Infections Surveillance (NNIS) Risk Index, which standardizes the risk of SSI for an aging population, will be greater. The NNIS report for 1986-1996 described an SSI rate of 2.6% for all operations at the reporting hospitals. It seems likely that overall SSI rates are likely to be greater than reported. All surgical wounds are contaminated by bacteria, but only a minority actually demonstrate clinical infection. The SSI are the biological summation of several factors: the inoculum of bacteria introduced into the wound during the procedure, the unique virulence of contaminants, the microenvironment of each wound, and the integrity of the patients host defense mechanisms. Risk factors were studied in single and multivariate analyses. Although an SSI rate of zero may not be achievable, continued progress in understanding the biology of infection at the surgical site and consistent applications of proven methods of prevention will allow us to further reduce the frequency, cost, and morbidity associated with SSI.     

Urinary microbes and postoperative urinary tract infection risk in urogynecologic surgical patients

Introduction and hypothesis

Women have a 20% risk of developing a urinary tract infection (UTI) following urogynecologic surgery. This study assessed the association of postoperative UTI with bacteria in preoperative samples of catheterized urine.

Methods

Immediately before surgery, vaginal swabs, perineal swabs, and catheterized urine samples were collected, and the V4 region of the 16S ribosomal RNA (rRNA) gene was sequenced. The cohort was dichotomized in two ways: (1) standard day-of-surgery urine culture result (positive/negative), and (2) occurrence of postoperative UTI (positive/negative). Characteristics of bladder, vaginal, and perineal microbiomes were assessed to identify factors associated with postoperative UTI.

Results

Eighty-seven percent of the 104 surgical patients with pelvic organ prolapse/urinary incontinence (POP/UI) were white; mean age was 57 years. The most common genus was Lactobacillus, with a mean relative abundance of 39.91% in catheterized urine, 53.88% in vaginal swabs, and 30.28% in perineal swabs. Two distinct clusters, based on dispersion of catheterized urine (i.e., bladder) microbiomes, had highly significant (p?<?2.2–16) differences in age, microbes, and postoperative UTI risk. Postoperative UTI was most frequently associated with the bladder microbiome; microbes in adjacent pelvic floor niches also contributed to UTI risk. UTI risk was associated with depletion of Lactobacillus iners and enrichment of a diverse mixture of uropathogens.

Conclusions

Postoperative UTI risk appears to be associated with preoperative bladder microbiome composition, where an abundance of L. iners appears to protect against postoperative UTI.

     

Risk factors associated with surgical site infection in upper and lower gastrointestinal surgery

Purpose To assess the risk factors of surgical site infection (SSI) in gastrointestinal surgery. Methods Surgical site infection surveillance was conducted in 27 hospitals. Results The incidence of SSI in the 941 patients studied was 15.5%. The factors associated with SSI were body mass index (BMI), comorbidity, emergency procedures, wound classification, blood loss, the suture material used for intra-abdominal ligation, the method of subcutaneous incision, the frequency of glove changes, and the absence of subcutaneous sutures. In lower alimentary tract procedures, additional factors influencing the incidence of SSI were sex, smoking status, operating time, the suture material used for abdominal wound closure and seromuscular sutures, and the combined resection procedures. According to a multiple logistic regression analysis, the independent risk factors for SSI were as follows: the type of operation, blood loss, wound classification, emergency procedures, the frequency of glove changes, the use of subcutaneous sutures, combined resection procedures, and the material used for seromuscular suturing. Conclusion Strict asepsis and minimal blood loss were associated with a lower incidence of SSI following gastrointestinal surgery. The use of absorbable suture material may be involved in reducing the risk of SSI.     

Negative pressure wound therapy reduces surgical site infections

ObjectiveSurgical site infection (SSI) with lower extremity incisions represents a modifiable source of major morbidity. Our institutional bundled care protocol to decrease SSI includes optimization of perioperative risk factors, dedicated wound closure tray, and voluntary use of a closed surface negative pressure wound therapy (cNPWT) device applied over closed incisions in the operating room. This study examined the individual effect of cNPWT on SSI reduction and other perioperative outcomes.MethodsAll patients with lower extremity or infrainguinal incisions between January 2016 and December 2017 were prospectively identified and tracked for infectious complications. All patients were treated with the same perioperative care bundle to reduce SSI. cNPWT was applied over closed incisions at the discretion of the surgeon. The 90-day outcomes regarding SSI, return to operating room, death, and readmission were tracked. Univariate and multivariate analysis using binary logistic regression for factors associated with SSI was performed for patients with and without cNPWT devices, with P < .05 determined to be significant.ResultsThere were 504 patients included, 225 with cNPWT and 279 with standard dressings. Between the groups, there were no major differences in mean age, mean body mass index, perioperative transfusions, use of prosthetic, reoperative field, dialysis status, and presence of diabetes. There were significantly more women (39.6% vs 27.2% female; P < .01) and active smokers (47.1% vs 30.2%; P < .01) in the cNPWT group along with increased mean operative times (238.3 vs 189.0 minutes; P < .01). Univariate analysis revealed significantly fewer SSIs with cNPWT (9.8% vs 19.0% in standard dressings; P < .01) along with decreased perioperative mortality (5.8% vs 11.2%; P = .04). There were no differences in return to operating room (27.6% cNPWT vs 27.7% standard; P = .97) or readmissions (29.8% cNPWT vs 26.5%; P = .43), but more returns to the operating room were for wound-related problems in the standard dressings group (48.3% vs 26.2%; P < .01). Binary logistic regression using an SSI end point demonstrated that female sex increases SSI (odds ratio, 2.43; confidence interval, 1.37-4.30; P < .01), whereas cNPWT reduces SSI (odds ratio, 0.32; confidence interval, 0.17-0.63; P < .01).ConclusionsThe use of negative pressure wound therapy devices decreases the incidence of infrainguinal wound infections. This occurs as an independent factor as part of a patient care bundle targeting modifiable variables in perioperative care.     

Female radical cystectomy patients have a higher risk of surgical site infections

Introduction

Surgical site infections (SSI) are common after radical cystectomy. The objectives of this study were to evaluate if female sex is associated with postoperative SSI and if experiencing an SSI was associated with subsequent adverse events.

Prevention of surgical site infections

Surgical site infection (SSI) is a common and potentially preventable post-operative complication. It has significant implications in terms of morbidity, mortality, length of hospital stay, readmission rate, post-hospital care and cost. Awareness and modification of pertinent risk factors is an important part of decreasing the rate of SSI. Risk factors may be related to either the patient or the operation itself. Pre-operative patient preparation includes bathing, appropriate hair removal and screening and eradication of potential pathogens. Use of antibiotic prophylaxis is only indicated for clean surgery when a foreign body is introduced, but is standard for clean-contaminated and contaminated procedures, albeit with several important caveats. Many fundamental day-to-day theatre practices are chiefly aimed at reduction of surgical site infection including standardized attire, hygiene protocols, hand scrubbing, skin preparation and draping. Environmental factors such as positive pressure ventilation are also aimed at producing a sterile environment. Special mechanisms such as laminar flow are used in high-risk surgery such as major joint replacement. Large quantities of devitalized tissue or wound haematoma should be prevented and therefore good surgical technique is also essential. Finally appropriate post-operative wound care and patient education are also vital components in preventing potentially hazardous wound infections.     

Prospective Identification of Risk Factors for Wound Infection After Lower Extremity Oncologic Surgery

Background: Surgical site infections (SSI) are frequent causes of morbidity and mortality after orthopaedic oncologic procedures. This study was conducted to identify the surgical site infection rate following a lower extremity or pelvic procedure and assess the risk factors for acquiring SSI by direct observation of orthopaedic oncology patients wounds at a comprehensive cancer center.Methods: One hundred ten consecutive patients were prospectively studied. The surveillance of surgical site infections was carried out by a surgeon-trained nurse from the Infectious Disease Service. Nineteen variables were analyzed as risk factors.Results: The overall SSI rate was 13.6% (15 of 110). Excluding those patients with known preoperative infections, the SSI rate was 9.5% (10 of 105). Two statistically significant risk factors for surgical site infection in these patients emerged in the multivariate analysis: blood transfusion (P = .007) and obesity (P = .016). Procedure category was significant in univariate analysis only. Preoperative length of stay, length of procedure, prior adjuvant treatment (chemotherapy or radiotherapy), prior surgery, and use of an implant or allograft were not statistically significant risk factors for wound infection. Antibiotic usage patterns did not influence SSI rate.Conclusions: Blood transfusion and obesity should be considered individual risk factors for the development of wound infection in patients having orthopaedic oncologic procedures.     

Prophylactic postoperative measures to minimize surgical site infections in spine surgery: systematic review and evidence summary

BACKGROUND CONTEXTThere are three phases in prophylaxis of surgical site infections (SSI): preoperative, intraoperative and postoperative. There is lack of consensus and paucity of evidence with SSI prophylaxis in the postoperative period.PURPOSETo systematically evaluate the literature, and provide evidence-based summaries on postoperative measures for SSI prophylaxis in spine surgery.STUDY DESIGNSystematic review, meta-analysis, evidence synthesis.METHODSA systematic review conforming to PRIMSA guidelines was performed utilizing PubMed (MEDLINE), EMBASE, and the Cochrane Database from inception to January 2019. The GRADE approach was used for quality appraisal and synthesis of evidence. Six postoperative care domains with associated key questions were identified. Included studies were extracted into evidence tables, data synthesized quantitatively and qualitatively, and evidence appraised per GRADE approach.RESULTSForty-one studies (nine RCT, 32 cohort studies) were included. In the setting of preincisional antimicrobial prophylaxis (AMP) administration, use of postoperative AMP for SSI reduction has not been found to reduce rate of SSI in lumbosacral spine surgery. Prolonged administration of AMP for more than 48 hours postoperatively does not seem to reduce the rate of SSI in decompression-only or lumbar spine fusion surgery. Utilization of wound drainage systems in lumbosacral spine and adolescent idiopathic scoliosis corrective surgery does not seem to alter the overall rate of SSI in spine surgery. Concomitant administration of AMP in the presence of a wound drain does not seem to reduce the overall rate of SSI, deep SSI, or superficial SSI in thoracolumbar fusion performed for degenerative and deformity spine pathologies, and in adolescent idiopathic scoliosis corrective surgery. Enhanced-recovery after surgery clinical pathways and infection-specific protocols do not seem to reduce rate of SSI in spine surgery. Insufficient evidence exists for other types of spine surgery not mentioned above, and also for non-AMP pharmacological measures, dressing type and duration, suture and staple management, and postoperative nutrition for SSI prophylaxis in spine surgery.CONCLUSIONSDespite the postoperative period being key in SSI prophylaxis, the literature is sparse and without consensus on optimum postoperative care for SSI prevention in spine surgery. The current best evidence is presented with its limitations. High quality studies addressing high risk cohorts such as the elderly, obese, and diabetic populations, and for traumatic and oncological indications are urgently required.     

Surgical site infections: reanalysis of risk factors

BACKGROUND: Surgical site infections (SSI) are the most common nosocomial infection in surgical patients, accounting for 38% of all such infections, and are a significant source of postoperative morbidity resulting in increased hospital length of stay and increased cost. During 1986-1996 the Center for Disease Control and Prevention's National Nosocomial Infections Surveillance system reported 15,523 SSI following 593,344 operations (2.6%). Previous studies have documented patient characteristics associated with an increased risk of SSI, including diabetes, tobacco or steroid use, obesity, malnutrition, and perioperative blood transfusion. In this study we sought to reevaluate risk factors for SSI in a large cohort of noncardiac surgical patients. METHODS: Prospective data (NSQIP) were collected on 5031 noncardiac surgical patients at the Veteran's Administration Maryland Healthcare System from 1995 to 2000. All preoperative risk factors were evaluated as independent predictors of surgical site infection. RESULTS: The mean age of the study cohort was 61 plus minus 13. SSI occurred in 162 patients, comprising 3.2% of the study cohort. Gram-positive organisms were the most common bacterial etiology. Multiple logistic regression analysis documented that diabetes (insulin- and non-insulin-dependent), low postoperative hematocrit, weight loss (within 6 months), and ascites were significantly associated with increased SSI. Tobacco use, steroid use, and chronic obstructive pulmonary disease (COPD) were not predictors for SSI. CONCLUSION: This study confirms that diabetes and malnutrition (defined as significant weight loss 6 months prior to surgery) are significant preoperative risk factors for SSI. Postoperative anemia is a significant risk factor for SSI. In contrast to prior analyses, this study has documented that tobacco use, steroid use, and COPD are not independent predictors of SSI. Future SSI studies should target early preoperative intervention and optimization of patients with diabetes and malnutrition.     

Prevalence of antimicrobial resistance in intestinal flora of patients undergoing prostatic biopsy: implications for prophylaxis and treatment of infections after biopsy

Study Type – Prevalence (non‐consecutive cohort)
Level of Evidence 3b OBJECTIVE To determine the prevalence of antimicrobial resistance in intestinal flora of patients undergoing transrectal ultrasonography (TRUS)‐guided prostate biopsies (TGB) and to examine if this information is useful in selecting appropriate antimicrobial agents for prophylaxis and treatment of biopsy‐associated infections. PATIENTS AND METHODS In 2007 and 2008, rectal swabs were cultured from patients before undergoing TGB. Antimicrobial sensitivity of coliforms to amikacin, ciprofloxacin and coamoxiclav was determined. Laboratory records were used to identify patients who had bacteraemia or significant bacteriuria within 30 days of the TGB and the antimicrobial sensitivity pattern of these organisms were compared to those from the rectal swab. RESULTS Of 592 patients who had TGB, 445 (75.1%) had a rectal swab beforehand; 0.2%,10.6% and 13.3% of the coliforms were resistant to amikacin, ciprofloxacin and coamoxiclav, respectively. After TGB, six patients presented with urinary tract infections (UTI) and two with bacteraemia. All the infections were caused by coliforms except one UTI which was caused by ciprofloxacin‐sensitive Pseudomonas aeruginosa. The blood culture isolates were sensitive to amikacin but resistant to ciprofloxacin and coamoxiclav. All the coliforms in the urine were resistant to ciprofloxacin but sensitive to coamoxiclav. Urine isolates were not tested for amikacin sensitivity. There was a strong correlation between the antimicrobial sensitivity of the coliforms from the rectal swabs and those cultured from urine or blood in both patients for amikacin, six of eight for ciprofloxacin and seven of eight for coamoxiclav. CONCLUSIONS Our study shows that in the coliforms in the bowel flora of our local population there is a relatively high level of resistance to ciprofloxacin and coamoxiclav, and very low level of resistance to amikacin. As there was a strong correlation between the antimicrobial sensitivity of organisms causing infections after TGB and those isolated from the rectal swabs, we conclude that rectal swab cultures before TGB provide useful evidence for selecting appropriate antimicrobials for prophylaxis and treatment of TGB‐associated 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.     

How Can We Control Intraoperative Bacterial Contamination and Surgical-Site Infection During an Anterior Resection or Hartmann’s/Miles’ Operation?

Purpose  Intraoperative bacterial contamination (IBC) is a major cause of surgical-site infection (SSI). Therefore, we investigated whether the ingenuity of surgical procedures could reduce the incidence of IBC/SSI. Methods  Sixty patients who were surgically treated for recto-sigmoid cancer were investigated. Among these patients, the colon was transected during the early perioperative period (ET) in 29 patients and during the late period (LT) in 31 patients. Three samples for IBC were obtained from the irrigation fluid before abdominal closure (LAVAGE), the remaining cut sutures after peritoneal closure (SUTURE), and a subcutaneous swab of the wound (SUBCUT). Results  The overall SSI and IBC rates were 25% and 55.2%, respectively. Patients who developed SSI had an extremely high IBC rate (85%), and IBC patients also had a high SSI rate (68%). IBC was highest in the LAVAGE (26%) followed by the SUBCUT (26%), and the SUTURE (12%). The incidence of IBC in the LT was significantly lower than that in the ET (19% vs. 55%, p < 0.01), although the incidence of SSI was similar in both IBC groups. Conclusion  Shortening the exposure of the colonic mucosa decreased the incidence of IBC/SSI; thus, careful operations to minimize IBC are recommended.     

A methodological, systematic review of evidence-based independent risk factors for surgical site infections after spinal surgery

Objective

To identify the independent risk factors, based on available evidence in the literature, for patients developing surgical site infections (SSI) after spinal surgery.

Methods

Non-interventional studies evaluating the independent risk factors for patients developing SSI following spinal surgery were searched in Medline, Embase, Sciencedirect and OVID. The quality of the included studies was assessed by a modified quality assessment tool that had been previously designed for observational studies. The effects of studies were combined with the study quality score using a best-evidence synthesis model.

Results

Thirty-six observational studies involving 2,439 patients with SSI after spinal surgery were identified. The included studies covered a wide range of indications and surgical procedures. These articles were published between 1998 and 2012. According to the quality assessment criteria for included studies, 15 studies were deemed to be high-quality studies, 5 were moderate-quality studies, and 16 were low-quality studies. A total of 46 independent factors were evaluated for risk of SSI. There was strong evidence for six factors, including obesity/BMI, longer operation times, diabetes, smoking, history of previous SSI and type of surgical procedure. We also identified 8 moderate-evidence, 31 limited-evidence and 1 conflicting-evidence factors.

Conclusion

Although there is no conclusive evidence for why postoperative SSI occurs, these data provide evidence to guide clinicians in admitting patients who will have spinal operations and to choose an optimal prophylactic strategy. Further research is still required to evaluate the effects of these above risk factors.     

Urinary tract infections in the surgical patient

Urinary tract infection (UTI) continues to be a common nosocomial infection. From a 2-year city-county hospital experience, 212 nosocomial UTI were identified in 153 patients from 3747 admissions. Mean age was 54 years; 102 were men. Foley catheterization was an associated factor in 129 patients (84%). UTI was caused by 40 different species of bacteria. In 28 infections (13%), the UTI was polymicrobial. Only nine patients had bacteremia. The bacteriology of the UTI depended on whether the patient had received systemic antibiotics previously during the hospitalization. Prior antibiotic administration increased the probability of Pseudomonas and Serratia as pathogens. Thus, patients that have had antibiotic therapy demonstrate a distribution of pathogens that are different from patients not receiving antibiotics, and a distribution different from the community-acquired UTI. Continued emphasis on the shorter duration and more judicious use of systemic antibiotics for both prophylaxis and therapy is warranted.