Reduction of periprosthetic Staphylococcus aureus infection by preoperative screening and decolonization of nasal carriers undergoing total knee arthroplasty

ObjectiveThe aim of this study was to evaluate whether the establishment of a preoperative screening and decolonization protocol for Staphylococcus aureus carriers undergoing total knee arthroplasty (TKA) could decrease the incidence of periprosthetic joint infection (PJI) caused by this microorganism.MethodsWe conducted a retrospective study comparing a control group comprising 400 patients (134 men, and 266 women; mean age: 72.2 ± 6.8 years) who went through surgery between January 2009 and December 2013, with a second intervention group of 403 patients (125 men, and 278 women; mean age: 72.4 ± 6.9 years) in which the protocol of screening and decolonization of S. aureus nasal carriers was applied between January 2014 and December 2016. During this latter period patients were preoperatively screened and, if positive, treated with mupirocin nasal ointment and chlorhexidine soap, for 5 days prior to surgery.ResultsIn the control group, 17 of 400 patients (4.2%) had a SSI, 8 (2%) of them caused by S. aureus and 9 (2.2%) by other microorganisms. In the intervention group 20.6% of patients had a positive S. aureus nasal swab and were treated according to the protocol. 5 of 403 patients (1.2%) in this group had a SSI, 1 (0.2%) due to S. aureus and 4 (1%) to other microorganisms. When comparing surgical-site infection (SSI) rates between the two groups, we found a statistically significant reduction in both global SSI (p = 0.009) and specifically S. aureus SSI (p = 0.02), in the intervention group. No decolonized S. aureus nasal carrier presented a SSI.DiscussionIn patients undergoing TKA a preoperative screening and decolonization protocol for S. aureus nasal carriers, using mupirocin nasal ointment and chlorhexidine soap, is an effective measure to reduce the rate of SSI caused by this microorganism.Level of EvidenceLevel III; Therapeutic Study.     

Lack of efficacy of mupirocin in the prevention of infections with Staphylococcus aureus in liver transplant recipients and candidates

BACKGROUND: Infections with Staphylococcus aureus are a significant problem in patients in liver transplant units. An association between prior nasal carriage with and subsequent infections has been documented previously in liver transplant recipients and patients with cirrhosis. However, the role of decolonization with mupirocin applied intranasally for the prevention of S. aureus infections in these patients has not been determined. METHODS: S. aureus nasal carriage was prospectively sought in 70 consecutive liver transplant candidates. Mupirocin two times per day for 5 days was administered to the carriers. Follow-up nasal cultures to document decolonization were performed 5 days after the final application of mupirocin. The primary endpoint was the development of S. aureus infections. RESULTS: Thirty-one of 70 patients (44%) were found to be nasal carriers and 27 of 31 nasal carriers (87%) were successfully decolonized. However, 12 of 27 patients (37%) successfully decolonized became recolonized with S. aureus, and an additional nine patients who were initially noncarriers became newly colonized with S. aureus during the study period. Despite the use of mupirocin, 16 of 70 patients (23%) developed an infection with S. aureus. No isolate was found to be mupirocin resistant. CONCLUSION: Elimination of S. aureus nasal carriage by mupirocin did not prevent S. aureus infections in patients in our liver transplant unit.     

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.     

Importance of methicillin-resistant Staphylococcus aureus eradication in carriers to prevent postoperative methicillin-resistant Staphylococcus aureus surgical site infection

Although infrequent, postoperative methicillin-resistant Staphylococcus aureus (MRSA) surgical site infection (SSI) is associated with significant morbidity and cost. Previous studies have identified the importance of MRSA screening to diminish the risk of postoperative MRSA SSI. The current study quantifies the importance of eradication of the MRSA carrier state to prevent MRSA SSI. Beginning February 2007, all admissions to an 800-bed tertiary care hospital were screened for MRSA by nasal swab using rapid polymerase chain reaction-based testing. Patients found to be nasal carriers of MRSA were treated with 2 per cent mupirocin nasal ointment and 4 per cent chlorhexidine soap before surgery. The subset of patients undergoing procedures that are part of the Surgical Care Improvement Project (SCIP) were followed for MRSA SSI (n = 8980). The results of preoperative MRSA screening and eradication of the carrier state were analyzed. Since the initiation of universal MRSA screening, 11 patients undergoing SCIP procedures have developed MRSA SSI (0.12%). Of these, six patients (55%) had negative preoperative screens. Of the five patients with positive preoperative screens, only one received treatment to eradicate the carrier state. In patients who develop MRSA SSI, failure to treat the carrier state before surgery results in MRSA SSI.     

The efficacy of intrawound vancomycin powder and povidone-iodine irrigation to prevent surgical site infections in complex instrumented spine surgery

BACKGROUND CONTEXTSurgical site infections (SSIs) are notorious complications in spinal surgery and cause substantial patient morbidity. Intraoperative decontamination of the wound with povidone-iodine irrigation or vancomycin powder has gained attention lately, but the efficacy of either intervention is unclear.PURPOSETo determine the efficacy of intrawound povidone-iodine or vancomycin in reducing the incidence of deep- and superficial SSIs in instrumented spinal surgery.STUDY DESIGN/SETTINGRetrospective cohort study.PATIENT SAMPLEA retrospective chart review was performed including all consecutive adult patients undergoing open, posterior, instrumented spinal surgery at any level between January 2012 and August 2017.OUTCOME MEASURESThe presence of SSI was evaluated according to the criteria published by the Centers for Disease Control and Prevention. The SSIs were divided into deep SSIs (below the muscular fascia) and superficial SSIs (above the muscular fascia).METHODSA retrospective cohort without intrawound treatment was compared with two separate, consecutive intervention groups. One intrawound group received 1.3g/L povidone-iodine irrigation and the other received 1-2 grams of intrawound vancomycin powder at the end of surgery. Incidence of SSIs, as well as demographic, surgical and patient-related variables were registered and compared between groups. In patients with SSI, additional microbiological data were collected.RESULTSIn total, 853 patients were included. In the control group (N=257), 25 (9.7%) patients developed a deep and 13 (5.1%) developed a superficial SSI. In the povidone-iodine group (N=217), 21 (9.7%) patients developed a deep and two (0.9%) developed a superficial SSI. Compared with the control group, there was no significant difference in the incidence of deep SSIs (risk ratio [RR]: 1.00, 95% CI 0.57–1.73), although the number of superficial SSIs was reduced significantly (RR 0.18, 95% CI 0.04–0.80). In the vancomycin group (N=379), 19 (5.0%) patients developed a deep and six (1.6%) developed a superficial SSI. Both deep (RR: 0.52, 95% CI 0.29–0.92) and superficial SSIs (RR: 0.31, 95% CI 0.12–0.81) were significantly reduced in the vancomycin group compared with the control group, even when correcting for several risk factors associated with SSIs in a multivariable logistic regression analysis. There were no significant differences in complications between the 3 groups. No gram-negative selection or vancomycin-resistance was seen in the vancomycin group.CONCLUSIONSIntrawound application of vancomycin was associated with a significant reduction in both deep and superficial SSIs in instrumented spinal surgery. A 1.3g/L intrawound povidone-iodine solution did not show a reduction in deep SSIs, although a reduction of superficial SSIs was observed.     

A randomised control trial using soap in the prevention of surgical site infection in Tanzania

BackgroundSurgical site infections (SSIs) are common and serious complications of surgery. Guidelines on preventing SSIs have been developed, but the role of preoperative bathing with plain soap among paediatric population is unclear. We aimed to assess the effectiveness of pre-operative bathing using plain soap in preventing SSIs among paediatric surgical patients.Materials and MethodsAn open-label, randomised trial was conducted at Muhimbili National Hospital in Tanzania. Preoperatively, patients in the intervention group washed their body using plain soap, while those in the control group did not. The primary outcome was SSI postoperatively. Statistical tests included χ2, Wilcoxon rank sum, and univariate and multivariable logistic regression.ResultsOf the 252 patients recruited,114 were randomised to the intervention arm. In the control arm, 40.6% (56/138) of participants developed SSIs compared to 11.4% (13/114) in the intervention arm (p < 0.01). After adjusting for confounding factors in multivariable analysis, the intervention reduced the odds of an SSI by 80% (OR: 0.20 [95% CI: 0.10, 0.41]; p < 0.01). Preoperative antibiotics were deemed to be an effect modifier of the association between the intervention and SSI (p = 0.05). The intervention significantly reduced the odds of an SSI by 88% among participants not given preoperative antibiotics (OR: 0.12 [95% CI: 0.05, 0.30]; p < 0.01).ConclusionThis study has shown that preoperative bathing with soap significantly reduces SSIs in paediatric surgical patients. It is a simple, cost effective and sustainable intervention.Level of EvidenceLevel II     

Preoperative screening/decolonization for Staphylococcus aureus to prevent orthopedic surgical site infection: prospective cohort study with 2-year follow-up

We quantified surgical site infections (SSIs) after preoperative screening/selective decolonization before elective total joint arthroplasty (TJA) with 2-year follow-up and 2 controls. Concurrent controls (n = 2284) were patients of surgeons not participating in screening/decolonization. Preintervention controls (n = 741) were patients of participating surgeons who underwent TJA the previous year. Staphylococcus aureus nasal carriers (321/1285 [25%]) used intranasal mupirocin and chlorhexidine baths as outpatients. Staphylococcal SSIs occurred in no intervention patients (0/321) and 19 concurrent controls. If all SSIs occurred in carriers and 25% of controls were carriers, staphylococcal SSI rate would have been 3.3% in controls (19/571; P = .001). Overall SSI rate decreased from 2.7% (20/741) in preintervention controls to 1.2% (17/1440) in intervention patients (P = .009). Preoperative screening/selective decolonization was associated with fewer SSIs after elective TJA.     

Staphylococcus aureus, the major pathogen in orthopaedic and cardiac surgical site infections: a literature review

Due to the increasing number of orthopaedic and cardiac procedures, these units are considered as high-risk areas because of the potentially serious consequences of surgical site infections (SSI), primarily caused by Staphylococcus aureus. The goal of this review was to evaluate the impact of S. aureus on the incidence of SSI in these high risk wards. Studies were identified by a search on the MEDLINE literature using the following mesh terms: S. aureus, cardiac, orthopaedic, surgery, SSI. Beside, data from different surveillance systems were also included. Overall, biological investigation was performed only on a small proportion of identified SSIs. Of those identified, S. aureus represented the most common pathogen accounting for approximately 20% of all SSIs. Of the 59,274 hip prostheses reported from the HELICS surveillance network, S. aureus formed 48.6% of the pathogens (416 bacteria isolated). Similarly, it represented 43.7% of pathogens after coronary artery bypass grafting. Although S. aureus turned out to be the major pathogen, this work identifies the relative lack of knowledge on the overall incidence of S. aureus infections and on the impact of this pathogenic agent when taking into consideration the degree of wound contamination and category of SSI. There is a need for more detailed information on the role of S. aureus in the burden of surgical site infections and consequently how to establish multiple approach prevention programs.     

Perioperative blood transfusion increases risk of surgical site infection after bariatric surgery

BackgroundSurgical site infection (SSI) is an important marker of postoperative morbidity and overall quality of care. Transfusion-related immunomodulation can lead to weakened immunity in response to blood transfusion and predispose patients to SSIs.ObjectivesThe aim of this study was to determine the impact of perioperative blood transfusions on SSIs in bariatric surgery patients.SettingNational data set.MethodsThe American College of Surgeons National Surgical Quality Improvement Program data sets were queried for laparoscopic and open bariatric operations between 2012 and 2014. Univariate analyses identified perioperative variables associated with postoperative SSIs. Multivariate regression analyses determined the effect of perioperative blood transfusions on postoperative SSI.ResultsThe study cohort included 59,424 patients: 480 (8.1%) biliopancreatic diversions, 28,268 (44.2%) gastric bypasses, 30,258 (50.9%) sleeve gastrectomies, and 418 (7.0%) bariatric revisions. Of the patients, 1107 (1.9%) developed a SSI: 662 (1.1%) superficial, 89 (0.1%) deep, and 356 (.6%) organ space. Patients receiving a perioperative blood transfusion were more likely to develop any type of SSI, organ space being most prevalent (Fig. 1). Among organ space SSIs, 198 (55.6%) were gastric bypasses and 125 (35.1%) were sleeve gastrectomies.ConclusionsBariatric surgery patients who receive a perioperative blood transfusion are at higher risk of developing SSIs, particularly organ space. The majority of organ space SSIs occur after gastric bypass, likely secondary to infected intra-abdominal hematomas. Close monitoring of postoperative signs of infection in these patients is important to determine if additional interventions are warranted.     

Seasonal variation in incidence and causal organism of surgical site infection after PLIF/TLIF surgery: A multicenter study

BackgroundPostoperative SSI is a common and potentially serious complication in spine surgery. Seasonal variation occurs in rates of nosocomial infection, with higher rates found in the summer, during which hot, humid conditions may be optimal for proliferation of bacteria. This might also influence the rate of SSI. The purpose of the study was to examine seasonal variation in SSI after PLIF/TLIF surgery, including relationships with experience of surgeons and causal organisms.MethodsCases with SSI after PLIF/TLIF surgery at 10 facilities between January 1, 2012, and December 31, 2014 were retrieved from a database. Infection was defined based on CDC guidelines for SSIs. Patients were followed for at least two years after surgery. Surgeries were examined in spring (April–June), summer (July–September), autumn (October–December), and winter (January–March). Seasonal variation and other factors with a potential association with SSIs were evaluated.ResultsA total of 1174 patients (607 males, 567 females) who underwent PLIF/TLIF surgery were identified. The operations were PLIF (n = 667), TLIF (n = 443), MIS-PLIF (n = 27), and MIS-TLIF (n = 37). The total SSI rate for the 2-year period was 2.5% (29/1174), and the 2-year average SSI rates for surgeries in each season were spring, 2.6% (7/266); summer, 3.9% (13/335); fall, 1.3% (4/302); winter, 1.8% (5/271). The SSI rate was significantly higher in summer than non-summer (3.9% vs. 1.9%, p < 0.05). SSIs were caused by a variety of pathogens, including Gram-positive cocci, and Staphylococcus aureus was the most common pathogenic organism to cause SSI.ConclusionSeasonality should be taken into account in strategies for SSI prevention, with particular attention on mitigation of increased temperature and humidity in the summer and on infection caused by Gram-positive cocci and S. aureus.     

Methicillin-resistant Staphylococcus aureus screening in total joint arthroplasty: a worthwhile endeavor

Infections with methicillin-resistant Staphylococcus aureus (MRSA) are an ever growing problem in the community, hospitals, and for orthopedic surgeons in particular. A conscious effort must be made to deal with this pathogen prior to total joint arthroplasty procedures. The drastic increase in prevalence of surgical-site infections (SSIs) after total joint replacement surgery has proved to be a major health care burden for both patients and surgeons from both a medical and financial standpoint. The development of screening techniques for detection of MRSA colonization in patients being admitted to hospitals is steadily increasing popularity. Particularly nasal swab rapid polymerase chain reaction detection of MRSA allows surgeons to identify patients at high risk for postoperative SSI. A variety of treatment regimens for eradication of MRSA colonization from the nares of surgical patients have surfaced, such as topical mupirocin prior to undergoing surgery. Decolonization of MRSA in patients undergoing joint arthroplasty procedures has demonstrated encouraging initial results in preventing SSIs and should be a serious focus of the future for orthopedic surgeons.     

Surgical site infection following elective orthopaedic surgeries in geriatric patients: Incidence and associated risk factors

The purposes of this study were to investigate the incidence of surgical site infection (SSI) following geriatric elective orthopaedic surgeries and identify the associated risk factors This was a retrospective two‐institution study. Between January 2014 and September 2017, patients aged 60 years or older undergoing elective orthopaedic surgeries were included for data collection and analysis. SSI was identified through the review of patients' medical records for the index surgery and through the readmission diagnosis of SSI. Patients' demographics, characteristics of disease, surgery‐related variables, and laboratory examination indexes were inquired and documented. Univariate and multivariate logistic analyses were performed to determine independent risk factors for SSI. There were 4818 patients undergoing elective orthopaedic surgeries, and within postoperative 1 year, 74 patients were identified to develop SSIs; therefore, the overall incidence of SSI was 3.64%, with 0.4% for deep and 1.1% for superficial infection. Staphylococcus aureus (25/47, 53.2%) and coagulase‐negative staphylococci (11/47, 23.4%) were the most common causative pathogens; half of S. aureus SSIs were caused by Methicillin‐resistant Staphylococcus aureus (MRSA) (12/25, 48.0%). Five risk factors were identified to be independently associated with SSI, including diabetes mellitus (odds ratio [OR], 3.7; 95% confidence interval [95% CI], 1.7‐5.6), morbid obesity (OR, 2.6; 95% CI, 1.3‐3.9), tobacco smoking (OR, 4.2; 95% CI, 2.1‐6.4), surgical duration>75th percentile (OR, 1.9; 95% CI, 1.0‐2.9), and ALB < 35.0 g/L (OR, 2.3; 95% CI, 1.3‐3.4). We recommend the optimisation of modifiable risk factors such as morbid obesity, tobacco smoking, and lower serum albumin level prior to surgeries to reduce the risk of SSI.     

How Successful Is Antibiotic Treatment for Superficial Surgical Site Infections After Open Fracture? A Fluid Lavage of Open Wounds (FLOW) Cohort Secondary Analysis

BackgroundAlthough many studies report the incidence and prevalence of surgical site infections (SSIs) after open fractures, there is limited information on the treatment and subsequent outcomes of superficial SSIs in patients with open fractures. Additionally, clinical studies describing the factors that are associated with persistent infection after nonoperative treatment with antibiotics for patients with superficial SSIs are lacking.Questions/purposesTherefore, we asked: (1) What proportion of patients with superficial SSIs after open fracture treatment developed persistent infection after nonoperative treatment (that is, treatment with antibiotics alone)? (2) What risk factors are associated with SSIs that do not resolve with nonoperative (antibiotic) treatment? As a secondary objective, we planned to analyze the microbiological information about participants wound cultures, when these were available, and the proportion of positive cultures for patients whose SSIs were not resolved by antibiotics alone.MethodsThis is a secondary analysis of the Fluid Lavage of Open Wounds (FLOW) trial dataset. The FLOW trial included 2445 patients with operatively managed open fractures. FLOW participants who had a nonoperatively managed superficial SSI diagnosed in the 12 months post-fracture were included in this analysis. Superficial SSIs were diagnosed in 168 participants within 12 months of their fracture. Of these, 83% (139) had their superficial SSI treated with antibiotics alone. Participants were grouped into two categories: (1) 97 participants whose treatment with antibiotics alone resolved the superficial SSI and (2) 42 participants whose treatment with antibiotics alone did not resolve the SSI (defined as undergoing surgical management or the SSI being unresolved at latest follow-up [12-months post-fracture for the FLOW trial]). Of the participants whose treatment with antibiotics alone resolved the SSI, 92% (89 of 97) had complete follow-up, 6% (6 of 97) were lost to follow-up before 12 months, 1% (1 of 97) withdrew consent from the study before 12 months, and 1% (1 of 97) experienced mortality before 12 months. Of the participants whose treatment with antibiotics alone did not resolve the SSI, 90% (38 of 42) had complete follow-up, 7% (3 of 42) were lost to follow-up before 12 months, and 2% (1 of 42) withdrew consent from the study before 12 months. A logistic binary regression analysis was conducted to identify factors associated with persistent infection despite superficial SSI antibiotic treatment. Based on biologic rationale and previous evidence, we identified a priori 13 potential factors (corresponding to 14 levels) to be included in the regression model.ResultsThe antibiotic treatment resolved the superficial SSI in 70% (97 of 139) of patients and did not resolve the SSI in 30% (42 of 139). After controlling for potential confounding variables, such as age, fracture severity, and time from injury to initial surgical irrigation and débridement, superficial SSIs diagnosed later in follow-up were associated with antibiotics not resolving the SSI (odds ratio 1.05 [95% CI 1.004 to 1.009] for every week of follow-up; p = 0.03). Sex, fracture pattern, and wound size were not associated with antibiotics not resolving the SSI.ConclusionsOur secondary analysis of prospectively collected FLOW data suggests that antibiotics alone can be an appropriate treatment option when treating superficial SSIs after an open fracture wound, especially when promptly diagnosed. Further research with longer follow-up time is needed to better identify the natural history of superficial SSIs and possibly some dormant or subclinical infections to help clinicians in the treatment decision-making process.Level of EvidenceLevel III, therapeutic study.     

The evaluation of nasal mupirocin to prevent Staphylococcus aureus burn wound colonization in routine clinical practice

BackgroundStaphylococcus aureus wound colonization frequently occurs in patients with burns and can cause impaired wound healing. Nasal mupirocin application may contribute to the reduction of burn wound colonization of endogenous origin, whereas colonization by the exogenous route can be reduced by blocking cross-infection from other sources. In this study we evaluated whether the implementation of routine treatment of patients and burn center personnel using nasal mupirocin ointment reduces S. aureus burn wound colonization.MethodsWe composed three study groups, consisting of a control period (Control), a mupirocin period (MUP), in which patients with burns were all receiving nasal mupirocin at admission, and a mupirocin + personnel period (MUP + P), in which we also screened the burn center personnel and decolonized S. aureus carriers by nasal mupirocin.ResultsThe patients who carried S. aureus in their nose and did not have S. aureus burn wound colonization at admission were considered as patients susceptible for the use of nasal mupirocin. In these patients, the S. aureus burn wound colonization rate was the same in all study groups. S. aureus nasal carriage was a significant independent risk factor for burn wound colonization (OR: 3.3; 95% CI: 1.4–7.6) when analyzed within the three study groups.ConclusionAlthough S. aureus carriage is a significant risk factor for developing burn wound colonization, the routine use of nasal mupirocin did not contribute to a reduction of burn wound colonization.     

Six years of surgical wound infection surveillance at a tertiary care center: review of the microbiologic and epidemiological aspects of 20,007 wounds.

HYPOTHESES: (1) Antibiotic restriction policies result in alteration of microbiologic features of surgical site infections (SSIs) and (2) reported SSI rates are underestimated when postdischarge surveillance is not included in SSI surveillance efforts. DESIGN: Retrospective analysis of prospectively collected SSI surveillance data. PATIENTS AND METHODS: We compared initial microbial isolates from SSIs between (1) January 1, 1993, and December 31, 1995, and (2) January; 1, 1996, and December 31, 1998. Antibiotic restriction policies were implemented at Fairview-University Medical Center, Minneapolis, Minn, on March 1, 1995. For the combined periods (January 1, 1993, to December 31, 1998), we determined SSI rates for 20007 operations according to the extent of bacterial contamination at surgery (wound class). Then, we analyzed SSI rates for 10559 of these operations (selected based on availability of Anesthesia Society of America score and type of procedure) using the surgical wound risk index (wound class, Anesthesia Society of America score, and length of operation). We categorized SSI rates by 17 procedures for comparison with SSI rates reported by 286 hospitals that contributed data confidentially and voluntarily to the National Nosocomial Infections Surveillance System in 1998. We compared SSI rates with and without postdischarge surveillance. RESULTS: Coagulase-negative staphylococcus and group D enterococcus were the 2 most frequent isolates before and after antibiotic restriction policies were implemented. Candida albicans isolates decreased from 7.9% (1993-1995) to 6.5% (1996-1998; P=.46). Methicillin-resistant Staphylococcus aureus (1.8% of isolates) and vancomycin-resistant enterococcus (2.4% of isolates) organisms were first identified between 1996 and 1998. Our SSI rates were 2.6% for class I wounds, 3.6% for class II wounds, and 10.5% for class III/IV wounds; 53.9% of SSIs were identified after hospital discharge. CONCLUSIONS: Antibiotic restriction policies did not alter the microbial spectrum of SSIs during the observation period. Reporting SSI rates in the absence of postdischarge surveillance dramatically underestimates actual SSI rates, especially in tertiary care hospitals that provide care for large populations of elderly and immunosuppressed patients.     

Risk factors of surgical site infections after supratentorial elective surgery: A focus on the efficacy of the wound-drain-tip culture

Background

Surgical site infection (SSI) is one of the most dangerous complications after neurological surgery and is related to additional postoperative hospital days and an increased risk of death. One method for the early detection of SSI, the wound-drain-tip culture (WDC), has been widely used. However, no investigations on the relation between SSIs and wound drains after neurological surgery have been conducted. We performed this study to identify the risk factors for SSIs and to assess the relationship between SSIs and the results of WDC after elective supratentorial craniotomy.

Methods

A total of 535 patients underwent elective primary supratentorial craniotomy, and the results of their WDC were analyzed. The mean follow-up period was 14.1?±?12.2 months. In 347 (64.9 %) patients, the wound drain was removed within 2 days after operation.

Results

Until follow-up, 14 (2.62 %) patients suffered from SSIs. Among the 21 patients with positive WDCs, 8 (38.1 %) patients experienced SSIs. The organisms cultured from the SSIs were matched with the WDC results in 7 (87.5 %) patients. In the multivariate analysis, underweight group (OR?=?15.41, p?=?0.002), maintenance wound drain over 3 days (OR?=?4.202, p?=?0.043), and positive WDC (OR?=?36.67, p?<?0.001) were significantly associated with postoperative SSIs. In 6 (85.7 %) of 7 patients with a positive WDC for Serratia marcescens, SSIs ultimately developed.

Conclusions

The prognostic value of the positive WDC still falls short of our expectations in the field of neurological surgery. And, the positive WDC results should be cautiously interpreted, considering the virulence of the cultured micro-organisms.