Sternal Surgical Site Infections Research Articles

The Association of Infection with Delirium in the Post-Operative Period after Elective CABG Surgery.

Delirium is one of the most common complications of coronary artery by-pass graft (CABG) surgery. The identification of patients at increased risk of delirium and the implementation of preventive measures to reduce the risk of postoperative delirium is necessary to improve treatment outcomes after CABG. The aim of this study was to assess the association between postoperative delirium and postoperative infection and 10-year mortality in patients undergoing CABG surgery. This is a retrospective, observational cohort study of patients undergoing planned on-pump CABG between April 2010 and December 2012. We analysed a group of 3098 patients operated on in our cardiac surgery centre, from whom we selected a cohort of patients undergoing planned CABG surgery. All patients were assessed for postoperative infection, such as pneumonia, bloodstream infections (BSIs) and surgical site infections (SSIs). Patients who experienced postoperative delirium were significantly more likely to have infection (7.4% vs. 22%; p = 0.0037). As regards particular types of infection, significant differences were only found for pneumonia and sternal SSIs. Patients who experienced postoperative delirium had significantly lower 5-year (p = 0.0136) and 10-year (p = 0.0134) survival. Postoperative delirium significantly increases long-term mortality in patients undergoing CABG surgery. Pneumonia and sternal SSIs significantly increase the risk of postoperative delirium in cardiac surgery patients.

Reducing Sternal Site Surgical Site Infections by Postdischarge Follow-Up Using WhatsApp

Background: We conduct ∼180–200 CABG surgeries a year, and >70% of these patients are diabetic. Our SSI rate for sternal site was 4.4%, above the global benchmarks, and on review of the risk factors, poor glycemic control was identified as a major risk factor. Despite focusing on and achieving excellent glycemic control in the perioperative period, the SSI rates did not decrease significantly. We identified that the predischarge insulin regimens were inadequate for the patient once they returned to meals at home. Hence, we extended the interventions to the postdischarge phase and observed the impact of this change on SSIs. Methods: We developed a multidisciplinary and cross-functional team of cardiac surgeons, endocrinologists, physician assistants, infection control nurses and quality professionals. The CABG admissions information was obtained when financial clearance was sought for the procedure; the quality improvement professionals tracked these patients to ensure involvement of the endocrinology team. The physician assistant conducted the education to the patient and family regarding sugar management and use of a glucometer at home. The quality improvement team took a weekly report from the physician assistant and from the patient regarding the frequency of interactions and achievement of glycemic control. At the time of discharge, each of the diabetic patients who underwent CABG were educated by the physician assistant in the use of a glucometer, were provided with a sugar monitoring and insulin dosing chart as well as a WhatsApp number. The patient’s were instructed to monitor the sugars at specified intervals, to input the data into the personalized chart, and to send it to the PA through WhatsApp. The physician assistant then provided instructions on the insulin dosages using a standing order (dynamic insulin prescription regimen) developed by the endocrinologist. Results: The sternal site infection rate among the CABG patients dropped from 4.44% (4 cases of 90 surgeries) to 1.78% (2 cases of 112 patients), a 60% improvement. Readmissions among the CABG patients dropped from 3 cases in the study period to zero during the project phase. Conclusion: We have achieved significant reduction in sternal site SSI by (1) implementing a novel strategy of focusing on the postdischarge period and home management of blood sugar; (2) using freely available technology, WhatsApp; and (3) effectively using physician assistants by training and developing standing order sets for insulin.Funding: NoneDisclosures: None

EVALUATION OF SURGICAL SUPPORT BRAS IN POST-CARDIAC SURGERY FEMALE PATIENTS

Breast size in females is a risk factor for sternal surgical site infections and incision pain post-cardiac surgery. Current limited research has shown that providing surgical support bras to females can be beneficial in reducing risk of infection and possible pain experience post operatively. Certain populations have been shown to benefit most, including females with a higher Body Mass Index (BMI), and those with larger breast cup sizes. The aim is to explore the experience of females using a surgical support bra post-cardiac surgery (with a sternotomy).

Effect of Water Chlorination on Development and Persistence of Biofilm in Shower Heads

Background: A cluster of sternal surgical site infections caused by Pseudomonas aeruginosa led to sampling of shower heads in patient rooms. Multiple subtypes of Pseudomonas aeruginosa were found and were genetically diverse from the patient isolates. Visible biofilm was found in showerheads in the cardiothoracic ward. Ways of minimizing formation and persistence of biofilm in the shower heads were sought. Methods: A low-dose chlorination dosing system was introduced in September 2018 to the circulating warm-water system supplying the building block where the cardiac surgery ward is situated. Of the 145 showers in that block, 70 shower heads were sampled and the shower heads were replaced. Of these, 35 were sampled at 3 months and 35 were tested at 6 months (biofilm prevention group). Of the remaining 70 shower heads, 35 were tested at 3 months and 35 at 6 months (biofilm removal group). Heterotrophic colony count (HCC) in CFU/mL was chosen as the outcome measure. Analysis was conducted in accordance with AS 4276.3.2 (2003). The microbial growth data followed a log-normal distribution due to the exponential growth of bacteria. The natural log of the data was therefore calculated, and results from each period were compared using analysis of variance (ANOVA). Free chlorine residual levels were controlled using a combination of feed-forward and oxidation reduction potential (ORP) feedback control, and levels were retested and adjusted during the review period using N,N-diethyl-p-phenylenediamine (DPD) chemistry. Results: Mean and median levels of log HCC data are shown in Fig. 1. We detected a statistically significant difference in HCC between the 6-month-old untreated shower heads (group B) and treated shower heads (Group D) (P < .001). Hypochlorite was generally dosed at a concentration of 0.5 mg/L free chlorine for the first 3 months, and 1.5 mg/L for the second 3 months. Approximately 65% of the chlorine was lost as it travelled around the system. Discussion: Waterborne pathogens, especially multiresistant Gram-negative bacilli, have been increasingly recognized as hospital-acquired pathogens. Many instances of the transmission of these pathogens have been reported, from premise plumbing to patients, and have been confirmed using molecular typing techniques. Conclusions: A low-dose chlorination system of the circulating warm-water supply seemed effective in preventing biofilm formation and reducing existing biofilm in shower heads using HCCs as a measure of biofilm. This information adds to the potential armamentarium for controlling the spread of these waterborne pathogens.Funding: NoneDisclosures: None

Implications of Methicillin-Resistant Staphylococcus aureus Carriage on Cardiac Surgical Outcomes

Staphylococcus aureus remains the most common cause of sternal surgical site infections (SSIs). Opinions on the postoperative implications of preoperative methicillin-resistant S aureus (MRSA) colonization currently differ. This study aimed to investigate whether MRSA carriage affects postoperative outcomes and safety of operation. A total of 1,774,811 cardiac surgical patients from 2009 to 2014 were identified from the National Inpatient Sample database. Among these patients, 5798 (0.33%) were MRSA carriers. Propensity-score matching was used to determine the effect of MRSA colonization on outcomes. MRSA carriers did not differ in age or sex from noncarriers, but they more often presented for urgent surgery (P< .001). Among matched pairs, there was no difference in mortality (P= .76), stroke, SSIs, pneumonia, renal failure, cardiac complications, respiratory failure, or prolonged mechanical ventilation. MRSA infection (P < .001), MRSA septicemia (P= 0.03), and blood transfusion (P= .003) occurred more often among MRSA carriers. There was no increase in cost (P= .12), but the hospital length of stay was longer (P= .005). Predictors of MRSA infection among carriers included age older than 85 years, rural hospital location, and diabetes. Carriers with endocarditis and drug abuse were at highest risk for MRSA infection. MRSA carriers undergoing cardiac surgery are not at higher risk for mortality or SSIs and can expect outcomes similar to those of noncarriers. Higher rates of postoperative MRSA infection and septicemia among carriers, although still very low, support the need for selective preoperative screening and prophylaxis when possible.

Prevention of Infections in Cardiac Surgery study (PICS): study protocol for a pragmatic cluster-randomized factorial crossover pilot trial

BackgroundA wide range of prophylactic antibiotic regimens are used for patients undergoing open-heart cardiac surgery. This reflects clinical equipoise in choice and duration of antibiotic agents. Although individual-level randomized control trials (RCT) are considered the gold standard when evaluating the efficacy of an intervention, this approach is highly resource intensive and a cluster RCT can be more appropriate for testing clinical effectiveness in a real-world setting.Methods/designWe are conducting a factorial cluster-randomized crossover pilot trial in cardiac surgery patients to evaluate the feasibility of this design for a definite trial to evaluate the optimal duration and choice of perioperative antibiotic prophylaxis. Specifically, we will evaluate: (a) the non-inferiority of a single preoperative dose compared to prolonged prophylaxis and (b) the potential superiority of adding vancomycin to routine cefazolin in terms of preventing deep and organ/space sternal surgical site infections (s-SSIs). There are four strategies: (i) short-term cefazolin, (ii) long-term cefazolin, (iii) short-term cefazolin + vancomycin, and (iv) long-term cefazolin + vancomycin. These strategies are delivered in a different order in each health-care center participating in the trial. The centers are randomized to an order, and the current strategy becomes the standard operating procedure in that center during the study.The three feasibility outcomes include: (1) the proportion of patients receiving preoperative, intra-operative, and postoperative antibiotics according to the study protocol, (2) the proportion of completed follow-up assessments, and (3) a full and final assessment of the incidence of s-SSIs by the outcome adjudication committee.DiscussionWe believe that a cluster-randomized factorial crossover trial is an effective and feasible design for these research questions, allowing an evaluation of the clinical effectiveness in a real-world setting. A waiver of individual informed consent was considered appropriate by the research ethics boards in each participating site in Canada as long as an information letter with an opt-out option was provided. However, a waiver of consent was not approved at two sites in Germany and Switzerland, respectively.Trial registrationClinicaltrials.gov, NCT02285140. Registered on 15 October 2015.

Preoperative cigarette smoking and short-term morbidity and mortality after cardiac surgery: a meta-analysis

Currently, the choice of whether or not to electively operate on current smokers is varied among cardiothoracic surgeons. This meta-analysis aims to determine whether preoperative current versus ex-smoking status is...

Routine Surveillance Versus Independent Assessment by an Outcome Adjudication Committee in Assessing Patients for Sternal Surgical Site Infections After Cardiac Surgery.

Based on a cohort of 966 patients, routine surveillance data were not sufficiently accurate for use in clinical trials investigating surgical site infections. Surveillance data can only be used if adequate 90-day follow-up is provided and if cases identified by surveillance are independently reviewed by a blinded outcome adjudication committee.

Routine Surveillance Versus Independent Assessment by an Outcome Adjudication Committee in Assessing Patients for Sternal Surgical Site Infections After Cardiac Surgery

Routine Surveillance Versus Independent Assessment by an Outcome Adjudication Committee in Assessing Patients for Sternal Surgical Site Infections After Cardiac Surgery

A polymicrobial outbreak of surgical site infections following cardiac surgery at a community hospital in Florida, 2011-2012

We describe an outbreak of 22 sternal surgical site infections following cardiac surgery, including 4 Gordonia infections. Possible operation room environmental contamination and suboptimal infection control practices regarding scrub attire may have contributed to the outbreak.

Incidence, aetiology, and control of sternal surgical site infections

Since sternal surgical site infections (SSIs) can be life-threatening, every effort should be made to reduce their rate of occurrence. To measure the rate of sternal SSIs after open heart surgery and to define the efficacy of infection control interventions in reducing this rate. Surveillance of sternal SSIs was carried out prospectively for adult patients who underwent sternotomy between 2005 and 2012. Infection control interventions that were undertaken during the study period at different time intervals were prophylaxis with cefazolin or vancomycin, surveillance of sternal SSIs and feedback, preoperative nasal Staphylococcus aureus screening and decolonization with mupirocin, isolation of patients infected with or colonized by meticillin-resistant S.aureus, appropriate management of perioperative blood glucose level and chlorhexidine/alcohol usage for skin antisepsis. There were 479 sternal SSIs in 18,460 patients during the study period (2.59%). The most frequent causes of sternal SSIs were coagulase-negative staphylococci (CoNS) (36%) and S.aureus (31%). Infection control interventions reduced the rate of sternal SSIs from 3.63% in 2005 to 1.65% in 2012 (P<0.0001). Our study shows that the rate of sternal SSIs can be decreased with proper infection control interventions. However, the interventions that were undertaken were effective only in reducing the rate of sternal SSIs caused by S.aureus. It is time to find interventions to control sternal SSIs caused by CoNS, the pathogen responsible for most sternal SSIs in hospitals where S.aureus SSIs are successfully controlled.

Risk factors for sternal surgical site infection-is there any rationale for further improvement in prevention?

Objectives: There is an increasing interest in nosocomial infections. Among those surgical site infections play a major role. Moreover in coronary bypass surgery sternal surgical site infections (SSSI) remain a significant source of morbidity and mortality. The aim of this study was to elucidate predisposing factors in order to further improve strategies of prevention. Methods: 580 consecutive patients who had isolated CABG using extracorporeal circulation were retrospectively screened by use of the institutional database (95 variables). Patients were categorized as those with SSSI (n = 19) and those without (n = 561). Data are presented as mean and range. Univariate analysis was done by contingency tables and Fisher exact test (categoric variables) or Mann-Whitney U test (non parametric continuous variables). A p < 0.05 was considered significant. Results: The overall SSSI rate was 3.2% (1.3% superficial and 1.9% deep). In most cases (n = 10) coagulase neg. staphylococci were isolated. Other species were staph. aureus, enterococci, e. coli and enterobacter. Operative mortality was higher in case of SSSI (5.3%: 2.2%). Adipositas (BMI 30.22; 22.0 to 40.7 and 27.0; 16.0 to 44.0), diabetes (Odds ratio 3.85; 95% CI 1.44 to 2.90) and terminal renal failure (Odds ratio 13.8; 95% CI 2.37 to 72.32) were found to be significant risk factors. This was not true for age, gender and general risk scores (Euro- and KCH score). Patients with SSSI had longer duration of the operation, bypass time and higher intraoperative positive fluid balance (p < 0.05). Moreover there was a significant difference in postoperative fluid balance at 12, 24 and 48h. Patients who later on suffered from SSSI exhibited higher positive values. Notably, in the group with SSSI there was a still positive fluid balance even at 48h (450 ml; -1130 to 4730 ml against -120 ml; -3990 to 7950 ml, p = 0.016). This was paralleled by a higher lactate at 24h postop.(1.3 mmol/l; 0.8 to 2.5 against 0.9 mmol/l; 0.3 to 16, p = 0.016) and max. creatinine level (1.6 mg%; 0.9 to 7.7 against 1.3 mg%; 0.5 to 10.3, p = 0.0002). The strongest predictor of infection was the need for reexploration (Odds ratio 21.98; 95% CI 8.25 to 58.57). Conclusions: Our study confirmed risk factors for SSSI as described by others. However, as risk factors not yet reported in detail signs of post ECC SIRS and postop. fluid balance were identified. By means of paying alert attention to these facts infection rates might be further reduced.

Temporal Trends in the Incidence of Surgical Site Infections in Patients Undergoing Coronary Artery Bypass Graft Surgery: A Population-Based Cohort Study, 1993 to 2008

ObjectiveTo determine the incidence of and temporal trends in surgical site infections (SSIs) in patients underoing coronary artery bypass graft (CABG) surgery. MethodsA population-based cohort study was conducted to describe the epidemiologic features of SSI in Olmsted County, Minnesota, between January 1, 1993, and December 31, 2008, using the Rochester Epidemiology Project. Period-specific incidence rates (in-hospital or within 30 days outside the hospital) were calculated. Logistic regression analysis was used to adjust for potential confounders that could affect temporal trends in SSI incidence rates. ResultsDuring the 16-year study, of 1424 residents of Olmsted County who underwent CABG surgery, 1189 (83%) had isolated CABG and 235 (17%) had combined CABG and valve surgery. The overall SSI incidence rate was 7.0% (95% confidence interval [CI], 5.7%-8.4%). The incidence rate of superficial sternal SSI was 2.0% (95% CI, 1.2%-2.7%) and of deep sternal SSI was 1.5% (95% CI, 0.9%-2.2%). The leg harvest site infection rate was 3.6% (95% CI, 2.6 %-4.5%). The incidence rate decreased over time with a statistically significant linear trend. The adjusted odds ratio (95% CI) of SSI showed a decreasing linear trend: 0.39 (0.19-0.81) vs 0.50 (0.27-0.93) vs 0.83 (0.48-1.42) vs reference for 2005-2008 vs 2001-2004 vs 1997-2000 vs 1993-1996. ConclusionIn this population-based surveillance study of patients undergoing CABG surgery, the incidence of SSI decreased markedly between 1993 and 2008 in patients in Olmsted County. The factors responsible for this decrease are the focus of ongoing investigations.

Antibiotic prophylaxis in cardiac surgery: systematic review and meta-analysis

Antibiotic prophylaxis is recommended in cardiac surgery. Current debate concerns the type of antibiotic(s), dosing and the duration of prophylaxis. Systematic review of randomized controlled trials comparing one antibiotic regimen versus another in cardiac surgery. We searched The Cochrane Library, PubMed, LILACS, conference proceedings and bibliographies. Two reviewers independently extracted the data. The primary outcome was deep sternal wound infections (DSWIs). Meta-analysis was performed using the Mantel-Haenszel fixed-effect method. Risk ratios (RRs) with 95% confidence intervals (95% CIs) are reported. Fifty-nine trials were included. There were no significant differences in DSWI or all other categories of surgical site infections (SSIs) for antibiotic prophylaxis with β-lactams comprising a Gram-negative spectrum of coverage versus prophylaxis targeting Gram-positive bacteria, but the former led to a significantly lower rate of post-operative pneumonia (RR 0.68, 95% CI 0.51-0.90) and all-cause mortality (RR 0.66, 95% CI 0.47-0.92). In trials comparing different antibiotic regimens for different durations, prophylaxis duration of ≤24 h post-operation led to higher rates of DSWI (RR 1.83, 95% CI 1.25-2.66), any sternal SSI, surgical interventions for SSI and endocarditis compared with longer duration prophylaxis. There was no advantage of regimens lasting >48 h post-operation. In the comparison of glycopeptides versus β-lactams, an advantage of glycopeptides was observed when comparators were given for similar duration and for β-lactams when given for a longer duration than the glycopeptides. There was no significant advantage of high antibiotic dosing. Evidence supports second- or third-generation cephalosporins for cardiac surgery prophylaxis and points at a possible advantage of prophylaxis prolongation up to 48 h post-operatively.

Quality Assurance Data Collection Provides Opportunity for Organizational Improvement Following a Rise in Sternal Surgical Site Infections (SSI) Post-Coronary Artery Bypass Graft (CABG) Surgery

Katherine Matteson, RN, BSN, MS, CIC, Infection Control Practitioner; Russell Hynek, PharmD, Paul Lata, PharmD, Pharmacist; Linda McKinley, RN, MPH, CIC, Infection Control Practitioner; Lynn Michel, RN, MSN, APRN, BC, VA NSQIP/CICSP Coordinator; Athanasia Schreiner, RN, MSN, APNP-BC, Nurse Practitioner; Catherine Stampfli, RN, BSN, MRSA Prevention Coordinator; Sandra Tainter, RN, BSN, Nurse Manager; Christopher Crnich, MD, MS, Staff Physician & Hospital Epidemiologist; William S. Middleton Memorial VA Hospital, Madison, WI

Surveillance and epidemiology of surgical site infections after cardiothoracic surgery in The Netherlands, 2002–2007

Surgical site infections after cardiothoracic surgery substantially increase the risk for illness, mortality, and costs. Surveillance of surgical site infections might assist in the prevention of these infections. This study describes the Dutch surveillance methods and results of data collected between 2002 and 2007. Three cardiothoracic procedures were included: coronary artery bypass graft procedures, valve surgery, and a combination of coronary artery bypass graft procedures with concomitant valve surgery. The surgical site infections were divided into sternal and harvest-site infections. Postdischarge surveillance of surgical site infections was mandatory for sternal wounds and elective for harvest-site wounds, with a follow-up period of 42 postoperative days. Multivariate logistic regression was used for risk factor analysis of coronary artery bypass grafts, with adjustment for random variation among hospitals. Eight of the 16 Dutch cardiothoracic centers participated and collected data on 4066 procedures and 183 surgical site infections, revealing a surgical site infection rate of 2.4% for sternal wounds and 3.2% for harvest sites. Sixty-one percent of all surgical site infections were recorded after discharge. For sternal surgical site infections after coronary artery bypass graft procedures, the significant risk factors were rethoracotomy, diabetes, preoperative length of stay, and obesity; for harvest-site infections, the most relevant risk factor was a long time on extracorporeal circulation. Adjusted surgical site infection rates regarding coronary artery bypass graft procedures varied between hospitals from 0.0% to 9.7%. Large differences were found in surgical site infection rates between Dutch hospitals, which indicate room for improvement. The follow-up of patients after hospital discharge reduces underestimation of surgical site infection rates.

Decrease of deep sternal surgical site infection rates after cardiac surgery by a comprehensive infection control program

When we noticed an increasing incidence of deep sternal surgical site infections (DSSI), a bundle of interdisciplinary infection control measures was initiated in order to prevent further cases of DSSI. Adherence to infection control measures was re-inforced, which included (1) methicillin-resistant Staphylococcus aureus (MRSA) screening, (2) bacterial decolonisation measures, (3) hair clipping instead of shaving, (4) education, (5) good stewardship for antibiotic prophylaxis, (6) change of surgical gloves after sternotomy and after sternal wiring, (7) new bandage techniques, (8) leaving the wound primarily covered for at least 48 h. We checked for potential risk factors in a case-control study (120 patients each) by multivariate analysis. A significant decrease of DSSI from 3.61% (CI 95: 2.98-4.35) down to 1.83% (CI 95: 1.08-2.90) occurred. Independent significant risk factors for DSSI were age >68 years (OR=2.47; CI 95: 1.33-4.60), diabetes mellitus (OR=4.84; CI 95: 2.25-10.4), and intra-operative blood glucose level >8 mmol/l (OR=2.27; CI 95: 1.17-4.42). Protective factors were preoperative antibiotic prophylaxis (OR=0.31; CI 95: 0.13-0.70) and extubation on the day of surgery (OR=0.25; CI 95: 0.11-0.55). Close co-operation between clinical physicians and the infection control team significantly reduced the rate of DSSI. Thus, cardiac surgeons should know the local baseline DSSI rate, e.g. by surveillance, and should be aware of the risk factors for DSSI cases.

Role of Hyperbaric Oxygen Therapy in the Treatment of Postoperative Organ/Space Sternal Surgical Site Infections

A prospective trial was designed to evaluate the effect of hyperbaric oxygen (HBO) therapy on organ/space sternal surgical site infections (SSIs) following cardiac surgery that requires sternotomy. A total of 32 patients who developed postoperative organ/space sternal SSI were enrolled in this study from 1999 through 2005. All patients were offered HBO therapy. Group 1 included the patients who accepted and were able to undergo HBO therapy (n = 14); group 2 included patients who refused HBO therapy or had contraindications to it (n = 18). The two groups were well matched at baseline with comparable preoperative clinical characteristics and operative factors. Staphylococcus was the most common pathogen for both groups. The duration of infection was similar in groups 1 and 2 (31.8 7.6 vs. 29.3 5.7 days, respectively, p = 0.357). The infection relapse rate was significantly lower in group 1 (0% vs. 33.3%, p = 0.024). Moreover, the duration of intravenous antibiotic use (47.8 +/- 7.4 vs. 67.6 +/- 25.1 days, p = 0.036) and total hospital stay (52.6 +/- 9.1 vs. 73.6 +/- 24.5 days, p = 0.026) were both significantly shorter in group 1. Hyperbaric oxygen is a valuable addition to the armamentarium available to physicians for treating postoperative organ/space sternal SSI.

Acinetobacter (ACBA) in sternal surgical site infections (SSI) after cardiac surgery: Case control study to determine significance and outcome

BACKGROUND/OBJECTIVES: Between January 2003 and December 2004, our hospital experienced a hospital-wide outbreak of ACBA, with a nosocomial incidence increase of 48% compared with 2002. The crude mortality for nosocomial acquisition of ACBA was 24%. The hospital-wide antibiogram for nosocomial ACBA demonstrated the following percentages of sensitive organisms: imipenem, 61%; ampicillinsulbactam, 21%; gentamicin, 14%; and quinolone, 13%. The approximately 2000 cardiovascular surgery (CVS) patients per year are admitted to surgical intensive care units, where 43% of ACBA cases are first identified. METHODS: Surveillance for SSIs is conducted concurrently with retrospective record review and post-discharge patient surveys. ACBA incidence is analyzed with CERNER Information System, a 48-hour interval as a marker of probable nosocomial acquisition, and no distinction for colonization or infection. Cases were patients with sternal SSI and positive ACBA cultures; controls were patients with sternal SSI without ACBA. Student's T test was used to compare continuous variables, and chi square was used to compare categorical variables. RESULTS: Between 2003 and 2004, nine patients (0.2% of all CVS; 11.7% of all sternal SSI) had post-operative sternal cultures positive for ACBA. ACBA was only found following a previous diagnosis of sternal SSI or dehiscence. ACBA was never found as the sole organism associated with SSI, and all case patients had debridement with subsequent open wounds before ACBA was cultured. A case control study demonstrated that colonization or infection with a secondary organism was statistically significant. Unexpectedly, blood loss was more severe in controls. All other variables (listed in table) were not significant. Patients with ACBA Patients without ACBA Significance Secondary organisms/infection 9/9 5/65 RR = 13.6 (5.9 – 31.6) Diabetes 6/9 40/68 NS Outcome-expired 2/7 10/67 NS Estimated blood loss 383.3 ± 19.5 504.4 ± 22.4 p = 0.14 Age 60.4 ± 7.8 62.1 ± 7.9 NS Pre-op days 2.7 ± 1.6 2.1 ± 1.5 NS Pre-op blood sugar 139.3 ± 11.8 122.5 ± 11.1 NS Body Mass Index 35.3 ± 5.8 32.6 ± 8.0 NS OR Time 3:39 ± 0:38 4:07 ± 1:19 NS Days -Surgery to Diagnosis 21.3 ± 4.6 23.6 ± 4.9 NS CONCLUSIONS: Although ACBA transmission is relatively common in the surgical intensive care setting, its contribution to diagnosis of SSI appears minimal. In our institution, ACBA associated with CVS SSI appears as secondary infection or colonization and appears as an opportunistic organism, possibly related to devitalized tissue.

Risk Factors for Sternal and Leg Surgical Site Infections after Cardiac Surgery in Taiwan

To account for time factors related to hospitalization, the authors calculated incidence rates of surgical site infection (SSI) instead of cumulative incidence and assessed risk factors for SSI after cardiac surgery. From July 1999 to August 2000, all cardiac surgery patients in the Taipei Veterans General Hospital (Taipei, Taiwan) were invited to join the study. Data were collected by chart review, including information on patient characteristics and potential risk factors at the preoperative, intraoperative, and postoperative stages. The authors employed multiple logistic regression analyses using a generalized logit model to assess associations of interest. SSI incidence rates were 2.5 episodes per 1,000 person-days for the sternum and 3.6 episodes per 1,000 person-days for the leg. After adjustment for covariates, age (in years), gender (female vs. male), New York Heart Association classification (moderate/severe vs. normal/mild), creatinine concentration (mg/dl), and duration of surgery (in minutes) were significantly associated with sternal SSI, while age, peripheral arterial occlusive disease, and length of stay in the intensive care unit (in hours) were significantly associated with leg SSI. In addition to patients' characteristics and health situations, the significant findings for duration of surgery and length of intensive care unit stay indicate that the incidence rate is more appropriate than cumulative incidence for studying risk factors for SSI.