Surgical-site infection after cardiac surgery: incidence, microbiology, and risk factors

Topical skin adhesive PRINEO as the ideal wound closure system in cardiac surgery to limit surgical site infection

OBJECTIVE

Surgical site infections (SSIs) are a major source of morbidity after cardiac surgery, involving prolonged hospitalisation. Among the numerous techniques of skin closure and dressings available, the optimal method remains undetermined. The DERMABOND-PRINEO (PRINEO) (PRINEO, Ethicon, J&J) is the only skin closure system which combines a topical skin adhesive with a mesh. Other surgical disciplines have highlighted remarkable results with PRINEO. The aim of this study was to evaluate the effects of PRINEO, used as the final layer in sternotomy closure, in the incidence of postoperative SSIs.

METHOD

This was a retrospective single-centre cohort study including adult patients who underwent cardiac surgery between January 2015 and December 2018. Patients who had undergone heart transplantation or ventricular assist surgery were excluded. Included patients were divided into two groups depending on the type of post-operative wound care technique used. Group 1 consisted of patients who had their sternotomy closed with a standard dressing and group 2 consisted of patients who were treated with PRINEO. The primary endpoint of our study was the occurrence of SSIs and secondary outcomes were the length of hospitalisation and mortality.

RESULTS

A total of 1603 patients were reviewed with the occurrence of 44 SSIs. Both groups were homogeneous in terms of risk factors. The incidence of SSIs was significantly lower in group 2 (PRINEO) than in group 1 (standard dressing) (n=29, 3.8% vs n=15, 1.8%, respectively; p=0.042). However, there was no significant difference in the duration of hospitalisation and mortality.

CONCLUSION

In our practice, PRINEO has proven to be a safe wound closure system after sternotomy, with a reduced SSI rate compared to conventional wound care techniques.

Incidence and predictors of sternal surgical wound infection in cardiac surgery: A prospective study

Sternal surgical wound infection (SSWI) in cardiac surgery is associated with increased morbidity. We investigated the incidence of SSWI, the main germs implicated and predictors of SSWI. Prospective study including patients undergoing full median sternotomy between January 2017 and December 2019. Patients were followed-up for 3 months after hospital discharge. All sternal wound infections up to 90 days after discharge were considered SSWI. 1004 patients were included. During follow-up, 68 (6.8%) patients presented SSWI. Patients with SSWI had a higher incidence of postoperative renal failure (29.4% vs 17.1%, P = .007), a higher incidence of early postoperative reoperation for non-infectious causes (42.6% vs 9.1%, P < .001), longer ICU stay (3 [2-9] days vs 2 [2-4] days, P = .006), and longer hospital stay (24.5 [14.8-38.3] days vs 10 [7-18] days, P < .001). Gram-positive germs were presented in 49% of the cultures, and gram-negative bacteria in 35%. Early reoperation for non-infectious causes (OR 4.90, 95% CI 1.03-23.7), and a longer ICU stay (OR 1.37 95% CI 1.10-1.72) were independent predictors of SSWI. SSWI is rare but leads to more postoperative complications. The need for early reoperation because of non-infectious cause and a longer ICU stay were independently associated with SSWI.

Predictors of sternal wound infection post cardiac surgery in a Saudi Centre: a case control study

BACKGROUND

Sternal wound infection (SWI) post cardiac surgery remains an important cause of extra morbidity, mortality and cost. The objective was to identify risk factors for SWI in a cardiac centre in Eastern Saudi Arabia as part of the investigation into Surveillance variance in the local rates of SWI.

METHODS

We included cases and controls from a cross section of patients who underwent major cardiac surgery between 2017 and 2020 matched for age, sex and time of surgery. An explanatory logistic regression model was fitted to estimate the risk factors.

RESULTS

N = 204 (51 cases and 153 controls matching ratio 1:3, from a source population of 985 patients). factors significantly associated with SWI in the final multivariate model: hospital stay OR (1.05, Cl 1.01-1.10), Graft Conduit BIMA versus No Graft OR (10.94, Cl 1.60-74.63), transfusion of both packed cells plus other blood products versus no transfusion OR (3.53, Cl 93-13.44), HbA1c OR (1.09 Cl 0.84-1.41), BMI OR (1.25, Cl 1.04-1.50), perioperative blood glucose OR (1.02, Cl 1.004-1.03), surgery time OR (1.19, Cl 1.00-1.58).

CONCLUSIONS

The diverse aetiology, cross-disciplinary nature of SWI prevention, and despite improved prevention and control practices, including related care bundles with their proven value, SWI remain a serious challenge in cardiac surgery. Multidisciplinary consensus guidelines are well overdue.

Pyoderma Gangrenosum after Cardiac Surgery

BACKGROUND

Pyoderma gangrenosum after cardiac surgery is a rare, noninfectious ulcerating skin disease mimicking sternal wound infection.

METHODS

A systematic search of literature for pyoderma gangrenosum complicating cases of cardiac surgery was conducted between September 1985 and September 2020 on PubMed and Cochrane databases. A systematic review and detailed overview of clinical presentation, diagnostic, treatment, and outcome is provided.

RESULTS

A total of 15 studies enclosing 15 patients suffering from pyoderma gangrenosum following cardiac surgery were identified. Onset of symptoms was observed after a median of 5 days. Patients were predominantly male (81.3%) with a median age of 64 years. Typical clinical presentation mimicked sternal site infection, mainly by means of mediastinitis. Specific signs were rapid progression, erythematous to violaceous color of the wound border, accompanied by unspecific symptoms including fever, malaise, and severe pain. Additionally, pathergy (development of ulcers at the sites of minor cutaneous trauma) was reported frequently. Biopsy is mandatory with a cutaneous neutrophilic inflammation confirming the diagnosis. Initial treatment mostly (75.0% of reported cases) was misled, addressing suspicion of surgical site infection. After correct diagnosis, the treatment was switched to an immunosuppressive therapy. Full sternal wound closure took between 5 weeks and 5 months. Reported case mortality was 12.5% in actually low-risk surgeries.

CONCLUSION

Despite pyoderma gangrenosum has typical signs, it remains an exclusion diagnosis. The treatment is completely opposite to the main differential diagnosis-the typical surgical site infection. Knowledge about diagnosis and treatment is essential in the context of avoiding fatal mistreatment.

Risk Factors for Post-cardiac Surgery Infections

Background Cardiac surgery infection is a life-threatening complication associated with high morbidity and mortality. One of the main types of these infections, surgical site infections (SSIs), also called postoperative wound infections basically delayed the post-surgical recovery in many patients. These infections rarely happen within 30 days after surgery due to different risk factors. Objectives The purpose of this study is to determine the risk factors that are involved in causing post-cardiac surgical infections. Methods This study was a retrospective study. The data of postoperative cardiac patients was obtained from the Cardiology and Cardiac Surgery Center in King Fahad Armed Force Hospital, Jeddah. Data on the patients were collected from 2016 to 2021. Eligible patients were those of age 18 and greater. These patients were evaluated on basis of the pre and postoperative risk factors and were analyzed for 30 days after discharge and those that developed SSIs were identified. Results Out of the total number of 2366 patients, 151 patients (6.4%) were identified with post-surgery infections out of which 107 (4.5%) had developed superficial wound infections (SSWIs) and 44 (1.9%) had developed deep wound infections (DSWIs). Infection mainly occurs in the male population (n=88, 58.3%). Major risk factors that were the main cause of post-cardiac surgery infections were diabetes (61.5%), hypertension (56.9%), smoking (38.4%), renal failure (27.1%), and re-do operation (25.1%). Conclusion Our study has demonstrated major risk factors that are involved in the occurrence of post-cardiac surgery infections like smoking, diabetes mellitus, sex, more than one operation during a single stay, etc. In the future, the contribution of various other factors involved in the occurrence of surgical site infections and best practices and methods should be studied and implemented to prevent the occurrence of post-cardiac surgery infections. Various simple techniques can still be utilized to prevent these sorts of infections, which will decrease the mortality rate.

Coronary Artery Bypass Grafting Versus Percutaneous Coronary Intervention for Multivessel Coronary Artery Disease: A One-Stage Meta-Analysis

Background and Aims

Data are emerging on 10-year mortality comparing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) with stenting for multivessel disease (MVD) without left main (LM) involvement. We conducted an updated two-stage meta-analysis using reconstructed individual patient data to compare long-term mortality between CABG and PCI for patients with MVD without significant LM coronary disease.

Methods

Medline and Embase databases were searched for articles comparing CABG with PCI for MVD. A two-stage meta-analysis was conducted using reconstructed patient level survival data for all-cause mortality with subgroups by SYNTAX score. The shared-frailty and stratified Cox models were fitted to compare survival endpoints.

Results

We screened 1,496 studies and included six randomized controlled trials with 7,181 patients. PCI was associated with greater 10-year all-cause mortality risk (HR: 1.282, CI: 1.118-1.469, p < 0.001) compared with CABG. In patients with low SYNTAX score, 10-year all-cause mortality after PCI was comparable to CABG (HR: 1.102, 0.822-1.479, p = 0.516). However, in patients with moderate to high SYNTAX score, 10-year all-cause mortality was significantly higher after PCI compared with CABG (HR: 1.444, 1.122-1.858, p < 0.001; HR: 1.856, 1.380-2.497, p < 0.001, respectively).

Conclusion

This updated reconstructed individual patient-data meta-analysis revealed a sustained lower cumulative all-cause mortality of CABG over PCI for multivessel disease without LM involvement.

Cost and clinical effectiveness of aggressive surgical debridement and delayed primary closure of infected cardiac surgical wounds

OBJECTIVE

Postoperative wound infection in cardiac surgery remains a subject of significant concern due to associated morbidity, prolonged hospital stay and rise in treatment cost. A conservative management approach to postoperative wound infection with topical dressings and healing by secondary intention is not cost-effective and cosmetic results are less acceptable. We developed our institutional protocol for the treatment of infected postoperative cardiac surgical wounds to reduce hospital stay and improve cosmetic outcome. This study aims to compare our institutional protocol with the conservative management approach.

METHODS

Adult patients with postoperative superficial or deep sternal and/or leg wound infection were divided into two equal-sized groups and data collected from medical records. Group A was treated according to our institutional protocol of aggressive surgical debridement and delayed primary closure. Group B was treated according to conservative management with topical antiseptic wound dressings and healing by secondary intention. Data were analysed in retrospect with comparative statistics.

RESULTS

A total of 30 patients took part in the study. Group A (n=15, seven male, eight female) had a mean age of 55.34±12.84 years. Group B (n=15, eight male, seven female) had a mean age of 56.46±10.21 years. Mean length of hospital stay in Group A and Group B was 5.13±2.06 and 36.67±22.28 days, respectively (p<0.0001). Calculated mean hospital costs were 16,271.61±6815.50 Saudi Riyals (approximately equivalent to $4330±700 USD) in Group A and 116,212.2±26,311 Saudi Riyals (approximately equivalent to $30,932±1813 USD) in Group B (p<0.05). Patients in Group A had linear scars comparable with primary postoperative wound scars, whereas patients in Group B had excessive non-linear scarring.

CONCLUSION

In this study, cost and clinical effectiveness of aggressive surgical debridement and delayed primary closure was superior to conservative management with topical antiseptic wound dressings and healing by secondary intention in terms of a shorter hospital stay and better cosmetic outcome.

Nisin-based antibacterial and antiadhesive layer-by-layer coatings

Some removable medical devices such as catheters and cardiovascular biomaterials require antiadhesive properties towards both prokaryotic and eukaryotic cells in order to prevent the tissues from infections upon implantation and, from alteration upon removal. In order to inhibit cell adhesion, we developed ultrathin hydrated Layer-by-Layer (LbL) coatings composed of biocompatible polyelectrolytes, namely chondroitin sulfate A (CSA) and poly-l-lysine (PLL). The coatings were crosslinked with genipin (GnP), a natural and biocompatible crosslinking agent, to increase their resistance against environmental changes. In order to confer antibacterial activity to the coatings, we proceeded to the electrostatically-driven immobilization of nisin Z, an antimicrobial peptide (AMP) active against gram-positive bacteria. The nisin-enriched coatings had a significantly increased anti-proliferative impact on fibroblasts, as well as a strong contact-killing activity against Staphylococcus aureus in the short and long term.

Risk Factors and Outcome of Multidrug-Resistant Infections after Heart Transplant: A Contemporary Single Center Experience

(1) Background: The aim of this study was to assess risk factors for multidrug-resistant/extensively drug-resistant (MDR/XDR) bacterial infections in heart transplant (HT) patients within three months after surgery and its impact on patient outcome. (2) Methods: Retrospective analysis of clinical, hemato-chemical, imaging, treatment and outcome data from 47 heart transplant recipients from January 2016 to December 2018. MDR/XDR infections were compared to non-MDR/XDR and noninfected patients. (3) Results: Most participants were males, median age 51 years: 35 (74.5%) developed an infection after HT; 14 (29.8%) were MDR/XDR infections. Prolonged hospital stay before HT correlated to MDR/XDR infection (p < 0.001). Sequential organ failure assessment (SOFA) score at sampling day was higher in MDR/XDR (p = 0.027). MDR/XDR were mostly blood-stream (BSI) (p = 0.043) and skin-soft tissue (SSTI) (p = 0.047) infections. Gram-negative infections were the most frequent, specifically carbapenem-resistant Klebsiella pneumoniae. Antibiotic therapy duration for MDR/XDR infections was longer (p = 0.057), eradication rate lower (p = 0.083) and hospital stay longer (p = 0.005) but not associated with a worse outcome. (4) Conclusions: MDR/XDR infections affect compromised HT recipients with a history of prolonged hospitalization, causing a lower rate of eradication and increased hospital stay. These frequently present as BSI and SSTI. We emphasize the need to prevent contamination of central venous catheters and the surgical site.

The association between preoperative length of hospital stay and deep sternal wound infection: A scoping review

BACKGROUND

Deep sternal wound infection (DSWI) is a serious complication of cardiac surgery, associated with a significantly longer hospital stay, an increased mortality, and an almost doubling of treatment costs. The preoperative length of hospital stay has been suggested in a small number of studies as a modifiable risk factor yet is not included in surgical site infection prevention guidelines. The aim of this scoping review was to review the existing evidence on the association between preoperative length of hospital stay and DSWI, and to identify established risk factors for DSWI.

METHODS

A literature search of six electronic databases yielded 2297 results. Titles concerning risk factors for DSWI, sternal or surgical wound infection, or poststernotomy complications were included. Abstracts relating to preoperative length of stay as a risk factor for DSWI proceeded to full article review. Articles regarding paediatric surgery, DSWI management or unavailable in English were excluded.

RESULTS

The review identified 11 observational cohort studies. DSWI prevalence was between 0.9% and 6.8%. Preoperative length of stay ranged from 0-15.5 days and was found to be associated with DSWI in all studies. Preoperative length of stay and DSWI were inconsistently defined. Other risk factors for DSWI included diabetes, obesity, respiratory disease, heart failure, renal impairment, complex surgery, and reoperation (p < 0.05).

CONCLUSION

In this scoping review, an association between preoperative length of stay and the development of DSWI following cardiac surgery was identified. Thus, preoperative length of stay as a modifiable risk factor for DSWI should be considered for inclusion in cardiothoracic surgical infection prevention guidelines.

Role of targeted and universal mupirocin-based decolonization for preventing surgical-site infections in patients undergoing cardiothoracic surgery: A systematic review and meta-analysis

The purpose of the present study was to provide a systematic literature review and pool evidence on the efficacy of mupirocin-based decolonization protocol in reducing surgical-site infections (SSIs) in patients undergoing cardiothoracic (CT) surgery based on their Staphylococcus (S.) aureus carrier state. The PubMed, Embase, Ovid, BioMed Central, Cochrane Central Register of Controlled Trials and Google Scholar databases were searched for studies comparing mupirocin-based decolonization with controls for reducing SSIs in patients following CT surgery. Studies were grouped based on the targeted population of intervention, i.e. carriers or all patients. A total of 17 studies were included. Of these, 8 studies used targeted mupirocin-based decolonization, while universal decolonization was performed in 9 studies. The results were conflicting for studies performing targeted decolonization and it was not possible to perform a meta-analysis due to non-homogenous studies. Pooled analysis of 34,859 patients indicated that universal mupirocin-based decolonization significantly reduced the risk of all SSIs [risk ratio (RR): 0.54; 95% CI: 0.40,0.75; I²=73.35%]. The intervention significantly reduced the risk of superficial SSIs (RR: 0.37; 95% CI: 0.25,0.55; I²=0%) but not of deep SSIs (RR: 0.45; 95% CI: 0.19,1.09; I²=80.67%). The results indicated a significantly reduced risk of S. aureus SSIs (SA-SSIs) with mupirocin-based decolonization (RR: 0.44; 95% CI: 0.32,0.61; I²=0%) but not for methicillin-resistant S. aureus (MRSA-SSIs; RR: 0.25; 95% CI: 0.05,1.28; I²=79.07%). Evidence on the role of targeted mupirocin-based decolonization to reduce SSIs after CT surgery was non-coherent and inconclusive. Analysis of low-quality retrospective studies suggested that universal mupirocin-based decolonization may reduce all SSIs, superficial SSIs and SA-SSIs, but not deep SSIs or MRSA-SSIs in patients after CT surgery.

Plasma concentrations of cefazolin in pediatric patients undergoing cardiac surgery

Background

The guideline for antibiotic prophylaxis in pediatric cardiac surgery is currently unavailable, and the effects of cardiopulmonary bypass (CPB) may result in low plasma cefazolin concentrations and subsequent postoperative surgical site infections (SSIs).

Aims

To demonstrate the calculated-unbound plasma concentrations of cefazolin during uncomplicated pediatric cardiac surgery.

Settings and Design

A prospective observational study that included 18 patients <seven years of age, undergoing elective cardiac surgery with CPB.

Materials and Methods

An intravenous infusion of cefazolin (25 mg.kg^-1) was administered to patients over 30 minutes within 1 hour before skin incision (first dose). Another 25 mg.kg^-1 infusion was administered to the CPB prime volume (second dose). Blood samples were obtained at eight time points: 15 minutes after the first dose (T1); before aortic cannulation (T2); immediately after CPB initiation (T3); 30 (T4), 60 (T5), and 120 (T6) minutes after CPB; 15 minutes after CPB discontinuation (T7), and at skin closure (T8). The total plasma cefazolin concentrations were measured using liquid chromatography tandem mass spectrometry.

Results

The unbound cefazolin concentrations were calculated assuming 80%-protein binding. The median cefazolin levels were 18.1 (range 4.3-27.0), 11.9 (2.8-24.1), 31.4 (18.3-66.1), 23.4 (13.7-35.9), 20.2 (15.4-24.9), 17.7 (14.8-18.0), 15.6 (9.8-26.2), and 13.3 (8.3-24.6) μg.mL^-1 from T1-T8, respectively. The cefazolin levels remained four times above the minimum inhibitory concentrations (MICs) for Methicillin-sensitive S. aureus (MSSA) and S. epidermidis in most patients, but they were inadequate for Enterobacter and E. coli.

Conclusion

This regimen produced adequate plasma cefazolin concentrations for common organisms that cause SSIs after cardiac surgery.

[Negative pressure wound therapy for deep sternal wound infections: microbiological characteristics and antibiotic resistance]

OBJECTIVE

To evaluate bacterial flora in patients with deep sternal wound infection and the effect of negative pressure wound therapy on eradication of the pathogen.

MATERIAL AND METHODS

There were 102 patients with deep wound infection after cardiac surgery. Mean age was 66.9±9.9 years. Diabetes mellitus was detected in 21 (20.5%) cases, chronic obstructive pulmonary disease - in 15 (14.7%). Wound debridement via daily dressings was performed in 64 patients; vacuum-assisted dressings were applied in 38 patients. Bacteriological analysis of discharge was carried out every week.

Results. Mixed infection was observed in 38 (37.3%) patients. S.aureus was the most common pathogen (n=51, 50%), Gram negative bacteria were found in 36 (35.3%) patients. Negative pressure wound therapy ensured eradication of S.aureus within 3 weeks while dressings were associated with only 40% decrease of the incidence of positive analyses (p<0.05). Effectiveness of the method was not obtained for Gram negative bacteria.

CONCLUSION

Negative pressure wound therapy accelerates eradication of Gram positive pathogens but does not affect eradication of Gram negative microbes.

Methicillin-resistant Staphylococcus aureus nasal colonization in cardiovascular surgery patients at a university hospital in Bogotá, Colombia

Introducción.

Staphylococcus aureus resistente a la meticilina (SARM) es un microorganismo que coloniza las fosas nasales y diferentes partes del cuerpo, lo cual se considera un factor de riesgo para adquirir infecciones invasivas, especialmente en pacientes sometidos a cirugía cardiovascular.

Objetivo.

Determinar la colonización nasal por SARM y establecer las características clínicas en pacientes programados para cirugía cardiovascular.

Materiales y métodos.

Se hizo un estudio descriptivo entre febrero y diciembre de 2015. Se incluyeron pacientes adultos programados para cirugía cardiovascular en el Hospital Universitario San Ignacio de Bogotá. La colonización se identificó mediante reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) en tiempo real en muestras obtenidas mediante hisopados nasales. Los pacientes fueron descolonizados con mupirocina al 2,0 % intranasal dos veces al día y baños con gluconato de clorhexidina al 4 % del cuello hacía abajo durante cinco días, al cabo de lo cual se hizo una PCR de control.

Resultados.

Se incluyeron 141 pacientes, 52 hospitalizados y 89 ambulatorios. Del total, 19 (13,4 %) tenían colonización nasal por SARM, correspondientes a 9 (17,3 %) de los 52 hospitalizados y 10 (11,2 %) de los 89 ambulatorios. Todos los pacientes sometidos a descolonización tuvieron resultado negativo en la PCR al final del proceso y ninguno presentó infección del sitio operatorio por S. aureus.

Conclusiones.

Se demostró colonización nasal por SARM tanto en los pacientes hospitalizados como en los ambulatorios. La descolonización con mupirocina fue efectiva para erradicar el estado de portador a corto plazo, lo que podría tener efecto en las tasas de infección del sitio operatorio en las cirugías cardiovasculares.

Use of Smart Technology for the Early Diagnosis of Complications After Cardiac Surgery: The Box 2.0 Study Protocol

BACKGROUND

Atrial fibrillation (AF), sternal wound infection, and cardiac decompensation are complications that can occur after cardiac surgery. Early detection of these complications is clinically relevant, as early treatment is associated with better clinical outcomes. Remote monitoring with the use of a smartphone (mobile health [mHealth]) might improve the early detection of complications after cardiac surgery.

OBJECTIVE

The primary aim of this study is to compare the detection rate of AF diagnosed with an mHealth solution to the detection rate of AF diagnosed with standard care. Secondary objectives include detection of sternal wound infection and cardiac decompensation, as well as assessment of quality of life, patient satisfaction, and cost-effectiveness.

METHODS

The Box 2.0 is a study with a prospective intervention group and a historical control group for comparison. Patients undergoing cardiac surgery at Leiden University Medical Center are eligible for enrollment. In this study, 365 historical patients will be used as controls and 365 other participants will be asked to receive either The Box 2.0 intervention consisting of seven home measurement devices along with a video consultation 2 weeks after discharge or standard cardiac care for 3 months. Patient information will be analyzed according to the intention-to-treat principle. The Box 2.0 devices include a blood pressure monitor, thermometer, weight scale, step count watch, single-lead electrocardiogram (ECG) device, 12-lead ECG device, and pulse oximeter.

RESULTS

The study started in November 2018. The primary outcome of this study is the detection rate of AF in both groups. Quality of life is measured with the five-level EuroQol five-dimension (EQ-5D-5L) questionnaire. Cost-effectiveness is calculated from a society perspective using prices from Dutch costing guidelines and quality of life data from the study. In the historical cohort, 93.9% (336/358) completed the EQ-5D-5L and patient satisfaction questionnaires 3 months after cardiac surgery.

CONCLUSIONS

The rationale and design of a study to investigate mHealth devices in postoperative cardiac surgery patients are presented. The first results are expected in September 2020.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03690492; http://clinicaltrials.gov/show/NCT03690492.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/16326.

Clinical and Microbiological Analysis of Deep Sternal Wound Infections in Fifty-Two Consecutive Patients

Background: Mediastinitis after cardiac surgery can lead to devastating consequences such as deep sternal wound infections (DSWI). Staphylococcus epidermidis and other coagulase-negative staphylococci belong to the physiological skin flora and therefore generally are not considered pathogenic agents. Thus, local resistance patterns of these bacterial species often recovered from wound specimens generally are ignored while choosing antibiotics for peri-operative prophylaxis in cardiac surgery as well as in the selection of empiric antibiotic therapy of DSWI. Methods: During the period May 2012-May 2013, 52 patients suffering from DSWI were treated at our institution. For every patient, deep tissue samples were obtained during surgical debridement procedures and submitted to microbiologic analysis. The frequency of and the time to occurrence of a DSWI was recorded, and baseline data, previous operative interventions, complications, and the technique used for soft tissue reconstruction, as well as the microbiologic results and individual risk factors, were documented. Results: There were 32 male patients (62%) and 20 female. The patients' age at the time of revision was a mean of 67 ± 11.5 years (range 35-83 years). There was bacterial growth in 31 cases (60%), the predominant species being S. epidermidis (20 patients; 65%). Extended antibiotic therapy was indispensable to controlling the infection. Conclusion: The local resistance patterns of antibiotics should have a greater influence on the standardized prophylaxis or empirical therapy of DSWI and need to be discussed specifically for this high-risk population. Because of its multi-resistance spectrum, S. epidermidis must be classified as a potential pathogen. In the cases reported here, extended antibiotic therapy was necessary to support wound healing and thus good patient outcomes.

Mediastinitis in open heart surgery: a systematic review and meta-analysis of risk factors

Objective. We aimed to summarize the evidence from observational studies examining the risk factors of the incidence of mediastinitis in open heart surgery. Design. The study was a systematic review and meta-analysis of cohorts and case-control studies. Material and methods. We searched the literature and 74 studies with at least one risk factor were identified. Both fixed and random effects models were used. Heterogeneity between studies was examined by subgroup and meta-regression analysis. Publication bias or small study effects were evaluated and corrected by limit meta-analysis. Results. When correcting for small study effect, presence of obesity as estimated from 43 studies had Odds Ratio OR = 2.26. (95% CI: 2.17-2.36). This risk was increasing with decreasing latitude of study place. Presence of diabetes mellitus from 63 studies carried an OR = 1.90 (95% CI: 1.59-2.27). Presence of Chronic Obstructive Pulmonary Disease (COPD) from 30 studies had an OR = 2.59 (95% CI: 2.22-2.85). Presence of bilateral intramammary graft (BIMA) from 23 studies carried an OR = 2.54 (95% CI: 2.07-3.13). This risk was increasing with increasing frequency of female patients in the study population. Conclusion. Evidence from this study showed the robustness of the risk factors in the pathogenesis of mediastinitis. Preventive measures can be implemented for reducing obesity, especially in lower latitude countries. Furthermore, it is mandatory to monitor perioperative hyperglycemias with continuous insulin infusion. Use of skeletonized BIMA carries higher risk of mediastinitis especially in female patients without evidence of beneficial effect on survival for the time being.

Detection and phenotypic characterization of methicillin-resistant Staphylococcus aureus from clinical and community samples in Abakaliki, Ebonyi State, Nigeria

OBJECTIVE

The objective of this study was to isolate and phenotypically characterize methicillin-resistant Staphylococcus aureus (MRSA)from clinical and community samples in Abakaliki, Nigeria.

METHODS

A total of 709 clinical (303) and community samples (406) samples were obtained for this study. MRSA isolates were detected using Kirby-Bauer disc diffusion method with the inclusion of 1 µg oxacillin and cefoxitin antibiotic disc. The isolates were screened for the β-lactamase production using nitrocefin sticks.

RESULTS

A total of 44 MRSA isolates were obtained from the samples with prevalence frequency of 22.6 % and 20.8 % from clinical and community samples respectively. The clinical isolates were completely resistant (100 %) to ceftazidime, tetracycline and penicillin. Gentamicin and ciprofloxacin were the most effective antibiotics against the clinical and community isolates respectively with a susceptibility frequency of 63.2 % and 80 %. Exactly 38.1 % and 24.2 % of the clinical and community S. aureus isolates were positive for beta-lactamase production respectively. The HA-MRSA and CA-MRSA isolates had MARI values within the range of 0.3 to 1.0.

CONCLUSION

This present findings of multi-drug resistance MRSA is very worrisome as it further highlights the pressing need to keep a strict watch on MRSA emerging from this study area.

Surgical Site Infection Prevention Bundle in Cardiac Surgery

BACKGROUND

Surgical site infections (SSI) are among the most prevalent infections in healthcare institutions, attributing a risk of death which varies from 33% to 77% and a 2- to 11-fold increase in risk of death. Patients submitted to cardiac surgery are more susceptible to SSI, accounting for 3.5% to 21% of SSI. The mortality rate attributable to these causes is as high as 25%. Prevention of SSI in cardiac surgery is based on a bundle of preventive measures, which focus on modifiable risks.

OBJECTIVE

The objective of this study was to identify SSI risk factors in clean cardiac surgery.

METHODS

A retrospective cohort study analyzed 1,846 medical records from patients who underwent clean cardiac surgery. Fisher's exact test was used for bivariate comparison, and Poisson regression was used for independent analysis of SSI risk, considering a significance level of p < 0.05.

RESULTS

The results of the study comprised a multivariate analysis. The variables that were associated with the diagnosis of SSI were: surgical risk index (OR: 2.575; CI: 1.224-5.416), obesity (OR: 2.068; CI: 1.457-2.936), diabetes mellitus (OR: 1,678; CI: 1.168-2.409), and blood glucose level (OR: 1.004; CI: 1.001-1.007).

CONCLUSIONS

This study evidenced that complete adherence to the bundle was not associated with a reduction in the risk of surgical infections. Diabetes mellitus, obesity, and surgical risk index assessment were, however, identified to increase association and consequently risk of SSI in cardiac surgery.

Staphylococcus aureus nasal decolonization strategies: a review

Introduction: Staphylococcus aureus (S. aureus) infections are associated with increased morbidity, mortality and health-care costs. Persistent nasal carriage of S. aureus found in 10-30% of the general population, constitutes a risk factor for these infections. Nasal decolonization is one of the used strategies to prevent this risk in some situations. Areas covered: Mupirocin nasal ointment has been used for the nasal decolonization and prevention of staphylococcal infections in various settings like surgeries. However, rising rates of resistance to mupirocin require the development of new decolonization agents. In this review, we will discuss mupirocin, its origins, studies that proved its efficacy and the associated resistance, as well as other decolonization agents under investigation. Expert opinion: As some limitations exist to mupirocin use, further research for alternatives is encouraged. Some old approved antiseptics (chlorhexidine, povidone-iodine) or antibiotics (rifampicin, bacitracin) have been investigated for their efficacy in this indication. Other new agents (tea tree oil, retapamulin, LTX-109, XF-73, phages, lysostaphin, squalamine analogues, etc.) are being studied. Some of them are still in preclinical phases, and others have reached clinical trials, but further research is needed. Special interest should be given to single dose decolonization strategies and to molecules that do not select resistant strains.

Staphylococcus aureus Nasal Colonization: An Update on Mechanisms, Epidemiology, Risk Factors, and Subsequent Infections

Up to 30% of the human population are asymptomatically and permanently colonized with nasal Staphylococcus aureus. To successfully colonize human nares, S. aureus needs to establish solid interactions with human nasal epithelial cells and overcome host defense mechanisms. However, some factors like bacterial interactions in the human nose can influence S. aureus colonization and sometimes prevent colonization. On the other hand, certain host characteristics and environmental factors can predispose to colonization. Nasal colonization can cause opportunistic and sometimes life-threatening infections such as surgical site infections or other infections in non-surgical patients that increase morbidity, mortality as well as healthcare costs.

Coronary artery bypass graft surgery complications: A review for emergency clinicians

INTRODUCTION

Coronary artery bypass graft (CABG) surgery remains a high-risk procedure, and many patients require emergency department (ED) management for complications after surgery.

OBJECTIVE

This narrative review provides an evidence-based summary of the current data for the emergency medicine evaluation and management of post-CABG surgery complications.

DISCUSSION

While there has been a recent decline in all cardiac revascularization procedures, there remains over 200,000 CABG surgeries performed in the United States annually, with up to 14% of these patients presenting to the ED within 30 days of discharge with post-operative complications. Risk factors for perioperative mortality and morbidity after CABG surgery can be divided into three categories: patient characteristics, clinician characteristics, and postoperative factors. Emergency physicians will be faced with several postoperative complications, including sternal wound infections, pneumonia, thromboembolic phenomena, graft failure, atrial fibrillation, pulmonary hypertension, pericardial effusion, strokes, renal injury, gastrointestinal insults, and hemodynamic instability. Critical patients should be evaluated in the resuscitation bay, and consultation with the primary surgical team is needed, which improves patient outcomes. This review provides several guiding principles for management of acute complications. Understanding these complications and an approach to the management of hemodynamic instability is essential to optimizing patient care.

CONCLUSIONS

Postoperative complications of CABG surgery can result in significant morbidity and mortality. Physicians must rapidly diagnose these conditions while evaluating for other diseases. Early surgical consultation is imperative, as is optimizing the patient's hemodynamics, including preload, heart rate, cardiac rhythm, contractility, and afterload.

Thirteen-year experience with universal Staphylococcus aureus nasal decolonization prior to cardiac surgery: a quasi-experimental study

INTRODUCTION

Sternal wound infection (SWI) after cardiac surgery is a severe complication. Among preventive measures, pre-operative decolonization of nasal carriage of Staphylococcus aureus has recently been shown to be beneficial. This quasi-experimental study assessed the effect of decolonization on the incidence of S. aureus-associated SWI based on 19 years of prospective surveillance.

METHODS

Segmented negative binomial regression was used to analyse the change over time in the incidence of S. aureus mediastinitis requiring re-operation after cardiac surgery in a French university hospital between 1996 and 2014. Universal nasal decolonization with mupirocin was introduced in December 2001. The association between pre-operative nasal carriage and SWI due to S. aureus was analysed between 2006 and 2012.

RESULTS

Among 17,261 patients who underwent a cardiac surgical procedure, 565 developed SWI (3.3%), which was caused by S. aureus in 181 cases (1%). The incidence of mediastinitis caused by S. aureus decreased significantly over the study period (1.43% in 1996-2001 vs 0.61% and 0.64% in 2002-2005 and 2006-2014, respectively; P<0.001). In segmented analysis, there was a significant break in 2002, corresponding to the introduction of decolonization. Despite this intervention, pre-operative nasal carriage remained a significant risk factor for S. aureus mediastinitis (adjusted odds ratio 2.2; 95% confidence interval 1.2-4.2), as were obesity, critical pre-operative status, coronary artery bypass grafting (CABG), and combined surgery with valve replacement and CABG.

CONCLUSION

Universal nasal decolonization before cardiac surgery was effective in decreasing the incidence of mediastinitis caused by S. aureus. Nasal carriage of S. aureus remained a risk factor for S. aureus-associated SWI.

European Association for Cardio-Thoracic Surgery expert consensus statement on the prevention and management of mediastinitis

Mediastinitis continues to be an important and life-threatening complication after median sternotomy despite advances in prevention and treatment strategies, with an incidence of 0.25-5%. It can also occur as extension of infection from adjacent structures such as the oesophagus, airways and lungs, or as descending necrotizing infection from the head and neck. In addition, there is a chronic form of 'chronic fibrosing mediastinitis' usually caused by granulomatous infections. In this expert consensus, the evidence for strategies for treatment and prevention of mediatinitis is reviewed in detail aiming at reducing the incidence and optimizing the management of this serious condition.

Nosocomial infections and antibiotic resistance pattern in open-heart surgery patients at Imam Ali Hospital in Kermanshah, Iran

Background: Patients undergoing open heart surgery have a relatively high risk of acquiring nosocomial infections. The development of antibiotic-resistant infections is associated with prolonged hospital stays and mortalities.

Objectives: The present study was conducted to investigate nosocomial infections and the antibiotic resistance pattern in bacteria causing these infections in open heart surgery patients at Imam Ali Hospital in Kermanshah in the west of Iran over a 4-year period from March 2011 to March 2014.

Materials and methods: The present cross-sectional study was conducted on 135 cases of nosocomial infection among open heart surgery patients. The demographic characteristics and the risk factors of each case of infection were recorded. The antibiotic susceptibility test was carried out using the Minimum Inhibitory Concentration (MIC) method based on the Clinical and Laboratory Standards Institute (CLSI) protocol. The data collected were then analyzed in SPSS-16.

Results: Out of the 6,000 patients who underwent open heart surgery during this 4-year period at the selected hospital, nosocomial infections developed in 135 patients (2.25%), 59.3% of whom were female and 40.7% male. Surgery site infection (SSI), pneumonia (PNEU), urinary tract infection (UTI) and blood stream infection (BSI) affected 52.6%, 37%, 9.6% and 0.8% of the cases, respectively. E.coli, Klebsiella spp. and S. aureus were the most common bacteria causing the nosocomial infections. E. coli was most frequently resistant to imipenem (23.3%) Klebsiella spp. to gentamicin (38.5%) S. aureus to co-trimoxazole (54.2%).

Conclusion: SSI had a high prevalence in this study. Further studies should therefore be conducted to examine the risk factors associated with SSI in open heart surgery. Various studies have shown that antibiotic resistance patterns are different in different regions. Finding a definitive treatment therefore requires an antibiogram.

Latitude of the study place and age of the patient are associated with incidence of mediastinitis and microbiology in open-heart surgery: a systematic review and meta-analysis

Objective

We aimed to summarize the pooled frequency of mediastinitis following open-heart surgery caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and Gram-negative bacteria.

Design

This study was a systematic review and a meta-analysis of prospective and retrospective cohort studies.

Materials and methods

We searched the literature, and a total of 97 cohort studies were identified. Random-effect model was used to synthesize the results. Heterogeneity between studies was examined by subgroup and meta-regression analyses, considering study and patient-level variables. Small-study effect was evaluated.

Results

Substantial heterogeneity was present. The estimated incidence of mediastinitis evaluated from 97 studies was 1.58% (95% confidence intervals [CI] 1.42, 1.75) and that of Gram-positive bacteria, Gram-negative bacteria, and MRSA bacteria evaluated from 63 studies was 0.90% (95% CI 0.81, 1.21), 0.24% (95% CI 0.18, 0.32), and 0.08% (95% CI 0.05, 0.12), respectively. A meta-regression pinpointed negative association between the frequency of mediastinitis and latitude of study place and positive association between the frequency of mediastinitis and the age of the patient at operation. Multivariate meta-regression showed that prospective cohort design and age of the patients and latitude of study place together or in combination accounted for 17% of heterogeneity for end point frequency of mediastinitis, 16.3% for Gram-positive bacteria, 14.7% for Gram-negative bacteria, and 23.3% for MRSA bacteria.

Conclusion

Evidence from this study suggests the importance of latitude of study place and advanced age as risk factors of mediastinitis. Latitude is a marker of thermally regulated bacterial virulence and other local surgical practice. There is concern of increasing risk of mediastinitis and of MRSA in elderly patients undergoing sternotomy.

Effect of Preoperative Antibiotic Prophylaxis on Surgical Site Infections Complicating Cardiac Surgery

Objective.

To evaluate the effect of an optimized policy for antibiotic prophylaxis on surgical site infection (SSI) rates in cardiac surgery.

Design.

Prospective cohort study.

Setting.

Tertiary medical center in Israel.

Methods.

SSIs were recorded during a 10-year study period and ascertained through routine surveillance using the National Healthcare Safety Network (NHSN) methodology. Multivariable analyses were conducted to determine which significant covariates, including the administration of preoperative prophylaxis, affected these outcomes.

Results.

A total of 2,637 of 3,170 evaluated patients were included, and the overall SSI rate was 8.4%. A greater than 50% reduction in SSI rates was observed in the last 4 years of the study. Overall and site-specific infection rates were similar for patients receiving cefazolin or vancomycin. SSIs developed in 206 (8.1%) of the 2,536 patients who received preoperative prophylaxis (within 2 hours of the first incision) compared with 14 (13.9%) of 101 patients who received antibiotic prophylaxis at a different time (P= .04; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.0–3.3). After accounting for covariates, preoperative hospital stay (5 days or more), an NHSN risk category (2 or 3), age (60 years or more), surgeon's role, and the period of measurement were significantly associated with SSIs. Emergency surgery, age, surgeon's role, and nonpreoperative prophylaxis were found to be independent predictors of superficial SSI.

Conclusions.

We observed a progressive and significant decrease in SSI rates after the implementation of an infection control program that included an optimized policy of preoperative prophylaxis in cardiac surgery.

Perioperative management of bariatric surgery patients

PURPOSE

The perioperative management of bariatric surgery patients is described.

SUMMARY

Obesity and anatomical changes create unique challenges for clinicians when caring for bariatric surgery patients. Common bariatric surgery procedures performed include Roux-en-Y gastric bypass, sleeve gastrectomy, and adjustable gastric banding. Pain management in the acute postoperative period depends on careful dosing of opioid agents and the use of adjunctive agents. Prevention and management of infectious complications include appropriate surgical prophylaxis, monitoring and rapid treatment of suspected intra-abdominal infections, and detection and treatment of Helicobacter pylori infection. Venous thromboembolism (VTE) prophylaxis and treatment are complicated by obesity, and the use of pharmacologic agents must be balanced with bleeding risk. Bleeding is a serious complication that should be closely monitored in the immediate postoperative period. Blood products remain first-line therapy for the treatment of bleeding in this population. Acute differences in drug absorption as well as emerging hormonal changes necessitate the immediate postoperative adjustment of chronic medications to ensure both safety and efficacy. Pharmacists are valuable members of interprofessional teams for bariatric surgery patients because they provide expertise on the availability of dosage forms and dosage modification to ensure that patient pharmacotherapy is not interrupted; assist in the management of hypertension, diabetes, and psychotropic medications; and ensure appropriate antimicrobial prophylaxis and VTE prophylaxis and treatment dosages.

CONCLUSION

The management of patients in the perioperative period of bariatric surgery requires appropriate selection and dosing of medications for pain management and treatment of infectious complications, VTE, bleeding, and other chronic diseases.

Novel Method of Infection Prophylaxis in Heart Transplantation by Retrosternal Gentamycin Sponge Application

BACKGROUND

Surgical wound infections are more frequent in patients undergoing heart transplantation than in other heart surgery patients. There is a wide spread of sternal wound infection incidence in transplant patients ranging from 4% to 40%. It is first study describing local gentamicin sponge application during heart transplantation procedure.

MATERIALS AND METHODS

We enrolled 75 patients in a retrospective, single-center study, including 25 patients who underwent orthotopic heart transplantation (heart transplant group) and 50 in the cardiac surgery group. They were in mean age of 49 ± 12 years and 51 ± 13 years in heart transplantation and cardiac surgery group, respectively. A gentamicin sponge was inserted intraoperatively between sternal borders before chest closure in all heart transplantation patients.

RESULTS

There was 1 early death (4%) on postoperative day 7 owing to Clostridium difficile infection in the heart transplant group. There was 1 death (2%) in the cardiac surgery group owing to multiorgan failure secondary to perioperative heart ischemia. There was neither bacterial sternal wound infection nor sternal instability in the heart transplant group. None of the patients who had gentamicin sponge applied had wound healing problems. Two patients (4%) had a deep sternal wound infection in the cardiac surgery group, who had no sponge application; 1 (2%) was treated by surgical debridement and active drainage and 1 (2%) by vacuum therapy. There were 11 patients (44%) discharged on insulin therapy in the heart transplant group and 21 (21%) in the cardiac surgery group. Mean overall postoperative hospital stay was 35 ± 19 days in the heart transplant group and 10 ± 4 days in the cardiac surgery group.

CONCLUSIONS

Gentamicin sponge is an effective local infection prophylaxis in heart transplant patients.

Resistance Pattern of Antibiotics in Patient Underwent Open Heart Surgery With Nosocomial Infection in North of Iran

Background:

Patients who undergo cardiac surgery appear to be at increased risk for the development of Nosocomial infections (NIs). The development of antibiotic-resistant infections has been associated with significantly greater hospital mortality rates compared to similar infections caused by antibiotic-sensitive pathogens.

Objectives:

The purpose of this study is survey of Nis and antibiotic resistance patterns of causative bacteria among patients who underwent open heart surgery in the north of Iran during a 2-year period between September 2012 and September 2014.

Methods:

In this cross-sectional study we evaluated 187 patients that underwent open heart surgery with NIs. Demographic feature, clinical characteristics and risk factors of each infection were recorded. The antibiotic susceptibility test was performed using the Minimum inhibitory concentration (MIC) method according to the standard protocol of Clinical & Laboratory Standards Institute (CLSI). Detection of Extended-spectrum beta-lactamase (ESBL) producing bacteria was performed by the double-disk synergy (DDS) test; also Methicillin-resistant Staphylococcus (MRSA) strains were identified by MRSA Screen Agar. The collected data were analyzed using the SPSS software (ver. 16) and, descriptive statistics were used.

Results:

Out Of total of 2253 hospitalized patients who underwent open heart surgery, 187(5.05%) patients had NIs. 51.9% of the patients were female. The rates of surgical site infection (SSI), respiratory tract infection, endocarditis, Urinary tract infection (UTI), blood Infection and mediastinitis were 27.80, 25.66%, 17.64, 17.11% 8.55% and 3.20% respectively. E.coli and S.aureus were the most causative agents of NIs. The rate of ESBL-producing bacteria was 14.28- 71.42% among enterobacteriaceae and the rate of MRSA was 54.2% among S.aureus strains. All isolated Acinetobacter.spp were Multi-drug resistance (MDR).

Conclusions:

We showed that the rate of NIs among these high-risk patients was in the average level. But the emergence of MRSA and ESBL bacteria is increasing in our region.

Diabetes mellitus is associated with increased risk of surgical site infections: A meta-analysis of prospective cohort studies

BACKGROUND AND OBJECTIVE

Observational studies have suggested an association between diabetes mellitus and the risk of surgical site infections (SSIs), but the results remain inconclusive. We conducted a meta-analysis of prospective cohort studies to elucidate the relationship between diabetes mellitus and SSIs.

METHODS

We searched PubMed, Embase, and Web of Science databases and reviewed the reference lists of the retrieved articles to identify relevant studies. Associations were tested in subgroups representing different patient characteristics and study quality criteria. The random-effect model was used to calculate the overall relative risk (RR).

RESULTS

Fourteen prospective cohort studies (N = 91,094 participants) were included in this meta-analysis, and the pooled crude RR was 2.02 (95% confidence interval, 1.68-2.43) with significant between-study heterogeneity observed (I(2) = 56.50%). Significant association was also detected after we derived adjusted RRs for studies not reporting the adjusted RRs and calculated the combined adjusted RR of the 14 studies (RR, 1.69; 95% confidence interval, 1.33-2.13). Results were consistent and statistically significant in all subgroups. Stratified analyses found the number of confounders adjusted for, sample size, and method of diabetes case ascertainment might be the potential sources of heterogeneity. Sensitivity analysis further demonstrated the robustness of the result.

CONCLUSIONS

This meta-analysis suggests diabetes mellitus is significantly associated with increased risk of SSIs. Future studies are encouraged to reveal the mechanisms underlying this association.

Effect of perioperative mupirocin and antiseptic body wash on infection rate and causative pathogens in patients undergoing cardiac surgery

INTRODUCTION

Preoperative nasal mupirocin has been shown to reduce surgical site infections (SSIs) in patients undergoing cardiac surgery. We analyzed the effect of mupirocin plus antiseptic body wash on SSI rate and etiology.

METHODS

Prospective SSI surveillance was done for patients undergoing cardiac surgery before and after implementation of mupirocin nasal ointment and chlorhexidine/octenidine body wash.

RESULTS

Overall SSI rate was 8.6% (81 out of 945) for the control and 6.9% (58 out of 842) for the intervention cohort (P = .19). In multivariable analysis, the study protocol was associated with an odds ratio of 0.61 (95% confidence interval, 0.41-0.91; P = .015) with regard to any SSI. This effect was exclusively due to a reduction in superficial SSIs and was observed both in patients with preoperative and postoperative treatment initiation. Coagulase-negative staphylococci (CoNS), the most commonly isolated pathogen, were found in 37% and 48% (P = .19) of patients in the control and the intervention cohort, respectively. CoNS were methicillin resistant in 69% of cases.

CONCLUSIONS

Mupirocin and antiseptic body wash reduced the rate of superficial but not deep or organ/space SSIs. Postoperative patient treatment may be critical in reducing the risk for superficial SSI, presumably due to a reduction of bacterial skin load. A high proportion of SSI was due to methicillin-resistant CoNS and thus not covered by routine perioperative antimicrobial prophylaxis.

Factors associated with methicillin-resistant coagulase-negative staphylococci as causing organisms in deep sternal wound infections after cardiac surgery

Established preoperative antibiotic prophylaxis in cardiac surgery is ineffective against methicillin-resistant coagulase-negative staphylococci (CoNS). This case-control study aimed to determine factors predicting deep sternal wound infections due to methicillin-resistant CoNS. All cardiac surgery patients undergoing sternotomy between June 2009 and March 2013 prospectively documented in a Swiss tertiary care center were included. Among 1999 patients, 82 (4.1%) developed deep sternal wound infection. CoNS were causal in 36 (44%) patients, with 25/36 (69%) being methicillin resistant. Early reintervention for noninfectious causes (odds ratio (OR) 4.3; 95% confidence interval (CI) 1.9-9.5) was associated with methicillin-resistant CoNS deep sternal wound infection. Among CoNS deep sternal wound infection, perioperative antimicrobial therapy (p 0.002), early reintervention for noninfectious causes (OR 7.9; 95% CI 0.9-71.1) and time between surgery and diagnosis of infection over 21 days (OR 10.8; 95% CI 1.2-97.8) were associated with methicillin resistance. These findings may help to better tailor preoperative antimicrobial prophylaxis.

Is There a Role for Robotic Totally Endoscopic Coronary Artery Bypass in Patients with a Colostomy?

Preoperative colostomy presents a significant risk of sternal wound complications, mediastinitis, and ostomy injury in patients requiring coronary artery bypass grafting. Less invasive procedures in coronary surgery have a potential to reduce the risk of sternal wound healing problems. Robotic totally endoscopic coronary artery bypass grafting in patients with a colostomy has not been reported. We describe a case of completely endoscopic coronary surgery using the da Vinci Si system in a patient with a transverse colostomy. Single left internal mammary artery grafting to the left anterior coronary artery was performed successfully on the beating heart. We regard this technique as the least invasive method of surgical coronary revascularization with a potential to reduce the risk of surgical site infection and mediastinitis in patients with a colostomy.

A systematic review of risk factors associated with surgical site infections among surgical patients

IMPORTANCE

Surgical site infection (SSI) complicates 2-5% of surgeries in the United States. Severity of SSI ranges from superficial skin infection to life-threatening conditions such as severe sepsis, and SSIs are responsible for increased morbidity, mortality, and economic burden associated with surgery. Staphylococcus aureus (S. aureus) is a commonly-isolated organism for SSI, and methicillin-resistant S. aureus SSI incidence is increasing globally.

OBJECTIVE

The objective of this systematic review was to characterize risk factors for SSI within observational studies describing incidence of SSI in a real-world setting.

EVIDENCE REVIEW

An initial search identified 328 titles published in 2002-2012; 57 were identified as relevant for data extraction. Extracted information included study design and methodology, reported cumulative incidence and post-surgical time until onset of SSI, and odds ratios and associated variability for all factors considered in univariate and/or multivariable analyses.

FINDINGS

Median SSI incidence was 3.7%, ranging from 0.1% to 50.4%. Incidence of overall SSI and S. aureus SSI were both highest in tumor-related and transplant surgeries. Median time until SSI onset was 17.0 days, with longer time-to-onset for orthopedic and transplant surgeries. Risk factors consistently identified as associated with SSI included co-morbidities, advanced age, risk indices, patient frailty, and surgery complexity. Thirteen studies considered diabetes as a risk factor in multivariable analysis; 85% found a significant association with SSI, with odds ratios ranging from 1.5-24.3. Longer surgeries were associated with increased SSI risk, with a median odds ratio of 2.3 across 11 studies reporting significant results.

CONCLUSIONS AND RELEVANCE

In a broad review of published literature, risk factors for SSI were characterized as describing reduced fitness, patient frailty, surgery duration, and complexity. Recognition of risk factors frequently associated with SSI allows for identification of such patients with the greatest need for optimal preventive measures to be identified and pre-treatment prior to surgery.

Enterobacteriaceae surgical site infection after cardiac surgery: the hypothetical role of vancomycin

BACKGROUND

In the middle of October 2011, the Hygiene Department of Caen University Hospital suspected an outbreak of surgical site infections (SSI) after open-heart operations with an unusually high proportion of microorganisms belonging to the Enterobacteriaceae family. The attack rate was 3.8%, significantly different (p = 0.035) from the attack rate of 1.2% in 2010 over the equivalent period. A case-control study was conducted to search specifically for risk factors for Enterobacteriaceae infections after median sternotomy in cardiac patients.

METHODS

Case patients were defined retrospectively as patients with superficial or deep surgical site infection with Enterobacteriaceae within 30 days of median sternotomy. Four control patients were selected per case patient from patients matched for date of operation (± 15 days) and European System for Cardiac Operative Risk Evaluation (<5, [5-10], >10).

RESULTS

Univariate analysis identified the following risk factors: inappropriate skin preparation on the morning of the intervention (p = 0.046), use of vancomycin (p = 0.030), and number of sternotomy dressings (p = 0.033). A multivariate logistic regression analysis found that vancomycin use was independently associated with an increased risk of postoperative SSI with Enterobacteriaceae (p = 0.019; odds ratio = 7.4).

CONCLUSIONS

Although vancomycin is known to be effective for preventing infection with methicillin-sensitive organisms, our results suggest that it was associated with a risk for the development of SSI with gram-negative organisms after median sternotomy. This study led to a multidisciplinary meeting that defined new guidelines for prophylactic antibiotic therapy before open-heart operations.