Postoperative mediastinitis in children: epidemiology, microbiology and risk factors for Gram-negative pathogens

Efficiency of an algorithm for the prevention of sternal infection after cardiac surgery in children under 1 year of age: A single-center retrospective study

Background

Sternal infection is one of the most challenging complications to manage after heart surgery. The aim of our study is to evaluate the effectiveness of a developed algorithm for preventing sternal infection in pediatric patients after surgery for congenital heart disease (CHD).

Methods

We conducted a single-center study examining the treatment of 478 children with CHD. Patients were divided into 2 groups, taking into account the application of a developed management algorithm. A multivariate logistic regression analysis was used to identify the factors influencing the development of sternal infection following heart surgery using median sternotomy.

Results

A developed algorithm was applied in 308 children. In total, there were 16 cases of sternal infection (3.34 %) across both groups. Deep wound infection developed in 6 patients (1.26 %). Sternal infection developed in 2 children (0.65 %) in the first group (in which the algorithm was applied) and 14 children (8.2 %) in the second group. Deep sternal infection developed in 1 patient in the first group (0.33 %) and in 5 patients in the second group (2.94 %). As a result, perioperative risk factors as postoperative resternotomy (OR 23.315; p < 0.001), delayed sternal closure (OR 9.087; p = 0.003), development of acute renal failure (OR 5.322; p = 0.018) were associated with increased risk of infection and application of the developed algorithm resulted in a significant reduction in risk (OR 0.032; p < 0.001).

Conclusion

The suggested method for the prevention of sternal infection has significantly reduced the incidence of sternal infection after cardiac surgery in children less than 1 year of age. In patients with moderate to high risk for surgical site infection, surgeons can enhance wound healing and prevent wound infections with simple, inexpensive, and readily available tools and techniques. Surgical aspects, topical use of antibiotics, prevention of peripheral vasoconstriction, maintenance of normal oxygen delivery rates, and an individual approach to intensive care are essential.

Broad- Versus Narrow-Spectrum Perioperative Antibiotics and Outcomes in Pediatric Congenital Heart Disease Surgery: Analysis of the Vizient Clinical Data Base

BACKGROUND

Despite guidelines recommending narrow-spectrum perioperative antibiotics (NSPA) as prophylaxis for most children undergoing congenital heart disease (CHD) surgery, broad-spectrum perioperative antibiotics (BSPA) are variably used, and their impact on postoperative outcomes is poorly understood.

METHODS

We used administrative data from U.S. hospitals participating in the Vizient Clinical Data Base. Admissions from 2011 to 2018 containing a qualifying CHD surgery in children 0-17 years old were evaluated for exposure to BSPA versus NSPA. Propensity score-adjusted models were used to compare postoperative length of hospital stay (PLOS) by exposure group, while adjusting for confounders. Secondary outcomes included subsequent antimicrobial treatment and in-hospital mortality.

RESULTS

Among 18 088 eligible encounters from 24 U.S. hospitals, BSPA were given in 21.4% of CHD surgeries, with mean BSPA use varying from 1.7% to 96.1% between centers. PLOS was longer for BSPA-exposed cases (adjusted hazard ratio 0.79; 95% confidence interval [CI]: 0.71-0.89, P < .0001). BSPA was associated with higher adjusted odds of subsequent antimicrobial treatment (odds ratio [OR] 1.24; 95% CI: 1.06-1.48), and there was no significant difference in adjusted mortality between exposure groups (OR 2.06; 95% CI: 1.0-4.31; P = .05). Analyses of subgroups with the most BSPA exposure, including high-complexity procedures and delayed sternal closure, also did not find (but could not exclude) a measurable benefit from BSPA on PLOS.

CONCLUSIONS

BSPA use was common in high-risk populations, and varied substantially between centers. Standardizing perioperative antibiotic practices between centers may reduce unnecessary broad-spectrum antibiotic exposure and improve clinical outcomes.

MEDIASTINITIS AFTER CONGENITAL HEART SURGERY: EPIDEMIOLOGY, CLINICAL FEATURES AND OUTCOMES

Mediastinitis after surgery for congenital heart disease has a great impact on morbidity and mortality. However, there are scarce studies focused on the epidemiology of postsurgical mediastinitis in pediatric patients. In this 18-year period retrospective study, the cumulative incidence of mediastinitis was low: 0.64%, (95% confidence interval: 0.36-1.1). Gram-negative bacilli were common (35%). The mortality rate was 7.1%, associated with fungal infection.

Norwood Operation: Immediate vs Delayed Sternal Closure

BACKGROUND

The Norwood operation is a complex neonatal surgery. There are limited data to inform the timing of sternal closure. After the Norwood operation, delayed sternal closure (DSC) is frequent. We aimed to examine the association of DSC with outcomes, with a particular interest in how sternal closure at the time of surgery compared with the timing of DSC. Our outcomes included mortality, length of ventilation, length of stay, and postoperative complications.

METHODS

This retrospective study included neonates who underwent a Norwood operation reported in the Pediatric Cardiac Critical Care Consortium registry from February 2019 through April 2021. Outcomes of patients with closed sternum were compared to those with sternal closure prior to postoperative day 3 (early closure) and prior to postoperative day 6 (intermediate closure).

RESULTS

The incidence of DSC was 74% (500 of 674). The median duration of open sternum was 4 days (interquartile range 3-5 days). Comparing patients with closed sternum to patients with early sternal closure, there was no statistical difference in mortality rate (1.1% vs 0%) and the median hospital postoperative stay (30 days vs 31 days). Compared with closed sternum, patients with intermediate sternal closure required longer mechanical ventilation (5.9 days vs 3.9 days) and fewer subsequent sternotomies (3% vs 7.5%).

CONCLUSIONS

For important outcomes following the Norwood operation there is no advantage to chest closure at the time of surgery if the chest can be closed prior to postoperative day 3.

Extended systemic antibiotic prophylaxis in ventricular assist device recipients, an infectious disease perspective

OBJECTIVES

To evaluate whether mediastinitis/deep sternal wound infection (Med/DSWI) is more common in ventricular assist device (VAD) with delayed sternal closure (DSC) compared to VAD with primary sternal closure (PSC).

METHODS

A literature search was done over the last four decades for studies that addressed this comparison.

RESULTS

Two studies met our inclusion criteria, and their results are contradictory. The first study compared 184 VAD recipients with PSC to 180 VAD recipients with DSC. There was no difference in VAD-related infections between DSC and PSC (15% vs. 16%, respectively; odds ratio = 0.965, 95% confidence interval [CI] = 0.525-1.635). The second study compared 464 VAD recipients with PSC to 94 VAD recipients with DSC. The rate of surgical site infection was higher in the DSC patients (12.5% vs. 1.4%, respectively; odds ratio = 10.1; 95% CI = 3.8-27.0). DSC was identified as an independent risk factor for postoperative mortality, but no detailed infection information was given.

CONCLUSIONS

There is no clear evidence of the association between DSC, compared to PSC, and Med/DSWI. Therefore, DSC is not an absolute indication for extended systemic antibiotic prophylaxis. The decision to extend the duration of systemic antibiotic prophylaxis should be made on a case-by-case basis, in collaboration with an infectious disease specialist.

Peri-Operative Prophylaxis in Patients of Neonatal and Pediatric Age Subjected to Cardiac and Thoracic Surgery: A RAND/UCLA Appropriateness Method Consensus Study

Surgical site infections (SSIs) represent a potential complication of surgical procedures, with a significant impact on mortality, morbidity, and healthcare costs. Patients undergoing cardiac surgery and thoracic surgery are often considered patients at high risk of developing SSIs. This consensus document aims to provide information on the management of peri-operative antibiotic prophylaxis for the pediatric and neonatal population undergoing cardiac and non-cardiac thoracic surgery. The following scenarios were considered: (1) cardiac surgery for the correction of congenital heart disease and/or valve surgery; (2) cardiac catheterization without the placement of prosthetic material; (3) cardiac catheterization with the placement of prosthetic material; (4) implantable cardiac defibrillator or epicardial pacemaker placement; (5) patients undergoing ExtraCorporal Membrane Oxygenation; (6) cardiac tumors and heart transplantation; (7) non-cardiac thoracic surgery with thoracotomy; (8) non-cardiac thoracic surgery using video-assisted thoracoscopy; (9) elective chest drain placement in the pediatric patient; (10) elective chest drain placement in the newborn; (11) thoracic drain placement in the trauma setting. This consensus provides clear and shared indications, representing the most complete and up-to-date collection of practice recommendations in pediatric cardiac and thoracic surgery, in order to guide physicians in the management of the patient, standardizing approaches and avoiding the abuse and misuse of antibiotics.

Early Versus Late Sternal Closure in Infants-Perioperative Associations and Outcomes

BACKGROUND

Delayed sternal closure (DSC) has been used for patients who develop bleeding, chest wall edema, and malignant arrhythmia following cardiopulmonary bypass. Multiple factors can influence the timing of when to perform DSC. We aimed to describe our DSC experience in neonates and infants by comparing outcomes between patients undergoing early (<48 hours) versus late DSC (> 48 hours). We explored the associations between specific clinical and laboratory variables and the timing of DSC.

METHODS

Retrospective chart review of neonates and infants (<one-year-old) with DSC after heart surgery from December 2012 to December 2018. Patients requiring extracorporeal membrane oxygenation were excluded.

RESULTS

A total of 121 patients were included in the analysis, 34% (n = 41) met late DSC criteria. The overall cohort had a 75% survival rate and a median time for open sternum of 42.5 hours (Q1:23-Q3:65). The median time for open sternum in the early and late DSC groups was 24 hours (Q1:21-Q3:43) and 93 hours (Q1:65-Q3:141), respectively (P < .01). There was no statistical difference in mortality rate between groups. Patients with late DSC endured longer intensive care unit stays (median 24.3 days [Q1:13-Q3:35.3] vs 36.8 [Q1:23.9, 73.6]; P< .01) and a two-fold longer hospital stay compared to the early DSC group (multivariable analysis: relative risk = 2, 95% CI: 1.5-2.7; P < .01). Univariate analysis revealed patients with late DSC had higher median lactates both intraoperatively (7.6 [Q1:5.9-Q3:10.7] vs 9.3 [Q1:7.5-Q3:12.1]; P < .01) and 24 hours postoperatively (6.5 [Q1:4.3-Q3:10.3] vs 8.7 [Q1:5.7-Q3:14.70]; P = .03). A higher vasoactive inotrope score at 36 hours was associated with late DSC (odds ratio = 1.1, 95% CI: 1.01-1.2; P = .02).

CONCLUSIONS

Future research that explores additional clinical and laboratory variables that can help guide DSC decision-making and timing is needed.

Extracardiac Complications in Intensive Care Units after Surgical Repair for Congenital Heart Disease: Imaging Review with a Focus on Ultrasound and Radiography

Pediatric patients show various extracardiac complications after cardiovascular surgery, and radiography and ultrasound are routinely performed in the intensive care unit to detect and evaluate these complications. This review presents images of these complications, sonographic approach, and timing of occurrence that are categorized based on their extracardiac locations and include complications pertaining to the central nervous system, mediastinum, thorax and lung parenchyma, diaphragm, liver and biliary system, and kidney along with pleural effusion and iatrogenic complications. This pictorial review will make it easier for medical doctors in intensive care units to identify and manage various extracardiac complications in pediatric patients after cardiovascular surgery.

Computed tomography findings of mediastinitis after cardiovascular surgery

BACKGROUND

To our knowledge, no systematic study has been conducted on computed tomography (CT) imaging of mediastinitis in children post-cardiovascular surgery. We aimed to assess the CT findings of pediatric patients diagnosed with mediastinitis after cardiovascular surgery.

METHODS

We included 28 pediatric patients with suspected mediastinitis after undergoing cardiovascular surgery and who underwent CT. Patients were divided into a group with mediastinitis requiring antibiotic therapy (n = 15) confirmed by positive bacterial culture from the mediastinum and a group without mediastinitis (n = 13). Fisher's exact test was used to compare the following CT findings between the two groups: (i) mediastinal fluid collection; (ii) free gas bubble within fluid collection; (iii) sternal destruction; and (iv) capsular ring enhancement. The enhancement extent was categorized into the following four grades: whole rim enhancement, >50% of the rim enhancement, <50% of the rim enhancement, and no rim enhancement. A receiver operating characteristic curve analysis was performed to establish a cut-off point for obtaining the maximum diagnostic accuracy.

RESULTS

A significant difference was observed between patients, with and without mediastinitis in sternal destruction (73.6% vs 0%, P = <0.0001) and capsular ring enhancement (100.0% vs 38.5%, P = 0.0004). By using a cut-off grade of the whole rim enhancement, the estimated sensitivity and specificity for mediastinitis diagnosis were 100% and 92.3%, respectively.

CONCLUSION

Computed tomography findings of sternal destruction and capsular ring enhancement were observed more in patients with mediastinitis than in those without mediastinitis, and should be assessed carefully to diagnose mediastinitis accurately in pediatric patients who have undergone cardiac surgery.

Diagnosing infection after infant open heart surgery: role of procalcitonin

Background

Diagnosing infection in infants after cardiac surgery with cardiopulmonary bypass remains challenging. We aimed to determine whether procalcitonin discriminates post-cardiopulmonary bypass systemic inflammatory response syndrome from bacterial infection in infants better than C-reactive protein and leukocyte count.

Method

One hundred and eight infants underwent cardiac surgery with cardiopulmonary bypass. Leukocyte count, C-reactive protein, and procalcitonin were measured on arrival in the intensive care unit as baseline, and repeated on postoperative day 3. Bacterial infection was defined as proven infection with a positive blood or sputum culture.

Results

Twenty-four infants had proven bacterial infection. Baseline leukocyte counts and C-reactive protein levels did not differ significantly between the 2 groups. On postoperative day 3, C-reactive protein (62 vs. 38.5 mg·L−1, p = 0.01) and procalcitonin levels (6.58 vs. 0.41 ng·mL−1, p < 0.01) were higher in patients with bacterial infection. Leukocyte counts did not differ significantly between the two groups ( p = 0.94). The area under the receiver operating curve for leukocyte count, C-reactive protein, and procalcitonin was 0.49 ( p = 0.94), 0.67 ( p = 0.01), and 0.87 ( p < 0.0010), respectively. The optimal cutoff value of procalcitonin was 2.5 ng·mL−1 (sensitivity 75%, specificity 88%).

Conclusion

In infants undergoing cardiac surgery with cardiopulmonary bypass, procalcitonin discriminates bacterial infection from post-cardiopulmonary bypass systemic inflammatory response syndrome better than C-reactive protein and leukocyte count.

Antibiotic Prophylaxis for Open Chest Management After Pediatric Cardiac Surgery

OBJECTIVES

Although open chest management optimizes hemodynamics after cardiac surgery, it increases postoperative infections and leads to increased mortality. Despite the importance of antibiotic prophylaxis during open chest management, no specific recommendations exist. We aimed to compare the occurrence rates of bloodstream infection and surgical site infection between the different prophylactic antibiotic regimens for open chest management after pediatric cardiac surgery.

DESIGN

Retrospective, single-center, observational study.

SETTING

PICU at a tertiary children's hospital.

PATIENTS

Consecutive patients younger than or equal to 18 years old with open chest management after cardiac surgery followed by delayed sternal closure, between January 2012 and June 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We compared the composite occurrence rate of postoperative bloodstream infection and surgical site infection within 30 days after cardiac surgery between three prophylactic antibiotic regimens: 1) cefazolin, 2) cefazolin + vancomycin, and 3) vancomycin + meropenem. In 63 pediatric cardiac surgeries with open chest management, 17 bloodstream infections, and 12 surgical site infections were identified postoperatively. The composite occurrence rates of bloodstream infection and surgical site infection were 10 of 15 (67%), 10 of 19 (53%), and nine of 29 (31%) in the cefazolin, cefazolin + vancomycin, and vancomycin + meropenem regimens, respectively (p = 0.07). After adjusting for age, open chest management duration, extracorporeal membrane oxygenation use, and nasal methicillin-resistant Staphylococcus aureus colonization in multivariable analysis, there was no significant difference between the cefazolin and the cefazolin + vancomycin regimens (p = 0.19), while the vancomycin + meropenem regimen had a lower occurrence rate of bloodstream infection and surgical site infection than the cefazolin regimen (odds ratio, 0.0885; 95% CI, 0.0176-0.446; p = 0.003).

CONCLUSIONS

In this study, a lower occurrence rate of postoperative bloodstream infection and surgical site infection was observed among patients with broad-spectrum antibiotic regimen after pediatric cardiac surgery with open chest management. Further studies, ideally randomized controlled studies investigating the efficacy of broad-spectrum antibiotics and their complications, are warranted before routine implementation of broad-spectrum prophylactic antibiotic regimen.

Outcomes of Delayed Sternal Closure in Pediatric Heart Surgery: Single-Center Experience

Background

Delayed sternal closure (DSC) after cardiac surgery is a therapeutic option in the treatment of the severely impaired heart in pediatric cardiac surgery.

Methods

A single-center retrospective review of all bypass surgeries performed over a 10-year period (2003–2012).

Results

Of a total of 2325 patients registered in our database, the DSC group included 259 cases (11%), and the remaining 2066 cases (89%) constituted the control group (PSC). RACHS-1 risk was higher for the DSC group (74% had a score of 3 or 4) than for the PSC group (82% had a score of 2 or 3). The most frequent diagnosis for the DSC group was transposition of the great arteries (28%). We found out that hemodynamic instability was the main indication observed in patients aged ≤ 8 years (63%), while bleeding was the principal indication for patients aged ≥ 8 years (94%) (p ≤ 0.001). The average time between surgery and sternal closure was 2.3 ± 1.4 days. Overall mortality rates were higher for patients of the DSC group (22%) than for the PSC group (8.7%) (OR: 0.4 (95% CI: 0.4 to 0.5), p < 0.05). There were six patients with DSC who developed mediastinitis (2.3%). The risk of mediastinitis was significantly higher when DSC was performed 4 days after the primary surgery.

Conclusions

DSC is an important management strategy for congenital cardiac surgery in infants and children. The prolonged sternal closure time is associated with an increased rate of postoperative mediastinitis.

Preoperative Staphylococcus aureus Carriage and Risk of Surgical Site Infection After Cardiac Surgery in Children Younger than 1 year: A Pilot Cohort Study

Surgical site infections (SSI) increase length of stay, morbidity, mortality and cost of hospitalization. Staphylococcus aureus (SA) carriage is a known risk factor of SSI in adults, but its role in pediatrics remains uncertain. The main objective of this pilot prospective monocentric cohort study was to describe the prevalence of SA colonization in children under 1 year old before cardiac surgery. The secondary objectives were to compare the incidence of SSI and other nosocomial infections (NI) between preoperative carriers and non-carriers. From May 2012 to November 2013, all children <1 year old undergoing cardiac surgery under cardiopulmonary bypass underwent preoperative methicillin-resistant (MRSA) and methicillin-sensitive SA (MSSA) screening using real-time PCR. The only exclusion criterion was invalid PCR. All patients were followed up to 1 year after the surgery regarding SSI and other nosocomial infections. Among the 68 studied patients, SA colonization prevalence was 26.5%, comprising 23.5% MSSA and 2.9% MRSA. There was no significant difference between colonized and non-colonized children regarding SSI rate (16.7 vs 20%; p = 0.53), but ventilator-associated pneumonia rate was significantly higher among the SA carriers (22.2 vs 2%; p < 0.05). The colonization rate was different depending on the age of the patients (p < 0.05). This pilot study highlights that colonization with MSSA is frequent whereas MRSA prevalence is low in our population. In this cohort, there was no association between SA colonization and SSI incidence but further studies are needed to analyze this association.

Avoidance of Hospital-Acquired Infections in Pediatric Cardiac Surgical Patients

OBJECTIVES

The objectives of this review are to discuss the prevalence and risk factors associated with the development of hospital-acquired infections in pediatric patients undergoing cardiac surgery and the published antimicrobial prophylaxis regimens and rational approaches to the diagnosis, prevention, and treatment of nosocomial infections in these patients.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSION

Hospital-acquired infections remain a significant source of potentially preventable morbidity and mortality in pediatric cardiac surgical patients. Through improved understanding of these conditions and implementation of avoidance strategies, centers caring for these patients may improve outcomes in this vulnerable population.

Immunologic and Infectious Diseases in Pediatric Cardiac Critical Care: Proceedings of the 10th International Pediatric Cardiac Intensive Care Society Conference

Since the inception of the Pediatric Cardiac Intensive Care Society (PCICS) in 2003, remarkable advances in the care of children with critical cardiac disease have been developed. Specialized surgical approaches, anesthesiology practices, and intensive care management have all contributed to improved outcomes. However, significant morbidity often results from immunologic or infectious disease in the perioperative period or during a medical intensive care unit admission. The immunologic or infectious illness may lead to fever, which requires the attention and resources of the cardiac intensivist. Frequently, cardiopulmonary bypass leads to an inflammatory state that may present hemodynamic challenges or complicate postoperative care. However, inflammation unchecked by a compensatory anti-inflammatory response may also contribute to the development of capillary leak and lead to a complicated intensive care unit course. Any patient admitted to the intensive care unit is at risk for a hospital acquired infection, and no patients are at greater risk than the child treated with mechanical circulatory support. In summary, the prevention, diagnosis, and management of immunologic and infectious diseases in the pediatric cardiac intensive care unit is of paramount importance for the clinician. This review from the tenth PCICS International Conference will summarize the current knowledge in this important aspect of our field.

A pilot and feasibility study of the plasma and tissue pharmacokinetics of cefazolin in an immature porcine model of pediatric cardiac surgery

BACKGROUND

Surgical site infection (SSI) prevention for children with congenital heart disease is imperative and methods to assess and evaluate the tissue concentrations of prophylactic antibiotics are important to help maximize these efforts.

AIM

The purposes of this study were to determine the plasma and tissue concentrations with standard of care, perioperative cefazolin dosing in an immature porcine model of pediatric cardiac surgery, and to determine the feasibility of this model.

METHODS

Piglets (3-5 days old) underwent either median sternotomy (MS) or cardiopulmonary bypass with deep hypothermic circulatory arrest (CPB + DHCA) and received standard of care prophylactic cefazolin for the procedures. Serial plasma and microdialysis sampling of the skeletal muscle and subcutaneous tissue adjacent to the surgical site was performed. Cefazolin concentrations were measured, noncompartmental pharmacokinetic analyses were performed, and tissue penetration of cefazolin was assessed.

RESULTS

Following the first intravenous dose, maximal cefazolin concentrations in the subcutaneous tissue and skeletal muscle were similar between groups with peak tissue concentrations 15-30 min after administration. After the second cefazolin dose given with the initiation of CPB, total plasma cefazolin concentrations remained relatively constant until the end of DHCA and then decreased while muscle- and subcutaneous-unbound cefazolin concentrations showed a second peak during or after rewarming. For the MS group, 60-67% of the intraoperative time showed subcutaneous and skeletal muscle concentrations of cefazolin >16 μg·ml(-1) while this percentage was 78-79% for the CPB + DHCA group. There was less tissue penetration of cefazolin in the group that underwent CBP + DHCA (P = 0.03).

CONCLUSIONS

The cefazolin dosing used in this study achieves plasma and tissue concentrations that should be effective against methicillin-sensitive Staphylococcus aureus but may not be effective against some gram-negative pathogens. The timing of the cefazolin administration prior to incision and a second dose given during cardiopulmonary bypass may be important factors for achieving goal tissue concentrations.

Rigid sternal fixation in the management of pediatric postmedian sternotomy mediastinitis: A 20-year study

BACKGROUND AND AIM

Pediatric patients are at a risk of mediastinitis, a life-threatening complication of median sternotomy, following cardiac surgery for congenital conditions. Our experience with rigid internal sternal fixation in pediatric patients with postmedian sternotomy mediastinitis is presented.

METHODS AND MATERIALS

A retrospective chart review was performed of patients <18 years of age diagnosed with postoperative mediastinitis between January 1, 1990 and December 31, 2009. Charts were reviewed for demographic data, cardiac history, causative microorganism, and infectious risk factors. The methods of surgical intervention including flap coverage and use and type of sternal plating (resorbable and/or titanium) were also recorded. The primary end point of interest was overall survival.

RESULTS

Twenty-five pediatric patients were diagnosed with postoperative mediastinitis. Rigid fixation of the sternum following debridement was performed in 20 patients (age range: 1 month-18 years), all of whom successfully tolerated the procedure. Resorbable plates were used in 13 patients. Five patients did not undergo rigid fixation due to either serious ill-health or lack of adequate sternal bone stock. No patient experienced recurrent sternal wound infection. A total of 20 patients (80%) survived to discharge. Three patients succumbed to their heart condition prior to rigid fixation, one died following sternal closure from unrelated causes, and one patient was lost to follow-up.

CONCLUSIONS

Post-sternotomy mediastinitis in pediatric patients may be addressed using wide debridement, rigid sternal fixation, and flap coverage. In our series of 25 patients with pediatric mediastinitis, none died from mediastinitis. Placement of hardware did not adversely affect patient survival. This study demonstrates the feasibility of rigid sternal fixation.

Risk Adjustment for Surgical Site Infection After Median Sternotomy in Children

Objective.

To determine whether the National Nosocomial Infections Surveillance (NNIS) System risk index adequately stratified a population of pediatric patients undergoing cardiac surgery according to the risk of developing surgical site infection (SSI).

Design.

A retrospective, case-control study.

Setting.

An urban tertiary care children's hospital.

Patients.

Patients who had a median sternotomy performed between January 1,1995, and December 31, 2003, were eligible for inclusion in the study. For all case patients, medical records were reviewed to verify that all patients met the case definition for SSI. Control subjects were chosen randomly from among all patients who underwent median sternotomy during the study period who did not develop SSI.

Results.

Thirty-eight patients with SSI and 172 patients without SSI were included. One hundred six patients (50%) were male. The median patient age was 4 months. The sensitivity of the NNIS risk index with cutoff scores of 0 to 1 and 2 to 3 was 20%. The distribution of patients with SSI for an NNIS risk index score of 0 was 0%; for a score of 1, 80%; for a score of 2, 20%; and for a score of 3, 0%. The distribution of patients without SSI for a scores of 0 was 4%; for a score of 1, 87%; for a score of 2, 9%; and for a score of 3, 0%. The area under the receiver-operating characteristic curve (AUC) of the original NNIS risk index was 0.57. The modified risk indices did not perform significantly better, with an AUC range of 0.58 to 0.73.

Conclusions.

The NNIS risk index did not adequately stratify pediatric patients undergoing median sternotomy according to their risk of developing an SSI. Various modifications to the risk index yielded only slightly higher AUC values.

A statewide collaborative to reduce pediatric surgical site infections

BACKGROUND

Surgical site infections (SSIs) are preventable events associated with significant morbidity and cost. Few interventions have been tested to reduce SSIs in children.

METHODS

A quality improvement collaboration was established in Ohio composed of all referral children's hospitals. Collaborative leaders developed an SSI reduction bundle for selected cardiac, orthopedic, and neurologic operations. The bundle was composed of 3 elements: prohibition of razors for skin preparation, chlorhexidine-alcohol use for incisional site preparation, and correct timing of prophylactic antibiotic administration. The incidence of SSIs across the collaborative was compared before and after institution of the bundle. The association between 1 of the bundle elements, namely correct timing of antibiotic prophylaxis, and the proportion of centers achieving 0 SSIs per month was measured.

RESULTS

Eight pediatric hospitals participated. The proportion of months in which 0 SSIs per center was recorded was 56.9% before introduction of the bundle, versus 81.8% during the intervention (P < .001). Correct timing of preoperative prophylactic antibiotics also significantly improved; 39.4% of centers recorded correct timing in every eligible surgical procedure per month ("perfect timing") before the intervention versus 78.7% after (P < .001). The achievement of 0 SSIs per center in a given month was associated with the achievement of perfect antibiotic timing for that month (P < .003).

CONCLUSIONS

A statewide collaborative of children's hospitals was successful in reducing the occurrence of SSIs across Ohio.

Significance of positive mediastinal cultures in pediatric cardiovascular surgical procedure patients undergoing delayed sternal closure

BACKGROUND

Many pediatric cardiac surgery centers obtain mediastinal cultures at the time of delayed sternal closure (DSC). There are no recommendations regarding how to treat patients with positive cultures. We explored the clinical significance of positive mediastinal cultures with regard to surgical site infections (SSI).

METHODS

A retrospective study was performed on all patients who underwent DSC at our institution between December 2006 and December 2011. National Healthcare Safety Network criteria were used to prospectively identify SSIs. Univariate and multivariate logistic regression analyses were performed to evaluate potential risk factors for SSI and predictors for positive mediastinal cultures obtained at DSC.

RESULTS

A total of 178 patients underwent DSC during the study period; 155 patients met the eligibility criteria for the study and were included in the analysis. Of the 155 included patients, 11 patients (7.1%) experienced SSI. Patients with a positive mediastinal culture obtained at DSC were more likely to experience SSI than were patients with a negative culture (p=0.003). In univariate analysis, a positive mediastinal culture was the only factor associated with SSI (odds ratio [OR], 7.4; 95% confidence interval [CI], 2.1 to 26.7). In multivariate analysis, age at operation≥2 weeks (adjusted OR [aOR], 4.9; 95% CI, 1.84 to 12.8), receipt of stress-dosed hydrocortisone while the chest was open (aOR, 2.9; 95% CI, 1.1 to 7.6), and gestational age≤37 weeks (aOR, 2.7; 95% CI, 1.01 to 7.27) were independent predictors for a positive mediastinal culture.

CONCLUSIONS

Patients with positive mediastinal cultures obtained at DSC had a significantly higher rate of subsequent SSI, and a positive mediastinal culture was the only statistically significant predictor of SSI.

Hospital variation in postoperative infection and outcome after congenital heart surgery

BACKGROUND

Several initiatives aim to reduce postoperative infection across a variety of surgical patients as a means to improve overall quality of care and reduce variation across centers. However, the association of infection rates with hospital-level outcomes and resource utilization has not been well described. We evaluated this association across a multicenter cohort undergoing congenital heart surgery.

METHODS

The Society of Thoracic Surgeons Congenital Heart Surgery Database was linked to resource utilization data from the Pediatric Health Information Systems Database for hospitals participating in both (2006 to 2010). Hospital-level infection rates (sepsis, wound infection, mediastinitis, endocarditis, pneumonia) adjusted for patient risk factors and case mix were calculated using Bayesian methodology, and association with hospital mortality rates, postoperative length of stay (LOS), and total costs evaluated.

RESULTS

The cohort included 32,856 patients (28 centers); 3.7% had a postoperative infection. Across hospitals, the adjusted infection rate varied from 0.9% to 9.8%. Hospitals with the highest infection rates had longer (LOS) (13.2 vs 11.7 days, p < 0.001) and increased hospital costs ($71,100 vs $65,100, p < 0.001), but similar mortality rates (odds ratio 0.99, 95% confidence interval 0.80 to 1.21, p = 0.9). The proportion of variation in costs and LOS explained by infection was 15% and 6%, respectively.

CONCLUSIONS

Infection after congenital heart surgery contributes to prolonged LOS and increased costs on a hospital level. However, given that infection rates alone explained relatively little of the variation in these outcomes across hospitals, further study is needed to identify additional factors that may be targeted in initiatives to reduce variation and improve outcomes across centers.

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.

Risk factors for surgical site infection after delayed sternal closure

We examined the rates and risk factors for surgical site infections (SSIs) following delayed sternal closure after pediatric cardiac surgery by way of retrospective review of prospectively collected infection control data. Of 130 patients, 13.7% developed an SSI, and 6.9% developed mediastinitis following delayed sternal closure. There was a trend toward increased SSIs in patients undergoing delayed sternal closure in beds in the open bay of a pediatric intensive care unit.

Volumetric Computed Tomography Angiography in the Evaluation of Mediastinal Fluid Collections following Congenital Cardiac Surgery

We present 3 patients with 4 causes of mediastinal fluid collection after congenital cardiac surgery in this extended case report. Volumetric computed tomography played an essential role in diagnosing causes and extent, relevant to subsequent management. Recent advances in volumetric computed tomography allow fast and accurate imaging of cardiovascular and extravascular structures in children with acceptable radiation dose, providing a powerful imaging tool for the evaluation of complications after congenital cardiac surgery.

Delayed sternal closure after pediatric cardiac operations; single center experience: a retrospective study

BACKGROUND

Delayed sternal closure (DSC) after cardiac surgery is a therapeutic option in the treatment of the severely impaired heart in pediatric cardiac surgery. The results with the technique of DSC over a 4-year period are examined with regard to mortality and morbidity.

METHODS

We retrospectively reviewed records of 38 patients who had undergone DSC among 1100 congenital cardiac operations. Indication of DSC, time to sternal closure, pre and post closure cardiopulmonary and metabolic status, mortality, rate of wound and bloodstream infections were recorded.

RESULTS

The mean sternal closure time was 2.9 days. The mortality rate was 34.2% (n = 13). Twenty (52.6%) patients required prolonged antibiotic use due to postoperative infection. There was gram negative microorganism predominance. There were 4 (10.5%) patients with postoperative mediastinitis. Postoperative infection rate statistically increased with cardiopulmonary bypass time (CPBT), sternal closure time (SCT) and intensive care unit (ICU) stay time (p = 0.039;p = 0.01;p = 0.012). On the other hand, the mortality rate significantly increased with increased cross clamp time (CCT), SCT, and extracorporeal membrane oxygenation (ECMO) use (p = 0.017; p = 0.026; p = 0.03). Single ventricular physiology was found to be risk factor for mortality in delayed sternal closure (p < 0.007).

CONCLUSIONS

Elective DSC does not reduce the morbidity. The prolonged sternal closure time is associated with increased rate of postoperative infection rate; therefore early closure is strongly advocated.

A Comprehensive Intervention Associated With Reduced Surgical Site Infections Among Pediatric Cardiovascular Surgery Patients, Including Those With Delayed Closure

BACKGROUND

Surgical site infections (SSIs) cause significant morbidity and mortality in patients undergoing cardiovascular (CV) surgery. Following an increase in SSIs in this population, driven by a high rate in those with delayed closure, we implemented an intervention to reduce these infections and assessed the intervention using both population- and patient-level analyses.

METHODS

An intervention drawing from existing guidelines and targeting preoperative preparation of the patient, prophylactic antibiotics, and postoperative incision care was implemented. Special attention was paid to standardizing the care of the incision of patients with delayed closure. National Healthcare Safety Network criteria were used to prospectively identify SSIs. Population-level intervention effect was assessed using interrupted time series. To assess intervention adherence and effect in our patient population, retrospective chart review was performed on a cohort of patients undergoing cardiac procedures pre- and postintervention. Multivariate analysis was used to assess risk of SSI at the patient level.

RESULTS

Timely preoperative prophylactic antibiotic dosing increased from 60% preintervention to 92% postintervention, and redosing during prolonged surgeries increased from 5% to 79% (both, P < .001). At the population-level, a decrease of 6.7 infections per 100 surgeries per 6 months was observed directly following the intervention (P = .002). The SSI rate decreased from 40% to 0.8% (P < .001) in patients with delayed closure and from 4.3% to 1.8% (P = .02) in patients with immediate closure. In multivariate analyses, surgery prior to the intervention was the strongest predictor for SSI (incidence rate ratio, 3.98; 95% confidence interval, 1.59 to 9.97).

CONCLUSIONS

Our intervention decreased SSIs in pediatric CV surgery patients, particularly those with delayed closures.

Role of C-reactive protein velocity in the diagnosis of early bacterial infections in children after cardiac surgery

Fever after cardiac surgery in children may be due to bacterial infection or noninfectious origin like systemic inflammatory response syndrome (SIRS) secondary to bypass procedure. A marker to distinguish bacterial from nonbacterial fever in these conditions is clinically important. The purpose of our study was to evaluate, in the early postcardiac surgery period, whether serial measurement of C-reactive protein (CRP) and its change over time (CRP velocity) can assist in detecting bacterial infection. A series of consecutive children who underwent cardiac surgery with bypass were tested for serum levels of CRP at several points up to 5 days postoperatively and during febrile episodes (>38.0°C). Findings were compared among febrile patients with proven bacterial infection (FWI group; sepsis, pneumonia, urinary tract infection, deep wound infection), febrile patients without bacterial infection (FNI group), and patients without fever (NF group). In all, 121 children were enrolled in the study, 31 in the FWI group, 42 in the FNI group, and 48 patients in the NF group. Ages ranged from 4 days to 17.8 years (median 19.0, mean 46 ± 56 months). There was no significant difference among the groups in mean CRP level before surgery, 1 hour, and 18 hours after. A highly significant interaction was found in the change in CRP over time by FWI group compared with FNI group (P < .001). Mean CRP velocity ([fCRP - 18hCRP]/[fever time (days) - 0.75 day]) was significantly higher in the infectious group (4.0 ± 4.2 mg/dL per d) than in the fever-only group (0.60 ± 1.6 mg/dL per d; P < .001). A CRP velocity of 4 mg/dL per d had a positive predictive value (PPV) of 85.7% for bacterial infection with 95.2% specificity. Serial measurements of CRP/CRP velocity after cardiac surgery in children may assist clinicians in differentiating postoperative fever due to bacterial infection from fever due to noninfectious origin.

Bloodstream infections increased after delayed sternal closure: cause or coincidence

BACKGROUND

Infants who undergo major cardiac operations are at risk for developing bloodstream infections which contribute to the morbidity, mortality, and cost of treatment. Determining what factors are associated with this increased risk of infection may aid in prevention. We sought to evaluate the practice of delayed sternal closure after neonatal cardiac surgery to determine its role as a risk factor for postoperative bloodstream infection.

METHODS

We reviewed 110 consecutive patients with hypoplastic left heart syndrome after stage 1 Norwood procedure at Children's Healthcare of Atlanta. The rates of bloodstream infections were determined and risks analyzed with regard to postoperative status of sternal closure; primary versus delayed.

RESULTS

Delayed sternal closure was utilized in 67 of 110 patients (61%), while 43 patients had primary sternal closure in the operating room. Overall rate of bloodstream infection was 22% (24 of 110), with 83% (20 of 24) of infections occurring in the delayed closure group. Among infants with delayed closure, 30% developed bloodstream infection, as compared with 9% of patients with primary closure (p = 0.017). Patients with delayed closure had a fourfold increased risk (odds ratio 3.9, p = 0.03) of developing bloodstream infection in-hospital. Predominant organisms were coagulase negative Staphylococcus species; there was one case of mediastinitis.

CONCLUSIONS

Delayed sternal closure is associated with an increased likelihood of bloodstream infection and should be recognized as a risk factor after neonatal cardiac operations.

Mediastinitis in pediatric cardiac surgery: Prevention, diagnosis and treatment

In spite of advances in the management of mediastinitis following sternotomy, mediastinitis is still associated with significant morbidity. The prognosis is much better in pediatric surgery compared to adult surgery, but the prolonged hospital stays with intravenous therapy and frequent required dressing changes that occur with several therapeutic approaches are poorly tolerated. Prevention includes nasal decontamination, skin preparation, antibioprophylaxis and air filtration in the operating theater. The expertise of the surgical team is an additional factor that is difficult to assess precisely. Diagnosis is often very simple, being made on the basis of a septic state with wound modification, while retrosternal puncture and CT scan are rarely useful. Treatment of mediastinitis following sternotomy is always a combination of surgical debridement and antibiotic therapy. Continued use of numerous surgical techniques demonstrates that there is no consensus and the best treatment has yet to be determined. However, we suggest that a primary sternal closure is the best surgical option for pediatric patients. We propose a simple technique with high-vacuum Redon's catheter drainage that allows early mobilization and short term antibiotherapy, which thus decreases physiological and psychological trauma for patients and families. We have demonstrated the efficiency of this technique, which is also cost-effective by decreasing intensive care and hospital stay durations, in a large group of patients.

Major infection after pediatric cardiac surgery: a risk estimation model

BACKGROUND

In pediatric cardiac surgery, infection is a leading cause of morbidity and mortality. We created a model to predict risk of major infection in this population.

METHODS

Using the Society of Thoracic Surgeons Congenital Heart Surgery Database, we created a multivariable model in which the primary outcome was major infection (septicemia, mediastinitis, or endocarditis). Candidate-independent variables included demographic characteristics, comorbid conditions, preoperative factors, and cardiac surgical procedures. We created a reduced model by backward selection and then created an integer scoring system using a scaling factor with scores corresponding to percent risk of infection.

RESULTS

Of 30,078 children from 48 centers, 2.8% had major infection (2.6% septicemia, 0.3% mediastinitis, and 0.09% endocarditis). Mortality and postoperative length of stay were greater in those with major infection (mortality, 22.2% versus 3.0%; length of stay >21 days, 69.9% versus 10.7%). Young age, high complexity, previous cardiothoracic operation, preoperative length of stay more than 1 day, preoperative ventilator support, and presence of a genetic abnormality were associated with major infection after backward selection (p < 0.001). Estimated infection risk ranged from less than 0.1% to 13.3%; the model discrimination was good (c index, 0.79).

CONCLUSIONS

We created a simple bedside tool to identify children at high risk for major infection after cardiac surgery. These patients may be targeted for interventions to reduce the risk of infection and for inclusion in future clinical trials.

Center variation and outcomes associated with delayed sternal closure after stage 1 palliation for hypoplastic left heart syndrome

OBJECTIVE

There is debate whether primary or delayed sternal closure is the best strategy after stage 1 palliation for hypoplastic left heart syndrome. We describe center variation in delayed sternal closure after stage 1 palliation and associated outcomes.

METHODS

Society of Thoracic Surgeons Congenital Database participants performing stage 1 palliation for hypoplastic left heart syndrome from 2000 to 2007 were included. We examined center variation in delayed sternal closure and compared in-hospital mortality, prolonged length of stay (length of stay > 6 weeks), and postoperative infection in centers with low (< or = 25% of cases), middle (26%-74% of cases), and high (> or = 75% of cases) delayed sternal closure use, adjusting for patient and center factors.

RESULTS

There were 1283 patients (45 centers) included. Median age at surgery was 6 days (interquartile range, 4-9 days), and median weight at surgery was 3.2 kg (interquartile range, 2.8-3.5 kg); 59% were male. Delayed sternal closure was used in 74% of cases (range, 3%-100% of cases/center). In centers with high (n = 23) and middle (n = 17) versus low (n = 5) delayed sternal closure use, there was a greater proportion of patients with prolonged length of stay and infection, and a trend toward increased in-hospital mortality in unadjusted analysis. In multivariable analysis, there was no difference in mortality. Centers with high and middle delayed sternal closure use had prolonged length of stay (odds ratio, 2.83; 95% confidence interval, 1.46-5.47; P = .002 and odds ratio, 2.23; confidence interval, 1.17-4.26; P = .02, respectively) and more infection (odds ratio, 2.34; confidence interval, 1.20-4.57; P = .01 and odds ratio, 2.37; confidence interval, 1.36-4.16; P = .003, respectively).

CONCLUSION

Use of delayed sternal closure after stage 1 palliation varies widely. These observational data suggest that more frequent use of delayed sternal closure is associated with longer length of stay and higher postoperative infection rates. Further evaluation of the risks and benefits of delayed sternal closure in the management of these complex infants is necessary.

Continuous Infusion of Nafcillin for Sternal Osteomyelitis in an Infant After Cardiac Surgery

We report the use of the continuous infusion of nafcillin for the treatment of an infant who had methicillinsusceptible Staphylococcus aureus sternal osteomyelitis not responsive to traditional nafcillin dosing. The patient was successfully treated with surgical debridement and the continuous infusion of nafcillin. To our knowledge, this is the first report describing the successful use of the continuous infusion of nafcillin to treat an infant who had sternal osteomyelitis after cardiac surgery.

Postoperative hyperglycemia is associated with mediastinitis following pediatric cardiac surgery

INTRODUCTION

Mediastinitis is an infrequent, but significant complication of median sternotomy. Perioperative hyperglycemia is associated with increased morbidity, including infection in pediatric and adult cardiac surgical patients. We hypothesized that perioperative blood glucose levels would be higher in patients who later developed mediastinitis.

METHODS

We examined the medical records of all infants and children diagnosed with poststernotomy mediastinitis (n = 24) from July 2001 to December 2005. Data recorded included postoperative blood glucose levels, age, diagnosis, operation, surgical complexity score, duration of operation and cardiopulmonary bypass, delayed sternal closure, perioperative use of steroids and total parenteral nutrition, and duration of postoperative inotropic and ventilatory support. Records of patients without mediastinitis matched for age, complexity score, and month of operation (control group, n = 32) were also reviewed. Data were analyzed with t-tests and chi-square tests. Variables with P < 0.21 on univariate tests were entered into a multivariate logistic regression model.

RESULTS

Initially, postoperative blood glucose levels were elevated, but similar in both mediastinitis and control groups. The number of subjects having peak blood glucose levels >7.2 mm (>130 mg.dl(-1)) during the first 24 h was greater in the mediastinitis group (P = 0.07). The significant multivariate predictor of mediastinitis was 24 h peak blood glucose >7.2 mM (>130 mg.dl(-1)) (P = 0.039).

CONCLUSION

Our data support the hypothesis that postoperative hyperglycemia is a risk factor for the development of mediastinitis in infants and children following cardiac surgery.

Congenital cardiac surgical complications of the integument, vascular system, vascular-line(s), and wounds: consensus definitions from the Multi-Societal Database Committee for Pediatric and Congenital Heart Disease

A complication is an event or occurrence that is associated with a disease or a healthcare intervention, is a departure from the desired course of events, and may cause, or be associated with, suboptimal outcome. A complication does not necessarily represent a breech in the standard of care that constitutes medical negligence or medical malpractice. An operative or procedural complication is any complication, regardless of cause, occurring (1) within 30 days after surgery or intervention in or out of the hospital, or (2) after 30 days during the same hospitalization subsequent to the operation or intervention. Operative and procedural complications include both intraoperative/intraprocedural complications and postoperative/postprocedural complications in this time interval. The MultiSocietal Database Committee for Pediatric and Congenital Heart Disease has set forth a comprehensive list of complications associated with the treatment of patients with congenital cardiac disease, related to cardiac, pulmonary, renal, haematological, infectious, neurological, gastrointestinal, and endocrinal systems, as well as those related to the management of anaesthesia and perfusion, and the transplantation of thoracic organs. The objective of this manuscript is to examine the definitions of operative morbidity as they relate specifically to a collection of loosely related topics that include the following groups of complications: 1) Complications of the Integument, 2) Complications of the Vascular System, 3) Complications of the Vascular-Line(s), 4) Complications of Wounds. These specific definitions and terms will be used to track morbidity associated with surgical and transcatheter interventions and other forms of therapy in a common language across many separate databases. As surgical survival in children with congenital cardiac disease has improved in recent years, focus has necessarily shifted to reducing the morbidity of congenital cardiac malformations and their treatment. A comprehensive list of complications is presented. This list is a component of a systems-based compendium of complications that will standardize terminology and thereby allow the study and quantification of morbidity in patients with congenital cardiac malformations. Clinicians caring for patients with congenital cardiac disease will be able to use this list for databases, initiatives to improve quality, reporting of complications, and comparing strategies of treatment.

Risk factors for sternal wound infection in children undergoing cardiac surgery: a case-control study

SUMMARY

Complex and prolonged cardiovascular operations are increasingly performed on young infants and children. The aims of this study were to define the incidence, causative bacterial pathogens and risk factors for sternal wound infections (SWIs) in infants and children undergoing cardiac surgery. The study group included all children who underwent cardiac surgery by median sternotomy at a tertiary paediatric centre from 1999 to 2003 and who were diagnosed with a postoperative SWI. Charts were reviewed for pre-, intra- and postoperative variables. The findings were compared with control patients operated on immediately before and after the cases and analysed by a stepwise logistic regression model. Of the 1821 children who underwent cardiac surgery, 49 (2.69%) had SWI; full data were available for 47. Twenty-nine (61.7%) had superficial wound infection and 18 (38.3%) deep wound infection. The main bacterial pathogens were Staphylococcus aureus in 14 patients (39%) and Pseudomonas aeruginosa in 12 (33%). Three variables emerged as significant independent risk factors for SWI: young age (odds ratio: 0.63; 95% confidence interval: 0.47-0.85; P<0.001 for each additional year), cyanotic heart disease (4.93; 1.98-12.3; P<0.001), and central venous catheter (CVC) dwell time (1.15; 1.06-1.24; P<0.001 for each additional day). Gram-negative infections were significantly associated with preoperative oxygen treatment (P=0.007) and prolonged urinary catheter dwell time (P=0.004). This study confirms younger age as risk factor for SWI and adds cyanotic heart disease and duration of CVC as new independent risk factors. Specific risks for Gram-negative infections are identified and should help to introduce new preventive strategies to decrease the incidence and severity of SWI.