Case-control study of pediatric cardiothoracic surgical site infections

Open Chest Duration Following Congenital Cardiac Surgery Increases Risk for Surgical Site Infection

Surgical site infections (SSI) following congenital heart surgery (CHS) remain a significant source of morbidity. Delayed sternal closure (DSC) is often required to minimize the potential for hemodynamic instability. The purpose of this study was to determine the incidence of SSI among patients undergoing DSC versus primary chest closure (PCC) and to define a potential inflection point for increased risk of SSI as a function of open chest duration (OCD).A retrospective review of our institutional Society of Thoracic Surgeons dataset is to identify patients undergoing CHS at our institution between 2015 and 2020. Incidences of SSI were compared between DSC and PCC patients. DSC patients were evaluated to determine the association of OCD and the incidence of SSI.2582 operations were performed at our institution between 2015 and 2020, including 195 DSC and 2387 PCC cases. The incidence of SSI within the cohort was 1.8% (47/2,582). DSC patients had significantly higher incidences of SSI (17/195, 8.7%) than PCC patients (30/2387, 1.3%, p < 0.001). Further, patients with an OCD of four or more days had a significantly higher incidence of SSI (11/62, 17.7%, p = 0.006) than patients with an OCD less than 4 days (6/115, 5.3%).The incidence of SSI following CHS is higher in DSC patients compared to PCC patients. Prolonged OCD of 4 days or more significantly increases the risk of SSI and represents a potentially modifiable risk factor for SSI predisposition. These data support dedicated, daily post-operative assessment of candidacy for chest closure to minimize the risk of SSI.

Sternotomy with electrocautery and sternal wound infection in congenital heart surgery in patients under 1 year of age

OBJECTIVE

The present study aimed to compare the rate of wound site infection in patients <1 year of age who underwent sternotomy using electrocautery, a routinely performed procedure in our clinic, with those reported in the literature.

METHODS

This double-center study included patients <1 year of age who underwent cardiac surgery via sternotomy performed with electrocautery for congenital heart disease between January 2017 and June 2019. Patient's data were retrospectively obtained from the hospital records.

RESULTS

In our study, seven patients developed SSI, which was superficial in six (1.3%) patients and in the form of mediastinitis in one (0.2%) patient.

CONCLUSION

Sternotomy with electrocautery, which we consider an easy and safe method, was also not found to be statistically different from the other methods in terms of SWI.

Original Article--Surgical site infections following pediatric cardiac surgery in a tertiary care hospital: Rate and risk factors

BACKGROUND

Surgical site infections [SSIs] are the second most common type of healthcare-associated infections and leading cause of postoperative morbidity and mortality in pediatric cardiac surgery. This study aims to determine the rate of, risk factors for, and most common pathogen associated with the development of SSIs after pediatric cardiac surgery.

METHODS

Patients aged ≤14 years who underwent cardiac surgery at our tertiary care hospital between January 2010 and December 2015 were retrospectively reviewed.

RESULTS

The SSI rate was 7.8% among the 1510 pediatric patients reviewed. Catheter-associated urinary tract infection [CAUTI] [odds ratio [OR] 5.7; 95% confidence interval [CI] 2.3-13.8; P < 0.001], ventilator-associated pneumonia [VAP] [OR 3.2; 95% CI 1.4-7.2; P = 0.005], longer postoperative stay [≥25 days] [OR 4.1; 95% CI 2.1-8.1; P < 0.001], and a risk adjustment in congenital heart surgery [RACHS-1] score of ≥2 [OR 2.4; 95% CI 1.2-5.6; P = 0.034] were identified as risk factors for SSIs. Staphylococcus aureus was the most common pathogen [32.2%].

CONCLUSIONS

SSI risk factors were longer postoperative stay, CAUTI, VAP, and RACHS-1 score of ≥2. Identification and confirmation of risk factors in this study is important in order to reduce the rate of SSIs following cardiac surgery.

Pulmonary infection after cardiopulmonary bypass surgery in children: a risk estimation model in China

OBJECTIVES

The occurrence of pulmonary infection after congenital heart disease (CHD) surgery can lead to significant increases in intensive care in cardiac intensive care unit (CICU) retention time, medical expenses, and risk of death risk. We hypothesized that patients with a high risk of pulmonary infection could be screened out as early after surgery. Hence, we developed and validated the first risk prediction model to verify our hypothesis.

METHODS

Patients who underwent CHD surgery from October 2012 to December 2017 in the Children's Hospital of Chongqing Medical University were included in the development group, while patients who underwent CHD surgery from December 2017 to October 2018 were included in the validation group. The independent risk factors associated with pulmonary infection following CHD surgery were screened using univariable and multivariable logistic regression analyses. The corresponding nomogram prediction model was constructed according to the regression coefficients. Model discrimination was evaluated by the area under the receiver operating characteristic curve (ROC) (AUC), and model calibration was conducted with the Hosmer-Lemeshow test.

RESULTS

The univariate and multivariate logistic regression analyses identified the following six independent risk factors of pulmonary infection after cardiac surgery: age, weight, preoperative hospital stay, risk-adjusted classification for congenital heart surgery (RACHS)-1 score, cardiopulmonary bypass time and intraoperative blood transfusion. We established an individualized prediction model of pulmonary infection following cardiopulmonary bypass surgery for CHD in children. The model displayed accuracy and reliability and was evaluated by discrimination and calibration analyses. The AUCs for the development and validation groups were 0.900 and 0.908, respectively, and the P-values of the calibration tests were 0.999 and 0.452 respectively. Therefore, the predicted probability of the model was consistent with the actual probability.

CONCLUSIONS

Identified the independent risk factors of pulmonary infection after cardiopulmonary bypass surgery. An individualized prediction model was developed to evaluate the pulmonary infection of patients after surgery. For high-risk patients, after surgery, targeted interventions can reduce the risk of pulmonary infection.

Compliance with perioperative prophylaxis guidelines and the use of novel outcome measures

Postoperative wound infections represent an important source of morbidity and mortality in children. Perioperative antibiotic prophylaxis has been shown to decrease the risk of developing infections and hospital guidelines surrounding antibiotic use exist to standardize patient care. Despite supporting evidence, rates of compliance with guidelines vary. Quality improvement initiatives have been introduced to improve compliance with intraoperative antibiotic guidelines. Thorough infection surveillance, including antibiotic provision in presurgical checklists, computerized voice antibiotic administration prompts, and national feedback systems are now increasingly common. Few studies have been conducted investigating the effectiveness of prophylactic antibiotics in children. Outcome measures such as morbidity and mortality and return to the operating room can be used to examine the relationship between antibiotic use and patient outcome but these measures are limited in that they occur infrequently or are subjective and difficult to measure. Metrics such as days alive out of hospital and length of hospital stay may be useful alternatives for ongoing monitoring of infections and identifying improvements in patient outcomes. Guidelines on antibiotic prophylaxis have facilitated an increase in the correct provision of perioperative antibiotics and a reduction in the incidence of postoperative infection. Measures of patient outcome such as days alive out of hospital and length of hospital stay are easy to collect and calculate but further work is needed to confirm the utility of these measures for monitoring infection rates.

Pharmacokinetics of cefuroxime in infants and neonates undergoing cardiac surgery

AIMS

Very little data exist regarding the effect of cardiopulmonary bypass (CPB) on cefuroxime (CXM) pharmacokinetics in children less than one year of age.

METHODS

50 mg kg^-1 CXM i.v. after induction were followed by 75 mg kg^-1 into the CPB circuit. In 42 patients undergoing cardiac surgery, 15-20 samples were obtained between 5 and 360 min after the first dose. Total CXM concentrations were measured by high-performance liquid chromatography and a pharmacokinetic/pharmacodynamic (PK/PD) modelling was performed.

RESULTS

Using a fixed protein binding of 15.6% for CXM, peak plasma concentrations of unbound CXM were 229 ± 52 μg ml^-1 after the first bolus and 341 ± 86 μg ml^-1 on CPB. Nadir concentrations before CPB were 69 ± 20 μg ml^-1 and six hours later decreased to 41 ± 19 μg ml^-1 with and 24 ± 14 μg ml^-1 without CPB. A two-compartment model was fitted with the main covariates body weight, CPB and postmenstrual age (PMA). PK parameters were as follows: systemic clearance, 5.15 [95% CI 4.5-5.8] l h^-1 ; central volume of distribution, 11.25 [9.41-13.09] l; intercompartmental clearance, 18.19 [14.79-21.58] l h^-1 ; and peripheral volume, 17.07 [15.7-18.5] L. ƒT > MIC of 32 μg ml^-1 for an 8-h time period was between 70 and 100% (2.5-10 kg BW). According to our simulation, 25 mg ml^-1 CXM as a primary bolus and into the prime plus a 5 mg kg^-1  h^-1 infusion maintain CXM concentrations continuously above 32 μg ml^-1 .

CONCLUSIONS

The routine dosing regimen provided was sufficient for prophylaxis, but continuous dosing can provide a higher percentage of ƒT > MIC.

Impact of standardization of antimicrobial prophylaxis duration in pediatric cardiac surgery

OBJECTIVES

The optimal duration of antimicrobial prophylaxis following pediatric cardiac surgery is still debated. Adult studies suggest that shorter durations are adequate, but there is a paucity of data on pediatric patients.

METHODS

This quasi-experimental study reviewed the charts of patients 18 years and younger who underwent cardiac surgery from April 2011 to November 2014 at a single institution. Starting in April 2013, a protocol was implemented to limit antimicrobial prophylaxis to 48 hours following sternal closure. Two analyses were performed: (1) identification of risk factors for surgical site infections from the entire cohort, and (2) comparison of surgical site infection incidence in the pre- and postprotocol groups.

RESULTS

In the entire cohort, delayed sternal closure (adjusted odds ratio [OR], 5.7; 95% confidence interval [CI], 1.8-17.9) and younger age (adjusted OR, 2.1; 95% CI, 1.1-3.8) were associated with incidence of surgical site infection. Following the protocol change, duration of antimicrobial prophylaxis decreased from 4.2 ± 2.7 to 1.9 ± 1.3 days (P < .0001). After adjusting for age and delayed sternal closure, the postprotocol group had an adjusted OR of 0.98 (95% CI, 0.32-3.00) for occurrence of surgical site infection. Other outcomes were not altered following the protocol change.

CONCLUSIONS

Restricting antimicrobial prophylaxis to 48 hours following pediatric cardiac surgery did not increase the incidence of surgical site infection at our institution. Further study is needed to validate this finding and to identify practices that reduce surgical site infections in those with delayed sternal closure.

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.

Impact of the implementation of an interdisciplinary infection control program to prevent surgical wound infection in pediatric heart surgery

Surgical site infection (SSI) remains a major source of morbidity, mortality, and increased health care costs in children undergoing heart surgery. The aim of this study was to assess the effectiveness of an intervention program designed to reduce the high incidence of SSI observed at our center in pediatric patients. An interdisciplinary infection control program including pre-, intra-, and postoperative measures was introduced for children undergoing heart surgery with cardiopulmonary bypass. We conducted a quasi-experimental interventional study comparing a pre-intervention cohort (June 2009 to March 2010) and a post-intervention cohort (July 2011 to July 2012). A significant drop in SSI incidence from 10.9 % (95 % CI 4.7-18.8) to 1.92 % (95 % CI 0.4-5.52) was observed. Variables significantly associated with infection risk were median age (14 days in infected vs 2.3 years in non-infected patients; p<0.01), hospitalization unit (10.3 % SSI cumulative incidence in the neonatal intensive care unit vs 0 cases in the pediatric intensive care unit; p<0.01), and median preoperative hospital stay (14 days in infected vs 1 day in non-infected patients; p=0.03).

CONCLUSIONS

The implementation of a new intervention program was associated with an 82 % (95 % CI 34-94) reduction in SSI incidence in children undergoing heart surgery at our center.

WHAT IS KNOWN

• Surgical site infection (SSI) is associated with significant morbidity and mortality following pediatric cardiac surgery. • Younger patients and longer cardiopulmonary bypass times are associated with higher SSI rates. What is New: • Comprehensive infection control program including preoperative, intraoperative and postoperative nonpharmacologic measures is a key factor for the prevention of SSI. • A significant reduction in SSI rates can be achieve despite a narrower-spectrum antibiotic usage.

Nasal methicillin-resistant S. aureus is a major risk for mediastinitis in pediatric cardiac surgery

BACKGROUND

Mediastinitis caused by methicillin-resistant Staphylococcus aureus (MRSA) is a serious complication after pediatric cardiac surgery. An outbreak of surgical site infections (SSIs) provided the motivation to implement SSI prevention measures in our institution.

METHODS

Subjects comprised 174 pediatric patients who underwent open-heart surgery after undergoing preoperative nasal culture screening. The incidence of SSIs and mediastinitis was compared between an early group, who underwent surgery before SSI measures (Group E, n = 73), and a recent group, who underwent surgery after these measures (Group R, n = 101), and factors contributing to the occurrence of mediastinitis were investigated.

RESULTS

The incidence of both SSIs and Mediastinitis has significantly decreased after SSI measures. With regard to factors that significantly affected mediastinitis, preoperative factors were "duration of preoperative hospitalization" and "preoperative MRSA colonization," intraoperative factors were "Aristotle basic complexity score," "operation time," "cardiopulmonary bypass circuit volume" and "lowest rectal temperature." And postoperative factor was "blood transfusion volume." Patients whose preoperative nasal cultures were MRSA-positive suggested higher risk of MRSA mediastinitis.

CONCLUSIONS

SSI prevention measures significantly reduced the occurrence of SSIs and mediastinitis. Preoperative MRSA colonization should be a serious risk factor for mediastinitis following pediatric cardiac surgeries.

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.

Skeletal muscle and plasma concentrations of cefazolin during cardiac surgery in infants

OBJECTIVE

To describe the pharmacokinetics and tissue disposition of prophylactic cefazolin into skeletal muscle in a pediatric population undergoing cardiac surgery.

METHODS

The subjects included 12 children, with a median age of 146 days (interquartile range, 136-174) and median weight of 5.5 kg (interquartile range, 5.2-7.3) undergoing cardiac surgery and requiring cardiopulmonary bypass with or without deep hypothermic circulatory arrest. Institutional cefazolin at standard doses of 25 mg/kg before incision and 25 mg/kg in the bypass prime solution were administered. Serial plasma and skeletal muscle microdialysis samples were obtained intraoperatively and the unbound cefazolin concentrations measured. Noncompartmental pharmacokinetic analyses were performed and the tissue disposition evaluated.

RESULTS

After the first dose of cefazolin, the skeletal muscle concentrations peaked at a median microdialysis collection interval of 30 to 38.5 minutes. After the second dose, the peak concentrations were delayed a median of 94 minutes in subjects undergoing deep hypothermic circulatory arrest. Skeletal muscle exposure to cefazolin measured by the area under concentration time curve 0-last measurement was less in the subjects who underwent deep hypothermic circulatory arrest than in those who received cardiopulmonary bypass alone (P = .04). The skeletal muscle concentrations of cefazolin exceeded the goal concentrations for methicillin-sensitive Staphylococcus aureus prophylaxis; however, the goal concentrations for gram-negative pathogens associated with surgical site infections were achieved only 42.1% to 84.2% and 0% to 11.2% of the intraoperative time in subjects undergoing cardiopulmonary bypass alone or deep hypothermic circulatory arrest, respectively.

CONCLUSIONS

This cefazolin dosing strategy resulted in skeletal muscle concentrations that are likely not effective for surgical prophylaxis against gram-negative pathogens but are effective against methicillin-sensitive S aureus in infants undergoing cardiac surgery.

Surgical site infection rates and risk factors in orthopedic pediatric patients in Madrid, Spain

BACKGROUND

The objective of the study is to study surgical site infection (SSI) rates and risk factors in a pediatric population.

METHODS

We conducted a prospective cohort study to estimate the SSI rate at a national pediatric referral center, covering all patients managed at the Orthopedic Surgery Department of the Niño Jesús Children's University Teaching Hospital from January 2010 through December 2012. Risk factors and antibiotic prophylaxis were monitored. A comparison between Spanish and US data was performed, with a breakdown by National Nosocomial Infection Surveillance risk indices. We also conducted a comparative study of SSI rates from 2010 to 2012 to assess the impact of the epidemiologic surveillance system.

RESULTS

The study population of 1079 patients had a SSI rate of 2.8%. SSI rates were calculated for spinal fusion and other musculoskeletal procedures according to the National Nosocomial Infection Surveillance risk index. In the case of other musculoskeletal procedures, our SSI rates were 0.8 times lower than the overall Spanish rate, but higher than US rates for all risk categories. For spinal fusion procedures, our SSI rates were 1.2 times higher than the Spanish rates and 3.5 times higher than National Nosocomial Infection Surveillance rates. This latter finding should be interpreted with caution because it was based on a small sample. The multivariate analysis indicated that the only predictive factors of SSI were American Society of Anesthesiologists score and age.

CONCLUSIONS

The surveillance program showed that for clean procedures, SSI incidence decreased from 4% in 2010 to 3.2% in 2011 and to 2.4% in 2012.

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.

Preoperative antiseptic skin preparations and reducing SSI

Surgical site infection (SSI) can affect the quality of care and increase the morbidity and mortality rate in after-surgical procedure. The use of an antiseptic skin preparation agent before the procedure can reduce the pathogens in the skin surface around the incision. Indicating the type of skin antiseptic preparation could prevent the infection and contamination of the wound. The most commonly used types of skin preparations are chlorhexidine and povidone iodine. However, the antiseptic solutions of both agents are strengthened with alcohol to prevent postoperative wound infection. The aim of this paper is to identify the best antiseptic agent in terms of skin preparation by evaluating the evidence in the literature. The factors associated with choosing the antiseptic skin agent, such as patients' allergies, skin condition and environmental risk, are also taken into account. This review suggests that cholorhexdine with alcohol may be the most effective in terms of reducing SSI.

Surgical site infections and bloodstream infections in infants after cardiac surgery

OBJECTIVE

Few recent studies have assessed the epidemiology of and risk factors for surgical site infections (SSIs) and bloodstream infections (BSIs) in infants after cardiac surgery. We hypothesized that infants younger than 30 days old and those with higher Risk Adjustment in Congenital Heart Surgery-1 scores would have an increased risk of SSIs, but not an increased risk of BSIs after surgery.

METHODS

We performed a retrospective cohort study of infants younger than 1 year of age undergoing cardiac surgery from January 2010 to December 2011 to determine the rates of SSIs and BSIs occurring within 3 months of surgery, risk factors associated with these infections, and causative pathogens. Multivariable associations using Cox proportional hazard modeling assessed potential risk factors for BSIs or SSIs.

RESULTS

Overall, 8.7% (48 of 552) of surgical procedures were complicated by SSIs (n = 19) or BSIs (n = 29). Thus, SSIs and BSIs occurred after 3.4% and 5.3% of procedures, respectively. Multivariate models found age younger than 30 days, incorrect timing of preoperative antibiotics, and excessive bleeding within 24 hours of surgery to be significant predictors for SSIs, and duration of use of arterial lines to be a significant predictor for BSIs. Gram-positive bacteria caused 75% of SSIs and BSIs and methicillin-susceptible Staphylococcus aureus caused 63% of SSIs.

DISCUSSION

We identified some potential strategies to reduce risk, including closer monitoring of timing of preoperative antimicrobial prophylaxis and enhanced efforts to achieve intraoperative hemostasis and earlier removal of arterial lines.

CONCLUSIONS

SSIs and BSIs remain important complications after cardiac surgery in infants.

Postoperative differences between colonization and infection after pediatric cardiac surgery-a propensity matched analysis

Background

The objective of this study was to identify the postoperative risk factors associated with the conversion of colonization to postoperative infection in pediatric patients undergoing cardiac surgery.

Methods

Following approval from the Institutional Review Board, patient demographics, co-morbidities, surgery details, transfusion requirements, inotropic infusions, laboratory parameters and positive microbial results were recorded during the hospital stay, and the patients were divided into two groups: patients with clinical signs of infection and patients with only positive cultures but without infection during the postoperative period. Using propensity scores, 141 patients with infection were matched to 141 patients with positive microbial cultures but without signs of infection. Our database consisted of 1665 consecutive pediatric patients who underwent cardiac surgery between January 2004 and December 2008 at a single center. The association between the patient group with infection and the group with colonization was analyzed after propensity score matching of the perioperative variables.

Results

179 patients (9.3%) had infection, and 253 patients (15.2%) had colonization. The occurrence of Gram-positive species was significantly greater in the colonization group (p = 0.004). The C-reactive protein levels on the first and second postoperative days were significantly greater in the infection group (p = 0.02 and p = 0.05, respectively). The sum of all the positive cultures obtained during the postoperative period was greater in the infection group compared to the colonization group (p = 0.02). The length of the intensive care unit stay (p < 0.001) was significantly longer in the infection group compared to the control group.

Conclusions

Based on our results, we uncovered independent relationships between the conversion of colonization to infection regarding positive S. aureus and bloodstream results, as well as significant differences between the two groups regarding postoperative C-reactive protein levels and white blood cell counts.

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.

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.

[Antibiotic prophylaxis for surgical wound infection in cardiac surgery: results of a Spanish survey]

INTRODUCTION

No Spanish guidelines for the prevention of surgical wound infection in paediatric cardiac surgery are currently available. The aim of this study was to analyse the nationwide variability in antibiotic prophylaxis use.

MATERIAL AND METHODS

An online questionnaire was distributed to all members of the Cardiology Group of the Spanish Society of Paediatric Intensive Care. Fifteen centres participated in the study.

RESULTS

In heart surgery with no delayed sternal closure, all 15 centres used a 1st or 2nd generation cephalosporin in paediatric patients, while 3 hospitals used a broader-spectrum antibiotic therapy in neonates. Prophylaxis was maintained for 12-72h in 11 centres and until drainage removal in four. Thirteen centres used delayed sternal closure, eight of which followed the same protocol for these patients as for standard procedures. Prophylaxis was maintained for 12-72h in 6 centres, and until sternal closure at the rest. Five out of 10 centres performing extracorporeal membrane oxygenation (ECMO) maintained the same antibiotic protocol as in standard surgery.

CONCLUSIONS

A wide variability was observed in antibiotic prophylaxis use in high-risk patients. Thus, national protocols need to be standardised.

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.

Bedside prediction rule for infections after pediatric cardiac surgery

Purpose

Infections after pediatric cardiac surgery are a common complication, occurring in up to 30% of cases. The purpose of this study was to develop a bedside prediction rule to estimate the risk of a postoperative infection.

Methods

All consecutive pediatric cardiac surgery procedures between April 2006 and May 2009 were retrospectively analyzed. The primary outcome variable was any postoperative infection, as defined by the Center of Disease Control (2008). All variables known to the clinician at the bedside at 48 h post cardiac surgery were included in the primary analysis, and multivariable logistic regression was used to construct a prediction rule.

Results

A total of 412 procedures were included, of which 102 (25%) were followed by an infection. Most infections were surgical site infections (26% of all infections) and bloodstream infections (25%). Three variables proved to be most predictive of an infection: age less than 6 months, postoperative pediatric intensive care unit (PICU) stay longer than 48 h, and open sternum for longer than 48 h. Translation into prediction rule points yielded 1, 4, and 1 point for each variable, respectively. Patients with a score of 0 had 6.6% risk of an infection, whereas those with a maximal score of 6 had a risk of 57%. The area under the receiver operating characteristic curve was 0.78 (95% confidence interval 0.72–0.83).

Conclusions

A simple bedside prediction rule designed for use at 48 h post cardiac surgery can discriminate between children at high and low risk for a subsequent infection.

Corticosteroids and outcome in children undergoing congenital heart surgery: analysis of the Pediatric Health Information Systems database

BACKGROUND

Children undergoing congenital heart surgery often receive corticosteroids with the aim of reducing the inflammatory response after cardiopulmonary bypass; however, the value of this approach is unclear.

METHODS AND RESULTS

The Pediatric Health Information Systems Database was used to evaluate outcomes associated with corticosteroids in children (0 to 18 years of age) undergoing congenital heart surgery at 38 US centers from 2003 to 2008. Propensity scores were constructed to account for potential confounders: age, sex, race, prematurity, genetic syndrome, type of surgery (Risk Adjustment in Congenital Heart Surgery [RACHS-1] category), center, and center volume. Multivariable analysis, adjusting for propensity score and individual covariates, was performed to evaluate in-hospital mortality, postoperative length of stay, duration of ventilation, infection, and use of insulin. A total of 46 730 children were included; 54% received corticosteroids. In multivariable analysis, there was no difference in mortality among corticosteroid recipients and nonrecipients (odds ratio, 1.13; 95% confidence interval, 0.98 to 1.30). Corticosteroids were associated with longer length of stay (least square mean difference, 2.18 days; 95% confidence interval, 1.62 to 2.74 days), greater infection (odds ratio, 1.27; 95% confidence interval, 1.10 to 1.46), and greater use of insulin (odds ratio, 2.45; 95% confidence interval, 2.24 to 2.67). There was no difference in duration of ventilation. In analysis stratified by RACHS-1 category, no significant benefit was seen in any group, and the association of corticosteroids with increased morbidity was most prominent in RACHS-1 categories 1 through 3.

CONCLUSION

In this observational analysis of children undergoing congenital heart surgery, we were unable to demonstrate a significant benefit associated with corticosteroids and found that corticosteroids may be associated with increased morbidity, particularly in lower-risk patients.

Risk factors and risk adjustment for surgical site infections in pediatric cardiothoracic surgery patients

BACKGROUND

The complexity of congenital cardiac defects and the aggressive medical management required to support patients through their recovery place children at high risk for surgical site infection (SSI).

METHODS

We conducted a retrospective review of children undergoing cardiothoracic surgery at a tertiary care referral center between January 1, 2000, and June 30, 2001. Preoperative, intraoperative, and postoperative data were assessed by multivariate analysis.

RESULTS

Of 726 surgical procedures performed in 626 patients, SSIs occurred after 46 procedures performed in 46 patients (6.3%). Infections were superficial (n = 22; 47.8%), deep tissue (n = 7; 15.2%), or organ space (n = 17; 37.0%), including 5 episodes of mediastinitis. Median time to SSI was 10 days; 36% of the infections were identified after discharge. On multivariate analysis, children with SSIs were more likely to have been <30 days old (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.2-70), to have a perioperative medical device, and to use parenteral nutrition (OR, 3.3; 95% CI, 1.4-7.9). Multiple severity of illness scores, the Risk Adjustment for Congenital Heart Surgery (RACHS-1) category, and longer duration of postoperative antimicrobials were not associated with SSI.

CONCLUSION

The use of perioperative medical interventions increases the risk of SSI in young children after cardiac surgery. Prolonged postoperative courses of antimicrobials should be avoided in the absence of documented infection.

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.