Characterizing Sleep Disruption and Delirium in Children After Cardiac Surgery: A Feasibility Study.

OBJECTIVES: Patients in the pediatric cardiac ICU are frequently exposed to pharmacologic and environmental factors that predispose them to sleep disturbances and may increase the risk of delirium. In this pilot study, we sought to demonstrate the feasibility of actigraphy monitoring in pediatric cardiac ICU patients to investigate the association between sleep characteristics and delirium development. DESIGN: Prospective observational pilot study. SETTING: Pediatric cardiac ICU in an academic children's hospital in the United States. PATIENTS: Children admitted to the pediatric cardiac ICU after cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Nineteen enrolled patients wore actigraphy watches that provided data for a total of 63 pediatric cardiac ICU days. The median pediatric cardiac ICU length of stay was 2 days (interquartile range, 1-3 d). The median sleep episode among all patients was 37 minutes in duration (interquartile range, 18-46 min), and the longest sleep episode was a median of 117 minutes (interquartile range, 69-144 min). Sixty-one percent of patients (95% CI, 36-83%) screened positive for delirium at least once during admission, and the median number of delirious days among those who were positive was 2 days (interquartile range, 1-3 d). The median percent sleep time was 43% for delirious patients and 49% for those with no delirium, with similar median sleep and longest sleep episodes. The median ratio of daytime activity/24-hr activity was 54% (interquartile range, 49-59%) in both groups. CONCLUSIONS: Actigraphy monitoring in conjunction with delirium screening is feasible in infants and children admitted to the pediatric cardiac ICU after cardiac surgery. Our data suggest that most children in the pediatric cardiac ICU experience severe sleep disruption and delirium is common. These pilot data provide important insights for the design of a large-scale observational study to investigate potential causal relationships between sleep disruption and delirium in the pediatric cardiac ICU.

Fluid Overload and Cumulative Thoracostomy Output Are Associated With Surgical Site Infection After Pediatric Cardiothoracic Surgery.

OBJECTIVES: To determine the impact of cumulative, postoperative thoracostomy output, amount of bolus IV fluids and peak fluid overload on the incidence and odds of developing a deep surgical site infection following pediatric cardiothoracic surgery. DESIGN: A single-center, nested, retrospective, matched case-control study. SETTING: A 26-bed cardiac ICU in a 303-bed tertiary care pediatric hospital. PATIENTS: Cases with deep surgical site infection following cardiothoracic surgery were identified retrospectively from January 2010 through December 2013 and individually matched to controls at a ratio of 1:2 by age, gender, Risk Adjustment for Congenital Heart Surgery score, Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery category, primary cardiac diagnosis, and procedure. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Twelve cases with deep surgical site infection were identified and matched to 24 controls without detectable differences in perioperative clinical characteristics. Deep surgical site infection cases had larger thoracostomy output and bolus IV fluid volumes at 6, 24, and 48 hours postoperatively compared with controls. For every 1 mL/kg of thoracostomy output, the odds of developing a deep surgical site infection increase by 13%. By receiver operative characteristic curve analysis, a cutoff of 49 mL/kg of thoracostomy output at 48 hours best discriminates the development of deep surgical site infection (sensitivity 83%, specificity 83%). Peak fluid overload was greater in cases than matched controls (12.5% vs 6%; p < 0.01). On receiver operative characteristic curve analysis, a threshold value of 10% peak fluid overload was observed to identify deep surgical site infection (sensitivity 67%, specificity 79%). Conditional logistic regression of peak fluid overload greater than 10% on the development of deep surgical site infection yielded an odds ratio of 9.4 (95% CI, 2-46.2). CONCLUSIONS: Increased postoperative peak fluid overload and cumulative thoracostomy output were associated with deep surgical site infection after pediatric cardiothoracic surgery. We suspect the observed increased thoracostomy output, fluid overload, and IV fluid boluses may have altered antimicrobial prophylaxis. Although analysis of additional pharmacokinetic data is warranted, providers may consider modification of antimicrobial prophylaxis dosing or alterations in fluid management and diuresis in response to assessment of peak fluid overload and fluid volume shifts in the immediate postoperative period.

Surgical Site Infection After Pediatric Cardiothoracic Surgery.

BACKGROUND: Surgical site infection (SSI) occurs in 0.25% to 6% of children after cardiothoracic surgery (CTS). There are no published data regarding the financial impact of SSI after pediatric CTS. We sought to determine the attributable hospital cost and length of stay associated with SSI in children after CTS. METHODS: We performed a retrospective, matched cohort study in a 26-bed cardiac intensive care unit (CICU) from January 2010 through December 2013. Cases with SSI were identified retrospectively and individually matched to controls 2:1 by age, gender, Risk Adjustment for Congenital Heart Surgery score, Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery category, and primary cardiac diagnosis and procedure. RESULTS: Of the 981 cases performed during the study period, 12 with SSI were identified. There were no differences in demographics, clinical characteristics, or intraoperative data. Median total hospital costs were higher in participants with SSI as compared to controls (US$219,573 vs US$82,623, P < .01). Children with SSI had longer median CICU length of stay (9 vs 3 days, P < .01), hospital length of stay (18 vs 8.5 days, P < .01), and duration of mechanical ventilation (2 vs 1 day, P < .01) and vasoactive administration (4.5 vs 1 day, P < .01). CONCLUSIONS: Children with SSI after CTS have an associated increase in hospital costs of US$136,950/case and hospital length of stay of 9.5 days/case. The economic burden posed by SSI stress the importance of infection control surveillance, exhaustive preventative measures, and identification of modifiable risk factors.

More serious infectious morbidity and mortality associated with simultaneous candidemia and coagulase-negative staphylococcal bacteremia in neonates and in vitro adherence studies between Candida albicans and Staphylococcus epidermidis.

BACKGROUND: Candida species and coagulase-negative staphylococci (CoNS) are common etiologies of hospital acquired bloodstream infection in the neonatal intensive care unit (NICU). Sepsis with either organism may result in serious infectious sequelae and along with other staphylococci are the most common causes of abscess formation in preterm infants. This increased incidence of abscess formation may be in part due to adherence factors of both pathogens. METHODS: All cases of concurrent positive blood cultures for both Candida species and CoNS were identified from the microbiology database in NICU patients from January 1998 to December 2000 and analyzed for risk factors and outcomes. In vitro co-aggregation studies between Candida albicans and Staphylococcus epidermidis were also performed. RESULTS: Six premature infants were identified as having concurrent Candida and CoNS bloodstream infections during this time period. Four of the six patients developed end-organ dissemination with abscess or infected thrombus formation. Three of the six patients expired during or after their infection. In vitro, co-aggregation studies did not demonstrate reproducible direct adherence between C. albicans and S. epidermidis. CONCLUSIONS: Simultaneous bloodstream infection with Candida and CoNS, compared to either one alone, is more likely to predispose to abscess formation, septic thrombophlebitis and mortality. Further studies are needed to examine the pathogenesis of these complex infections.

Frontiers in pulmonary hypertension in infants and children with bronchopulmonary dysplasia.

Pulmonary hypertension (PH) is an increasingly recognized complication of premature birth and bronchopulmonary dysplasia (BPD), and is associated with increased morbidity and mortality. Extreme phenotypic variability exists among preterm infants of similar gestational ages, making it difficult to predict which infants are at increased risk for developing PH. Intrauterine growth retardation or drug exposures, postnatal therapy with prolonged positive pressure ventilation, cardiovascular shunts, poor postnatal lung and somatic growth, and genetic or epigenetic factors may all contribute to the development of PH in preterm infants with BPD. In addition to the variability of severity of PH, there is also qualitative variability seen in PH, such as the variable responses to vasoactive medications. To reduce the morbidity and mortality associated with PH, a multi-pronged approach is needed. First, improved screening for and increased recognition of PH may allow for earlier treatment and better clinical outcomes. Second, identification of both prenatal and postnatal risk factors for the development of PH may allow targeting of therapy and resources for those at highest risk. Third, understanding the pathophysiology of the preterm pulmonary vascular bed may help improve outcomes through recognizing pathways that are dysregulated in PH, identifying novel biomarkers, and testing novel treatments. Finally, the recognition of conditions and exposures that may exacerbate or lead to recurrent PH is needed to help with developing treatment guidelines and preventative strategies that can be used to reduce the burden of disease.

Inhaled epoprostenol therapy for pulmonary hypertension: Improves oxygenation index more consistently in neonates than in older children.

The purpose of this study was to determine the efficacy of inhaled epoprostenol for treatment of acute pulmonary hypertension (PH) in pediatric patients and to formulate a plan for a prospective, randomized study of pulmonary vasodilator therapy in this population. Inhaled epoprostenol is an effective treatment for pediatric PH. A retrospective chart review was conducted of all pediatric patients who received inhaled epoprostenol at a tertiary care hospital between October 2005 and August 2007. The study population was restricted to all patients under 18 years of age who received inhaled epoprostenol for greater than 1 hour and had available data for oxygenation index (OI) calculation. Arterial blood gas values and ventilator settings were collected immediately prior to epoprostenol initiation, and during epoprostenol therapy (as close to 12 hours after initiation as possible). Echocardiograms were reviewed during two time frames: Within 48 hours prior to therapy initiation and within 96 hours after initiation. Of the 20 patients in the study population, 13 were neonates, and the mean OI for these patients improved during epoprostenol administration (mean OI before and during therapy was 25.6±16.3 and 14.5±13.6, respectively, P=0.02). Mean OI for the seven patients greater than 30 days of age was not significantly different during treatment (mean OI before and during therapy was 29.6±15.0 and 25.6±17.8, P=0.56). Improvement in echocardiographic findings (evidence of decreased right-sided pressures or improved right ventricular function) was demonstrated in 20% of all patients. Inhaled epoprostenol is an effective therapy for the treatment of selected pediatric patients with acute PH. Neonates may benefit more consistently from this therapy than older infants and children. A randomized controlled trial is needed to discern the optimal role for inhaled prostanoids in the treatment of acute PH in childhood.

Cardiac myofilaments: from proteome to pathophysiology.

This review addresses the functional consequences of altered post-translational modifications of cardiac myofilament proteins in cardiac diseases such as heart failure and ischemia. The modifications of thick and thin filament proteins as well as titin are addressed. Understanding the functional consequences of altered protein modifications is an essential step in the development of targeted therapies for common cardiac diseases.