Epidemiology of Postoperative Junctional Ectopic Tachycardia in Infants Undergoing Cardiac Surgery.

BACKGROUND: Junctional ectopic tachycardia (JET) complicates congenital heart surgery in 2% to 8.3% of cases. JET is associated with postoperative morbidity in single-center studies. We used the Pediatric Cardiac Critical Care Consortium data registry to provide a multicenter epidemiologic description of treated JET. METHODS: This is a retrospective study (February 2019-August 2022) of patients with treated JET. Inclusion criteria were (1) <12 months old at the index operation, and (2) treated for JET <72 hours after surgery. Diagnosis was defined by receiving treatment (pacing, cooling, and medications). A multilevel logistic regression analysis with hospital random effect identified JET risk factors. Impact of JET on outcomes was estimated by margins/attributable risk analysis using previous risk-adjustment models. RESULTS: Among 24,073 patients from 63 centers, 1436 (6.0%) were treated for JET with significant center variability (0% to 17.9%). Median time to onset was 3.4 hours, with 34% present on admission. Median duration was 2 days (interquartile range, 1-4 days). Tetralogy of Fallot, atrioventricular canal, and ventricular septal defect repair represented >50% of JET. Patient characteristics independently associated with JET included neonatal age, Asian race, cardiopulmonary bypass time, open sternum, and early postoperative inotropic agents. JET was associated with increased risk-adjusted durations of mechanical ventilation (incidence rate ratio, 1.6; 95% CI, 1.5-1.7) and intensive care unit length of stay (incidence rate ratio, 1.3; 95% CI, 1.2-1.3), but not mortality. CONCLUSIONS: JET is treated in 6% of patients with substantial center variability. JET contributes to increased use of postoperative resources. High center variability warrants further study to identify potential modifiable factors that could serve as targets for improvement efforts to ameliorate deleterious outcomes.

Predictors of Mediastinal Exploration While on Extracorporeal Membrane Oxygenation After Pediatric Cardiac Surgery.

Cardiac surgical patients requiring extracorporeal membrane oxygenation (ECMO) are at increased risk for hemorrhage due to necessary anticoagulation, in-situ cannulas, and disturbed hemostasis. We performed a retrospective, cross-sectional study of patients 0-18 years old in our cardiac intensive care unit (CICU) cannulated to ECMO within 48 h of cardiopulmonary bypass. The 69 patients included in the study were divided into three analysis groups based on serial chest tube output per hour: no bleeding (NB) on admission to the CICU (21/69, 30%), bleeding stopped (BS) with medical management (26/69, 38%), bleeding requiring emergent mediastinal exploration (BME) (22/69, 32%). The NB group had a more favorable coagulation profile upon admission to the CICU (PTT 53 s NB, 105 s BS, 83 s BME p < 0.001, ACT 169 s NB, 225 s BS, 211 s BME, p =0.013). Only chest tube output during the first three postcannulation hours remained associated with the need for mediastinal exploration by multivariable analysis. An average chest-tube output of 11.6 mL/kg/h during the first three hours had the highest percentage of patients classified correctly (84%) for requiring mediastinal exploration during their ECMO run (sensitivity 91%, specificity 81%).

Preventing Cardiac Arrest in the Pediatric Cardiac Intensive Care Unit Through Multicenter Collaboration.

Importance: Preventing in-hospital cardiac arrest (IHCA) likely represents an effective strategy to improve outcomes for critically ill patients, but feasibility of IHCA prevention remains unclear. Objective: To determine whether a low-technology cardiac arrest prevention (CAP) practice bundle decreases IHCA rate. Design, Setting, and Participants: Pediatric cardiac intensive care unit (CICU) teams from the Pediatric Cardiac Critical Care Consortium (PC4) formed a collaborative learning network to implement the CAP bundle consistent with the Institute for Healthcare Improvement framework; 15 hospitals implemented the bundle voluntarily. Risk-adjusted IHCA incidence rates were analyzed across 2 time periods, 12 months (baseline) and 18 months after CAP implementation (intervention) using difference-in-differences (DID) regression to compare 15 CAP and 16 control PC4 hospitals that chose not to participate in CAP but had IHCA rates tracked in the PC4 registry. Patients deemed at high risk for IHCA, based on a priori evidence-based criteria and empirical hospital-specific criteria, were selected to receive the CAP bundle. Data were collected from July 2018 to December 2019, and data were analyzed from March to August 2020. Interventions: CAP bundle included 5 elements developed to promote increased situational awareness and communication among bedside clinicians to recognize and mitigate deterioration in high-risk patients. Main Outcomes and Measures: Risk-adjusted IHCA incidence rate across all CICU admissions (IHCA events divided by all admissions). Results: The bundle was activated in 2664 of 10 510 CAP hospital admissions (25.3%); admission characteristics were similar across study periods. There was a 30% relative reduction in risk-adjusted IHCA incidence rate at CAP hospitals (intervention period: 2.6%; 95% CI, 2.2-2.9; baseline: 3.7%; 95% CI, 3.1-4.0), but no change at control hospitals (intervention period: 2.7%; 95% CI, 2.3-2.9; baseline: 2.7%; 95% CI, 2.2-3.0). DID analysis confirmed significantly reduced odds of IHCA among all admissions at CAP hospitals compared with control hospitals during the intervention period vs baseline (odds ratio, 0.72; 95% CI, 0.56-0.91; P = .01). DID odds ratios were 0.72 (95% CI, 0.53-0.98) for the surgical subgroup, 0.74 (95% CI, 0.48-1.14) for the medical subgroup, and 0.72 (95% CI, 0.50-1.03) for the high-risk admission subgroup at CAP hospitals after intervention. All-cause risk-adjusted mortality rate did not change after intervention. Conclusions and Relevance: Implementation of this CAP bundle led to significant IHCA reduction across multiple pediatric CICUs. Future studies may determine if this bundle can be effective in other critically ill populations.

Deposition studies of aerosol delivery by nasal cannula to infants.

AIM: Nasal cannulas are used to provide oxygen support for infants and have been considered as a means for delivering aerosols to the lungs. To measure mucociliary clearance in the lungs of infants with congenital heart defects, we delivered radiopharmaceutical aerosols via a nasal cannula. Here we report on the pulmonary and nasal deposition of these aerosols. METHOD: A total of 18 infants (median age = 26 days; quartiles = 11-74 days) performed clearance measurements soon before or after corrective cardiac surgery. The regional aerosol deposition was assessed using gamma camera imaging. RESULTS: Cannula flow rate significantly affected pulmonary dosing. Flow rates useful for oxygen support were associated with low pulmonary deposition (2 L/min; mean, 4.5% of deposited dose; range, 2%-9%; n = 7) and high nasal deposition. Much lower cannula flow rates increased the pulmonary deposition (0.2 L/min; mean, 33.5% of deposited dose; range, 15%-51%; n = 5; P = 0.005 vs 2 L/min). The ratio of nose/lung dosing was approximately 26:1 at 2 L/min and 2:1 at 0.2 L/min. Bench studies demonstrated cannula output rates of 10.2 ± 1.7% (2 L/min) and 3.3 ± 0.4% (0.2 L/min) of the loaded nebulizer dose during a 2-minute delivery. Combining in vitro and in vivo results, we estimate that 0.46% of the loaded nebulizer dose reaches the lungs at 2 L/min vs 1.10% at 0.2 L/min during a 2-minute delivery. CONCLUSION: With the delivery system used here, pulmonary aerosol delivery via nasal cannula was very inefficient at the flow rates required to provide oxygen support. Even at low flows, nasal deposition was substantial and local toxicity must be considered.

Acute Neurologic Injury in Children Admitted to the Cardiac Intensive Care Unit.

BACKGROUND: Children with acquired and congenital heart disease both have low mortality but an increased risk of neurologic morbidity that is multifactorial. Our hypothesis was that acute neurologic injuries contribute to mortality in such children and are an important cause of death. METHODS: All admissions to the pediatric cardiac intensive care unit (CICU) from January 2011 through January 2015 were retrospectively reviewed. Patients were assessed for any acute neurologic events (ANEs) during admission, as defined by radiologic findings or seizures documented on an electroencephalogram. RESULTS: Of the 1,573 children admitted to the CICU, the incidence of ANEs was 8.6%. Mortality of the ANE group was 16.3% compared with 1.5% for those who did not have an ANE. The odds ratio for death with ANEs was 8.55 (95% confidence interval, 4.56 to 16.03). Patients with ANEs had a longer hospital length of stay than those without ANEs (41.4 ± 4 vs 14.2 ± 0.6 days; p < 0.001). Need for extracorporeal membrane oxygenation, previous cardiac arrest, and prematurity were independently associated with the presence of an ANE. CONCLUSIONS: Neurologic injuries are common in pediatric CICUs and are associated with an increase in mortality and hospital length of stay. Children admitted to the CICU are likely to benefit from improved surveillance and neuroprotective strategies to prevent neurologic death.

Associations of Perioperative Renal Oximetry Via Near-Infrared Spectroscopy, Urinary Biomarkers, and Postoperative Acute Kidney Injury in Infants After Congenital Heart Surgery: Should Creatinine Continue to Be the Gold Standard?

OBJECTIVES: Examine the relationship between perioperative renal regional tissue oximetry, urinary biomarkers, and acute kidney injury in infants after congenital cardiac surgery with cardiopulmonary bypass. DESIGN: Prospective, observational. SETTING: Cardiac operating room and cardiac ICU. PATIENTS: Neonates and infants without history of kidney injury or anatomic renal abnormality. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Renal regional tissue oximetry was measured intraoperatively and for 48 hours postoperatively. Urinary levels of neutrophil gelatinase-associated lipocalin and tissue inhibitor of metalloproteinases 2 together with insulin-like growth factor-binding protein 7 were measured preoperatively, 2, 12, and 24 hours postoperatively. Patients were categorized as no acute kidney injury, stage 1, or Stage 2-3 acute kidney injury using the Kidney Disease: Improving Global Outcomes criteria with 43 of 70 (61%) meeting criteria for any stage acute kidney injury. Stage 2-3 acute kidney injury patients had higher tissue inhibitor of metalloproteinases 2, insulin-like growth factor-binding protein 7 at 2 hours (0.3 vs 0.14 for stage 1 acute kidney injury and 0.05 for no acute kidney injury; p = 0.052) and 24 hours postoperatively (1.71 vs 0.27 for stage 1 acute kidney injury and 0.19 for no acute kidney injury, p = 0.027) and higher neutrophil gelatinase-associated lipocalin levels at 24 hours postoperatively (10.3 vs 3.4 for stage 1 acute kidney injury and 6.2 for no acute kidney injury, p = 0.019). Stage 2-3 acute kidney injury patients had lower mean cardiac ICU renal regional tissue oximetry (66% vs 79% for stage 1 acute kidney injury and 84% for no acute kidney injury, p = 0.038). Regression analyses showed that tissue inhibitor of metalloproteinases 2, insulin-like growth factor-binding protein 7 at 2 hours postoperatively and nadir intraoperative renal regional tissue oximetry to be independent predictors of postoperative kidney damage as measured by urinary neutrophil gelatinase-associated lipocalin. CONCLUSIONS: We observed modest differences in perioperative renal regional tissue oximetry and urinary biomarker levels compared between acute kidney injury groups classified by creatinine-dependent Kidney Disease: Improving Global Outcomes criteria, but there were significant correlations between renal regional tissue oximetry, tissue inhibitor of metalloproteinases 2, insulin-like growth factor-binding protein 7, and postoperative neutrophil gelatinase-associated lipocalin levels. Kidney injury after infant cardiac surgery may be undetectable by functional assessment (creatinine) alone, and continuous monitoring of renal regional tissue oximetry may be more sensitive to important subclinical acute kidney injury.

The Epidemiology of Healthcare-associated Infections in Pediatric Cardiac Intensive Care Units.

BACKGROUND: Healthcare-associated infections (HAIs) represent serious complications for patients within pediatric cardiac intensive care units (CICU). HAIs are associated with increased morbidity, mortality and resource utilization. There are few studies describing the epidemiology of HAIs across the entire spectrum of patients (surgical and nonsurgical) receiving care in dedicated pediatric CICUs. METHODS: Retrospective analyses of 22,839 CICU encounters from October 2013 to September 2016 across 22 North American CICUs contributing data to the Pediatric Cardiac Critical Care Consortium clinical registry. RESULTS: HAIs occurred in 2.4% of CICU encounters at a rate of 3.3 HAIs/1000 CICU days, with 73% of HAIs occurring in children <1 year. Eighty encounters (14%) had ≥2 HAIs. Aggregate rates for the 4 primary HAIs are as follows: central line-associated blood stream infection, 1.1/1000 line days; catheter-associated urinary tract infections, 1.5/1000 catheter days; ventilator-associated pneumonia, 1.9/1000 ventilator days; surgical site infections, 0.81/100 operations. Surgical and nonsurgical patients had similar HAIs rates/1000 CICU days. Incidence was twice as high in surgical encounters and increased with surgical complexity; postoperative infection occurred in 2.8% of encounters. Prematurity, younger age, presence of congenital anomaly, Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Categories (STAT) 4-5 surgery, admission with an active medical condition, open sternum and extracorporeal membrane oxygenation were independently associated with HAIs. In univariable analysis, HAI was associated with longer hospital length of stay and durations of urinary catheter, central venous catheter and ventilation. Mortality was 24.4% in patients with HAIs versus 3.4% in those without, P < 0.0001. CONCLUSIONS: We provide comprehensive multicenter benchmark data regarding rates of HAIs within dedicated pediatric CICUs. We confirm that although rare, HAIs of all types are associated with significant resource utilization and mortality.

Serum Neuronal Biomarkers in Neonates With Congenital Heart Disease Undergoing Cardiac Surgery.

BACKGROUND: Newborns with congenital heart disease have associated brain damage that affects short-and long-term neurodevelopment. Several neuronal biomarkers exist that could predict brain damage. We investigated the pattern of neuron-specific enolase (NSE) and s100B levels after cardiopulmonary bypass surgery in neonates with congenital heart disease. METHODS: We completed a prospective observational study of neonates with congenital heart disease who were undergoing cardiopulmonary bypass surgery. NSE and s100B levels were measured from serum samples obtained preoperatively, immediately postoperatively, and once daily on postoperative days one to seven. Cranial ultrasounds were obtained preoperatively and postoperatively and findings were scored using an internally developed scoring system. RESULTS: Eighteen neonates were included. Immediate postoperative and peak levels of both NSE (58.0 [21.6] and 68.1 [55.7] µg/L) and s100B (0.14 [0.3] and 0.14 [0.3] µg/L) were significantly increased when compared with preoperative levels (34.0 [21.6] µg/L; P < 0.01 and 0.08 [0.1] µg/L; P < 0.02). By postoperative day seven, NSE and s100B levels were lower than preoperative levels: NSE (18 [5.7]; P = 0.09) and s100B (0.03 [0.05]; P < 0.01). Postoperative s100B levels were negatively correlated with age at surgery and positively correlated with circulatory arrest time. Although there was no significant correlation between either NSE or s100B levels and intensive care unit length of stay, hospital length of stay, and pediatric cerebral performance category score, there was a negative correlation between postoperative levels of NSE and ventriculomegaly. CONCLUSIONS: NSE and s100B levels increase after bypass surgery and return below preoperative baseline levels by postoperative day seven. The levels of s100B were positively correlated with circulatory arrest time and negatively correlated with age at time of surgery. This finding may be supportive of pre-existing prenatal brain injury that could be enhanced by longer surgical times but also of some brain protection effect associated with longer wait until surgery.

Clinical epidemiology and centre variation in chylothorax rates after cardiac surgery in children: a report from the Pediatric Cardiac Critical Care Consortium.

Introduction Chylothorax after paediatric cardiac surgery incurs significant morbidity; however, a detailed understanding that does not rely on single-centre or administrative data is lacking. We described the present clinical epidemiology of postoperative chylothorax and evaluated variation in rates among centres with a multicentre cohort of patients treated in cardiac ICU. METHODS: This was a retrospective cohort study using prospectively collected clinical data from the Pediatric Cardiac Critical Care Consortium registry. All postoperative paediatric cardiac surgical patients admitted from October, 2013 to September, 2015 were included. Risk factors for chylothorax and association with outcomes were evaluated using multivariable logistic or linear regression models, as appropriate, accounting for within-centre clustering using generalised estimating equations. RESULTS: A total of 4864 surgical hospitalisations from 15 centres were included. Chylothorax occurred in 3.8% (n=185) of hospitalisations. Case-mix-adjusted chylothorax rates varied from 1.5 to 7.6% and were not associated with centre volume. Independent risk factors for chylothorax included age <1 year, non-Caucasian race, single-ventricle physiology, extracardiac anomalies, longer cardiopulmonary bypass time, and thrombosis associated with an upper-extremity central venous line (all p<0.05). Chylothorax was associated with significantly longer duration of postoperative mechanical ventilation, cardiac ICU and hospital length of stay, and higher in-hospital mortality (all p<0.001). CONCLUSIONS: Chylothorax after cardiac surgery in children is associated with significant morbidity and mortality. A five-fold variation in chylothorax rates was observed across centres. Future investigations should identify centres most adept at preventing and managing chylothorax and disseminate best practices.

Brain Dysplasia Associated with Ciliary Dysfunction in Infants with Congenital Heart Disease.

OBJECTIVE: To test for associations between abnormal respiratory ciliary motion (CM) and brain abnormalities in infants with congenital heart disease (CHD) STUDY DESIGN: We recruited 35 infants with CHD preoperatively and performed nasal tissue biopsy to assess respiratory CM by videomicroscopy. Cranial ultrasound scan and brain magnetic resonance imaging were obtained pre- and/or postoperatively and systematically reviewed for brain abnormalities. Segmentation was used to quantitate cerebrospinal fluid and regional brain volumes. Perinatal and perioperative clinical variables were collected. RESULTS: A total of 10 (28.5%) patients with CHD had abnormal CM. Abnormal CM was not associated with brain injury but was correlated with increased extraaxial cerebrospinal fluid volume (P < .001), delayed brain maturation (P < .05), and a spectrum of subtle dysplasia including the hippocampus (P < .0078) and olfactory bulb (P < .034). Abnormal CM was associated with higher composite dysplasia score (P < .001), and both were correlated with elevated preoperative serum lactate (P < .001). CONCLUSIONS: Abnormal respiratory CM in infants with CHD is associated with a spectrum of brain dysplasia. These findings suggest that ciliary defects may play a role in brain dysplasia in patients with CHD and have the potential to prognosticate neurodevelopmental risks.

Spray-dried lipid-hyaluronan-polymethacrylate microparticles for drug delivery in the peritoneum.

Application of controlled release technology to the peritoneum would allow for sustained drug levels. However, some polymeric systems either create adhesions, or rapidly exit the peritoneum; neither result is desirable. Here we have produced particles based on sphyngomyelin, a phospholipid that occurs naturally in the peritoneum, along with hyaluronic acid and the polymethacrylate Eudragit E100 (to modulate drug release). Particles with a low proportion of E100 (5% (w/w); "high SPM") release albumin rapidly over 2 days, then more slowly; increasing the E100 to 20% (w/w; high "E100") slowed drug release markedly. When injected in the murine peritoneum, high SPM particles were disseminated as free particles, without forming collections. There was a mild inflammatory response but no formation of adhesions. High E100 particles formed collections in all animals, with an intense inflammatory response. Even so, there were very few adhesions. These results suggest that microparticulate formulations can be produced that have acceptable drug-releasing properties and are suitable for use in the peritoneum from the standpoint of biocompatibility.