Activation of renal epithelial Na+ channels (ENaC) in infants with congenital heart disease

Introduction

This study was designed to measure the concentration and activity of urinary proteases that activate renal epithelial sodium channel (ENaC) mediated Na+ transport in infants with congenital heart disease, a potential mechanism for fluid retention.

Methods

Urine samples from infants undergoing cardiac surgery were collected at three time points: T1) pre-operatively, T2) 6-8 h after surgery, and T3) 24 h after diuretics. Urine was collected from five heathy infant controls. The urine was tested for four proteases and whole-cell patch-clamp testing was conducted in renal collecting duct M-1 cells to test whether patient urine increased Na+ currents consistent with ENaC activation.

Results

Heavy chain of plasminogen, furin, and prostasin were significantly higher in cardiac patients prior to surgery compared to controls. There was no difference in most proteases before and after surgery. Urine from cardiac patients produced a significantly greater increase in Na+ inward currents compared to healthy controls.

Conclusion

Urine from infants with congenital heart disease is richer in proteases and has the potential to increase activation of ENaC in the nephron to enhance Na+ reabsorption, which may lead to fluid retention in this population.

Epinephrine dosing strategies during pediatric extracorporeal cardiopulmonary resuscitation reveal novel impacts on survival: A multicenter study utilizing time-stamped epinephrine dosing records

OBJECTIVES

To describe epinephrine dosing distribution using time-stamped data and assess the impact of dosing strategy on survival after ECPR in children.

METHODS

This was a retrospective study at five pediatric hospitals of children <18 years with an in-hospital ECPR event. Mean number of epinephrine doses was calculated for each 10-minute CPR interval and compared between survivors and non-survivors. Patients were also divided by dosing strategy into a frequent epinephrine group (dosing interval of ≤5 min/dose throughout the first 30 minutes of the event), and a limited epinephrine group (dosing interval of ≤5 min/dose for the first 10 minutes then >5 min/dose for the time between 10 and 30 minutes).

RESULTS

A total of 191 patients were included. Epinephrine was not evenly distributed throughout ECPR, with 66% of doses being given during the first half of the event. Mean number of epinephrine doses was similar between survivors and non-survivors the first 10 minutes (2.7 doses). After 10 minutes, survivors received fewer doses than non-survivors during each subsequent 10-minute interval. Adjusted survival was not different between strategy groups [OR of survival for frequent epinephrine strategy: 0.78 (95% CI 0.36-1.69), p = 0.53].

CONCLUSIONS

Survivors received fewer doses than non-survivors after the first 10 minutes of CPR and although there was no statistical difference in survival based on dosing strategy, the findings of this study question the conventional approach to EPCR analysis that assumes dosing is evenly distributed.

Impact of Extubation Time on Feeding Outcomes after Neonatal Cardiac Surgery: A Single-Center Study

This study aimed to examine the impact of timing of extubation on feeding outcomes in neonates after surgery for congenital heart disease. This was a single-center retrospective study between December 2014 and June 2020. Patients were divided into three categories: extubated in the OR (immediate), extubated in the intensive care unit (ICU) between 0 and 3 days post-procedure (early), and extubated >3 days post-procedure (delayed). Comparing the immediate and early groups, we found no difference in time to first enteral feed (1.3 days (1.0–3.4) vs. 2.3 days (1.1–3.3), p = 0.27). There was no difference in time to first oral feed (2.0 days (1.1–4.5) vs. 3.1 days (1.8–4.4), p = 0.34) and time to goal feed (6.0 days (3.2–8.3) vs. 6.9 days (5.0–9.0), p = 0.15)). There was no difference in all oral feeds at one year: 88% vs. 98%, p = 0.16. The delayed extubation group performed significantly worse on all measures. Immediate and early extubation displayed no differences in feeding outcomes and length of stay in this study, while delayed extubation performed worse on all measures. Thus, we believe that clinicians should emphasize extubation within 3 days post-surgery to improve feeding outcomes while minimizing time hospitalized.

Antibiotic use in nonintubated children with bronchiolitis in the intensive care unit

INTRODUCTION

Antibiotic use may shorten mechanical ventilation duration and length of stay for patients with bronchiolitis that require intubation. The goals of this study were to describe antibiotic use in previously healthy children with bronchiolitis admitted to the intensive care unit (ICU) for noninvasive respiratory support and to describe associations of early antibiotic use with clinical outcomes.

METHODS

The Pediatric Health Information Systems database was queried for children <2 years of age without significant comorbidities admitted to the ICU for bronchiolitis. Children requiring mechanical ventilation on the first ICU day were excluded. Two groups were analyzed: those patients receiving antibiotics on the first day of their ICU stay (early antibiotics), and those receiving no antibiotics on their first ICU day (no antibiotics). Primary outcome was the length of ICU stay.

RESULTS

A total of 11,029 admissions met criteria, 2522 (22.9%) in the early antibiotic group, and 8507 (77.1%) in the no antibiotic group. The use of early antibiotics varied by center from 10% to 54%. In multivariate analysis, the early antibiotic group had similar ICU length of stay compared to the no antibiotic group (relative risk, RR [95% confidence interval, CI] 1.01 [0.98-1.05]). For patients on noninvasive ventilation, the first ICU day early antibiotics did not impact ICU length of stay (RR [95% CI] 0.97 [0.92-1.02]) or need for intubation (RR [95% CI] 1.11 [0.77-1.58]).

CONCLUSION

Early antibiotic use was common with significant variation between centers. Early antibiotic use was not associated with improved clinical outcomes in children admitted to the ICU for noninvasive respiratory support for bronchiolitis.

Association Between Postoperative Dexmedetomidine Use and Arrhythmias in Infants After Cardiac Surgery

BACKGROUND

Dexmedetomidine has been suggested as an arrhythmia prophylactic agent after surgery for congenital heart disease due to its heart rate lowering effect, though studies are conflicting. We sought to study the effect of dexmedetomidine in infants that are at highest risk for arrhythmias.

METHODS

Retrospective cohort study of infants less than six months of age undergoing cardiopulmonary bypass for congenital heart disease. The arrhythmia incidence in the first 48 hours after surgery in infants receiving dexmedetomidine for sedation was compared to those that did not receive dexmedetomidine.

RESULTS

A total of 309 patients were included, 206 patients who did not receive dexmedetomidine and 103 patients who did. The incidence of tachyarrhythmias was similar between the non-DEX group and the DEX group (19% vs 15%, P = .34). When adjusted for baseline differences, the non-DEX group did not have an increased risk of postoperative tachyarrhythmias (odds ratio [OR]: 1.4, 95% confidence interval [CI]: 0.5-3.8). The non-DEX group had an increased need for treatment for arrhythmias (18% vs 8%, P = .012). The three lesions with baseline higher risk for arrhythmias (tetralogy of Fallot, transposition of the great arteries, and complete atrioventricular canal) had an increased incidence of tachyarrhythmias in the non-DEX group (34% vs 6%, P = .027). This risk was not significant in multivariate analysis (OR: 2.5, 95% CI: 0.4-15.5).

CONCLUSIONS

High-risk infants had decreased incidence of tachyarrhythmias when receiving dexmedetomidine, though this was not significant after accounting for baseline differences between groups.