Catheter ablation of orthodromic reciprocating tachycardia and atrioventricular nodal reentrant tachycardia in children with hypoplastic left heart syndrome.

INTRODUCTION: Experience with catheter ablation of orthodromic reciprocating tachycardia (ORT) and atrioventricular nodal reentrant tachycardia (AVNRT) in young children with hypoplastic left heart syndrome (HLHS) is limited. We report the feasibility, safety, and outcomes of catheter ablation of ORT and AVNRT in children with HLHS. METHODS AND RESULTS: This was a retrospective review of patients with HLHS who underwent catheter ablation for reentrant supraventricular tachycardias (excluding atrial tachycardias) between 2005 and 2017 at a single center. Descriptive data including demographics, clinical history, procedural data, and outcomes were recorded. Ten children with HLHS underwent eleven catheter ablation procedures. Median age and weight at ablation were 2.7 years (range: 0.1-10.5) and 11.4 kg (range: 3.6-30.4), respectively. Tachycardia mechanism was AVNRT in four, ORT in five (two with preexcitation), and both in one. Acute procedural success was 100% and there was no spontaneous recurrence of tachycardia orpreexcitationin median 92 months (range: 21-175 months) follow-up. Five patients underwent subsequent EP studies at catheterization (intracardiac) or after surgery (via epicardial wires): three were noninducible, one after AVNRT ablation had inducible atrial tachycardia, and one after initial ORT ablation had inducible ORT at fenestration closure and underwent successful repeat ablation. Thus, long-term freedom from clinical tachycardia was 100% and from inducible AVNRT or ORT was 80%. CONCLUSION: Transcatheter ablation for ORT and AVNRT in children with HLHS can be performed with excellent acute and long-term success without major complications.

Pilot Study of Pharyngoesophageal Dysmotility Mechanisms in Dysphagic Infants of Diabetic Mothers.

OBJECTIVE: Swallowing difficulties are common in infants of diabetic mothers (IDM) and mechanisms are unclear. We tested the hypothesis that pharyngoesophageal motility reflexes are distinct in IDMs compared with healthy controls in a pilot study. STUDY DESIGN: Basal and adaptive pharyngoesophageal motility characteristics of 20 dysphagic IDMs and 10 controls were studied using purpose-built micromanometry system. RESULTS: During basal swallows, IDMs had lower frequency of deglutition apneas (62.5 vs. 95.4%) and longer active upper esophageal sphincter (UES) relaxation duration (0.8 ± 0.1 vs. 0.4 ± 0.1 second), whereas during adaptive swallows, IDMs had longer response latency to esophageal peristalsis onset (24.4 ± 2.1 vs. 9.7 ± 2.9 seconds) and longer lower esophageal sphincter nadir duration (28.9 ± 3.2 vs. 12.9 ± 4.6) (all p < 0.05) compared with controls. Nine in the IDM group needed gastrostomy feeding tube at hospital discharge versus none in controls. CONCLUSION: Feeding difficulties in IDMs are likely to be associated with maladapted or maldeveloped vagal neuropathy mechanisms manifesting as dysregulation of pharyngeal-airway interactions, longer active UES relaxation response, delays in the activation of esophageal contractile apparatus during peristalsis, and prolonged inhibition at the gastroesophageal junction.

Feeding Methods at Discharge Predict Long-Term Feeding and Neurodevelopmental Outcomes in Preterm Infants Referred for Gastrostomy Evaluation.

OBJECTIVE: To test the hypothesis that oral feeding at first neonatal intensive care unit discharge is associated with less neurodevelopmental impairment and better feeding milestones compared with discharge with a gastrostomy tube (G-tube). STUDY DESIGN: We studied outcomes for a retrospective cohort of 194 neonates <37 weeks' gestation referred for evaluation and management of feeding difficulties between July 2006 and July 2012. Discharge milestones, length of hospitalization, and Bayley Scales of Infant Development-Third Edition scores at 18-24 months were examined. χ2, Mann-Whitney U, or t tests and multivariable logistic regression models were used. RESULTS: A total of 60% (n = 117) of infants were discharged on oral feedings; of these, 96% remained oral-fed at 1 year. The remaining 40% (n = 77) were discharged on G-tube feedings; of these, 31 (40%) remained G-tube dependent, 17 (22%) became oral-fed, and 29 (38%) were on oral and G-tube feedings at 1 year. Infants discharged on a G-tube had lower cognitive (P <.01), communication (P = .03), and motor (P <.01) composite scores. The presence of a G-tube, younger gestation, bronchopulmonary dysplasia, or intraventricular hemorrhage was associated significantly with neurodevelopmental delay. CONCLUSIONS: For infants referred for feeding concerns, G-tube evaluations, and feeding management, the majority did not require a G-tube. Full oral feeding at first neonatal intensive care unit discharge was associated with superior feeding milestones and less long-term neurodevelopmental impairment, relative to full or partial G-tube feeding. Evaluation and feeding management before and after G-tube placement may improve long-term feeding and neurodevelopmental outcomes.

Impact of Process Optimization and Quality Improvement Measures on Neonatal Feeding Outcomes at an All-Referral Neonatal Intensive Care Unit.

AIM: We hypothesized that the implementation of a feeding quality improvement (QI) program among premature neonates accelerates feeding milestones, safely lowering hospital length of stay (LOS) compared with the baseline period. METHODS: Baseline data were collected for 15 months (N = 92) prior to initiating the program, which involved development and implementation of a standardized feeding strategy in eligible premature neonates. Process optimization, implementation of feeding strategy, monitoring compliance, multidisciplinary feeding rounds, and continuous education strategies were employed. The main outcomes included the ability and duration to reach enteral feeds-120 (mL/kg/d), oral feeds-120 (mL/kg/d), and ad lib oral feeding. Balancing measures included growth velocities, comorbidities, and LOS. RESULTS: Comparing baseline versus feeding program (N = 92) groups, respectively, the feeding program improved the number of infants receiving trophic feeds (34% vs 80%, P < .002), trophic feeding duration (14.8 ± 10.3 days vs 7.6 ± 8.1 days, P < .0001), time to enteral feeds-120 (16.3 ± 15.4 days vs 11.4 ± 10.4 days, P < .04), time from oral feeding onset to oral feeds-120 (13.2 ± 16.7 days vs 19.5 ± 15.3 days, P < .0001), time from oral feeds-120 to ad lib feeds at discharge (22.4 ± 27.2 days vs 18.6 ± 21.3 days, P < .01), weight velocity (24 ± 6 g/d vs 27 ± 11 g/d, P < .03), and LOS (104.2 ± 51.8 vs 89.3 ± 46.0, P = .02). Mortality, readmissions within 30 days, and comorbidities were similar. CONCLUSIONS: Process optimization and the implementation of a standardized feeding strategy minimize practice variability, accelerating the attainment of enteral and oral feeding milestones and decreasing LOS without increasing adverse morbidities.

Gestational and postnatal modulation of esophageal sphincter reflexes in human premature neonates.

BACKGROUND: Effects of gestational age (GA) and postnatal maturation on upper and lower esophageal sphincter (UES and LES) reflex development remain unclear. We hypothesized very-preterm (VPT) born neonates (< 32 wk GA) have delayed maturation of UES contractile reflex (UESCR) and LES relaxation reflex (LESRR) vs. preterm (PT) born (32-37 wk GA) neonates. METHODS: Using provocative manometry, effects of 1,263 graded mid-esophageal stimuli (air, liquid) on sensory-motor characteristics of UESCR and LESRR were investigated in 24 VPT-born and 12 PT-born neonates (37.8 ± 0.6 vs. 38.9 ± 0.4 wk postmenstrual age respectively, P = 0.14). RESULTS: In response to liquid stimuli (vs. air), VPT-born neonates displayed prolonged UESCR and LESRR response latencies (P < 0.001) and prolonged UESCR and LESRR durations (P < 0.01); unlike PT-born neonates, who exhibit prolonged LESRR response latency (P < 0.01), but similar UESCR and LESRR durations (P = 0.2). Differences were noted in LESRR duration in VPT vs. PT neonates for air stimuli (P = 0.04). With liquid stimuli, increasing GA was associated with decreasing response onset latencies to UESCR and LESRR (P < 0.05), and increasing LESRR duration (P = 0.02). CONCLUSION: Using GA as categorical or continuous variable, vagus-mediated mechano-sensitive and liquid-sensitive reflex characteristics of UESCR and LESRR are distinct; LESRR differs with varying intrauterine maturation suggesting inhibitory modulation progresses with advancing maturation.

The Role of Sleep in the Modulation of Gastroesophageal Reflux and Symptoms in NICU Neonates.

BACKGROUND: Newborns sleep about 80% of the time. Gastroesophageal reflux disease is prevalent in about 10% of neonatal intensive care unit infants. Concurrent polysomnography and pH-impedance studies clarify the relationship of gastroesophageal reflux with sleep. AIMS: To characterize spatiotemporal and chemical characteristics of impedance-positive gastroesophageal reflux and define symptom associations in sleep and wake states in symptomatic neonates. We hypothesized that frequency of impedance-positive gastroesophageal reflux events and their association with cardiorespiratory symptoms is greater during sleep. METHODS: Eighteen neonates underwent concurrent polysomnography with a pH-impedance study. Impedance-positive gastroesophageal reflux events (weakly acidic or acidic) were categorized between sleep versus wake states: Symptom Index = number of symptoms with gastroesophageal reflux/total symptoms*100; Symptom Sensitivity Index = number of gastroesophageal reflux with symptoms/total gastroesophageal reflux*100; Symptom Association Probability = [(1 - probability of observed association between reflux and symptoms)*100]). RESULTS: We analyzed 317 gastroesophageal reflux events during 116 hours of polysomnography. During wake versus sleep, respectively, the median (interquartile range) frequency of impedance-positive gastroesophageal reflux was 4.9 (3.1-5.8) versus 1.4 (0.7-1.7) events/hour (P < 0.001) and the proximal migration was 2.6 (0.8-3.3) versus 0.2 (0.0-0.9) events/hour (P < 0.001). The Symptom Index for cardiorespiratory symptoms for impedance-positive events was 22.5 (0-55.3) versus 6.1 (0-13), P = 0.04, whereas the Symptom Sensitivity Index was 9.1 (0-23.1) versus 18.4 (0-50), P = 0.04, although Symptom Association Probability was similar (P = 0.68). CONCLUSIONS: Contrary to our hypothesis, frequency of gastroesophageal reflux in sleep is lower; however, spatiotemporal and chemical characteristics of gastroesophageal reflux and symptom-generation mechanisms are distinct. For cardiorespiratory symptoms during sleep, a lower Symptom Index entails evaluation for etiologies other than gastroesophageal reflux disease, a higher Symptom Sensitivity Index implies heightened esophageal sensitivity, and similar Symptom Association Probability indicates other mechanistic possibilities.

Antecedent Predictors of Feeding Outcomes in Premature Infants With Protracted Mechanical Ventilation.

OBJECTIVES: The aim of the present study was to define risk factors associated with gastrostomy in premature infants receiving protracted mechanical ventilation (≥30 days). METHODS: Retrospective data collected on 170 preterm neonates (birth weight <1500 g) who received uninterrupted mechanical ventilation for ≥30 days were analyzed with logistic regression methods to predict the association of gastrostomy with cardiorespiratory, infectious, and neurological morbidities. RESULTS: A total of 32 of 170 infants had gastrostomy tubes. Including all of the covariates in 1 model, duration of cumulative ventilation (P < 0.001) and uninterrupted ventilation (P < 0.001), and ventriculoperitoneal shunt (P = 0.02) were significant predictors, whereas sepsis, intraventrical hemorrhage grade III or IV, and patent ductus arteriosus ligation were not. Respiratory severity score (mean airway pressure × fraction of inspired oxygen) calculated at 30 days of life was also a significant predictor (P = 0.01). CONCLUSIONS: In infants with protracted mechanical ventilation, the degree of respiratory support at 1 month of age, prolonged respiratory morbidity, and neuropathology are the significant predictors for gastrostomy.

Safety and Efficacy of Oral Feeding in Infants with BPD on Nasal CPAP.

Safety and efficacy of oral feeding was examined in infants with bronchopulmonary dysplasia (BPD) on nasal continuous positive airway pressure (NCPAP). We hypothesized that repetitive oral feeding enhances aero-digestive outcomes and reduces resource utilization. Data from infants with BPD (37-42 weeks post menstrual age) that were orally fed while on NCPAP (n = 26) were compared with those that were exclusively gavage fed on NCPAP (n = 27). Subject assignment was random and physician practice based. Specifically, we compared the differences in aero-digestive milestones, resource utilization, and safety metrics. Demographic characteristics such as gender distribution, gestational age, and birth weight, clinical characteristics such as frequency of intraventricular hemorrhage and patent ductus arteriosus needing surgical ligation were similar in both groups (p > 0.05). Characteristics of respiratory support and airway milestones were similar in both groups (p > 0.05). However, infants in NCPAP-oral fed group had earlier acquisition of full oral feeding milestone by 17 days (median) versus infants who were not orally fed during NCPAP (p < 0.05). Discharge weights and the frequency of gastrostomy tube placement were also similar in both groups (p > 0.05). There were no tracheostomies in either group. There was no incidence of clinically significant aspiration pneumonia in infants during the period of the oral feeding while on NCPAP. Controlled introduction of oral feedings in infants with BPD during NCPAP is safe and may accelerate the acquisition of oral feeding milestones.

Respiratory severity score on day of life 30 is predictive of mortality and the length of mechanical ventilation in premature infants with protracted ventilation.

OBJECTIVE: We tested the hypothesis that Respiratory Severity Score (RSS) on day of life 30 is predictive of mortality and length of mechanical ventilation in premature infants on prolonged mechanical ventilation. METHODS: A retrospective chart review was performed using the Nationwide Children's Hospital medical record and Vermont-Oxford Network databases. The primary outcome variable was survival to hospital discharge and the secondary outcome was length of mechanical ventilation after day of life 30. RESULTS: We identified 199 neonates admitted to Nationwide Children's Hospital between 2004 and 2007 with birth weight less than 1,500 g that received prolonged mechanical ventilation in the first 30 days of their life. A total of 184 infants were included in the analysis, excluding 14 patients with congenital anomalies and one infant with incomplete data. RSS on day of life 30 was significantly greater in the group of infants that died compared to those that survived (P = 0.003, 95% CI = [0.08, 0.40]). Further analysis demonstrated that the maximum difference in mortality was obtained with a threshold RSS of 6. Of the 109 patients who had RSS less than 6 on day of life 30, mortality rate was 4.6% (5/109) while those greater than or equal to 6 had a mortality rate of 21.3% (16/75). Both Kaplan-Meier survival curves comparing mortality and length of mechanical ventilation in infants with RSS < 6 versus those with RSS ≥ 6 demonstrated strong associations between RSS on day of life 30 and survival (P = 0.002) and length of ventilation after day of life 30 (P < 0.001). CONCLUSION: RSS ≥ 6 on day of life 30 is associated with higher mortality and longer period of mechanical ventilation in premature infants requiring mechanical ventilation through 30 days of life.

Neuromotor mechanisms of pharyngoesophageal motility in dysphagic infants with congenital heart disease.

BACKGROUND: Aero-digestive morbidities are common in congenital heart disease infants, and the mechanisms are unclear. We hypothesized that adaptive pharyngoesophageal motility reflexes are different in surgical congenital heart disease infants (S-CHD) vs. nonsurgical congenital heart disease infants (CHD) and healthy controls. METHODS: Abrupt pharyngeal provocation was performed with graded water infusions using purpose-built micromanometry. The data from 12 S-CHD were compared with data from 10 CHD and 12 controls. One hundred and ninety-seven water stimulations were examined for the frequency, latency, duration, and magnitude of pharyngo-upper esophageal sphincter contractile response (PUCR), pharyngeal reflexive swallow (PRS), esophageal body peristalsis, and lower esophageal sphincter (LES) relaxation characteristics. Mixed statistical models were applied. RESULTS: Frequency distribution (%) of PUCR: PRS: none in S-CHD vs. CHD vs. controls, respectively, were 36:46:17 vs. 9:80:11 vs. 15:61:24 (P < 0.05). Response latency to the final esophageal body waveform (P = 0.01) and the response duration of esophageal body peristalsis (P = 0.04) were prolonged in S-CHD vs. controls but were similar to CHD (P = 0.22). Pharyngeal infusion-induced LES relaxation characteristics were similar in all three groups. CONCLUSION: Abnormality in the recruitment of PUCR or PRS reflexes and esophageal body peristalsis in S-CHD implicate dysregulation in vagal cholinergic excitatory neuromotor responses.

Tracheostomy placement in infants with bronchopulmonary dysplasia: safety and outcomes.

Optimizing the timing and safety for the placement of a tracheostomy in infants with bronchopulmonary dysplasia (BPD) has not been determined. The purpose of the present study was to describe the data from a single institution about the efficacy and safety of tracheostomy placement in infants with BPD needing long-term respiratory support. We established a service line for the comprehensive care of infants with BPD and we collected retrospective clinical data from this service line. We identified patients that had a trachostomy placed using the local Vermont-Oxford database, and obtained clinical data from chart reviews. We identified infants who had a tracheostomy placed for the indication of severe BPD only. Safety and respiratory efficacy was assessed by overall survival to discharge and the change in respiratory supportive care from just before placement to 1-month post-placement. Twenty-two patients (750 ± 236 g, 25.4 ± 2.1 weeks gestation) had a tracheostomy placed on day of life 177 ± 74 which coincided with a post-conceptual age of 51 ± 10 weeks. At placement these infants were on high settings to support their lung disease. The mean airway pressure (MAP) was 14.3 ± 3.3 cmH(2) O, the peak inspiratory pressure was 43.7 ± 8.0 cmH(2) O, and the FiO(2) was 0.51 ± 0.13. The mean respiratory severity score (MAP × FiO(2) ) 1 month after tracheostomy was significantly (P = 0.03) lower than prior to tracheostomy. Survival to hospital discharge was 77%. All patients with tracheostomies that survived were discharged home on mist collar supplemental oxygen. In conclusion, the high survival rate in these patients with severe BPD and the decreased respiratory support after placement of a tracheostomy suggests that high ventilatory pressures should not be a deterrent for placement of a tracheostomy. Future research should be aimed at determining optimal patient selection and timing for tracheostomy placement in infants with severe BPD.

Impact of feeding strategies on the frequency and clearance of acid and nonacid gastroesophageal reflux events in dysphagic neonates.

BACKGROUND: Feeding difficulties and gastroesophageal reflux (GER) are common problems in neonates. The authors hypothesize that GER could be influenced by feeding mechanics by evaluating the effects of feeding volumes, feeding durations, feeding flow rates, and caloric density on the chemical composition and clearance of GER in dysphagic neonates. METHODS: Symptomatic dysphagic neonates (n = 35) underwent evaluation for suspected GER using pH-impedance methods. RESULTS: The proportions of acid and nonacid GER were different during the first, second, and third postprandial hours (P < .0001). Prolonged feeding duration was significantly associated with decreased total, nonacid GER and BCT (P < .03). Significant positive correlations (P < .05) were detected between feeding flow rate vs frequency of total, nonacid GER and BCT. Significant positive correlation (P = .002) was noted between feeding volume and BCT. BCT decreased with each hourly interval (analysis of variance [ANOVA] P < .05); however, ACT increased with each hourly interval (ANOVA P = .05). Comparison between BCT and ACT at each postprandial hour is remarkable for longer ACT during the second and third hours after the initiation of feed (P ≤ .001). No significant correlation was noted between the milk types (breast milk or formula) or caloric density with regard to the GER characteristics. Oral-fed infants had more GER events than gavage-fed infants. CONCLUSIONS: Prolonged feeding durations and slower flow rates are associated with decreased frequency of GER. Modification of feeding duration and flow rate can be a useful adjunct to ameliorate GER in dysphagic neonates.