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.

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.

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.