Chin Yee Chan

Significance of gastroesophageal refluxate in relation to physical, chemical, and spatiotemporal characteristics in symptomatic intensive care unit neonates.

Gastroesophageal reflux disease (GERD) is a frequent consideration in intensive care unit neonates. We tested the hypothesis that symptoms in GERD are dependent on the spatiotemporal and physicochemical characteristics of reflux events by evaluating the symptom sensitivity index (SSI) and symptom index (SI) in relation to the refluxate characteristics. Thirty symptomatic neonates (30.7 ± 0.8 wk gestation) were evaluated using manometry and pH-impedance methods. During 704.3 h of recordings, 2063 gastroesophageal reflux (GER) were observed; 54% of the GER were associated with symptoms. Defined by physical characteristics, there were 51.3% liquid, 29.1% gas, and 19.6% mixed GER. Defined by chemical characteristics, there were 48.5% acid and 51.5% nonacid GER. Defined by most proximal extent, 79.2% were supra-UES (upper esophageal sphincter) and 20.8% were infra-UES. Higher SSI was noted with pH-only events (p < 0.0001 versus pH-impedance events). Higher SI was noted with movement symptoms (versus sensory, p = 0.04). In a subset analysis, the frequencies of GER events, acid clearance time, and SSI were all greater in chronic lung disease versus none (p < 0.001). In conclusion, clinical significance of symptoms as measured by SSI and SI and characterization of spatial-temporal-physical-chemical nature of GER events as defined by pH-impedance methods clarifies the definition of GERD.

Maturation of upstream and downstream esophageal reflexes in human premature neonates: the role of sleep and awake states.

We tested the hypothesis that the sensory-motor characteristics of aerodigestive reflexes are dependent on stimulus type and volumes, sleep or awake states, and maturation. Thirteen neonates were studied at 33.6 ± 0.5 wk (time 1) and 37.3 ± 0.5 wk (time 2) postmenstrual age using multimodal provocative esophageal manometry concurrent with video polysomnography. Effects of graded volumes (399 infusions at time 1, 430 infusions at time 2) of midesophageal stimulation with air, water, and apple juice on the sensory thresholds and recruitment frequency of upper esophageal sphincter (UES), esophageal body, and lower esophageal sphincter (LES) reflexes were investigated during sleep and awake states. Sensory thresholds for aerodigestive reflexes between maturational stages were similar. Increased frequency recruitment of UES contractile reflex, LES relaxation reflex, and peristaltic reflexes were noted at time 2 (all, P < 0.05). Graded stimulus-response relationships were evident at time 1 and time 2 during awake and sleep states (P < 0.05). Secondary peristalsis vs. esophago-deglutition response proportions during sleep at time 1 vs. time 2 (P = 0.001) and awake vs. sleep at time 2 (P = 0.02) were distinct. We concluded that sensory-motor effects of esophageal mechanosensitivity, osmosensitivity, and chemosensitivity are advanced in sleep with maturation. Sleep further modulates the frequency recruitment and the type of aerodigestive reflexes.

Clinical Perspectives on Esophageal Disorders in Infants

Esophageal pathologies are complex and lend themselves to multivariable analysis before a definitive diagnosis can be considered. It is imperative that the clinician establish a methodology for selecting the appropriate technological assessment within scientific testing parameters to establish optimal clinicopathological presentation and determine best practice for patient care.

Physiology of esophageal sensorimotor malfunctions in neonatal neurological illness

We aimed to define the sensorimotor characteristics of aero-digestive reflexes evoked upon midesophageal provocations in neuropathology infants. Provocative esophageal motility testing was performed in 20 neuropathology infants and 10 controls at 42.3 ± 0.6 and 38.9 ± 0.9 wk postmenstrual age. Data from 1,073 infusions were examined for the sensory thresholds, response frequencies, response magnitude of upper esophageal sphincter (UES) contractile reflexes, lower esophageal sphincter (LES) relaxation reflexes, and peristaltic reflexes using mixed statistical models. Threshold volumes for air and liquid in neuropathology and control infants were similar for all reflexes. Graded air- and liquid volume-dependent UES contractile reflex, LES relaxation reflex, and peristaltic reflex frequency recruitment were present in neuropathology and control subjects for the media (P < 0.0001) and the reflexes (P < 0.0001). In neuropathology infants (vs. controls), UES contractile magnitude is higher (P < 0.0001); LES relaxation reflex occurred earlier (P = 0.008); LES nadir duration lasted longer (P = 0.006); secondary peristalsis is the chief method of esophageal clearance (P < 0.0001); pharyngeal swallows and deglutition apneas are less frequent (P = 0.001); proximal, midesophageal waveform magnitudes and duration are exaggerated (P < 0.008). UES contractile reflex was longer with liquid than air in both groups (P = 0.03). We concluded that 1) perception to midesophageal provocation remains preserved in neuropathology neonates; 2) sustained and exaggerated myogenic response from afferent activation is evident by increased excitatory efferent outputs to the UES and esophageal body and increased inhibitory efferent outputs to the LES; 3) dysfunctional regulation of pharyngeal swallowing and infrequent deglutition responses indicate the possibility of impaired descending modulation and central malfunctions of brainstem and vagal nuclei.

Su1899 Effect of Neonatal Neurological Disorders on Upstream Esophageal Reflexes: Role of Gestational Immaturity

aIncludes weak, frequent failed, rapid and hypertensive peristalsis bIncludes distal esophageal spasm, hypercontractile (jackhammer) esophagus and absent peristalsis cIncludes achalasia and EGJ outflow obstruction dKruskal-Wallis test eAll scores reported as median values with IQR fAdherence to surveys: HADS-A 96.4%, HADS-D 96.3%, GerdQ 59.3%, IDQ (inclusion criteria) 100%, HSEQ 45.4%, VSI 44.9%, BSI 48.5% HADS Hospital Anxiety and Depression Scale GerdQ GERD Questionnaire IDQ Impaction Dysphagia Questionnaire HSEQ Heartburn Symptom Experience Questionnaire VSI Visceral Sensitivity Index BSI Brief Symptom Inventory Table 2: Self-report measures in patients with high ( ≥6) and low (,6) IDQ scores, stratified by Chicago Classification Criteria