Respiratory events in infants presenting with apparent life threatening events: is there an explanation from esophageal motility?

Abstract

Objective: To test the hypothesis that proximal aerodigestive clearance mechanisms mediated by pharyngoesophageal motility during spontaneous respiratory events (SREs) are distinct in infants with apparent life threatening events (ALTEs).

Study design: Twenty infants (10 with proven ALTE, 10 healthy controls) had pharyngoesophageal manometry to investigate motility changes concurrent with respiratory events detected by respiratory inductance plethysmography and nasal thermistor methods. We measured changes in resting upper esophageal and lower esophageal sphincter pressures, esophageal peristalsis characteristics, and gastroesophageal reflux. Statistical analysis included mixed models; data presented as mean±SD, median (range), or percentage.

Results: Infants with ALTE (vs controls) had: (1) delays in restoring aerodigestive normalcy as indicated by more frequent (P=.03) and prolonged SREs (P<.01); (2) a lower magnitude of protective upper esophageal sphincter contractile reflexes (P=.01); (3) swallowing as the most frequent esophageal event associated with SREs (84%), with primary peristalsis as the most prominent aerodigestive clearance mechanism (64% vs 38%, P<.01); (4) a higher proportion of failed esophageal propagation (10% vs 0%, P=.02); and (5) more frequent mixed apneic mechanisms (P<.01) and more gasping breaths (P=.04).

Conclusions: In infants with ALTE, prolonged SREs are associated with ineffective esophageal motility characterized by frequent primary peristalsis and significant propagation failure, thus suggestive of dysfunctional regulation of swallow-respiratory junction interactions. Hence, treatment should not target gastroesophageal reflux, but rather the proximal aerodigestive tract.

Figure 1

Respiratory waveform patterns in control and ALTE. Notice normal breathing followed by a spontaneous respiratory event (shaded area) lasting longer than 2 seconds and two missed breaths succeeded by normal breathing.

Figure 2. Representative examples of pharyngo-esophageal and respiratory rhythm interactions in control (upper) and ALTE (lower)

Shaded areas denote the SRE. A) Swallow associated SRE characterized by deglutition. B) Gastro-esophageal reflux (GER) associated SRE characterized by transient lower esophageal sphincter relaxation (TLESR), retrograde movement, upper esophageal sphincter contractile reflexes, and peristalsis. C) Independent SRE characterized by absence of esophageal motility changes. Observe evidence of gasping on manometry and respiratory waveforms. Note the respiratory perturbations seen in Fig 1 are exactly the same, but in Fig 2 are synchronized with pharyngo-esophageal motility changes.

Figure 3. Esophageal characteristics during SRE

A) Upper esophageal sphincter characteristics – Note similar basal pressure; however, response magnitude of protective contractile reflex (CR) during pre- and post-deglutition is lesser in infants with ALTE. B) Lower esophageal sphincter characteristics – Note basal and relaxation nadir pressures are similar. C) Esophageal event associated with SRE- Deglutition is most frequent in both groups. D) Esophageal clearance mechanism- Primary peristalsis is more frequent in infants with ALTE with a low occurrence of secondary peristalsis; thus, respiratory perturbations can be frequent.