Polygraphic findings of 47 cases with respiratory inhibition after crying

Abstract

Objective: To report the polygraphic findings of infants with respiratory inhibition after crying (RIAC).Methods: We screened for RIAC among infants with a gestational age ≥36 weeks using our established method with cranial ultrasonography, SpO2 monitoring and polygraphy. RIAC is defined as central apnea that occurred immediately after crying with a decrease in SpO2 to <60%, followed by repeated irregular respiration and apnea as the respiration gradually recovered. The subjects were infants with RIAC for whom we could study the polygraphic findings in detail.Results: Forty-seven RIAC cases were included in the present analysis. The frequency of RIAC was 2.1 (1.2–7.0) times per 24 h. The maximum duration of respiratory inhibition was 78.0 (52.6–109.0) s. The maximum duration of SpO2 <60% during RIAC was 39.0 (9.8–93.2) s. The minimum SpO2 value during RIAC was 53.0% (42.2–58.0%). The minimum heart rate during RIAC was 103.0 (79.1–127.1) bpm.Conclusions: RIAC is observed among healthy infants, and they experience repeated prolonged hypoxemia.