A study of breathing pattern and ventilation in newborn infants and adult subjects

Abstract

Experimentally modified breathing pattern in human subjects, by varying the inspired gas mixture or administering different neuromodulators, has been studied extensively in the past, yet unmodified breathing has not. Moreover, most data refer to infants during sleep and adults during wakefulness. We studied the baseline breathing pattern of preterm infants [n = 10; GA 30 (27-34) wk (median, range)]; term infants [n = 10; GA 40 (39-41) wk)], and adult subjects [n = 10; age 31 (17-48) y)] during quiet sleep. A flow-through system was used to measure ventilation. We found: (i) instantaneous ventilation was 0.273+/-0.006, 0.200+/-0.003, and 0.135+/-0.002 L x min(-1) x kg(-1) in preterm, term infants, and adult subjects; the coefficients of variation were 39%, 25%, and 14% (p < 0.01). The greater coefficient of variation in neonates compared to adults related to increased variability in Vt (39% and 25% in preterm and term infants vs 14% in adults; p < 0.01) and f (39% and 22% vs 9%; p < 0.01). The major determinant of frequency in preterm infants was Te (81% variability), Ti varying less (25% variability); (ii) V(T)/Ti decreased and Ti/Ttot increased with age; (iii) the higher breath-to-breath variability in preterm infants was associated with larger changes in alveolar PCO2 and a larger variability in O2 saturation than later in life.

A cohort study reporting normal oximetry values in healthy infants under 4 months of age using Masimo technology

“…Instability of the breathing pattern is an inherent characteristic of normal healthy infants during sleep 7. Their unique physiology in relation to ventilatory control and susceptibility to periodic breathing make them predisposed to central apnoeas where there is a brief arrest in ventilation resulting from an interruption or decrease in respiratory drive within the central nervous system.…”

Polysomnography for the diagnosis of sleep disordered breathing in children under 2 years of age

“…For example, there is a dramatic change in sleep architecture over the first 6 months of life with the appearance of sleep spindles, K‐complexes, and the emergence of an adult pattern of SWS . Breathing patterns show decreased variability and slowing of the respiratory rate over the same time period . Studies of healthy infants show a decrease in both obstructive and central respiratory events in early life .…”

“…45,47 Breathing patterns show decreased variability and slowing of the respiratory rate over the same time period. 48,22,49 Studies of healthy infants show a decrease in both obstructive and central respiratory events in early life. 17,27 A cluster analysis of over 10,000 children with seven repeated parent reported measures from 6-81 months defined five distinct symptom patterns relating to important clinical characteristics including growth parameters 50 as always normal (47%), always SDB (10%), early marked snoring with resolution (10%), early marked apnea with resolution (11%), and late snoring and mouth breathing (22%).…”

Quantifying infant respiratory variability: how to capture complexity

“…All these respiratory events probably affected the change in respiratory variability with age in the material presented in this issue (1). In fact, descriptive box plots show how the distribution of expiratory times was narrow, symmetrical and similar in preterm and term infants-except for the upper 5% of values, breath cycles with expiratory time of 2-22 s. Thus, the much higher mean coef cient of variation in preterms may have been a consequence of a minority of breaths.…”

“…The study of pain in children has a short history. Much of what we know is based on clinical samples (1). In most studies, the pain is approached through the child in isolation or through parental reports.…”