A study of breathing pattern and ventilation in newborn infants and adult subjects (original) (raw)

Lung Volume, Breathing Pattern and Ventilation Inhomogeneity in Preterm and Term Infants

PLoS ONE, 2009

Background: Morphological changes in preterm infants with bronchopulmonary dysplasia (BPD) have functional consequences on lung volume, ventilation inhomogeneity and respiratory mechanics. Although some studies have shown lower lung volumes and increased ventilation inhomogeneity in BPD infants, conflicting results exist possibly due to differences in sedation and measurement techniques.

Immediate and Late Ventilatory Response to High and Low O2 in Preterm Infants and Adult Subjects

Pediatric Research, 1979

The differences in the immediate (30 sec or 1 min) and late (5 min) ventilatory response to high and low Oz have not been SUBJECTS quantitated in preterm infants and adult subjects using the same We compared the results obtained in nine "healthy" preternl methods. It was thought that these differences might explain the infants studied during the first days of life with those of paradoxical ventilatory response to COz at various O2 concentrations in preterm infants (12). Thus, 9 preterm infants and 10 adult healthy adult subjects studied at a mean age (+SE) of 27 + 3 yr.

Intrasubject variability of repeated pulmonary function measurements in preterm ventilated infants

Pediatric Pulmonology, 1996

This study set out to describe the variability and assess the reproducibility of repeated pulmonary function measurements in ventilated preterm infants. We measured tidal volume (VT), lung compliance (CJ, and resistance (R,) in 16 infants (mean I SO: birthweight 1222 I 343 g) during spontaneous breathing and during mechanical ventilation, suppressing breathing efforts by mild hyperventilation. CL and RL were calculated from the equation of motion using linear regression analysis (LR), and by the Mead and Wittenberger method (MW). Flow and transpulmonary pressure were recorded for at least two consecutive periods, after which the esophageal tube was removed and replaced 1 hour later for a second set of recordings. The mean percent change (YO A) between the initial and the repeated measurements with their respective 95% confidence intervals were calculated. Reproducibility was assessed by the intraclass correlation coefficient (ICC) (total agreement = 1, good reproducibility 20.75). The mean Yo A between initial and repeat measurements during spontaneous breathing ranged from 11% to 14% for CL and Vh and from 22% to 32% for RL. The variation for R, was even higher when the analysis was done separately for the inspiratory and expiratory phase. CL and V, had good reproducibility (ICC >0.9), while RL was significantly less reproducible (ICC <0.75).

Respiratory Development in Preterm Infants

Journal of Perinatology, 2004

This study examined the development of respiration during the preterm and early post-term periods and the effects of other biological and environmental variables, including sleep state, on this development.

Breathing Patterns in Preterm and Term Infants Immediately After Birth

Pediatric Research, 2009

There is limited data describing how preterm and term infants breathe spontaneously immediately after birth. We studied spontaneously breathing infants Ն29 wk immediately after birth. Airway flow and tidal volume were measured for 90 s using a hot wire anemometer attached to a facemask. Twelve preterm and 13 term infants had recordings suitable for analysis. The median (interquartile range) proportion of expiratory braking was very high in both groups (preterm 90 ͓74 -99͔ vs. term 87 ͓74 -94͔%; NS). Crying pattern was the predominant breathing pattern for both groups (62 ͓36 -77͔% vs. 64 ͓46 -79͔%; NS). Preterm infants showed a higher incidence of expiratory hold pattern (9 ͓4 -17͔% vs. 2 ͓0 -6͔%; p ϭ 0.02). Both groups had large tidal volumes (6.7 ͓3.9͔ vs. 6.5 ͓4.1͔ mL/kg), high peak inspiratory flows (5.7 ͓3.8͔ vs. 8.0 ͓5͔ L/min), lower peak expiratory flow (3.6 ͓2.4͔ vs. 4.8 ͓3.2͔ L/min), short inspiration time (0.31 ͓0.13͔ vs. 0.32 ͓0.16͔ s) and long expiration time (0.93 ͓0.64͔ vs. 1.14 ͓0.86͔ s). Directly after birth, both preterm and term infants frequently brake their expiration, mostly by crying. Preterm infants use significantly more expiratory breath holds to defend their lung volume.

Postnatal Development of Periodic Breathing Cycle Duration in Term and Preterm Infants

Pediatric Research, 2007

Previous studies of the maturation of periodic breathing cycle duration (PCD) with postnatal age in infants have yielded conflicting results. PCD is reported to fall in term infants over the first 6 mo postnatally, whereas in preterm infants PCD is reported either not to change or to fall. Contrary to measured values, use of a theoretical respiratory control model predicts PCD should increase with postnatal age. We re-examined this issue in a longitudinal study of 17 term and 22 preterm infants. PCD decreased exponentially from birth in both groups, reaching a plateau between 4 and 6 mo of age. In preterm infants, PCD fell from a mean of 18.3 s to 9.8 s [95% confidence interval (CI) is Ϯ 3.2 s]. In term infants, PCD fell from 15.4 s to 10.1 s (95% CI is Ϯ 3.1 s). The higher PCD at birth in preterm infants, and the similar PCD value at 6 mo in the two groups, suggest a more rapid maturation of PCD in preterm infants. This study confirms that PCD declines after birth. The disagreement between our data and theoretical predictions of PCD may point to important differences between the respiratory controller of the infant and adult.

Regional and overall ventilation inhomogeneities in preterm and term-born infants

Intensive Care Medicine, 2009

Objectives: We compared ventilation inhomogeneity assessed by electrical impedance tomography (EIT) and multiple breath washout (MBW) in preterm and term-born infants. We hypothesised that EIT measurements in spontaneously breathing infants are repeatable and that differences in regional ventilation distribution measured by EIT can distinguish between preterm and term-born infants. Design: Cross-sectional group comparison study. Setting: Lung function laboratory at a University Children's Hospital. Participants: Seventeen healthy term-born and 15 preterm infants at a matched postmenstrual age of 44 weeks. Measurements and results: We concurrently measured ventilation inhomogeneity by EIT, ventilation inhomogeneity (LCI) and functional residual capacity (FRC) by MBW and tidal breathing variables during unsedated quiet sleep. EIT measurements were highly repeatable (coefficient of variation 3.6%). Preterm infants showed significantly more ventilation of the independent parts of the lungs compared to healthy term-born infants assessed by EIT (mean difference 5.0, 95 CI 1.3-8%). Whereas the two groups showed no differences in lung volumes or ventilation inhomogeneities assessed by MBW, EIT discriminated better between term and preterm infants. (FRC/kg: mean difference 1.1 mL, 95% CI-1.4-3.8 mL; LCI: mean difference 0.03, 95% CI-0.32-0.25). Conclusions: EIT shows distinct differences in ventilation distribution between preterm and term-born infants, which cannot be detected by MBW. Although preterm infants are capable of dynamically maintaining overall functional residual volume and ventilation distribution, they show some spatial differences from fullterm infants.

Characterization of Neural Breathing Pattern in Spontaneously Breathing Preterm Infants

Pediatric Research, 2011

The aim was to characterize the neural breathing pattern in nonintubated preterm infants. The diaphragm electrical activity (EAdi) and heart rate were simultaneously measured repeatedly for 1 h over several days using a modified feeding tube equipped with miniaturized sensors. The EAdi waveform was quantified for phasic and tonic activity, neural timings, and prevalence of recurring patterns, including central apnea. Ten infants with mean age 7 d (range, 3-13 d) were studied. Their birth weight was 1512 g (1158-1800 g) and GA at birth 31 wk (28-36 wk). Neural inspiratory and expiratory times were 278 ms (195-450 ms) and 867 ms (668-1436 ms) and correlated with GA (p Ͻ 0.001). Tonic EAdi represented 29.5% of phasic EAdi (16-40%) and was related to GA (r ϭ 0.61, p Ͻ 0.001). For the group, 68% of the time was regular phasic breathing (without tonic activity) and 29% of the time with elevated tonic activity. Central apneas Ͼ5 s occurred on average 10 times per hour (2-29). Heart rate reductions were correlated to central apnea duration. In conclusion, esophageal recordings of the EAdi waveform demonstrate that neural breathing pattern is variable, with regards to timing, amplitude, and pattern with a distinct amount of tonic diaphragm activity.