Pre‐flight testing of preterm infants with neonatal lung disease: a retrospective review

Background: The low oxygen environment during air travel may result in hypoxia in patients with respiratory disease. However, little information exists on the oxygen requirements of infants with respiratory disease planning to fly. A study was undertaken to identify the clinical factors predictive of an in-flight oxygen requirement from a retrospective review of hypoxia challenge tests (inhalation of 14-15% oxygen for 20 minutes) in infants referred for fitness to fly assessment. Methods: Data from 47 infants (median corrected age 1.4 months) with a history of neonatal lung disease but not receiving supplemental oxygen at the time of hypoxia testing are reported. The neonatal and current clinical information of the infants were analysed in terms of their ability to predict the hypoxia test results. Results: Thirty eight infants (81%) desaturated below 85% and warranted prescription of supplemental in-flight oxygen. Baseline oxygen saturation was >95% in all infants. Age at the time of the hypoxia test, either postmenstrual or corrected, significantly predicted the outcome of the hypoxia test (odds ratio 0.82; 95% confidence intervals 0.62 to 0.95; p = 0.005). Children passing the hypoxia test were significantly older than those requiring in-flight oxygen (median corrected age (10-90th centiles) 12.7 (3.0-43.4) v 0 (-0.9-10.9) months;

Respiratory impedance and bronchodilator response in healthy Italian preschool children

Objective To define normal values for respiratory resistance (R(rs)) and reactance (X(rs)) and bronchodilator response (BDR) in a population of healthy Italian preschool children using a commercially available forced oscillation device Methods R(rs) and X(rs) were measured in kindergartens in Viterbo Italy Regression analysis was performed taking into account height weight age gender and reference equations calculated The coefficient of repeatability (CR) between two tests performed 15 min apart was calculated in a subset of children BDR was assessed by repeating the measurements 15 min after the administration of 200 mu g of inhaled salbutamol and calculated as an absolute change in R(rs) and X(rs) at 8 Hz as a percent change in baseline and as a change in Z score calculated from the reference equations Results Lung function was attempted in 175 healthy children and successful in 163 (81 male median age 4 8 range 2 9-6 1 years) R(rs) and X(rs) at 6 8 and 10 Hz were related to height but not other variables The CR was 1 53 hPa s L(-1) for R(rs8) and 091 hPa s L(-1) for X(rs8) The 5th percentile for absolute R(rs8) BDR was -3 16 hPa s L(-1) whereas the 95th percentile for absolute X(rs8) BDR was 2 25 hPa s L(-1) These cut off values corresponded to a change in the Z score of -1 88 and 2 48 respectively Conclusions We have established reference equations for R(rs) and X(rs) in healthy Italian preschool children using forced oscillations We recommend a change in Z score of -1 88 for R(rs8) and 2 48 for X(rs8) as cut off values for a positive BDR Pediatr Pulmonol 2010, 45 1086-1094 (C) 2010 Wiley Liss In

Assessment of bronchodilator responsiveness in preschool children using forced oscillations

Background: The forced oscillation technique (FOT) requires minimal patient cooperation and is feasible in preschool children. Few data exist on respiratory function changes measured using FOT following inhaled bronchodilators (BD) in healthy young children, limiting the clinical applications of BD testing in this age group. A study was undertaken to determine the most appropriate method of quantifying BD responses using FOT in healthy young children and those with common respiratory conditions including cystic fibrosis, neonatal chronic lung disease and asthma and/or current wheeze. Methods: A pseudorandom FOT signal (4-48 Hz) was used to examine respiratory resistance and reactance at 6, 8 and 10 Hz; 3-5 acceptable measurements were made before and 15 min after the administration of salbutamol. The post-BD response was expressed in absolute and relative (percentage of baseline) terms. Results: Significant BD responses were seen in all groups. Absolute changes in BD responses were related to baseline lung function within each group. Relative changes in BD responses were less dependent on baseline lung function and were independent of height in healthy children. Those with neonatal chronic lung disease showed a strong baseline dependence in their responses. The BD response in children with cystic fibrosis, asthma or wheeze (based on both group mean data and number of responders) was not greater than in healthy children. Conclusions: The BD response assessed by the FOT in preschool children should be expressed as a relative change to account for the effect of baseline lung function. The limits for a positive BD response of -40% and 65% for respiratory resistance and reactance, respectively, are recommended

Respiratory function and symptoms in young preterm children in the contemporary era

Objective: To determine the relationships between respiratory symptoms, lung function, and neonatal events in young preterm children. Methods: Preterm children (<32 w gestation), classified as bronchopulmonary dysplasia (BPD) or non-BPD, and healthy term controls were studied. Lung function was measured by forced oscillation technique (respiratory resistance [Rrs] and reactance [Xrs]) and spirometry. Respiratory symptom questionnaires were administered. Results: One hundred and fifty children (74 BPD, 44 non-BPD, 32 controls) 4–8 years were studied. Lung function (median Z-score [10,90th centile]) was significantly impaired in preterm children compared to controls for FVC (0.00 [-1.18, 1.76], 0.69 [-0.17,1.86]), FEV1 (-0.44 [-1.94, 1.11], 0.49 [-0.83, 2.51]), Xrs (-1.26 [-3.31, 0.11], -0.11 [-0.97, 0.73]), and Rrs (0.55 [-0.48, 1.82], 0.28 [-0.99, 0.96]). Only Xrs differed between the BPD and non-BPD (-1.51 [-3.59, -0.41], -0.89 [-2.64, 0.52]). The prevalence of recent respiratory symptoms (range: 32–36%) did not differ between BPD and non-BPD children. Supplemental O2 in hospital was positively associated with worsening Xrs and FEV1. Conclusion: Preterm children have worse lung function than healthy controls. Only respiratory reactance differentiated between preterm children with and without BPD and was influenced by days of O2 in hospital. Pediatr Pulmonol. 2016;51:1347–1355