Accuracy of optoelectronic plethysmography in childhood exercise-induced asthma.

OBJECTIVE: To assess the variations of end-expiratory volume of chest wall (EEVcw) measured by optoelectronic plethysmography (OEP) as a diagnostic tool in exercise-induced asthma (EIA) among asthmatic preschool children. METHODS: Forty children diagnosed with asthma were included in the study. Spirometry was used as a gold standard test for comparison with OEP. A 10% decline in forced expiratory volume in 1 second was considered positive for EIA. OEP was performed with 8 cameras at a frequency of 60 Hz and 89 markers were placed on the thoraco-abdominal surface of participants. Following bronchoprovocation testing on a treadmill, series of OEP and spirometry were conducted between 5 and 30 minutes after exercise. To obtain the ideal cut-off point, a receiver operating characteristic (ROC) curve was constructed for the largest EEVcw. The highest Youden index was used as criteria to obtain the cut-off point with the best sensitivity and specificity. RESULTS: Of the 40 children studied, 16 had EIA. According to the ROC curve, the cut-off point of 0.185% for EEWcw provided mean sensitivity (95% confidence interval) of 93.75% (0.69-0.99), for a specificity of 83.33% (0.63-0.95), when using the largest increase in the period of 5-30 minutes post-exercise. The low area of the ROC was 0.93 (0.85-1.00) for p < 0.001. CONCLUSION: OEP can be accurately used to replace spirometry in asthmatic children unable to adequately execute the required manoeuvres.

Tidal volume measurements in infants: Opto-electronic plethysmography versus pneumotachograph.

Tidal breathing measurements by Opto-Electronic Plethysmography (OEP) has been reported for infants limited to protocols with two chest wall compartments. Standard protocol for the analysis of adults, with three compartments of chest wall, has been unavailable for analysis of infants. We aimed to study the agreement of simultaneous measurements of tidal volume by OEP (VT,OEP ) and a heated pneumotachograph (PNT) (VT,PNT ) performed during sleeping in 20 infants (gestational age 35.1 ± 4.6 weeks) at 3-4 months postconceptual age with a three compartment protocol. From PNT and OEP measurements, tidal volume corrected (VT,PNT ) for ambient conditions were calculated with a total number of 200 breaths. The two methods were in good agreement with tidal volume mean difference of 0.02 ml and limit of agreement -4.11 to 4.08 ml (95%CI), no relationship was found between differences and means of OEP and PNT measurements. Pulmonary rib cage, abdominal rib cage and abdomen contributed by 12.4 ± 9.7%, 5.2 ± 5.1%, and 82.4 ± 11.4% to VT,OEP , respectively. The OEP experimental protocol based on 52 markers and a three-compartment model of the chest wall could be used in spontaneously sleeping infants. Pediatr Pulmonol. 2016;51:850-857. © 2016 Wiley Periodicals, Inc.