TY - JOUR T1 - Peripheral chemoresponses of infants measured by a minimally invasive method utilizing two-breath alternations in Fl,02 JF - European Respiratory Journal JO - Eur Respir J SP - 1261 LP - 1268 DO - 10.1183/09031936.96.09061261 VL - 9 IS - 6 AU - DA Thomas AU - K Poole AU - EK McArdle AU - CS Beardsmore AU - PC Goodenough AU - J Thompson AU - H Simpson Y1 - 1996/06/01 UR - http://erj.ersjournals.com/content/9/6/1261.abstract N2 - The aim of this study was to develop a minimally invasive and reliable method for measuring peripheral chemoresponsiveness to oxygen in infants, and to establish baseline data from normal infants at 12 weeks of age. Two-breath alternations in fractional inspired oxygen (FI,O2), switching between 0.42 to 0.00 were given for 2 min periods via a face mask (held close to the face but without contact) to 18 healthy infants during quiet sleep. End-tidal oxygen concentrations alternated between 21 and 11%. Instantaneous minute ventilation (V'E) and its components tidal volume (VT), respiratory frequency (fR) inspiratory and expiratory times (tI and tE), inspiratory flow (VT/tT), and inspiratory duty cycle (tI/ttot) were measured by respiratory inductance plethysmography. Two-breath alternations in each of the ventilatory components were matched with the corresponding alternating end-tidal oxygen record and compared with contiguous pre- and post-test data obtained in control periods of air breathing. Alternations in all ventilatory components except fR changed significantly during FI,O2 alternations; VT 26%, tE-8%, VT/tI 18%, tI/ttot 11% and V'E 28% of baseline values. Within and between infant variances are reported for the individual components of ventilation. Differences among infants were best detected by alternations in V'E; within infant variance 76, between infant variance 171. We conclude that the test described is a safe, reliable and relatively easily applied method of measuring peripheral chemoresponsiveness, which is suitable for clinical application in infancy. ER -