CO2 responses in infants: on-line display and analysis using a microcomputer and waveform analyzer.

This report describes a new system for measuring and recording ventilatory responses to inspired CO2 in infants, which consists of a nasal pneumotach, microcomputer, and a waveform analyzer. The waveform analyzer measures ventilatory responses on-line and displays them in real-time, breath-by-breath. Thirty-two ventilation studies were performed in 24 normal, full-term infants (3-300 days of age). The mean ratio of delta VE/ delta PACO2 was 44.3 +/- 22.9 (SD) ml/kg X min X mm Hg BTPS (range 15.0-121.2). We believe this new system is a significant improvement over previous methods for measuring and recording ventilatory responses of infants.