Abstract

Twenty premature infants ventilated for respiratory distress syndrome (RDS) were studied using a new computerised technique to determine spontaneous inspiratory and expiratory times. The technique is continuous and non-invasive. Infants were studied during intermittent positive pressure ventilation for periods of up to 45 minutes. Median birth weight and gestation were 1477 g and 30 weeks. The median number of breaths analysed for each baby was 925. The median (range) for spontaneous inspiratory time was 0.30 (0.26 to 0.34) seconds and for spontaneous expiratory time it was 0.46 (0.34 to 0.66) seconds. The spontaneous inspiratory and expiratory times were different from the ventilator settings.