Lung function testing--useless in ventilated newborns?
Several methods have been used for lung function testing in the ventilated newborn. The interest in the field has been stimulated by the recent appearance of commercially available equipment for assessment of mechanical parameters and of functional residual capacity in this group. Nevertheless, lung function testing is rarely used as a clinical routine, even such simple variables as tidal volume and minute ventilation. Among the many possible reasons for this condition, the fragile nature of the infants and the hands-off policy usually exercised, the difficulties in measuring flow accurately, and the complexity of the present methods deserve special attention. In order to change this situation more work needs to be done to elucidate basal physiology of the ventilated lung and the relationships between ventilator settings, lung function and side-effects in different conditions. If then sufficiently simple, safe and accurate methods to assess the most important functions can be offered, lung function testing would be likely to become a useful component of routine care in future neonatal intensive care.