Normal maximal expiratory and inspiratory pressures in healthy teenagers.

Maximal expiratory pressure at total lung capacity and maximal inspiratory pressure at residual volume were measured in 364 male and 325 female healthy teenage subjects. Predictive equations have been drawn based on coefficients of age, height and weight. The pressures may be used to evaluate respiratory muscle strength and follow the progress in patients with neuromuscular disorders, dyspnoea and respiratory failure.