Normal values of forced vital capacity (FVC), forced expiratory volume (FEV 1-0), and peak flow rate (PFR) in children.

In children, the respiratory tract is probably more often affected by disease than any other system of the body. In spite of this, quantitative methods of evaluation are seldom used outside special respiratory units. No clinician would manage a patient with potential renal failure without laboratory aids, even if it were only an estimation of the blood urea, but he would seldom give children with potential respiratory failure the benefit of the simplest functional studies.