Maximum Forced Expiratory Flow Rate as a Measure of Ventilatory Capacity

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 wi...

Peak expiratory flow rate as a surrogate for forced expiratory volume in 1 second in COPD severity classification in Thailand

BACKGROUND There are limited studies directly comparing correlation and agreement between peak expiratory flow rate (PEFR) and forced expiratory volume in 1 second (FEV1) for severity classification of COPD. However, clarifying the role of PEFR as a surrogate of COPD severity classification instead of FEV1 is essential in situations and areas where spirometry is not routinely available. PURPO...

Comparison of maximal midexpiratory flow rate and forced expiratory flow at 50% of vital capacity in children.

BACKGROUND The mid-portion of the maximal expiratory flow-volume (MEFV) curve is often described by values of the mean forced expired flow as lung volume decreases from 75% to 25% of vital capacity (ie, forced expiratory flow, midexpiratory phase [FEF(25-75)]). It is common practice to report also forced expired flow at 50% of vital capacity (FEF(50)). STUDY OBJECTIVE To investigate whether F...

Obstructive ventilatory defect with normal forced expiratory volume in one second/vital capacity ratio.

A Simple Measure to Assess Hyperinflation and Air Trapping: 1-Forced Expiratory Volume in Three Second / Forced Vital Capacity

BACKGROUND Several recent studies have suggested that 1 minus-forced expiratory volume expired in 3 seconds / forced vital capacity (1-FEV3/FVC) may be an indicator of distal airway obstruction and a promising measure to evaluate small airways dysfunction. AIMS To investigate the associations of 1-FEV3/FVC with the spirometric measures and lung volumes that assess small airways dysfunction an...