LIBRO + ANEXOS NEUMOLOGÍA PEDIÁTRICA

Neumología Pediátrica. Anexos ❚ 183 4. Know why slow vital capacity may be greater than forced vital capacity 5. Know the normal interindividual and intraindividual variation in FVC, FEV1, FEF 25-75, and peak expiratory flow b. Helium dilution 1. Know how to calculate functional residual capacity from helium dilution data 2. Understand the effect of gas trapping or a system leak on helium dilution measurements 3. Understand the principles and limitations of helium dilution measurement of lung volume c. Nitrogen washout 1. Understand the principle and limitations of nitrogen washout measurements of lung volume 2. Know how to calculate FRC from nitrogen washout data d. Plethysmography 1. Understand the principles of pressure and volume plethysmography 2. Know that lung cysts and airway obstruction can influence plethysmographic measurements of lung volume 3. Describe why functional residual capacity (FRC) and thoracic gas volume (TGV) may be different when measured by plethysmography versus gas dilution 2. Flows and timed volumes a. Forced expiratory volumes 1. Know how to calculate forced expiratory flow between 25-75% VC (FEF 25-75) and forced expiratory volume in one second from a sample spirogram 2. Know the reproducibility of PEF, FEF 25-75, FVC, and FEV1 in children 3. Know the criteria for a technically acceptable spirometric trace 4. Know the principle of backward extrapolation for correcting FEV1 measurements b. Peak expiratory flow 1. Know that peak expiratory flow is effort dependent 2. Understand the limitations of peak expiratory flow rate in evaluating pulmonary function c. Maximal expiratory flow volume curve 1. Recognize configurations of flow-volume loops that suggest lack of cooperation, poor effort, or glottic closure 2. Know the definitions of flows at various fractions of vital capacity (eg, maximum flow at 50% of vital capacity) 3. Know the variability of flows at various fractions of vital capacity (eg, maximum flow at 50% of vital capacity) 4. Understand criteria for an acceptable flow volume curve, including end of test and reproducibility 3. Diffusing capacity a. Know that a correction for hemoglobin is required in single-breath diffusing capacity measurements b. Know that a correction for lung volume is helpful in interpreting single-breath diffusing capacity measurements