Required number of forced expiratory maneuvers
In children, adolescents and adults three reproducible maneuvers are required (see FVC and FEV1). Do not try to obtain more than 8 maneuvers (ref. 1). There is little if anything to be gained from obtaining more than 3 correctly performed reproducible maneuvers.
Ref. 1 - Number of FVC
If 8 maneuvers have not led to a FVC or FEV1 meeting the requirements then further attempts are useless:
- Ferris BG Jr, Speizer FE, Bishop Y, Prang G, Weener J. Spirometry for an epidemiologic study: deriving optimum summary statistics for each subject. Bull Europ Physiopathol Respir 1978; 14: 145-166.
- Kanner RE, Schenker MB, Munoz A, Speizer FE. Spirometry in children: methodology for obtaining optimal results for clinical and epidemiological studies. Am Rev Respir Dis 1983; 127: 720-724.