BACKGROUND: Portable peak flow meters are used in clinical practice for measurement of peak expiratory flow (PEF) at many different altitudes throughout the world. Some PEF meters are affected by gas density. This study was undertaken to establish which type of meter is best for use above sea level and to determine changes in spirometric measurements at altitude. METHODS: The variable orifice mini-Wright peak flow meter was compared with the fixed orifice Micro Medical Microplus turbine microspirometer at sea level and at Everest Base Camp (5300 m). Fifty one members of the 1994 British Mount Everest Medical Expedition were studied (age range, 19-55). RESULTS: Mean forced vital capacity (FVC) fell by 5% and PEF rose by 25.5%. However, PEF recorded with the mini-Wright peak flow meter underestimated PEF by 31%, giving readings 6.6% below sea level values. FVC was lowest in the mornings and did not improve significantly with acclimatisation. Lower PEF values were observed on morning readings and were associated with higher acute mountain sickness scores, although the latter may reflect decreased effort in those with acute mountain sickness. There was no change in forced expiratory volume in one second (FEV1) at altitude when measured with the turbine microspirometer. CONCLUSIONS: The cause of the fall in FVC at 5300 m is unknown but may be attributed to changes in lung blood volume, interstitial lung oedema, or early airways closure. Variable orifice peak flow meters grossly underestimate PEF at altitude and fixed orifice devices are therefore preferable where accurate PEF measurements are required above sea level.
BACKGROUND: Portable peak flow meters are used in clinical practice for measurement of peak expiratory flow (PEF) at many different altitudes throughout the world. Some PEF meters are affected by gas density. This study was undertaken to establish which type of meter is best for use above sea level and to determine changes in spirometric measurements at altitude. METHODS: The variable orifice mini-Wright peak flow meter was compared with the fixed orifice Micro Medical Microplus turbine microspirometer at sea level and at Everest Base Camp (5300 m). Fifty one members of the 1994 British Mount Everest Medical Expedition were studied (age range, 19-55). RESULTS: Mean forced vital capacity (FVC) fell by 5% and PEF rose by 25.5%. However, PEF recorded with the mini-Wright peak flow meter underestimated PEF by 31%, giving readings 6.6% below sea level values. FVC was lowest in the mornings and did not improve significantly with acclimatisation. Lower PEF values were observed on morning readings and were associated with higher acute mountain sickness scores, although the latter may reflect decreased effort in those with acute mountain sickness. There was no change in forced expiratory volume in one second (FEV1) at altitude when measured with the turbine microspirometer. CONCLUSIONS: The cause of the fall in FVC at 5300 m is unknown but may be attributed to changes in lung blood volume, interstitial lung oedema, or early airways closure. Variable orifice peak flow meters grossly underestimate PEF at altitude and fixed orifice devices are therefore preferable where accurate PEF measurements are required above sea level.
Authors: Jacky Ann Rosati; Ken Y Yoneda; Shagufta Yasmeen; Steve Wood; Marlowe W Eldridge Journal: Arch Environ Occup Health Date: 2005 Mar-Apr Impact factor: 1.663
Authors: S Lalande; P J Anderson; A D Miller; M L Ceridon; K C Beck; K A O'Malley; J B Johnson; B D Johnson Journal: Eur J Appl Physiol Date: 2011-02-16 Impact factor: 3.078
Authors: Denny Z H Levett; Daniel S Martin; Mark H Wilson; Kay Mitchell; Sundeep Dhillon; Fabio Rigat; Hugh E Montgomery; Monty G Mythen; Michael P W Grocott Journal: BMC Med Res Methodol Date: 2010-10-21 Impact factor: 4.615
Authors: Troy J Cross; Courtney Wheatley; Glenn M Stewart; Kirsten Coffman; Alex Carlson; Jan Stepanek; Norman R Morris; Bruce D Johnson Journal: Physiol Rep Date: 2018-03
Authors: Katie A O'Brien; R Andrew Atkinson; Larissa Richardson; Albert Koulman; Andrew J Murray; Stephen D R Harridge; Daniel S Martin; Denny Z H Levett; Kay Mitchell; Monty G Mythen; Hugh E Montgomery; Michael P W Grocott; Julian L Griffin; Lindsay M Edwards Journal: Sci Rep Date: 2019-02-19 Impact factor: 4.379
Authors: Laura Gochicoa-Rangel; Keylin Yaoska Rodríguez-Peralta; Ana Karen Gutiérrez-Bautista; Carlos Guzmán-Valderrábano; Rosario Fernández-Plata; Luis Torre-Bouscoulet; David Martínez-Briseño Journal: BMC Pulm Med Date: 2022-04-19 Impact factor: 3.320