ABSTRACT Introduction: Respiratory muscle strength can be assessed by static mouth measurements of maximal inspiratory pressure (Pimax) and maximal expiratory pressure (Pemax). Impaired respiratory muscle strength is common in neuromuscular and obstructive pulmonary disease such as Cystic Fibrosis (CF). Maximal respiratory pressures can easily be measured with a portable manometer on the bedside and in the community. Our objective was to compare maximal respiratory pressures as measured by standard laboratory equipment and the portable mouth pressure meter Micro RPM. Methods: Pimax and Pemax were assessed in 296 healthy subjects and patients with CF with the Micro RPM and standard laboratory equipment. The Micro RPM measures and digitally displays maximal respiratory pressures after averageing over a one second period. Standard laboratory equipment consisted of a differential pressure transducer, whose amplified signals were analyzed by Lab-VIEW software. Each subject performed at least five reproducible maneuvers after familiarizing with the equipment. Results: The Micro RPM accurately measured maximal inspiratory and maximal expiratory pressures both in healthy individuals as well as in patients with CF. Mean difference (standard deviation) of the methods was 1.37 (17.73) cm H2O for Pimax maneuvers and 1.84 (9.09) cm H2O for Pemax maneuvers. Conclusions: The Micro RPM can relia-bly and accurately measure maximal respiratory mouth pressures and its use could be applied both in the clinical and the research setting.
Cite this paper
Dassios, T. , Katelari, A. , Doudounakis, S. and Dimitriou, G. (2013) Comparison of two methods of measurement of maximal respiratory pressures in health and cystic fibrosis. Journal of Biomedical Science and Engineering, 6, 43-48. doi: 10.4236/jbise.2013.68A2006.
 Fauroux, B. and Lofaso, F. (2005) Measurements of respiratory muscle function in children. In: Hammer, J. and Eber, E., Eds, Paediatric Pulmonary Function Testing, Karger, Basel, 138. doi:10.1159/000083531
 Similowski, T. and Derenne, J.P. (1994) Inspiratory muscle testing in stable COPD patients. European Respiratory Journal, 7, 1871-1876.
 Mulreany, L.T., Weiner, D.J., McDonough, J.M. et al. (2003) Noninvasive measurement of the tension-time index in children with neuromuscular disease. Journal of Applied Physiology, 95, 931-937.
 Barry, S.C. and Gallagher, C.G. (2003) Corticosteroids and skeletal muscle function in cystic fibrosis. Journal of Applied Physiology, 95, 1379-1384.
 Polkey, M.I., Kyroussis, D., Hamnegard, C.H., et al. (1996) Diaphragm strength in chronic obstructive pulmonary disease. American Journal of Respiratory and Critical Care Medicine, 154, 1310-1317.
 Hart, N., Tounian, P., Clement, A., et al. (2004) Nutritional status is an important predictor of diaphragm strength in young patients with cystic fibrosis. The American Journal of Clinical Nutrition, 80, 1201-1206.
 Hamnegard, C.H., Wragg, S., Kyroussis, D., et al. (1994) Portable measurement of maximum mouth pressures. European Respiratory Journal, 7, 398-401.
 Bruschi, C., Cerveri, I., Zoia, M.C., et al. (1992) Reference values of maximal respiratory mouth pressures: A population-based study. American Review of Respiratory Disease, 146, 790-793. doi:10.1164/ajrccm/146.3.790
 Black, L.F. and Hyatt, R.E. (1969) Maximal respiratory pressures: Normal values and relationship to age and sex. American Review of Respiratory Disease, 99, 696-702.
 Gaultier, C. and Zinman, R. (1983) Maximal static pressures in healthy children. Respiration Physiology, 51, 45-61. doi:10.1016/0034-5687(83)90101-9
 Hayot, M., Guillaumont, S., Ramonatxo, M., et al. (1997) Determinants of the tension-time index of inspiratory muscles in children with cystic fibrosis. Pediatric Pulmonology, 23, 336-343.
 Hahn, A., Ankermann, T., Claass, A., et al. (2008) Noninvasive tension time index in relation to severity of disease in children with cystic fibrosis. Pediatric Pulmonology, 43, 973-981. doi:10.1002/ppul.20887
 Soudon, P., Steens, M. and Toussaint, M. (2008) A comparison of invasive versus noninvasive full-time mechanical ventilation in Duchenne muscular dystrophy. Chronic Respiratory Disease, 5, 87-93.
 Klefbeck, B. and Hamrah Nedjad, J. (2003) Effect of inspiratory muscle training in patients with multiple sclerosis. Archives of Physical Medicine and Rehabilitation, 84, 994-999. doi:10.1016/S0003-9993(03)00133-3
 Dimitriadis, Z., Kapreli, E., Konstantinidou, I., et al. (2011) Test/retest reliability of maximum mouth pressure measurements with the MicroRPM in healthy volunteers. Respiratory Care, 56, 776-782. doi:10.4187/respcare.00783
 Carefusion (2010) Micro RPM, simple tests for respiretory muscle strength. Carefusion, Hoechberg.
 ATS/ERS (2002) ATS/ERS Statement on respiratory muscle testing. American Journal of Respiratory and Critical Care Medicine, 166, 518-624.
 Bland, J.M. and Altman, D.G. (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet, 1, 307-310.
 Syabbalo, N. (1998) Assessment of respiratory muscle function and strength. Postgraduate Medical Journal, 74, 208-215. doi:10.1136/pgmj.74.870.208
 Stefanutti, D. and Fitting, J.W. (1999) Sniff nasal inspiratory pressure. Reference values in Caucasian children. American Journal of Respiratory and Critical Care Medicine, 159, 107-111. doi:10.1164/ajrccm.159.1.9804052
 Severino, F.G., Resqueti, V.R., Bruno, S.S., et al. (2010) Comparison between a national and a foreign manovacuometer for nasal inspiratory pressure measurement. Revista Brasileira de Fisioterapia, 14, 426-431.
 Hart, N., Polkey, M.I., Clement, A., et al. (2002) Changes in pulmonary mechanics with increasing disease severity in children and young adults with cystic fibrosis. American Journal of Respiratory and Critical Care Medicine, 166, 61-66. doi:10.1164/rccm.2112059
 Fauroux, B. (2011) Why, when and how to propose non-invasive ventilation in cystic fibrosis? Minerva Anestesiologica, 77, 1108-1114.
 Dassios, T., Katelari, A., Doudounakis, S., et al. (2012) Respiratory muscle function in patients with cystic fibrosis. Pediatric Pulmonology, in press.