Reliability of a commercially available threshold loading device in healthy subjects and in patients with chronic obstructive pulmonary disease.

BACKGROUND: Threshold loading with the Nickerson and Keens' device is frequently applied in the training and assessment of inspiratory muscles. However, this equipment is not easily applied in clinical practice and training. A study was therefore designed to investigate the accuracy and reliability of the Threshold, a commercially available threshold loading device. METHODS: The resolution (accuracy) of the system was determined by measuring variation of pressure and flow during one minute in an experimental setup. The reproducibility and flow independence were then determined during threshold loading at six different inspiratory loads between 25% and 50% maximal inspiratory pressure (PImax) in 10 patients with chronic obstructive pulmonary disease (COPD) and eight healthy subjects. RESULTS: In the first experiment the mean variation of the sustained pressure for all loads was 1.7%. The mean coefficients of variation for pressure and flow measurements were 0.2% and 3%, respectively. In the second experiment the healthy subjects showed mean coefficients of variation for pressure and flow of 0.8% and 20.5%, respectively, and the patients showed mean coefficients of variation of 0.6% and 14.5%, respectively. CONCLUSIONS: During the in vitro experiment as well as during the experiments in patients with COPD and in healthy subjects only small variations in pressure were observed despite large variations in flow. The Threshold is a reliable and reproducible device for loading inspiratory muscles in patients with COPD as well as in healthy subjects.

[1]  R. Pardy,et al.  Measurement of inspiratory muscle performance with incremental threshold loading. , 2015, The American review of respiratory disease.

[2]  M. Decramer,et al.  Diaphragmatic breathing reduces efficiency of breathing in patients with chronic obstructive pulmonary disease. , 1995, American journal of respiratory and critical care medicine.

[3]  D. Hillman,et al.  A threshold loading device for testing of inspiratory muscle performance. , 1995, The European respiratory journal.

[4]  M. Decramer,et al.  Inspiratory muscle training: where are we? , 1994, The European respiratory journal.

[5]  H. Brath,et al.  Effects of combined inspiratory muscle and cycle ergometer training on exercise performance in patients with COPD. , 1994, The European respiratory journal.

[6]  T. Beroíza,et al.  Inspiratory muscle training in chronic airflow limitation: comparison of two different training loads with a threshold device. , 1994, The European respiratory journal.

[7]  K. Chon,et al.  Ventilatory load characteristics during ventilatory muscle training. , 1994, American journal of respiratory and critical care medicine.

[8]  D. Evans,et al.  Measurement of inspiratory muscle performance with incremental threshold loading: a comparison of two techniques. , 1993, Thorax.

[9]  D. B. Thomson,et al.  Sustainable inspiratory pressures over varying flows, volumes, and duty cycles. , 1990, Journal of applied physiology.

[10]  M. Fairbarn,et al.  Comparison of two-minute incremental threshold loading and maximal loading as measures of respiratory muscle endurance. , 1989, Chest.

[11]  R. Goldstein,et al.  Applicability of a threshold loading device for inspiratory muscle testing and training in patients with COPD. , 1989, Chest.

[12]  R. Shadmehr,et al.  Targeted resistive ventilatory muscle training in chronic obstructive pulmonary disease. , 1988, Journal of applied physiology.

[13]  J. Larson,et al.  Inspiratory muscle training with a pressure threshold breathing device in patients with chronic obstructive pulmonary disease. , 1988, The American review of respiratory disease.

[14]  D. Altman,et al.  STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENT , 1986, The Lancet.

[15]  T. Clanton,et al.  Effects of breathing pattern on inspiratory muscle endurance in humans. , 1985, Journal of applied physiology.

[16]  L. A. Engel,et al.  Pressure-time product, flow, and oxygen cost of resistive breathing in humans. , 1985, Journal of applied physiology.

[17]  T. Keens,et al.  Measuring ventilatory muscle endurance in humans as sustainable inspiratory pressure. , 1982, Journal of applied physiology: respiratory, environmental and exercise physiology.

[18]  D. Leith,et al.  Ventilatory muscle strength and endurance training. , 1976, Journal of applied physiology.

[19]  D. Hillman,et al.  Ventilatory responses to inspiratory threshold loading and role of muscle fatigue in task failure. , 1994, Journal of applied physiology.

[20]  H. Folgering,et al.  Target-flow inspiratory muscle training during pulmonary rehabilitation in patients with COPD. , 1991, Chest.

[21]  R. Pardy,et al.  Respiratory muscle performance in normal elderly subjects and patients with COPD. , 1989, Chest.

[22]  T. Clanton,et al.  Inspiratory muscle conditioning using a threshold loading device. , 1985, Chest.

[23]  L. F. Black,et al.  Maximal respiratory pressures: normal values and relationship to age and sex. , 1969, The American review of respiratory disease.