Peak flowmeter resistance decreases peak expiratory flow in subjects with COPD

Non-Pharmaceutical Techniques for Obstructive Airway Clearance Focusing on the Role of Oscillating Positive Expiratory Pressure (OPEP): A Narrative Review

Mucus secretion in the lungs is a natural process that protects the airways from inhaled insoluble particle accumulation by capture and removal via the mucociliary escalator. Diseases such as cystic fibrosis (CF) and associated bronchiectasis, as well as chronic obstructive pulmonary disease (COPD), result in mucus layer thickening, associated with high viscosity in CF, which can eventually lead to complete airway obstruction. These processes severely impair the delivery of inhaled medications to obstructed regions of the lungs, resulting in poorly controlled disease with associated increased morbidity and mortality. This narrative review article focuses on the use of non-pharmacological airway clearance therapies (ACTs) that promote mechanical movement from the obstructed airway. Particular attention is given to the evolving application of oscillating positive expiratory pressure (OPEP) therapy via a variety of devices. Advice is provided as to the features that appear to be the most effective at mucus mobilization.

Spirometry. Spanish Society of Pulmonology and Thoracic Surgery (SEPAR)

Spirometry is the main pulmonary function test and is essential for the evaluation and monitoring of respiratory diseases. Its utility transcends the field of Respiratory Medicine, is becoming increasingly important in primary care and applications have even been described outside the field of respiratory diseases. This document is therefore intended to serve as support for all health professionals who use spirometry, providing recommendations based on the best scientific evidence available. An update of the indications and contraindications of the test is proposed. The document sets out recommendations on the requirements necessary for conventional spirometers and portable office equipment, as well as on spirometer hygiene and quality control measures. Spirometric parameters that must be considered, performance of manoeuvres, criteria for acceptability and repeatability of measurements and their quality control are defined. A proposal is also established for presentation of the results and an evaluation and interpretation is proposed according to information generated in recent years. Finally, lines of adaptation and integration of spirometry in the field of new technologies are considered.

Comparison between peak expiratory flow and FEV(1) measurements on a home spirometer and on a pneumotachograph in children with asthma

BACKGROUND

The accuracy of electronic portable home spirometers has been demonstrated in vitro using computer-based waveforms. We assessed the agreement in vivo between measurements of lung function on an electronic spirometer (Koko Peak Pro) and those obtained by the gold standard, a hospital lung function laboratory pneumotachograph.

METHODS

Fifty stable asthmatic children (33 boys), aged 6-17 years, performed peak expiratory flow (PEF) and forced expiratory volume in 1 sec (FEV(1)) measurements according to international guidelines on a portable home spirometer and on the hospital pneumotachograph in random order. All measurements complied to standard quality criteria. The PEF and FEV(1) values recorded with the home spirometer and on the hospital pneumotachograph were compared.

RESULTS

All children performed reproducible high-quality measurements on both spirometers. PEF values on the home spirometer were considerably lower than on the laboratory pneumotachograph (95% CI for difference in PEF 14-30 L/min; P < 0.0001). Individual differences in PEF between the two devices could be >100 L/min. The FEV(1) values were slightly, but significantly, lower on the home spirometer (95% CI for difference in FEV(1) 0.02-0.1 L; P = 0.0018).

CONCLUSIONS

A home spirometer provides reproducible and quality acceptable measures in children with asthma when performed under professional supervision and encouragement. Mean PEF and FEV(1) values recorded on this home spirometer are significantly lower than those on a hospital pneumotachograph, and individual differences may be large. Therefore, home spirometry may not be interchanged with pneumotachography in a lung function laboratory.