All respiratory diseases affect the lungs’ ability to function effectively, and as a result affect lung function (spirometry) measurements. To respire, or to breathe, consists of three key components:
- Ventilation – the lungs inflation and deflation with air
- Pulmonary circulation – the functioning of the blood vessels that supply and drain the lungs
- Gas exchange – the uptake of oxygen and elimination of waste products
The most commonly reported symptoms of all lung diseases are shortness of breath and coughing. It is therefore vital that medical practitioners utilise alternative investigative tools to ensure accurate diagnosis.
The component, or components of effective lung function that are affected by disease will impact spirometry recordings in different ways. These can be categorised into restrictive or obstructive lung disease, though individuals can suffer a combination.
Restrictive and obstructive lung diseases
Restrictive lung diseases
Restrictive lung diseases affect the lung’s ventilation through a reduction in lung volume, likely due to diseased tissue, weak muscles, neuromuscular disorders or damaged nerves.
Obstructive lung diseases
Obstructive lung diseases affect the lung’s ability to exchange gases due to reduced air flow, possibly from airway narrowing.
These two categories of lung disease result in common patterns found when conducting lung function testing. The spirometry volume/time curve and flow loops differ between the disease groups, aiding diagnosis when interpreted by a specialist. Obstructive lung disease can result in a decrease in both FEV1 and FEV1/FVC ratio, whereas restrictive will have a normal FEV1/FVC ratio, but a reduced FVC and FEV1.
Therefore, when diagnosing obstructive lung diseases such as asthma, bronchitis, and COPD, or restrictive lung diseases such as ARDS, pneumoconiosis, or fibrosis, lung function testing is an invaluable tool.
Amplivox are proud to offer a suite of industry-leading spirometry solutions to meet the requirements of occupational and respiratory health professionals. With the inclusion of class-leading spirometry PC database applications, users can benefit from comprehensive data analysis, trending, and transfer capabilities. For more information on our spirometry products please visit our spirometers webpage, contact our customer support team on +44 (0)1865 880 846 or email.