Spirometry is the cornerstone of respiratory function laboratories and clinics as it is one of the most direct ways of determining the lung function and capacity of an individual. Whilst spirometry is used primarily for diagnostic purposes in clinics, it has a different purpose in the field of occupational health where there is an employee-healthcare provider-employer relationship to be considered and results will affect employment-related decisions. Incorrect spirometry results due to flawed technique or inaccurate interpretations can have significant impacts on conclusions drawn on an employees respiratory health.
Spirometry is a quick and powerful tool for the screening and clinical evaluation of work-place related lung disease.The practice of occupational health with respiratory programs can help identify whether exposure to particular inhalants in the work environment can affect lung function or exacerbate existing chronic lung disease in workers. Workers who are already living with asthma, chronic obstructive pulmonary disease or cystic fibrosis may be at increased risk of exposure to symptom triggers and benefit greatly from regular lung function testing in the workplace.
Spirometry can be physically difficult for many people as it generally requires forced breathing manoeuvers and the correct breathing technique for accurate results. The validity of results also depends on a number of other factors including but not limited to exposure of the patient to certain behaviours or substances prior to testing (for example, alcohol or smoking), the level of training by the operator of the device, environmental conditions and the calibration of the device. Workplace spirometry programs must therefore address how employees will be prepared for spirometry sessions, training and refresher courses for technicians or operators and the interpretation of results in light of each worker’s personal details such as baseline or prior tests.
Some important factors to consider for occupational health respiratory health programs include:
- Spirometer quality and performance: Spirometers used for the lung functions tests should meet the specifications of key ISO and ATS/ERS standards and should be validated against their criteria. Ultrasonic spirometers such as the Spirohome spirometers do not require regular calibration checks, however, outdated technologies such as turbine-based spirometers will need regular accuracy checks. Technicians must also ensure that manufacturer use conditions such as avoiding sensor blockage during use are observed.
- Test conditions: Technicians should be trained to help workers perform tests correctly. Workplaces should also have internal quality control procedures to ensure that technicians and employees are performing and reporting spirometry sessions correctly.
- Test Results: Technicians should be well informed about the interpretation of acceptable and repeatable test results and graphical displays of the full spirometry results. The significance and relevance of factors such as reference values, ethnic and personal background data, flow rates and obstructive versus restrictive impairment should be well comprehended by the operator. Referral to more experienced clinicians who can draw more detailed conclusions from longitudinal data assessment should also be an available option for both technicians and workers.
Employers who are implementing workplace respiratory health programs can incorporate methods for implementing these points that have been raised and brought to closer attention of late by many of the leading authorities on spirometry and lung function testing.