- The training program includes a pre-learning phase that allows participants to familiarize themselves with foundational concepts before engaging in in-person interactions with the facilitator.
- Following the pre-learning phase, participants will have the opportunity to meet with the facilitator in a physical classroom setting. This direct interaction is crucial for addressing any questions or concerns that may have arisen during the self-study period.
- Additionally, the physical classroom component is designed to facilitate hands-on practical training. This aspect of the program allows participants to apply theoretical knowledge in real-world scenarios, enhancing their understanding and retention of the material. Working under the guidance of an experienced facilitator, learners can practice skills, collaborate with peers, and gain valuable insights that are difficult to achieve through online learning alone.
- Overall, this structured approach—combining pre-learning with direct facilitator contact and practical classroom experiences—ensures a comprehensive and effective learning journey that accommodates various learning styles and maximizes participant engagement.
Step 8 Copy TEST COURSE Jan 2023
Step 8
Severity Grading
Grading the severity of the impairment
Impaired lung functions are generally graded to quantify respiratory impairment/disability for medico-legal purposes, and to optimise and standardise treatment. The ATS/ERS guidelines suggest grading both obstructive and restrictive ventilatory impairments solely according to FEV1, as there is little or no evidence for the use of FVC as a parameter of impairment. Where appropriate, post-bronchodilator FEV1 values should be used for grading (11). Large airway obstruction should not be graded according to the FEV1.
The table below is proposed by Quanjer, Pretto, Brazzale and Boros as the new grading system for the categorisation of airways obstruction for those still using % predicted as well as those using LLN and Z-score for interpretation. FEV1 is still the preferred parameter for severity grading.
Figure 9.25: Table for severity grading. Taken from Quanjer et al Grading the severity of airways obstruction: new wine in new bottles.
(http://erj.ersjournals.com/content/43/2/505)
Interpretation and grading step by step
Interpreting spirometry is easy when approached in a logical step by step manner. The steps below detail how best to make your final interpretation:
Step A – Assess quality and data validation
Was the equipment verified/calibrated?Have the correct reference values been used?
Is it necessary to correct for ethnic origin?
Is the test valid?
Was the best test used?
Figure 9.26: Example calibration and worker data to be checked
Step B – Assess the graphs
Analysing the shape of the flow/volume and volume/time graphs can provide information regarding the type of ventilatory defect. The flow/volume trials can take on a few distinguishable shapes that correspond to a certain type of pathology.
Figure 9.27: Comparison normal, obstructive, restrictive and mixed impairments on flow/volume and volume/time graphs
(https://www.slideshare.net/nileshkate79/pulmonary-function-tests-46140747)
Step C – Assess numerical values
Assess the numerical values. The following 5-step process is one of the easiest to understand:
- Begin by looking at the FEV1 / FVC. Below LLN or 70% in adults (80% in children/adolescents and 60% >65 years) suggests an obstructive impairment.
Above LLN or 70% in adults (80% in children/adolescents and 60% >65 years) suggests there is no obstruction and the test is either normal or restricted (depending on the FVC %’s of predicted) - Next look at the FVC to determine if it is above or below LLN or 80% predicted.
- Next, look at the FEV1 to see if it is above or below LLN or80% predicted.
- If everything to this point is above the lower levels of normal stop at this step – the spirometry test is normal.
- If the FVC and/or the FEV1 are decreased, there is a strong possibility of lung disease and you should go on to the next step
Step D – Bronchodilator responsiveness testing
For any obstructive spirometry result do a bronchodilator responsiveness study. This defines the obstructive abnormality as Asthma or COPD.
A significant response to inhaled bronchodilator is defined as an increase ≥12% and ≥200 mL in either FEV1 or FVC between the baseline and post-bronchodilator results (10).
There is a significant response to inhaled bronchodilator if:
Spirometry returns to within normal limits (FEV1/FVC, FEV1 and FVC within the normal range), then there is complete reversibility of airflow limitationObstruction remains apparent after inhaled bronchodilator, then there is incomplete reversibility of airflow limitation
Figure 9.28: Example bronchodilator responsiveness test
Step E – Grade the impairment
Assess the severity of the abnormality by using the ATS / ERS grading table.
In the real-life example below the best pre bronchodilator FEV1 is -1.90 = grade 1 mild
75%pred = grade 1 mild
the best post bronchodilator FEV1 is – 3.36 = grade 4 severe
56%pred = grade 3 moderately severe
Figure 9.29: Example bronchodilator responsiveness test for severity grading
Step F – Document your interpretation / comments
Write your interpretation, grading and bronchodilator responsiveness result where applicable.
The purpose of recording and reporting is that any person who picks up the spirogram at a later date will know exactly what happened at the time of testing and will have clues as to factors that will affect interpretation.
The operator should specifically record and report the following:
Reason for testingTest posture – only if this differs from requirements in the standard operating procedure for the unit
Recent use of bronchodilators (drug, dose and time taken)
Operators name and initials
Comments on effort, technique and co-operation. If the operator was unable to obtain a maximal effort, it should be noted with an explanation of the problem.
Step G – Compare results to previous test
Compare results to previous tests
Interpretation algorithm
Figure 9.30: An algorithm for the categorisation of spirometry.
(http://www.samj.org.za/index.php/samj/article/view/6197/4720)
Longitudinal evaluation – Interpreting change over time
Why look at change over time?
Adults experience a normal, gradual decline in lung function as they age, but some occupational and personal exposures can accelerate this loss of function over time. Periodic spirometry testing can be used to detect such accelerated losses. To evaluate lung function loss over time, periodic (or “serial”) spirometry testing measures baseline lung function, and then compares the baseline to follow-up values measured at later time points. This process is known as “longitudinal evaluation.”
Longitudinal evaluation of accurate serial test results can help OMPs make decisions about worker respiratory health or the need for medical referrals. Longitudinal evaluation may be especially important for workers who have above-average lung function (i.e., >100 percent of predicted). Such workers’ lung function may decline over time from the top to the bottom of the normal range, without dropping below their LLN. Although such declines may not be detected by repeatedly determining whether the results from single examinations are within the worker’s current normal range, these declines – which may indicate a significant loss of lung function – may be detected by longitudinal evaluation. In addition, careful monitoring of longitudinal results from groups of workers in a workplace may indicate that exposures to known respiratory hazards need to be reduced. Such group evaluations might also help to identify previously unrecognized occupational hazards.
When evaluating a worker’s changes in lung function over time the lead spirometrist should bear in mind that rates of pulmonary function change are affected by multiple factors. Some of those factors are work-related, e.g., job exposures, while others are non-occupational, e.g., weight gain, habits such as smoking, or pre-existing lung diseases such as asthma. Therefore, determinations of lung function decline should consider the whole clinical presentation in addition to spirometry results.
If a worker is determined to have “excessive” loss of function, two follow-up steps are recommended:
- Technical error should be ruled out by re-evaluating the test results for validity and repeating the spirometry test if needed
- The worker should be referred for further medical evaluation including an assessment of the complete clinical picture and possibly additional tests of pulmonary function.
