General Guideline Principles for Diagnostic Testing
for workers compensation patients
The New York State workers compensation board has developed these guidelines to help physicians, podiatrists, and other healthcare professionals provide appropriate treatment for Diagnostic Testing.
These Workers Compensation Board guidelines are intended to assist healthcare professionals in making decisions regarding the appropriate level of care for their patients with ankle and foot disorders.
The guidelines are not a substitute for clinical judgement or professional experience. The ultimate decision regarding care must be made by the patient in consultation with his or her healthcare provider.
Diagnostic Testing of Spirometry in Work-Related Asthma
Spirometry testing is a crucial part of evaluating and treating people who may have asthma due to their jobs. When WRA is a concern, spirometry with or
Without bronchodilator treatment has four specific possible roles:
Determining the presence of asthma.
Exclude other conditions that are “asthma-like”.
If asthma is present, it can determine whether it is occupationally related; and
Monitoring reaction to therapy (and a probable return to employment) (and a possible return to work).
Spirometry in Work-Related Asthma
Spirometry in Work-Related Asthma
Diagnostic Testing of Spirometry in Work-Related Asthma are recommended as the first line of defence in identifying work-related asthma
Spirometry with Bronchodilator Response Testing
Spirometry with Bronchodilator Response Testing
Spirometry with Bronchodilator Response Testing is recommended It is advised to measure and record any airflow blockage discovered during spirometry.
The rationale for Recommendation – The signs and symptoms linked to a history consistent with work-related asthma are indications for spirometry with or without a bronchodilator for the evaluation of work-related asthma.
In most circumstances, spirometry with a bronchodilator is a crucial test for assessing pulmonary function. Fundamentally, asthma is different from other obstructive illnesses in that the restriction to airflow varies.
One efficient and straightforward way to measure this variability is to compare the results of spirometry before and after the administration of a bronchodilator, as well as the variability of results when repeated over several days.
Spirometry with a bronchodilator is primarily used to identify and assess airflow restriction when taking WRA into account. The forced expiratory volume in one second (FEV1) and the FEV1 to FVC ratio are the most helpful measurements for this reason.
The presence of airflow restriction, such as a decline in the FEV1/FVC ratio and FEV1, or a positive response to a methacholine challenge, serve as indicators of asthma.
To prove that the obstruction is real and that it is changing rather than fixed, repeated spirometry, or spirometry followed by repeated peak flow measurements, is performed.
Important caveats to consider:
Serial measures can be used to monitor progression and variability under various circumstances and exposures, but it is important to keep in mind that
Changes in the data don’t always translate into changes in the disease.
Airflow obstruction is an indicator of status at any one time and may not necessarily reflect trends over time because asthma is characterized by variability,
But it can signal a worsening of the condition if it is much worse than a previous FEV1 measurement.
As a result, its principal benefit is showing variability (e.g., disproving irreversible occlusion).
The measurements of highest utility in spirometry for the evaluation of airways illness are:
Expressed in liters or as a percentage of expected values, forced expiratory volume in one second (FEV1)
FEV1 before and after (pre/post) bronchodilator delivery, often albuterol (salbutamol),
Measurement of FEV1 before and after (pre/post) a work shift while accounting for diurnal fluctuation is known as pre/post FEV1.
FEV1/FVC, or the ratio of forced vital capacity to forced expiratory volume
Peak expiratory flow (PEF), which is typically stated in liters per minute, is very helpful for monitoring employees who exhibit reactive airways, and
Forced expiratory flow rate (FEF25-75), also known as mudflows, is of less critical value. It is the volume expired between 25% and 75% of FVC.
The use of appropriate tools, the execution of proper tests, and skilled interpretation are all necessary for accurate results.
Spirometry can be performed both before and after bronchodilator therapy.
By measuring baseline airflow and then observing if volumes rise after the administration of a bronchodilator, pre-, and post-bronchodilator testing is carried out.
The American Thoracic Society (ATS) defines the reversibility of airflow obstruction in FVC or FEV1 values as a 12% improvement in the FEV1 or an absolute value increase of at least 200 mL after bronchodilator administration.
Rarely, people may experience a paradoxical response to the bronchodilator that causes additional blockage; this is a temporary effect linked to airways that are extremely reactive and sluggish to respond to the drug.
Peak flow variations are common and used to track therapy progress but not for diagnosis.
Interpretation of Spirometer of Diagnostic Testing
Spirometry, whether performed with or without a bronchodilator, is insufficient to distinguish between occupational and non-occupational asthma and must be evaluated in conjunction with information from the history or other testing.
The diagnosis of asthma or generalized airway reactivity is not ruled out if reversible airway obstruction is not present on a single test day.
On how to perform and interpret spirometry, the American Thoracic Society and European Respiratory Society (ATS/ERS) have produced declarations. Additionally, OSHA recently released guidelines on the best ways to conduct occupational spirometry tests.
Peak Expiratory Flow Rates (PEFR) of Diagnostic Testing
PEFR is defined as the maximum flow supplied with the greatest force, beginning at the level of maximum inspiration, and using straightforward portable meters.
Serial PEFR measures the circadian rhythm, with morning values being lower and afternoon values being the highest. In people with bronchial asthma, the disparities are more obvious.
To be effective in assessing occupational asthma, PEFR must be carried out by the patient outside of a medical setting. To document the existence or absence of changes in flow that may be connected to the workplace environment or exposures, PEFR can be easily collected both at and away from work.
- Peak Expiratory Flow Rates – Serial Measures
Peak Expiratory Flow Rates – Serial Measures is recommended to confirm an asthma diagnosis made by another method in patients who have already been given an asthma diagnosis. The patient should receive instruction from the doctor or other qualified staff members on how to use the meter correctly and the value of precise records.
Indications – can help in the screening of patients with a WRA-like history.
The rationale for Recommendation- Serial PEFR is advised as a starting point for OA and WRA investigations. Early in the examination of WRA, when patients are more likely to still be exposed to a potential asthma trigger, serial PEFR should be started.
Serial peak expiratory flow measurements are advised since they may provide information on airway resistance both at work and at home.
Method – As a practical means to confirm the link between exposure and bronchoconstriction, an assessment of serial PEFR measurements taken at and away from work has been suggested as the initial study in patients of suspected occupational asthma.
The ATS and the subcommittee on the occupational allergy of the European Academy of Allergy and Clinical Immunology group have developed standards for PEFR devices and their performance, along with suggestions for the overall duration and frequency of PEFR assessments both at and away from work.
There is no consensus on the ideal serial PEFR frequency or time period. Workers are typically encouraged to record their PEFR every two to three hours for four weeks, including their time at work and away from it, while keeping a diary of their activities and any symptoms they may be feeling, such as the need for bronchodilators. On www.occupational asthma.com, specific diary cards are offered.
The best three forceful expiratory maneuvers should be recorded and used for analysis during each measurement session.
If the top two values were within 20 L/minute of one another, the best of three PEFR measurements should be recorded on each occasion.
While longer periods boost the test’s usefulness, a recording time of four weeks is advised, including a period of at least two weeks after the suspected exposure. PEFR measurements should be taken in the morning, at noon, after the shift, and right before night (or at times similar for people who don’t work the day shift), while some researchers advise doing so every two hours while awake.
Utilizing a free automated data plotting and analysis system can reduce human error when interpreting PEF values, and it can be especially helpful for practitioners with little to no training (www.occupationalasthma.com).
Advantages and Limitations – PEFR can offer unbiased proof of the link between job and asthma symptoms getting worse. The worker’s performance of a forced expiratory manoeuvre and precise recording of the outcomes are crucial components of PEFR. PEF measurements are unable to distinguish between occupational asthma and OA.
Non-Specific Bronchial Provocation Test
When asthma is suspected and spirometry is normal or close to normal, the diagnosis of asthma is made via bronchoprovocation with methacholine, histamine, cold air, or exercise challenge. The most widely used tests are those involving methacholine and histamine challenges.
Histamine is preferred over methacholine because it has fewer side effects and more consistent lung function measurements. The heightened sensitivity of the airways to inhaled nonspecific stimuli or irritants, which is observed by many asthma patients, is assumed to be reflected by nonspecific bronchial provocation testing.
Although the mechanisms leading up to this impact differ, it is believed that these stimuli elicit airflow limitation primarily through an effect on airway smooth muscle. Although it has been shown to last for more than 13 years after exposure, increased methacholine reactivity may go away a few months after exposure.
Method – The two protocols for inhaling aqueous solutions of pharmacologic stimuli are the 5-breath dosimeter protocol and the 2-minute tidal breathing protocol. To perform non-specific bronchial provocation tests, baseline lung function must be evaluated before choosing a target FEV1 that reflects a 20% drop in FEV1.
Inhaling a placebo or diluent (0.9% NaCl) is optional. A bronchoconstrictor called methacholine is frequently inhaled at concentrations between 0.031 and 0.0625 mg/mL, and depending on the protocol, these concentrations are then doubled or quadrupled to 16, 25, or 32 mg/mL.
The test is terminated when the FEV1 has decreased by 20% from the baseline or diluent value after each inhalation. A 20% fall in forced expiratory volume in one second caused by a provocative concentration (PC20) is typically used to describe the response.
At a methacholine dose of 4 mg/mL or less, a decline in the FEV1 of at least 20% indicates the existence of asthma. Based on a dose of methacholine PC20 mg/mL, methacholine 4–16 mg/ml is regarded as borderline for full categorization of bronchial responsiveness.
- Non-Specific Bronchial Provocation Test
Non-Specific Bronchial Provocation Test is recommended if the clinical history is strong and other tests (such as spirometry and bronchodilator responsiveness) are not diagnostic, to be used in the diagnosis of asthma.
Criteria and Standards for Use – According to the 1999 ATS statement and the 1993 European Respiratory Society statement, bronchial challenge testing should be performed (updated 2008).
Indications/Contraindications – When asthma is suspected when spirometry is normal or close to normal, bronchoprovocation with methacholine or cold air may be used to make the diagnosis of asthma.
In general, NSBP is not advised if the baseline FEV1 is less than 65% of the anticipated. The following are categorical prohibitions against methacholine challenge testing:
- Significant airflow restriction (FEV1 50% expected or 1.0L), a heart attack or stroke during the last three months, uncontrolled hypertension (systolic BP > 200 or diastolic BP > 100), and an existing aortic aneurysm.
Relative contraindications include:
moderate airflow limitation (FEV1 60% predicted or 1.5L; impuissant to execute acceptable quality spirometry;
currently taking cholinesterase inhibitor medication) (for myasthenia gravis).
Mannitol Bronchial Provocation Test
- Mannitol Bronchial Provocation Test
Mannitol Bronchial Provocation Test is not recommended for use in identifying asthma at work; additional procedures are needed to prove the asthma is related to employment.
Specific Immunological Testing
It is frequently used to assist in the diagnosis of allergic rhinitis and occupational asthma to perform specific immunological tests for suspected allergens. In contrast to irritant-induced asthma, these tests are used to assess type I (IgE) hypersensitivity reactions to certain allergens.
They can be helpful in the diagnosis of some cases of occupational asthma produced by immunological or allergic mechanisms. However, the presence of particular antibodies is merely a sign of an immune response and is not always related to symptoms of occupational asthma.
Therefore, without establishing the work-relatedness of asthma, specific IgE and/or skin testing alone that shows sensitization to an occupational agent is insufficient to establish an OA diagnosis.
Skin prick testing (SPT) and serum IgE testing, where kits are available for the particular allergen, are effective ways to identify IgE to a specific allergen. To determine the antigenicity of occupational antigens, three techniques for detecting serum IgE antibodies have been used: Three tests RAST, ELISA, and ImmunoCAP.
Traditional classifications of sensitizing substances known to cause occupational asthma include high molecular weight (HMW) and low molecular weight (LWM) antigens.
High Molecular Weight Agents
Production of allergen-specific IgE antibodies is frequently linked to occupational asthma brought on by HMW agents, which are primarily proteins with either animal or plant origins.
Examples of HMW asthmagens include:
proteins with a biological origin, such as those from laboratory animals.
enzymes used in the food or detergent sectors.
grains found in bakeries; and
proteins from natural rubber latex, which are particularly common in healthcare settings.
Such proteins are regarded as total allergens because they can lead to the production of particular IgE antibodies.
IgE Specific Immunological Testing for High Molecular Weight Specific Antigens
- IgE Specific Immunological Testing for High Molecular Weight Specific Antigens
IgE Specific Immunological Testing for High Molecular Weight Specific Antigens is recommended for employees who exhibit symptoms of occupational asthma in response to particular high molecular weight allergens and where standardized antigens and assay techniques are available.
There is substantial evidence in quality studies for high molecular weight allergens such as laboratory and other animal allergens, bovine dander, and wheat dust. Serum IgE testing can be used to determine whether a person is allergic to natural rubber latex (NRL), however, because not all putative NRL allergens are included in the assay, a negative result does not always rule out the diagnosis of NRL allergy.
- IgG Specific Immunological Testing for High Molecular Weight Specific Antigens
IgG Specific Immunological Testing for High Molecular Weight Specific Antigens is not recommended as a diagnostic instrument for certain workers who exhibit symptoms of occupational asthma in response to high-molecular-weight allergens.
Low Molecular Weight Agents
Only after binding/connecting with one or two or more autologous serum, epithelium, or tissue proteins do they become allergenic.
Common LMW agents include:
in the electronics industry, cored solder releases colophony fume.
intricate platinum salts.
the group of compounds known as acid anhydrides, which are frequently used in the production of resins.
- IgE Specific Immunological Testing for Low Molecular Weight Specific Antigens
IgE Specific Immunological Testing for Low Molecular Weight Specific Antigens is not recommended for employees who exhibit symptoms of occupational asthma in response to certain low molecular weight allergens.
Method – Most LMW antigens lack commercial assays that have been approved for use in assessing particular antibodies.
Indications – Useful for allergens that have been demonstrated to have suitable positive and negative predictive value, specificity, and sensitivity using a validated approach in investigational research.
Advantages and Limitations – IgE is thought to be implicated in some subsets of symptomatically exposed workers notably to HMW antigens, although findings imply that IgG and/or IgE-mediated immune responses are not thought to be responsible for all occupational asthma.
Skin Prick Testing
In order to rule out or assert sensitization in IgE-mediated illnesses, such as asthma, skin tests are utilized in addition to a focused history and physical examination. In practical practice, skin tests come in two different varieties.
These comprise intracutaneous testing and percutaneous testing (pricking or puncturing) (intradermal). The release of preformed histamine from local tissue mast cells, which increases vascular permeability and results in the development of a wheal, is triggered by local tissue mast cells that have surface IgE specific for the allergen under test.
Inflammatory mediators also initiate a neural reflex that causes vasodilatation, which results in erythema (the flare). In test findings, the wheal and flare sizes are frequently given in millimeters as W/F mm/mm and are contrasted with the negative saline control response.
Results can alternatively be expressed on a scale from 0 to 4+, with 1+ denoting erythema less than the size of a nickel, 3+ denoting a wheal and erythema, and 4+ denoting a wheal with pseudopods and erythema.
According to the majority of the research, a positive intradermal skin test (IDST) result with a negative skin prick test results adds a little bit to the diagnostic assessment of inhalant allergy.
Only when there is a compatible or convincing history and a negative or ambiguous SPT test is IDST recommended and should be employed. Numerous studies have shown that the prick skin test response significantly better correlates with clinical allergy.
Puncture or scratch testing has been used to evaluate asthmagen allergies in a variety of patient types and workplace environments. Workers should be directed to a doctor with experience in puncture or scratch testing for an explanation to determine if they have atopy and to identify the allergen that may be the cause of it.
A physician who is skilled in the procedure should supervise and interpret skin prick tests carried out by trained and qualified people.
- Skin Prick Testing to High Molecular Weight Allergens
Skin Prick Testing to High Molecular Weight Allergens is recommended Commercial skin testing extracts are accessible for some employees who exhibit symptoms of occupational asthma to particular allergens and where the results have been validated.
Natural rubber latex, wheat and rye flour, grain dust, alpha-amylase, bovine dander, and laboratory and other animal allergens are examples of high molecular weight allergens for which there is enough evidence.
- Skin Prick Testing to Low Molecular Weight Allergens
Skin Prick Testing to Low Molecular Weight Allergens is recommended for individual workers who exhibit symptoms of occupational asthma in response to particular allergens and in situations where skin testing extracts are accessible.
Reactive dyes, halogenated platinum salts, and tremolitic anhydride are low molecular weight allergens for which there is sufficient evidence.
- Skin Prick Testing to Other Allergens Not Covered Above
Skin Prick Testing to Other Allergens Not Covered Above is not recommended for allergies not already mentioned. Skin prick testing for particular allergens is not advised if they have not been examined in reliable research with documented specificity and sensitivity.
Additionally, if a non-allergenic reason is suspected, skin prick testing is not advised.
The rationale for Recommendations – Skin prick testing is frequently used in studies as part of the diagnosis process, albeit it is typically used to diagnose atopy rather than occupational asthma.
Method – The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology have published a practice guideline on doing skin prick tests (ACAAI).
Indications – Allergens specificity, having positive and negative predictive value and acceptable sensitivity, should be used for prick skin testing. wheat and rye flour, Natural rubber latex, alpha-amylase, grain dust, cow dancers, reactive dyes, laboratory and other animal allergies, halogenated platinum salts, and tremolitic anhydride are among the allergens linked to occupational asthma and that fit these requirements.
Harms – Rare risk of severe asthmatic or anaphylactic reactions
Advantages and Limitations – Skin prick testing carries a very low risk of death, and severe/anaphylactic reactions are uncommon. However, in very vulnerable individuals, such as those with a history of past anaphylactic responses, pregnant women, people with uncontrolled asthma, or people with high levels of sensitivity, this risk cannot be entirely ruled out.
Pregnant women should not undergo skin testing, and only other high-risk persons should do so when the benefit of the outcome justifies the danger.
Specific Inhalation Challenge
By simulating workplace conditions with exposure to the suspect asthma gene, the specific inhalation challenge (SIC), also known as the specific bronchial provocation test (SBPT), is carried out.
The subject’s lung function is then monitored for an asthmatic reaction. It serves as a reference standard because there is no other conclusive diagnostic test and is employed when other techniques have failed to make the diagnosis.
Specific Inhalation Challenge
- Specific Inhalation Challenge
Specific Inhalation Challenge is recommended for use in determining the cause of latency for every When occupational asthma is strongly suspected but hasn’t been proven using less intrusive procedures in some circumstances.
Only facilities with the necessary equipment and direct medical supervision should be used for this testing.
Method – Serious consequences from these tests, including fatalities, are possible. The necessary tools and resources should be available at the few centers that can do these tests safely and accurately.
After a control day during which the patient is not exposed to the putative sensitizer and lung function is checked for stability, asthmagen exposure should be performed. The testing may only need to be done once, but it may also need to be done again the next day or with a larger dose to find favorable results.
Eight hours before the test, patients should cease taking short-acting beta 2-agonist drugs, and 24 hours before the test, they should stop taking longer-acting medications.
Positive reactions, defined as a 20% decrease in FEV1, may manifest in one of three ways: immediately (within 30 minutes of exposure), later (two to eight hours later), or in a dual pattern that exhibits both early and late reactions. Dual patterns may be present with both LMW and some HMW agents.
Positive reactions are defined as a 20% decrease in FEV1. The complete procedure and standards for determining whether a given inhalation challenge with diisocyanates was successful can be found in this reference.
Indications – The majority of individuals with suspected sensitizer-induced OA don’t need this test because the condition can usually be identified using less invasive techniques.
The indications for SIC include:
Repeated assessments of lung function are used to assess an employee who has left the workplace but is unable or reluctant to return to work.
the first evidence of a new factor contributing to occupational asthma
confirmation of the identification of job-related asthma
confirmation of the causal agent when other objective procedures are not practicable, are ineffective or have failed to yield conclusive results when there is work exposure to several agents.
Harms – asthma aggravation and excessive bronchoconstriction; rarely, systemic, and anaphylactic responses.
Advantages and Limitations – When a worker with a history of OA develops work-related airway blockage that is confirmed to be linked to exposure to a substance known to induce OA or when the person has been demonstrated to be sensitized to that substance, specific bronchoprovocation testing is not seen as being necessary. The following are some SIC validity restrictions:
the difficulty Exposure does not equal replication of the work
Not just one agent, but a combination of chemicals is what causes OA.
The employee has been exposed too long and no longer reacts immediately to the chemical.
The patient has unstable asthma, which causes airflow changes that are not related to exposure.
The rationale for Recommendation – SIC is only advised for extremely
Nitric Oxide (Fractional Exhaled Nitric Oxide, FENO)
A test for identifying endogenous inflammatory signals is the measurement of total exhaled nitric oxide (FENO). Asthma FENO is known to evaluate pathogenic rather than physiological changes.
With uncontrolled asthma, the fraction of nitric oxide in expired air rises, while it falls with anti-inflammatory medication. In asthma, FENO is regarded as a substitute marker of eosinophilic inflammation.
Other variables may affect FENO results, including inhaled steroid use (generally lower), smoking (generally lower), height (increase), exercise (lower), gender (males more likely to have atopy), ambient air levels of NO, recent pulmonary disease (higher), and another pulmonary function testing (lower).
Comparisons between diagnostic studies may be challenging if these aspects are not adequately stated or taken into account.
- Nitric Oxide (Fractional Exhaled Nitric Oxide, FENO)
Nitric Oxide (Fractional Exhaled Nitric Oxide, FENO) is recommended if strict protocols are in place, the test is well understood by the physician and the clinician explaining the test, and the examination of people with moderate to severe asthma is limited to monitoring medication and management.
- Exhaled Nitric Oxide Testing for Diagnosis of Asthma
Exhaled Nitric Oxide Testing for Diagnosis of Asthma is recommended When more information is needed to confirm an asthma diagnosis with sufficient clinical support and lung function tests or provocation tests are nondiagnostic, exhaled nitric oxide testing may be used.
- Exhaled Nitric Oxide Testing for Selective Monitoring of Asthma
Exhaled Nitric Oxide Testing for Selective Monitoring of Asthma is recommended Testing for exhaled nitric oxide for specialised use in observing airway inflammation in asthmatics with mild to severe symptoms This could be especially helpful if biologicals are employed to treat asthma.
What our office can do if you have workers compensation Diagnostic Testing
We have the experience to help you with their workers compensation injuries. We understand what you are going through and will meet your medical needs and follow the guidelines set by the New York State Workers Compensation Board.
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