Evaluating respiratory disorders can be a challenging undertaking for the disability representative.  Disabilities caused by disorders of this system are many in number and can cause a variety of symptoms.   The most important skill for the representative to master when dealing with breathing disorders is the interpretation of the pulmonary function studies or PFS.  In this chapter we will show you how to view and evaluate a PFS as well as several other tests associated with these types of impairments.

General Evaluation  

     When evaluating disorders of the respiratory system, it is important that you note the symptoms of the disorder, the specific diagnosis and the laboratory findings.  Let's begin this discussion with symptoms.  Most lung disorders you will encounter will manifest such symptoms as chronic cough, wheezing, hemoptysis (coughing up small amounts of blood), sputum production, dyspnea (difficulty breathing) and possible chest pain.  One or more of these symptoms will be found on physical examination of the person with a history of a chronic respiratory disease.  It is important to note symptoms because they are part of the supporting evidence, and can be incorporated into your argument as the basis for a specific restriction of the claimant's activities.  

     The chest x-ray is also an important tool to use as supporting evidence in a respiratory disorder.  The x-ray may or may not show a severe disorder, but any abnormal finding on x-ray can be used as strong ammunition for the existence of a serious condition.  Whenever you have an x-ray which shows an abnormal finding, use it as part of your argument to support your restrictions of the claimant's RFC.  

     Blood gases are another commonly used laboratory tool.  Blood gases are used in the evaluation of most serious breathing disorders and can give the physician an idea of how well the patient's lungs are functioning.  Blood gases show the arterial concentration of pCO2 and pO2 in the patient's blood.  These two gases are exchanged in the blood via the lungs.  

     Blood gases have values which indicate their normal concentrations for an adult at a given atmospheric pressure.  When these values are abnormal, they are indications of an underlying disorder.  Instead of confusing you with the details of gas exchange in humans, lets look at an example.

     A person with a significant lung disorder can have a reduced oxygen (O2) concentration in their blood and an elevated carbon monoxide (CO) level depending upon what type of disease the patient has.  The existence of any sustained abnormality of blood gases is an indication of an existing serious respiratory condition.  If the claimant is placed on oxygen, especially at home, that person probably has a serious pulmonary condition and should be given a reduced residual functional capacity.  

     The most common tool used in the evaluation of lung diseases by SSA is the PFS or pulmonary function study.  This test is performed by having the claimant breathe into a machine which measures several aspects of the patient's lung capacity.  From the disability standpoint, there are three variables you must be familiar with in order to properly argue for a physical reduction in the claimant's RFC.  Those variables are the FEV1, MVV and the VC.  All three of these variables can be determined from the PFS and their results will determine the extent of the claimant's physical restrictions.

     The FEV1 (forced expiratory volume in one second) is defined as the amount of air the patient can force out of his lungs in the first second.  Imagine that you are sitting beside a machine with a hose in your hand.   You are instructed to take a deep breath and blow as hard and fast as you can into the hose.  The machine will measure the force, amount, and speed of the air which left your lungs.  The results will be the FEV1, MVV and the VC.

     The MVV (maximum voluntary ventilation) is defined as the amount of air a patient can move through his lungs in twelve seconds.  The MVV is considered important because it reflects the severity of airway obstruction as well as the patient's level of motivation.  

     The last of the big three PFS variables is the VC (vital capacity).  The VC is defined as the maximum volume of air that can be expired slowly and completely after a full inspiratory effort.  In this situation, a claimant takes as deep a breath as possible, then releases it as slowly and completely as possible.

     This value will decrease as a restrictive lung disease worsens.  In other words, a person will be able to blow out less air if the lungs have a resistance (restriction) to air flow.

     These restrictions are caused by a number of disease states which are lumped into categories called restrictive airway disease, and chronic obstructive airway disease.  (See sample PFS chart)

Pulmonary Function Test

Height     FEV1     MVV        VC

60 "         1.0   +      40              1.2
61-63 "    1.1   +      44              1.3
64-65 "    1.2   +      48              1.4
66-67 "    1.3   +      52              1.5
68-69 "    1.4   +      56              1.6
70-71 "    1.5   +      60              1.7
72+above   1.6   +  64              1.8

The above height scale is the patient's height in inches.
The FEV1 values should be read as equal to or less than.
The MVV values    "        "        "           "      .
The VC values        "        "        "           "      .  

    The values above mean that if a person is sixty inches in height and has a FEV1 value of 1.0 or less (.09 as an example), and has an MVV of 40 or less, that person would meet the listings for any respiratory disorder.

     If a person is 60 inches in height and has a VC of 1.2 or less, that person would also meet the listings.

     Since the disability examiner would have noted if the claimant met the listings, it is not likely that you will see values as low as the above unless the claimant's condition is worsening fast.  However, you may see values that are close which indicate that the claimant is still severely restricted in his ability to do work activity.  Whenever you see a PFS value which is close to an allowance value, feel free to dramatically reduce the claimant's RFC.  Use the following rule of thumb:  

     For the FEV1, given the height of the claimant, any value within .7 points of the allowance value should significantly reduce the RFC.  For the MVV, any value within 6 points of the allowance value should reduce the claimant's RFC.

     Predicted values are usually supplied with the actual PFS test results.  The predicted values give you some idea of what the claimant's results should be if his lungs were normal.  The FEV1 and the MVV are used together.  If one of these values is normal while the other is low, restrict the RFC based on the low abnormal value.

Example:

     A claimant is 60 inches tall, has an FEV1 of 1.5 and an MVV of 43.  Althrough this claimant does not meet the listings, there is severe air flow restriction shown by this test.  Lower the RFC to sedentary if the claimant has other evidence supporting a severe respiratory condition.  If  the claimant's VC is within .6 of the allowance results, lower the RFC as with the other values.

Episodic impairments:

     In many respiratory disorders such as asthma and emphysema, the patient may suffer from acute exacerbation of the disease which may require emergency treatment.  If the claimant has an ongoing disorder which has required at least two doctor visits, a hospitalization or an emergency room visit for treatment, lower the claimant's RFC.  Consider any hospitalization for these impairments to be an emergency.

     Commonly, patients suffering from lung disorders which are episodic in nature tend to be denied benefits based on the duration requirement.  You must argue that although claimant has had only one or two emergency visits in a year, the claimant continually suffers the debilitating effects of  the disease and should be restricted to the appropriate allowance level.

Other common respiratory restrictions:

     In all respiratory impairments you should consider limiting claimant's working environment.  A claimant with a significant lung disorder should not work around chemical fumes or any other type of lung irritant.  If claimant is allergic to pollen and this is documented by the evidence, claimant should not work outside.  Using your common sense, you will be able to determine many practical restrictions which may help to win an allowance decision for your client.

     The   following is a list of the most commonly seen disorders of the respiratory system.  Since virtually all pulmonary impairments are evaluated using the same disability criteria, it will not be necessary to discuss each individual impairment.  For specific characteristics of each of the disease states below, use a medical text that discusses disease states such as the Merck Manual.

Pulmonary tuberculosis
Sarcoidosis
All infections of the lungs (bacterial, viral, or fungal).
Cystic fibrosis
Chronic pulmonary heart disease
Bronchitis
Emphysema (COPD)
Asthma (COPD)