Lung function and allergy tests
 |
| Foto: medicalsin.com |
At the initial examination, the doctor will first ask questions about the history of the disease. He wants to know possible risk factors, such as asthma cases in the family, the patents allergic diseases and infections of the respiratory tract. In addition, he is interested in precipitating factors, such as contact with animals, exercise or peculiarities of the profession. Add to that the physical examination. The interception of the airways, the doctor can find some noises when breathing. Also evidence of sequel of late, inadequately treated asthma, for example, damage to the heart or other organs, can be found already in the physical examination.
Lung function tests confirm the diagnosis
Another important contribution is made by lung function tests. They confirm the diagnosis, reveal causative factors, determine the severity of asthma and provide an indication of the potential success of a drug therapy. The simplest method is the spirometry. Here, the patient breathes via a tube system in a measuring device that determines the amount of one or the exhaled air. When breathing, the patient follows specific instructions from the doctor, because depending on the type of breathing detect different metrics. The most important are the vital capacity and the seconds. The vital capacity (VC) is the volume that can be exhaled after a maximum of maximal inspiration. By contrast, the second describes the volume capacity, which will launch the patient after a maximal inspiration in forciertem exhalation (as fast and as much as possible) within the first second. The latter is also called the forced expiratory volume (FEV1). Is the exhalation as disabled because of narrowed airways in asthma, the FEV1 values are lowered. In this case, the doctor will give brochienerweiterndes drug and repeat the test (Broncholysetest). Increase in FEV1 values then, the patient has probably asthma.
With normal lung function: provocation test
If the lung function test normal, check the doctor nor whether the bronchial hypersensitivity to stimuli (challenge). For this, the patient must breathe special agent acting constricting effect on the bronchi. In an asthmatic lung with hypersensitive this narrowing occurs very quickly. In healthy individuals, however, much higher concentrations of the drug are needed.
If the lung function test normal, check the doctor nor whether the bronchial hypersensitivity to stimuli (challenge). For this, the patient must breathe special agent acting constricting effect on the bronchi. In an asthmatic lung with hypersensitive this narrowing occurs very quickly. In healthy individuals, however, much higher concentrations of the drug are needed.
Allergy tests can be avoided by allergens
Is there any evidence that it is the asthma is an allergic reaction, in the review of pulmonary function may also be a specific challenge with a suspicious substance be useful - for example, with animal hair or certain types of flour. When cold or exercise-induced asthma is the provocation by inhalation of cold fog or running on a treadmill or the load on the bicycle ergo meter. Knows the patents allergens or trigger factors, they may try to avoid this and to reduce the risk of asthma attacks. But the test is not without risk and should only be done by a specialist. Apart from the challenge test to the physician to search for allergens are also skin tests or blood tests are available. When skin test substances are placed on or under the skin and recorded the reactions of the skin. If it is positive, but this is only an indication that the allergen is involved in the pathogenesis of asthma - a proof is not. When the blood tests, the doctor determined, however, the amounts of certain substances in the body defense (immunoglobulins). This can be inferred indirectly on the readiness for overreacting.
Peak flow-metry for the home
As an asthmatic lung function regularly his responsibility to check for the measurement at home smaller devices have been developed (peak flow meter). To determine the peak expiratory flow (peak flow), ie the largest flow rate in liters per minute forced exhales while the patient. With the peak flow meter measures the person several times a day his lung function and those listed in a special diary. Based on the notes, the physician can identify temporal fluctuations in the narrowing of the airways, and optimize the therapy. In addition to the patents test results to his, when his health deteriorated and he needs to see the doctor immediately.
Additional studies
complement the diagnosis
In addition to the aforementioned studies may in some cases be more useful to extend the verification of lung function or the search for allergens. Finally, other methods may be necessary, such as a chest X-ray to rule out other lung diseases safely or to recognize complications of asthma.
In addition to the aforementioned studies may in some cases be more useful to extend the verification of lung function or the search for allergens. Finally, other methods may be necessary, such as a chest X-ray to rule out other lung diseases safely or to recognize complications of asthma.
