Bronchial asthma exercise challenge test

The bronchial asthma exercise challenge test is performed on the following principle. The mechanism of exercise-induced bronchial asthma is unclear and may be related to the following factors: 1. Some media that release bronchial bronchus after exercise. 2. Excessive ventilation during exercise causes loss of airway moisture and heat, resulting in a decrease in airway temperature and an increase in osmotic pressure. 3. Hypocapnia and hypoxemia after exercise. 4. Inhalation of dry and cold air. 5. Adrenergic activity is too strong. 6. Parasympathetic excitability changes. This test is based on changes in respiratory function before and after exercise to determine whether there is an asthma attack and to judge the lung function of the subject. Basic Information Specialist classification: Respiratory examination classification: pulmonary function test Applicable gender: whether men and women apply fasting: not fasting Tips: Pay attention to normal eating habits and pay attention to personal hygiene. Normal value No positive reaction occurred in the test. Clinical significance Abnormal results exercise induced bronchial asthma, a positive reaction occurred 2min-15min after exercise. People who need to be examined for bronchial asthma, especially those with suspected sports bronchial asthma. Precautions Forbidden before examination: Pay attention to normal eating habits and pay attention to personal hygiene. Requirements for examination: 1. The test is carried out under electrocardiogram and blood pressure monitoring, and the emergency medicine is prepared. 2. Dizziness, pale complexion, cyanosis, angina pectoris, heart rhythm disorder, progressive ST segment decline, systolic blood pressure drop of 2.67 kPa (20 mmHg) or more than 26.7 kPa (200 mmHg), should stop exercising immediately. And give corresponding treatment. Inspection process Method 1: Activity tablet running method: 1. Preparation before the test: Prepare the test equipment, equipment and rescue equipment, medicines. Subjects discontinued bronchodilators before the test, theophylline, β2-receptor or anticholinergic drugs were stopped for 12 hours, antihistamines were stopped for 48 hours, corticosteroids were orally discontinued for 24 hours, and inhalation therapy was stopped for 12 hours. The method is explained to the subject and demonstrated if necessary. 2. Record calm ECG and measure blood pressure. The basic lung function was measured and repeated twice to obtain the best value. The forced expiratory volume (FEV1) of 1 s was used as an observation index. 3. Determine the target heart rate, target speed, and plate slope of the test. (1) Target heart rate: generally take the ultimate heart rate (90% limit heart rate, see P8, Table 1-1-2, omitted) (2) Target speed calculation formula: Miles per hour (MPH) = 0.72+0.02 × height ( Cm) (3) Slope: 10%-15% under 20 years old; 5%-10% from 20 years old to 30 years old; 5% over 30 years old. 4. The subject is placed on a horizontal movable plate, and the handle is held by both hands with the speed of the plate. The initial speed is 1MPH-2MPH, which gradually increases, reaching the target speed around 30s, and increasing to the corresponding slope. Generally, the movement of the target speed can reach 70% of the limit heart rate in about 2 minutes. If the difference is large, the speed and slope of the plate should be properly adjusted. After reaching the target heart rate, continue to run for 6 minutes. 5. FEV1 was measured at 1, 5, 10, 15 and 20 min after the exercise was stopped, and the lowest value was taken. 6. Calculate the percentage of decrease in FEV1 from baseline after exercise. FEV1 decrease rate (%) = [(FEV1 base value - FEV1 minimum value after exercise) / FEV1 base value] × 100%. Method 2: Treadmill method: 1. Prepare the first and second items of the same method before the inspection. 2. Using the bicycle power meter to measure, the treadmill load starts from 12W-16W (Watt), and increments 30W-40W per minute until the heart rate reaches about 80% of the expected maximum heart rate. Under this load, continue to tread for 6min, so that the heart rate is at At the end of the exercise, it reaches 90% of the expected maximum value, and the treadmill frequency during exercise is kept at 60 rpm/70 rpm. 3. After the exercise is stopped, the time of FEV1 is measured, and the decrease rate of FEV1 is calculated as the 5th and 6th items of the first method. result: FEV1 decline rate >10% is positive for exercise asthma or exercise challenge test. Not suitable for the crowd Inappropriate population: unstable angina, acute myocardial infarction, cardiomyopathy, pericarditis, blood pressure ≥ 23/14 kPa, heart failure, moderate to severe valvular heart disease or congenital heart disease, severe arrhythmia and obstructive emphysema, Physical activity disorders, acute or severe illness in pregnant women and other diseases.

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