What Is Tidal Breathing?

(1) No response to increase airway reactivity in bronchial challenge test. The airway is unobstructed and the gas is very easy to get in and out. (2) Bronchial diastolic test calculated that the improvement rate of FEV1 after inhalation was less than 12%, which was negative for diastolic test.

Children's pulmonary function test is one of the necessary tests for respiratory diseases. Children's pulmonary function plays an important role in the diagnosis, differential diagnosis, evaluation of the severity of the disease, judgment of the curative effect and prognosis of asthma. At present, children's pulmonary function tests include: infant pulmonary function meter to measure tidal respiratory lung function, school age and children to measure expiratory flow rate-volume curve. The main indicators include peak expiratory flow rate (PEF), forced expiratory volume in 1 second (FEV1), peak time ratio (TPTEF / TE), peak volume ratio (VPEF / VE), shape of flow-volume loop, etc. , Can reflect the airway obstruction in children with asthma.

Name: Child lung function test

category: Lung function

Normal pulmonary function test in children

Clinical significance of pulmonary function tests in children

Abnormal results: (1) Bronchial provocation test has increased airway responsiveness, and the diagnosis may be atypical asthma. (2) Short-acting 2 agonists should be discontinued within 12 hours before the bronchodilator test, and long-acting 2 agonists should be discontinued within 48 hours. Theophylline sustained-release tablets should be discontinued for 24 hours. Hours, first measure the subject's basic FEV1, and then aerosolize the inhaled 2 agonist. Repeat FEV1 measurement 15-20 minutes after inhalation. Calculate the improvement rate of FEV1 after inhalation> 12%. Positive diastolic test can help diagnose asthma. This suggests that there is currently airway spasm and mild asthma. People to check: Children with lung problems and respiratory problems. Coughing for up to 1 month, antibiotic treatment is not effective; or children who have recurrent wheezing more than 4 times in a year, and have no symptoms of cough after a period of acute asthma treatment.

Precautions for pulmonary function tests in children

Note: Unsuitable people: patients with cardiopulmonary insufficiency, hypertension, coronary heart disease, hyperthyroidism, pregnancy and other diseases. Contraindications before examination: There is no history of respiratory infections in the month before the test; asthma patients are in remission. Requirement during the inspection: Children may be afraid of the inspection, and they should be comforted and guided before and during the inspection.

Pulmonary function test in children

Children's respiratory diseases, like adults, are also reflected in lung function. The indications for pulmonary function tests are the same as those for adults, but children have their own characteristics. Attention should be paid when performing pulmonary function tests. (1) Force-dependent pulmonary function test Force-dependent pulmonary function test (MEFV) is limited by the age of children. The test requires the active cooperation of the subject. Because of the poor cooperation of young children, such as inability to breathe quickly and forcefully, and poor reproducibility, the application of these lung function tests is limited. For children's lung function tests, multiple tests may be required, as long as the expiratory flow rate curve is a straight line (change in flow rate <0.251 / s). Because children are in the growth and development stage, their lung functions are different from those of adults in some aspects. With the increase of age, height and weight, children's lung function indicators (such as FVC, FEV1, PEF, etc.) are also increasing. The evaluation of children's lung function cannot refer to the lung function value of adults, and is calculated based on the adult's expected equation , And can only refer to the normal value of pulmonary function in the children group. (2) Non-cooperating children. For some children who cannot be equipped with cooperative lung function tests, or in situations where continuous changes in their lung function need to be monitored, the peak expiratory flow meter (peak velocity meter) can be used for peak expiratory flow measurement. (3) Infants and young children (<3 years old) cannot apply the current routine force-dependent pulmonary function test because they cannot cooperate actively. Non-force-dependent lung function such as tidal volume, minute ventilation, functional residual capacity, repetitive breathing lung dispersion, respiratory mechanics such as airway resistance, chest and lung compliance, etc. can be applied to these children. Tidal breathing flow volume loop (TBFV) measurement. This technique does not require the subject's subjective cooperation, only tidal breathing is required after connecting the mouthpiece, and the pulmonary function meter can continuously record the flow volume loop. Pulse oscillation spectrum analysis method to measure airway resistance. With the pulse oscillation technology of the external signal source, the child can make multiple parameters such as viscous resistance, elastic resistance and inertia resistance of the airway, and compliance of the chest and lungs by simply using the mouthpiece for a few cycles of tidal breathing. Evaluation. (4) Blood gas analysis Blood gas analysis is an important part of lung function, and it is also the most important lung function test item for infants and young children. Make a judgment on the gas exchange capacity of the child. (5) Measurement of airway responsiveness For older children, reference is made to the method of airway responsiveness measurement in adults. Zheng Jinping reported on the measurement of airway responsiveness (inhaled histamine bronchial challenge test) in older children (11-14 years old). The measurement method is the same as that of adults and the results are similar to those of adults. Exercise challenge tests are also used clinically. . (6) Airway diastolic test: For infants and young children, the beta receptor development in the airway may be immature, so the reactivity to beta receptor stimulants may be poor. M receptor development is relatively mature, and the response to M receptor antagonists may be better. Therefore, it may be better to use M receptor antagonists (such as ipratropium bromide) in infant airway diastolic tests.

Diseases related to pulmonary function tests in children

Idiopathic pulmonary fibrosis in children, Wilson-Mikity syndrome in neonates, asthma in children, asthma, asthmatic pulmonary eosinophilia, food allergic asthma, bronchial asthma in children

Symptoms related to pulmonary function tests in children

Open your shoulders, cough in children, throat cough, persistent cough, spastic cough, severe cough in children, chest pain when coughing, fever with cough, expectoration, chest pain, paroxysmal cough ^[1]