Prolonged expiratory sounds

Introduction Exhalation tone extension: Bronchoalveolar breath sounds are heard in the normal alveolar breath sound area. Inhalation and exhalation are difficult when the lower airway resistance increases. Due to the expansion of the inspiratory alveolus, the airway diameter is relatively large, so the inspiratory airway resistance is smaller than the expiratory phase, so the increase in airway resistance is mainly due to the prolonged expiratory time. The intensity of alveolar breath sounds in normal people is related to the depth of breathing, the elasticity of lung tissue, the thickness of chest wall, and the age and gender of the subject.

Cause

1. Lower airway obstruction, spasm or stenosis, common in bronchial asthma.

2. The elasticity of the lung tissue is reduced, and the driving force for exhalation is reduced.

an examination

Related inspection

Breath test lung function test lung ventilation function

Found in chronic bronchitis and bronchial asthma attacks. In addition, due to the decrease in the elasticity of the lung tissue, the driving force of exhalation is weakened, and the exhalation sound can be prolonged, as seen in emphysema. The intensity of alveolar breath sounds in normal people is related to the depth of breathing, the elasticity of lung tissue, the thickness of chest wall, and the age and gender of the subject. Alveolar tissue with more alveolar tissue and thinner chest wall has stronger respiratory sounds, lower part of the breast, lower part of the scapula and lower part of the armpit, while the tip of the lung and the lower edge of the lung are weaker. The lungs of the stout people are weaker than those who are thinner. Male alveolar breath sounds are stronger than women. Children's alveolar breath sounds are stronger than older people. Because the child's chest wall is thin and the alveoli are elastic, while the elderly alveoli lack elasticity.

Differential diagnosis

Abnormal alveolar breath sounds:

(1) Alveolar breath sounds are weakened or disappeared. Common causes are decreased alveolar breath sound transmission, limited thoracic or pulmonary dilatation, or decreased ventilation or decreased alveolar gas flow and flow rate due to insufficient respiratory motility and increased resistance. Can be manifested as unilateral, bilateral and localized alveolar breath sounds weakened or disappeared.

1) Induction of alveolar respiratory sound conduction unilateral alveolar respiratory sound attenuation can be seen in pneumothorax, pleural effusion and pleural thickening. Both sides can be seen in bilateral pneumothorax, bilateral pleural effusion and bilateral pleural hypertrophy. Localized alveolar respiratory sounds can be seen in localized pneumothorax, encapsulated pleural effusion and localized pleural thickening.

2) affecting the expansion of the thoracic or lung unilateral alveolar respiratory sounds can be seen in the total atelectasis, tracheal intubation deep into one side of the main bronchus, rib fracture. Both sides can be seen in the third trimester of pregnancy, a large number of ascites and large abdominal tumors. Limitations can be seen in atelectasis.

3) Insufficient ventilation and unilateral alveolar respiratory sounds can be seen in diaphragmatic paralysis. Both sides can be seen in respiratory center depression, anesthetic or sedative overdose, hypokalemia, respiratory muscle weakness or fatigue.

4) Increased ventilation resistance Increased unilateral alveolar respiratory sounds can be seen in central lung cancer and lymphoma. Both sides can be seen in chronic bronchitis, asthma, obstructive emphysema. Limitations can be found in bronchial tuberculosis, bronchial foreign bodies and tumors.

(2) Alveolar breath sound enhancement: Respiratory exercise is mainly caused by pathological or physiological factors, resulting in increased alveolar ventilation, increased flow or increased flow rate. Or because the chest wall is thin, it is conducive to sound transmission. Common in the following situations:

1) Physiological alveolar breath sound enhancement: found in infants or small breasts and adult physical activity.

2) pathological alveolar breath sound enhancement: seen in fever, hypermetabolism, anemia and acidosis. Alveolar breath sound enhancement is generally bilateral, but when one side of the lung or pleural lesions, the contralateral side can be enhanced by modern compensatory alveolar breath sounds, such as tuberculosis, pneumonia, lung tumor, pneumothorax, pleural effusion and pleural hypertrophy.

(3) intermittent breath sounds: local inflammation or bronchoconstriction in the lungs, so that the air can not enter the alveoli evenly, can cause intermittent breath sounds. Due to the short intermittent irregularity, it is called the cogwheel breath sound, which is also called the cogwheel breath sound. It can be seen in patients with pneumonia. If it appears at the tip of the lung, it indicates the tuberculosis of the lung. It should also be noted that in the case of chills, pain, mental stress, etc., the respiratory muscles have intermittent and uneven contraction, and similar sounds can be heard, but not breathing sounds, so it has nothing to do with breathing.

(4) Rough breath sounds: It is caused by mild edema or inflammatory infiltration of bronchial mucosa, resulting in rough or narrow stenosis, resulting in rough airflow and ingress of rough breath sounds, which is seen in the early stage of bronchial or pulmonary inflammation.

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