What is Lung Percussion?

There are many types of lung-related diseases. When similar symptoms appear, we cannot rely solely on symptoms to determine the cause of the disease. Other methods, such as lung percussion examination, should also be combined. Lung percussion examination is a special examination item, and many patients do not fully understand its principles and specific methods, naturally leading to doubts about its effectiveness. So, what is lung percussion examination? Let's take a look below.

1. What is lung percussion examination?

Lung percussion examination is a commonly used physical examination method for detecting most lung diseases. The steps of percussion examination are from top to bottom, from inside to outside, and individual intercostal percussion. It mainly starts from the apex of the lung and proceeds to the lower boundary of the lung. The method of percussion mainly chooses indirect percussion. Place the palm of the left hand on the chest, with the middle finger in contact with the chest wall and the other four fingers separated as a percussion board. The right middle finger is naturally hung down as a percussion hammer, and the wrist is used to percussion the left middle finger. By listening to the percussion sound, it can be judged whether there is consolidation in the lung. In addition, it is necessary to combine chest X-ray and chest CT to comprehensively consider whether there is lung disease.

2. How to distinguish percussion sounds?

1. Clear sound is the normal lung percussion sound. It is a non-musical sound with a frequency of about 100-128 times/second, a long vibration duration, and inconsistent sound quality. It suggests that the elasticity, gas content, and density of the lung tissue are normal.

2. Dull sound is a non-musical percussion sound with a higher tone, weaker sound, and shorter vibration duration. In addition to the sound, the vibration felt by the board finger is also weaker. It occurs when percussion is applied to solid organs covered by a small amount of gaseous tissue, such as when percussion is applied to the heart or liver covered by the edge of the lung segment, or in pathological conditions such as pneumonia (reduced gas content in lung tissue).

3. Tympanic sound is similar to the sound of drumming, a harmonious musical sound with stronger sound quality and longer vibration duration than the clear sound. It appears when percussion is applied to hollow organs containing a large amount of gas. Under normal conditions, it can be seen in the gastric bubble area and abdomen. Under pathological conditions, it can be seen in lung cavities, pneumothorax, pneumoperitoneum, etc.

4. Flat sound is a non-musical sound with a higher tone than dull sound, weaker sound quality, and shorter vibration duration, such as the sound produced when percussion is applied to solid organs such as the heart and liver. Under pathological conditions, it can be seen in conditions such as a large amount of pleural effusion or lung consolidation.

5. Hyperresonant sound is a variant of tympanic sound, with a lower tone and stronger sound quality than clear sound. It is a quasi-musical sound that is not normally present in adults. Clinically, it is commonly seen when the lung tissue has increased gas content and decreased elasticity, such as in emphysema. Normal children may have a relatively hyperresonant sound.