What Is an Alveolus?

Alveoli are hemispherical vesicles composed of a single layer of epithelial cells. The bronchi in the lungs are repeatedly branched into numerous bronchioles. Their ends swell into cysts, and there are many prominent small vesicles around the sac, which are alveoli.

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Alveoli

The alveolus (alveolus, plural alveoli) varies in size and shape, with an average diameter of 0.2 mm. Adults have more than 700 million alveoli, with a total area of nearly 100 square meters. They are all about the size of 50 table tennis tables, which is several times larger than the surface area of human skin. Alveoli are the lungs

Small alveolar cells, also known as type I alveolar cells, are about 0.1 microns thick and have a basement membrane at the base and have no proliferation capacity.

Large alveolar cells, also known as

Lungs

Alveoli

After routine bronchoscopic airway examination, BAL was performed before brush biopsy. For diffuse interstitial lung disease, the right middle lobe (B4 or B5) or the left lung tongue is usually selected, and for localized lung disease, BAL is performed in the corresponding bronchopulmonary segment.

Alveolar lavage

First, inject 1 to 2 ml of 2% lidocaine through the biopsy hole in the lung segment to be irrigated, perform local anesthesia of the lung segment, then wedge the tip of the bronchoscope into the segment or sub-segment bronchus opening, and then from the biopsy hole Quickly inject 37 ° C sterilized physiological saline, and immediately attract the recovered liquid with a negative pressure of 50 100mmHg (6.66 13.3kPa). Each injection is 30 50ml, the total amount is 100 250ml, generally not more than 300ml, and the recovery rate can reach 40. % To 60%. The recovered liquid was immediately filtered through a double-layer sterile sand cloth to remove mucus, and the total amount was recorded.

Put it into a silicon plastic bottle or a silicon-coated sterilized glass container (to reduce cell adhesion), put it in a thermos bottle containing ice cubes, and immediately send it to the laboratory for inspection. In the technical operation of bronchoalveolar lavage, the following points must be paid attention to: The choice of fiberoptic bronchoscope is used to irrigate the end of the fiberoptic bronchoscope with a diameter of 5.5 6.0mm, which is suitable for tight wedging or subsegmental bronchial orifices to prevent Atmospheric secretions and spillage of lavage fluid ensure satisfactory recovery of BALF; Cough reflex must be satisfactorily suppressed during lavage, otherwise the bronchial wall mucosa may be damaged and the lavage fluid will be mixed, and It also affects the recovery amount. The irrigated saline needs to be warmed to 37 ° C. Too cold or overheating will cause bronchospasm and irritating cough. Negative pressure suction should be maintained at 50 100mmHg. If the negative pressure is too large, it will cause bronchial collapse Closed and damaged, and affect the recovery.