A brief analysis of the indications and contraindications of bronchoalveolar lavage

Bronchoalveolar lavage (bal) is a non-invasive technique performed by bronchoscopy that has been widely accepted in the diagnosis of disease. Bronchoalveolar lavage fluid (balf) is obtained by injecting sufficient amounts of lavage fluid into the alveoli and adequately attracting it, and the following important information, such as immune cells, inflammatory cells, cytology and infectious microbial pathogens, is analyzed at the alveolar level to assist in the diagnosis, observation and prognosis of respiratory diseases. Bronchoalveolar lavage is divided into total lung lavage and alveolar lavage of the lung segment. Whole lung lavage is the standard treatment for alveolar protein deposition; alveolar lavage in the lung segment is a method routinely used in the diagnosis of disease.

Indications for bronchoalveolar lavage:

1) Diagnosis of diffuse parenchymal lung diseases, such as sarcoidosis, allergic pneumonia, cryptogenic mechanized pneumonia, idiopathic pulmonary fibrosis, etc., balf has certain diagnostic value.

2) Special infections of the lungs: For opportunistic infections in immunosuppressed patients (such as kidney transplantation, liver transplantation, bone marrow transplantation, etc.), bal can help get pathogens, such as human pneumocystis pneumonia.

3) For some specific diseases, it can provide strong clues, such as: acute eosinophilic pneumonia and diffuse alveolar hemorrhage, alveolar protein deposition, etc., such as red gradually deepening balf suggests diffuse alveolar hemorrhage, while white cloudy balf suggests alveolar protein deposition.

4) Judge the course of certain diseases and the therapeutic efficacy. For example, in idiopathic interstitial pneumonia (IIP), there are important differences in the alteration of balf of idiopathic pulmonary fibrosis (IPF) and non-specific interstitial pneumonia (NSIP). The cell classification of NSIP balf is dominated by lymphocytosis, with mild neutrophils and eosinophilia, with a good prognosis. IPF's lavage fluid is dominated by neutropenia and often has a poor prognosis.

Bronchoalveolar lavage is contraindicated:

1) Active hemoptysis, fever, asthma attack;

2) Severe cardiopulmonary dysfunction;

3) Severe arrhythmias;

4) Severe coagulation dysfunction;

5) Recent myocardial infarction or unstable angina;

6) Suspected aortic aneurysms and esophageal varices are at risk of rupture;

7) Severe ventilation and ventilation dysfunction, pao2< 6.67kpa (50mmhg) or pao2< 9.33kpa (70mmhg) in oxygen-absorbed state.