Bronchial lavage. Bronchoscopic lavage in the treatment of bronchial asthma

Bronchoalveolar lavage- This medical procedure, which is used with diagnostic and therapeutic purpose in patients with pathology of the bronchopulmonary system. The technique for carrying out this manipulation consists of washing the bronchial tree with a special solution and then removing it. If the procedure is performed for diagnostic purposes, then laboratory study removed wash waters.

Indications

Bronchoalveolar lavage is prescribed as additional research to clarify the nature and cause of the pathology of the respiratory system.

The study is indicated for diagnosis:

• disseminated processes in the lungs (sarcoidosis, tuberculosis, asbestosis, fibrosing alveolitis);
• malignant neoplasms (including metastatic lesions);
• focal pathological processes unknown etiology(prolonged and recurrent pneumonia that cannot be treated with medication);
• chronic inflammatory processes in the bronchi (chronic bronchitis, bronchial asthma).

The procedure is contraindicated in patients with concomitant diseases in the stage of decompensation.

Diagnostic value

Washings obtained from the surface of the bronchi and alveoli are used for microbiological, biochemical, immunological and cytological studies. In some cases cytological examination rinsing water can even replace a biopsy. Most informative comprehensive implementation laboratory tests.

In some cases, it is impossible to establish a correct diagnosis without a study of bronchoalveolar lavage. It allows you to reliably confirm the diagnosis of the mediastinal form of sarcoidosis. There are no radiological changes in this pathology due to the specific location of the affected lymph nodes.

Preparation

Preparatory activities:

1. The patient must undergo all prescribed examinations so that the attending physician has a complete picture of the patient’s health status and can identify concomitant diseases.
2. A light dinner should be taken 10-12 hours before lavage (to prevent aspiration of gastric contents).
3. Smoking is strictly prohibited on the day of the test (this may lead to distorted results).
4. Sedatives are taken 2-3 hours before the test.
5. Immediately before starting the manipulation, it is necessary to empty bladder and intestines.

Patients suffering from bronchial asthma need to have a bronchodilator inhaler with them, since this procedure can provoke an attack of bronchospasm.

The doctor decides on an individual basis whether to temporarily cancel medicines which the subject uses on an ongoing basis.

Technique

Bronchoalveolar lavage is performed during bronchoscopy. The examination can be carried out using a rigid bronchoscope (under general anesthesia) and using a flexible fiberoptic bronchoscope (under local anesthesia).

The second method is more preferable because it does not require general anesthesia and is better tolerated by patients.

The technique consists of the following steps:

1. Adequate pain relief is provided. If the examination is planned to be carried out using a rigid bronchoscope, then the anesthesiologist will general anesthesia. If an elastic fiberoptic bronchoscope is used, local anesthetics are sprayed onto the mucous membranes of the mouth and pharynx. Local anesthesia allows you to avoid painful discomfort during the examination, and also helps to suppress gag and cough reflexes, which can complicate the procedure.
2. The examination is carried out in a sitting or lying position on a couch. After the subject has taken the required position, the specialist slowly inserts the bronchoscope into the airways through the nasal or oral cavity. With proper anesthesia, the patient does not experience any discomfort or pain.
3. Using video equipment, the mucous membranes of the respiratory tract are examined and any deviations from the norm are identified.
4. Through a special catheter, heated to a temperature of human body(37-39 °C) isotonic solution. The injected liquid is then aspirated using a vacuum electric extractor. The total volume of solution used is 150-300 milliliters (depending on how much material is needed for laboratory research). Saline solution is injected in small portions (10-30 milliliters), while the previously injected liquid is completely aspirated.
5. The removed wash water is placed in a sterile container and sent to the laboratory. The resulting swabs must be stored at a temperature below 5 °C for no more than 2 hours from the moment of collection. Glass containers should not be used for storing and transporting material, as some cellular elements are destroyed under such conditions.
6. The laboratory studies the cellular composition of material obtained from the mucous membranes of the bronchi and alveolar spaces. Counting total cells, the percentage of various cellular elements, atypical cells are identified.
7. When conducting a microbiological examination, various bacteria are identified (mycobacterium tuberculosis, pneumococci, Pseudomonas aeruginosa and others).
8. Biochemical study of wash water determines the qualitative and quantitative content of various chemical substances, as well as the presence and functional activity of enzymes and biologically active substances.

Decoding the results

In patients with acute purulent inflammation of the bronchi or lung parenchyma, cytological examination will reveal a significant increase in the number of neutrophils.

The tuberculous etiology of the process will be indicated by a moderate increase in the number of lymphocytes with a simultaneous decrease in the number of alveolar macrophages.

In case of bronchial asthma, changes characteristic of the allergic process will be detected (increase in the number of eosinophils by 10-15 times).

The detection of atypical cellular elements in the studied material indicates the presence malignant neoplasm or metastatic lesions of the lungs.

With hemosiderosis, specific hemosiderophages will be detected.

With asbestosis, microscopic accumulations of asbestos dust particles called asbestos bodies will be visible.

At bacteriological research the resulting material is placed on special nutrient media. In the presence of pathogens in the sputum, the growth of microbial colonies will be obtained. In addition to this, the sensitivity of the cultured bacterial flora to antibiotics is determined, which helps the doctor select the most appropriate treatment regimen for each individual patient.

Identified during biochemical analysis wash water increased activity elastase enzyme indicates the development of emphysema or pneumosclerosis. These data are of particular value at the initial stages of development pathological process, since other methods cannot yet detect any changes. Measures of protease activity vary in many diseases and are only valuable when assessed in conjunction with other data.

Bronchoalveolar lavage is a valuable method for diagnosing pathology of the bronchopulmonary system. The manipulation is well tolerated by all patients and has a low risk of complications. The advantage of the method is that it allows you to identify many pathologies at the most early stages development.

Microbiological and immunological studies of BS and ALS should be carried out to the same extent as sputum examination, and for similar indications. BS and ALS acquire the greatest diagnostic value when assessing the level of inflammation in the trachea bronchial tree, at lung tumors and with pulmonary proteinosis. Currently, a biochemical and immunological study of the supernatant of BS and BAS, as well as a study of the cell sediment, is being carried out. At the same time, the viability of BS and BAL cells, a cytogram are calculated, cytochemical studies of BAL cells are carried out, as well as a cytobacterioscopic assessment. IN Lately a method has been developed for calculating the macrophage formula of BAL fluid during various diseases bronchopulmonary system. The study of BAL allows, by measuring surface tension and studying the phospholipid composition of the surfactant, to assess the state of the surfactant system of the lungs.

Bronchial portion of bronchoalveolar lavage used to conduct qualitative and quantitative microbiological research. In addition, changes in the cellular composition of BS can determine the severity inflammatory reaction in the bronchial tree. According to the recommendations of the European Society of Pulmonology, the following composition of BS is typical for the norm:

It has high diagnostic value only for some lung diseases. Interstitial diseases in which the study of the cellular composition of ALS may be useful include histiocytosis X, in which Langerhans cells appear with characteristic X bodies in the cytoplasm, determined by electron microscopic examination (according to the immunophenotype, these are CD1+ cells). Using BAS it is possible to confirm the presence of pulmonary hemorrhage. The study of ALS is indicated in the diagnosis of alveolar proteinosis, which is characterized by the presence of an extracellular substance that is well determined using light (PIR reaction) and electron microscopy. In this disease, BAL is not only a diagnostic, but also a therapeutic procedure.

For interstitial lung diseases caused by inhalation of dust particles, using BAS testing it is only possible to confirm exposure to the dust agent. Specific diagnostics beryllium infection can be carried out by studying the functional proliferative activity of ALS cells in response to the action of beryllium salts. With asbestosis, silicate bodies can be found in the BAS in the form of characteristic fibers - the so-called “glandular” bodies. Such asbestos bodies are asbestos fibers with hemosiderin, ferritin, and glycoprotein aggregated on them. Therefore, they stain well when performing the CHIC reaction and Perls staining. The described fibers in the wash can be detected both extra- and intracellularly. It is extremely rare that asbestos bodies can be found in persons who have had unprofessional contact with asbestos, and the concentration of such particles in the BAS will not exceed 0.5 ml. Pseudoasbestos bodies, described for pneumoconiosis associated with exposure to coal, aluminum, glass fibers, etc., can also be found in ALS.

Bronchoalveolar lavage is the method of choice when it is necessary to obtain material from the lower parts of the lungs in patients with immunosuppressive conditions. At the same time, the effectiveness of the study for detecting infectious agents has been proven. Thus, the sensitivity of BAL fluid in diagnosing Pneumocystis infection, according to some data, exceeds 95%.

For other diseases, ALS testing is not highly specific, but can provide additional information in a complex of clinical, radiological, functional and laboratory data. Thus, with diffuse alveolar bleeding, free and phagocytosed erythrocytes and siderophages can be detected in the BAS. This condition can occur in various diseases, ALS is effective method to detect diffuse bleeding even in the absence of hemoptysis, when the diagnosis of this condition is extremely difficult. It should be remembered that diffuse alveolar hemorrhage should be differentiated from diffuse alveolar damage - adult respiratory distress syndrome, in which siderophages also appear in the lavage.

One of the most serious differential diagnostic problems- diagnosis of idiopathic fibrosing alveolitis. When solving this problem, cytological examination of ALS allows one to exclude other interstitial lung diseases. Thus, an increase in the proportion of neutrophils and eosinophils in ALS does not contradict the diagnosis of idiopathic alveolitis. A significant increase in the number of lymphocytes is not typical for this disease; in these cases, one should think about exogenous allergic alveolitis or other medicinal or occupational alveolitis.

Cytological examination of ALS is a sensitive method in the diagnosis of exogenous allergic alveolitis. A high percentage of lymphocytes, the presence of plasma cells and mast cells, as well as foamy macrophages in combination with anamnestic and laboratory data make it possible to diagnose this nosology. It is possible that eosinophils or giant multinucleated cells may appear in the ALS. Among lymphocytes, cells with the immunophenotype CD3+/CD8+/CD57+/CD16- predominate. It should be remembered, however, that in late phase disease, several months after the onset of the disease, along with suppressors, the number of T-helper cells begins to increase. Other research methods make it possible to exclude other diseases in which there is an increase in lymphocytes - collagen diseases, drug-induced pneumonitis, bronchiolitis obliterans with organizing pneumonia or silicosis.

For sarcoidosis an increase in the proportion of lymphocytes was also noted, however, it was shown that the ratio of helpers and suppressors (CD4+/CD8+) above 4 is characteristic of this particular nosological form (the sensitivity of this sign is, according to various authors, from 55 to 95%, specificity - up to 88% ). In the ALS of patients with sarcoidosis, giant multinucleated cells of the “foreign body” type may also be found.

For medicinal alveolitis morphological changes in the lungs can be varied, alveolar hemorrhagic syndrome or bronchiolitis obliterans with organizing pneumonia. In the cellular composition of ALS, an increase in eosinophils, neutrophils, and lymphocytes is noted, and sometimes a combined increase in these cells is possible. However, most often with drug-induced alveolitis, an increase in lymphocytes is described, among which suppressor cytotoxic cells (CD8+) usually predominate. An extremely high content of neutrophils occurs, as a rule, when taking the antidepressant nomifensine, especially in the first 24 hours. In this case, the proportion of neutrophils in BAS can reach 80%, followed by a decrease within 2 days to 2%, at the same time the proportion of lymphocytes in the washout increases . Similar observations have been described for exogenous allergic alveolitis. When taking amiodarone and developing drug-induced alveolitis (the so-called “amiodarone lung”), specific changes in BAS occur, characterized by the appearance of a large number of foamy macrophages. This is a very sensitive, but not very specific sign: the same macrophages can be found in other diseases, including exogenous allergic alveolitis and bronchiolitis obliterans with organizing pneumonia. The same macrophages can be found in individuals taking amiodarone, but without the development of alveolitis. This is due to the fact that this substance increases the content of phospholipids, especially in phagocytes.

Bronchoalveolar diagnostic lavage is a research method that provides the extraction of cellular elements, proteins and other substances from the surface of the smallest bronchi and alveoli by filling a subsegment of the lung with an isotonic solution followed by aspiration. Diagnostic subsegmental bronchoalveolar lavage is usually performed during bronchofibroscopy under local anesthesia after bringing the bronchofibroscope to the mouth of the subsegmental bronchus. Through the channel of the bronchofiberscope, 50-60 ml of an isotonic solution is instilled into the subsegmental bronchus. The liquid coming from the bronchial lumen, which is broncho-alveolar lavage, is aspirated through the bronchofiberscope channel into a plastic cup. Instillation and aspiration are repeated 2-3 times. In the aspirated liquid, cleared of mucus by filtering through gauze, the cellular and protein composition and functional activity of alveolar macrophages are studied. To study the cellular composition, the bronchoalveolar lavage is centrifuged. Smears are prepared from the sediment and stained with hematoxylin-eosin or Romanovsky. Diagnostic bronchoalveolar lavage is more often used to determine the activity of disseminated processes in the lung. A sign of high activity of idiopathic fibrosing alveolitis is a significant increase in the number of neutrophils in the bronchoalveolar lavage, and in sarcoidosis and exogenous allergic alveolitis - an increase in the number of lymphocytes.

BRONCHALVEOLAR MEDICAL LAVAGE

A method of treating lung diseases based on the endobronchial administration of a large amount of isotonic solution and washing out clots of mucus, protein and other contents of the small bronchi and alveoli. Therapeutic bronchoalveolar lavage can be performed through a bronchoscope or a double-lumen endotracheal tube. The procedure is usually performed under anesthesia. Artificial ventilation of the lungs is carried out using the injection method. An isotonic solution is sequentially instilled into each lobar or segmental bronchus through a controlled catheter and immediately aspirated along with the washed-out viscous secretion and mucus clots. The bronchoscopic technique is more often used in patients with bronchial asthma in status asthmaticus. To wash the bronchi, 500-1500 ml of isotonic solution is used. It is usually possible to aspirate about 1/3 - 1/2 of the injected volume of liquid. Indications for therapeutic bronchoalveolar lavage in patients with bronchial asthma rarely arise, since a complex of other therapeutic measures usually helps to relieve status asthmaticus.

Therapeutic bronchoalveolar lavage through a double-lumen endotracheal tube is performed for one-lung artificial ventilation. A catheter is inserted into the lumen of the endotracheal tube into the main bronchus, through which instillation and aspiration of an isotonic solution are carried out. 1000-1500 ml of solution is injected into the lung at once, and 90-95% of the volume of injected liquid is aspirated back. The procedure is repeated several times. The total volume of injected fluid varies from 3-5 to 40 liters. Total bronchoalveolar lavage through a double-lumen endotracheal tube is the most effective treatment for idiopathic alveolar proteinosis.

Directory in Pulmonology / Ed. N. V. Putova, G. B. Fedoseeva, A. G. Khomenko. - L.: Medicine

Today, fiberoptic bronchoscopy is the usual standard diagnostic procedure, which allows direct examination of the upper and lower respiratory tract. As the endoscope moves through the nasopharynx and trachea, large bronchi can easily determine the amount of mucus, as well as the degree of swelling of the mucous membrane and bronchospasm. In addition to examining the lumen of the airways, one of the great advantages of bronchoscopy is the ability to take samples from large and small airways and alveoli. The resulting samples are then analyzed for their cellular and non-cellular constituents.
IN last years in cases of suspected diffuse inflammatory disease bronchoalveolar lavage (BAL) using an endoscope or a special tube has become somewhat more popular than more traditional methods obtaining samples, such as tracheal aspiration. For many years, it was believed that obtaining samples from the lower trachea provides representative information about the condition of the alveoli and small airways, since free airway cells from the peripheral lung are eventually flushed toward the trachea for removal.
However, a large case study of young sport horses with poor performance associated with lower respiratory tract pathology showed that cytological and bacteriological results have poor correlation between samples obtained by tracheal aspiration and those obtained by BAL. Studies have shown that the numbers of different cells in cytological preparations from tracheal aspirates and BAL from the same horse varied significantly. This suggests that samples from tracheal fluid collections may not accurately reflect the population of cells and secretions present within the small airways and alveoli. This is important because exercise intolerance, inflammatory airway damage, and hyperresponsiveness are associated with small airway disease, and the best method diagnosis is cytology from BAL. In addition, bacterial culture of tracheal aspirates yielded more positive results than when culturing BAL performed in the same case. Thus, Bottom part The trachea apparently contains normal bacterial flora, which may be absent in the small airways and alveoli. For these reasons, BAL has become an increasingly popular tool for assessing inflammation of the distal (small) airways compared with obtaining samples by tracheal aspiration.
To substantiate the value of differential cell abundance in BAL fluid as an additional diagnostic tool for the evaluation of the respiratory system, other quantitative measurements are needed in addition to routine clinical examination. Emphysema syndrome has been studied in detail over the past two decades, and several research laboratories around the world have clearly demonstrated a high correlation between BAL cell differentiation and pulmonary function and histamine bronchochallenge testing in emphysema horses. In recent years, similarly characterized lung function in young performance horses with non-infectious inflammatory airway disease (IAD) has been consistent with these findings regarding the diagnostic utility of bronchoalveolar lavage.
The purpose of this chapter is to discuss the use of bronchoalveolar lavage technique as a tool to identify and characterize inflammation in the lungs of horses that suffer from diffuse pulmonary pathology, such as IAD in young performance horses and emphysema syndrome in adult animals. In addition, viral and bacterial lung diseases are briefly reviewed in terms of their diagnosis using bronchoalveolar lavage.

INDICATIONS FOR BRONCHOALVEOLAR LAVAGE

Inflammation of the lower respiratory tract in horses can develop due to various reasons. Horses of any age can suffer from infectious (bacterial/viral) and non-infectious IAD and may demonstrate a variety of clinical, physiological and pathological signs. In a large prospective study of 2- to 3-year-old Thoroughbred horses in training, cough and nasal discharge were ranked second only to lameness as the most common reason missing training days. Non-infectious IAD is the most common respiratory pathology occurring in both young and adult performance horses.
The dominant feature of IAD is airway obstruction resulting from accumulation of secretions, thickening of the airway walls, transformation of the airways and, ultimately, in advanced cases, loss of the ability to maintain the diameter of the lumen of the small airways. Airway hyperresponsiveness is a consequence of the inflammatory process and leads to further obstruction due to bronchospasm and other functional abnormalities. In healthy horses, bronchospasm occurs in response to inhalation of a histamine aerosol at a concentration of 16 mg/ml. In contrast, in older horses with emphysema, bronchoconstriction occurs from inhaled histamine concentrations of less than 8 mg/ml. In performance horses aged 2 to 5 years with IAD, bronchoconstriction occurs in response to inhaled histamine at concentrations as low as 2-3 mg/ml, indicating even greater airway hyperresponsiveness. This severe airway hyperresponsiveness correlates with increased levels of inflammatory cells in BAL samples, and BAL is therefore an extremely useful tool for investigating the nature of the underlying inflammatory airway disease.
Prevalence of low performance due to problems with respiratory system, is significant, especially in racehorses. Common respiratory abnormalities in this animal population include IAD, exercise-induced pulmonary hemorrhage, and upper airway dysfunction. In this context, IAD makes a significant contribution to substandard athletic performance, interrupted racing or training, and ultimately the premature end of a sporting career. Histological examination of lung specimens from older horses (>10 years) revealed a significant prevalence of non-infectious IAD in this age group. Therefore, IAD plays a significant role in the health and performance of all horses. age groups and sports disciplines. Bronchoscopy and bronchoalveolar lavage to determine the nature and extent of such inflammation are extremely important to determine appropriate treatment and prognosis in each case.
Less common pathologies, but also significant for performance horses of all ages, are septic lung diseases such as lung abscesses and parapneumonic effusions. Abscesses are usually localized in the cranial part of the right or left caudal lobe of the lung." These diseases can be easily recognized clinically due to the presence elevated temperature body, anorexia and pain on palpation chest. Suspicion of bronchopneumonia or lung abscess is confirmed by x-ray. However, bronchoscopy still has value in these patients for both diagnostic and therapeutic purposes. During bronchoscopy, a reddish-brown mucous secretion is easily detected in the lower trachea. By carefully advancing the endoscope further around this collection, being careful not to disturb these secretions, it is often possible to follow the streak of discolored mucopurulent secretion and identify the specific segmental bronchial source. Then, using the biopsy channel of the bronchoscope, a polyethylene catheter can be inserted into a specific bronchus in order to obtain a sterile sample of secretions for bacterial culture and cytological analysis. Once this procedure is completed, a small volume of fluid (approximately 200-250 ml in 2 or 3 injections) can be infused into the affected bronchus and immediately aspirated to remove excess exudate. This process is called "toilet" of the airways, not bronchoalveolar lavage. This procedure provides therapeutic benefits by reducing bacterial attack and reducing exudative overload in the affected region of the lung. After the final suction of the fluid and before removing the endoscope, a dose of dissolved antibiotic can be locally injected into the affected area. This procedure may be repeated daily or every other day as a component of treatment for bacterial bronchopneumonia in combination with systemic therapy.

BRONCHOALVEOLAR LAVAGE PROCEDURE

BAL can be performed in most horses under mild sedation (xylazine 0.3-0.5 mg/kg IV or romifidine 0.03-0.05 mg/kg IV) and airway anesthesia with local anesthetic(0.4% lidocaine solution without epinephrine). This procedure can be performed using a 1.8-2 m bronchoscope or a special BAL tube (Bivona Medical Technologies, Gary, Ind.). When the bronchoscope or BAL tube is in contact with the trachea, reaching the tracheal bifurcation usually provokes coughing. Therefore, at this stage it is useful to infuse 60-100 ml of pre-warmed lidocaine solution (0.4% without epinephrine) to desensitize the cough receptors located in the bifurcation. After this infusion, the endoscope or BAL tube is carefully, without excessive force (this is determined by the degree of resistance to further advancement ) is introduced deeper. Pre-warmed saline (200-300 ml) is quickly infused into the lung and then aspirated.
The total volume of saline solution for infusion should be divided into two separate boluses, while trying to get as much fluid as possible between each bolus. In general, a return of 40-60% of the total infusate volume indicates a satisfactory BAL. In horses with advanced disease, small volumes are collected and there is a lesser tendency for less foam (surfactant) to be present. BAL fluid samples are then pooled and kept on ice if processing is not possible within 1 hour of receipt. The fluid should be assessed macroscopically to identify any flocculent debris or discoloration. One or two serum or EDTA tubes are filled with VAL fluid and centrifuged (1500 rpm for 10 minutes); After removing the supernatant, smears are prepared from a drop of sediment, which are then air-dried. When preparing smears, slides must be air dried quickly using a small tabletop fan to well preserve cell morphology. Smears prepared in this way can be stored at room temperature for up to 8-10 months with minor cellular changes. Air-dried smears can be stained with Diff-Qnik, Wright-Giemsa, May Grmnwald, Leishman, or Gram stains for interpretation of cellular and noncellular components. Cellular profile and morphology may provide clues to the nature of airway injury, inflammation, and the lung's immunological response to infection or foreign antigens.

DIFFERENTIAL COUNTING OF CELLS IN BAL AND THEIR INTERPRETATION

In the field, the volume of fluid administered often varies, ranging from 60 to 300 ml of sterile saline per VAL. Additionally, in horses with severe bronchospasm, the volume of fluid withdrawn may be significantly reduced. Due to these circumstances, the dilution effect makes it difficult to accurately count the total number of nucleated cells, and given the wide range of TaKoii values, the count is of little clinical value in the interpretation of inflammatory conditions of the lungs and is considered to have no diagnostic value.

On the other hand, differential abundance of cell types is largely unaffected by dilution and is valuable for characterizing pathological increases in specific cell populations. Thus, with the help of differential cell counting, it is possible to identify the characteristic features of septic, non-septic and viral inflammatory diseases of the respiratory tract, which helps in deciding on the therapeutic approach in each specific case. Ranges of values ​​were established for differential BAL cell abundance in healthy horses, horses with emphysema, and performance horses with poor performance. In each of the corresponding groups, characteristic cytological features are present.

Differential cell counting in healthy horses

Ranges of differential BAL cell counts were established by obtaining BAL samples from horses not suffering from respiratory disease, which was confirmed various methods. including clinical examination, testing of pulmonary function and, in some cases, the absence of airway hyperresponsiveness in response to bronchoprovocation with histamine aerosol (Fig. 8.2-1). In young horses (6 years of age), the neutrophil population can average up to 15% of healthy animals (based on the diagnostic methods described above), with a corresponding decrease in the percentage of the macrophage and lymphocyte population.

Deviations in differential cell numbers

Emphysema syndrome is a commonly diagnosed respiratory disease in adult horses with a characteristic history clinical signs, abnormal pulmonary function tests, and airway hyperresponsiveness Horses with exacerbation of emphysema have at least 23% neutrophils in the BAL fluid (Figure 8.2-2). However, in such cases, neutrophils often account for more than a third of the differential abundance of all inflammatory cells and play a major role in clinical syndrome and the aforementioned airway hyperresponsiveness. BAL cytology specimens from emphysema horses often have a rich mucus background with many nontoxic and apoptotic (senescent) neutrophils. trapped inside this slime. In the BAL fluid of horses suffering from emphysema, in addition to the increased number of neutrophils, there is also a significant increase in the total number of mast cells, eosinophils, lymphocytes, macrophages and epithelial cells. These cells must be recognized and assessed separately from neutrophils. The number of desquamated epithelial cells is usually increased as a result of damage to the lining of the mucosa due to severe inflammation. In horses suffering from emphysema, in addition to the glandular higher cellular components, non-cellular structures such as Kurschmann coils are often present in BAL preparations, which indicate chronic nonseptic inflammatory disease of the respiratory tract.

CONCLUSION

BAL is clearly emerging as a powerful adjuvant diagnostic tool to aid in the diagnosis of clinical and subclinical lower respiratory tract diseases, such as non-infectious inflammatory airway disease in young performance horses and recurrent airway obstruction, or emphysema, in older horses. The differential cell abundance of BAL fluid for healthy horses has been clearly established using generally accepted standardized procedures, and any deviation of cytological profiles from normal values may help recognize a wide range of nonseptic inflammatory conditions. Although clinicians currently prescribe specific treatments based on BAL cell differential cytology, increased knowledge of various disorders in the future may allow equine clinicians to provide more accurate prognostic information regarding respiratory diseases to trainers and athletes. and owners. In addition, most young and adult sport horses with copious amounts of white mucopurulent secretion in respiratory tract and a markedly increased percentage of neutrophils in the cellular differential fails to detect the septic process. Rather, such cases demonstrate a nonseptic inflammatory disease of the airways.