Changes in ventilation and perfusion in anesthetized dogs following lobar lavage with saline solution

Bronchoalveolar lavage affects computed tomographic and radiographic characteristics of the lungs in healthy dogs

Bronchoalveolar lavage is a common diagnostic test for dogs with suspected pulmonary disease, however there is no published information on whether this procedure could affect the imaging characteristics of the lungs. Aims of this prospective experimental study were to describe computed tomography (CT) and radiographic features of the lungs after bronchoalveolar lavage in a sample of healthy dogs. Thoracic CT and radiographic images of eight healthy Beagles were acquired at the following time points: before bronchoalveolar lavage, immediately following bronchoalveolar lavage, and at 2, 4, 8, 12, and 24 h following bronchoalveolar lavage. Lung consolidation or interstitial patterns were seen in CT and radiographic images immediately after the procedure. Radiographic lung patterns resolved within 2 h and CT patterns resolved within 24 h. Resolution of the CT pulmonary patterns in the ventral areas of the lungs was delayed compared to the dorsal areas. Mean CT imaging scores differed over time (P < 0.001), while mean radiographic imaging scores did not differ over time. This study suggests that thoracic radiography and CT imaging assessments should precede bronchoalveolar lavage procedures if possible, or be performed at least 24 h afterward.

Safety of bronchoalveolar lavage in patients with adult respiratory distress syndrome

Although shown to be safe in many other lung disorders, the safety of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) in critically ill patients with adult respiratory distress syndrome (ARDS) remains unproven. We conducted a prospective study to evaluate the safety of BAL in patients with ARDS. There were 438 patients with ARDS at our institution during the study period. Of these, 110 underwent FOB and BAL for either research or clinical purposes. Data were collected at baseline, at 5-min intervals during the procedure, and 1 h after the procedure. We did not detect any statistically or clinically significant changes in PaO2/FlO2, mean arterial pressure, heart rate, peak inspiratory pressure, or static thoracic compliance after the procedure. A small decrease in SaO2 occurred after BAL. Although this change was statistically significant, the magnitude was not of clinical importance. Five patients (4.5%) had transient arterial oxygen desaturation to < 90% during FOB and one patient (0.9%) experienced desaturation to < 80%. There were no prolonged episodes of severe hypoxemia. No serious bleeding occurred. One pneumothorax developed during the procedure. No deaths occurred that were related to the procedure. We conclude that FOB and BAL can be performed safely and are reasonably well-tolerated in patients with ARDS.

Bronchoalveolar lavage in immunocompromised patients. Clinical and functional consequences

Fiberoptic bronchoscopy and bronchoalveolar lavage are major tools in the diagnosis of acute pneumonia in immunocompromised patients. We conducted a prospective study to assess the morbidity associated with this procedure in 14 patients with AIDS and 16 patients with drug-induced immunosuppression. No patient had a PaO2 lower than 70 mm Hg with additional oxygen. Clinical data, chest roentgenogram, pulmonary function test, forced vital capacity, forced expiratory volume in one second, and arterial blood gases were recorded before and after bronchoscopy. Arterial oxygen saturation was monitored during the procedure, and initial, lowest, and final saturation values were noted. The patients were separated into three groups on the basis of chest roentgenographic findings. No procedure-induced pneumonia or need for tracheal intubation occurred. Minor clinical symptoms induced by the lavage in seven patients resolved spontaneously. By contrast, mean SaO2 decreased markedly during the procedure from 94 +/- 3 to 87 +/- 5 percent (p less than 0.0001) and returned to only 89 +/- 5 percent at the end of the procedure. Lowest SaO2 during the procedure and final SaO2 correlated poorly with initial SaO2 but correlated well with initial FVC and FEV1 (p less than 0.01). The PFT values were lower following bronchoscopy. O2 desaturation was more pronounced in patients with severe roentgenographic abnormalities. No significant differences were found between the three groups of patients, or between the AIDS and DII patients in terms of changes in PFT values. We conclude that in immunocompromised patients, bronchoscopy with BAL induces severe arterial oxygen desaturation which is correlated with initial PFT and chest roentgenographic findings, and most of these abnormalities are transient and do not lead to major complications.

Pulmonary function in normal subjects after bronchoalveolar lavage

Twenty seven healthy individuals were divided randomly into three groups. The first group of nine subjects received only a routine bronchoscopic examination. The second group of nine subjects was examined with the bronchoscope followed by bronchoalveolar lavage (BAL) with 200 ml of 25 degrees C normal saline solution. The third group of nine subjects received a bronchoscopic examination followed by BAL, but with 200 ml of 37 degrees C normal saline solution. Examination in all groups included arterial blood gas (ABG) analysis and pulmonary function test (PFT), both pre- and post-procedure. In group 1 there was no statistical difference in the pulmonary function test result after routine bronchoscopic examination except for decrease in PaO2. The results in group 2 showed a statistical difference in both ABG and PFT data, especially PaO2, FEF 200-1200, FEF25%-75%, FEF25%, FEF50%, and FEF75%. In group 3, there was a significant decrease of PaO2 and no significant difference in PFT before and after BAL. From these data we conclude that BAL is a safe examination. However, the administration BAL fluid (BALF) with 25 degrees C normal saline solution can affect the results of the PFT significantly. Much of this adverse reaction can be minimized by using body temperature (37 degrees C) saline solution. At 37 degrees C, the ABG data showed a decrease in PaO2, but pulmonary function was not affected significantly.

Biochemical and morphologic changes in rabbit lung following endotracheal instillation of zymosan particles

In order to establish a model of lung disease in which the usefulness of potential antiinflammatory compounds can be evaluated, we have analyzed the biochemical and cellular responses of rabbits to zymosan deposition in their lungs. A suspension of zymosan particles was instilled into the lungs of rabbits using an intratracheal catheter. Because the influx of leukocytes and the transudation of plasma into affected lungs was expected to contribute to the total cellular enzyme and protein levels, lungs were homogenized and assayed after various time intervals for six cellular enzymes and for protein content. After one day, alkaline phosphatase and neutral protease levels were elevated by 90% and 50%, respectively, above normal values. After two and three days, all of the pulmonary enzymes assayed displayed maximal two- to fourfold increases in their levels of activity. After seven days, only the alkaline phosphatase and neutral protease levels remained slightly elevated by 50% and 30%, respectively. Histologic analysis revealed focal and diffuse intraalveolar, interstitial, peribronchiolar, and perivascular accumulations of macrophages, granulocytes, and lymphocytes. Severe pulmonary edema, evident microscopically after one to three days, correlated well with 100% increases in both the wet weight and protein content of the lungs. In control experiments, the intratracheal infusion of saline solution minus zymosan particles resulted in a variety of enzymatic changes in the lungs after three days, which could be distinguished both enzymatically and histologically from those following zymosan deposition; histopathologic analysis revealed a pattern of intravascular congestion with erythrocytes, edematous thickening of alveolar septa, and focal intraalveolar hemorrhages, but with no inflammatory infiltration. In summary, this study demonstrates the time course of an experimental model for acute and chronic lung inflammation, the extent of which may be quantitatively evaluated using cellular enzymatic markers.