A Modified Bronchoalveolar Lavage Procedure That Allows Measurement of Lung Epithelial Lining Fluid Volume

Abstract

We replaced the standard serial bronchoalveolar lavage technique with a new "rewash" lavage procedure to allow estimation of the volume and protein concentration of the epithelial lining fluid (ELF) in anesthetized sheep. A bronchoscope 6.0 mm in diameter wedged in an airway was used to lavage a segment of lung with four cycles of instillation and aspiration of the lavage solution containing a radioactive tracer (technetium pertechnetate, 99mTcO4-). Errors caused by the fall in concentration of the tracer during the lavage were minimized by extrapolating the tracer concentration back to time zero when the lavage solution had mixed with the ELF, but had not had time to be affected by loss of the tracer or influx of fluid from the interstitium. In control sheep, the ELF of these lavaged segments had a mean volume of 1.6 +/- 1.0 ml and a mean protein concentration that was 26 +/- 19% of the protein concentration measured in the plasma. Increasing the left atrial pressure 19 +/- 5 cm H2O to cause "cardiac lung edema" had no significant effect on the ELF volume, but it increased the mean protein concentration to 57 +/- 30% of the plasma value (p less than 0.01). Lung injury caused by intravenous oleic acid caused lung edema, increased the mean ELF volume to 6.8 +/- 2.2 ml, and increased the mean ELF protein concentration to 86 +/- 26% of the plasma value (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Surfactant composition reflects lung overinflation and arterial oxygenation in patients with acute lung injury

“…Although initially surprising, our present results are consistent with the work of others [31][32][33], and reflect concurrent lung dysfunction and an increase in alveolocapillary permeability in cardiac surgery patients. While it has been convenient to partition pulmonary oedema as due to either a hydrostatic or permeability origin, accumulating data [9,10,[31][32][33] suggests that this is only a notional classification, and that there is usually a variable component to both. Finally, we conclude that elevated plasma surfactant protein-A and -B reflect changes in lung permeability rather than absolute changes in alveolar levels.…”

“…Consistent with this, we have previously reported elevated blood levels of SP-A [9] and SP-B [10], and others have found elevated protein [31] and oxidized glutathione [32] in BAL fluid from patients with HPE. Furthermore, PETERSON et al [33] found a doubling of total protein in epithelial lining fluid when the left atrial pressure was raised 19 cmH 2 O in sheep, and the alveolar-to-plasma protein ratio was almost identical to that reported from HPE patients [18]. Of particular note, and consistent with the current study where 7 of the 11 CS patients required cardiac valve replacement for chronic and severe heart failure, NAKOS et al [31] found that ARDS and HPE patients had similar surfactant changes.…”

Caveolins and Lung Function

“…This notion is supported by the observation that the protein concentration in the alveolar lining fluid is substantially lower than in the plasma and rises during an acute inflammatory insult. 46–48 A number of experimental studies to address the issue of transcytotic protein removal from the airspace have been conducted. 49–52 The results indicate that transcytosis can account for albumin transport through epithelial cells at low concentrations.…”

Dinâmica da resposta imune inata do sistema respiratório de bezerros

“…Na medicina humana é uma técnica rotineira e segura (European Society of Pneumology Task Group on BAL, 1989;American Thoracic Society, 1990) e é a mais indicada para a realização da coleta de LBA, inclusive em animais de outras espécies (PETERSON et al, 1990;GRIFFITH et al, 2004) e não causa alterações nos componentes do LBA, mesmo quando realizada repetidas vezes (MUGGENBURG et al, 1980;BEGIN et al, 1981).…”

“…Em estudos com animais e humanos (PETERSON et al, 1990;GRIFFITH et al, 2004) esta técnica foi considerada como eficaz para a coleta do fluido broncoalveolar e tem sido demonstrado que repetidas lavagens broncoalveolares foram bem toleradas por animais de outras espécies (MUGGENBURG et al, 1980;BEGIN et al, 1981) e não induziram alterações no número e tipo de células recuperadas (KALTREIDER et al, 1975;CORSTVET et al, 1982;FOGARTY et al, 1983). Essas amostragens repetidas permitiram a determinação do metabolismo oxidativo celular, fagocitose e atividade antimicrobiana dos macrófagos alveolares de cães e de bezerros, antes, durante e após infecções respiratórias naturais ou experimentais.…”