Indirect estimate of perimicrovascular pressure rise in edema in isolated zone 1 lung.
J Appl Physiol (1985)
; 65(1): 337-42, 1988 Jul.
Article
en En
| MEDLINE
| ID: mdl-3403477
ABSTRACT
To determine how liquid accumulation affects extra-alveolar perimicrovascular interstitial pressure, we measured filtration rate under zone 1 conditions (25 cmH2O alveolar pressure, 20 or 10 cmH2O vascular pressure) in isolated dog lung lobes in which all vessels were filled with autologous plasma. In the base-line condition, starting with normal extra-alveolar water content, filtration rate decreased by about one-half over 1 h as edema liquid slowly accumulated. We repeated each experiment after inducing edema (up to 100% lung weight gain). The absolute values and time course of filtration in the edema condition did not differ from base-line, i.e., the edema did not affect the time course of filtration. To compute the maximal initial and maximal change in extra-alveolar perimicrovascular pressure that occurred over each 1-h filtration study, we first assumed that the reflection coefficient is 0 in the Starling equation, then calculated perimicrovascular pressure and filtration coefficient from two equations with two unknowns. The mean filtration coefficient in 10 lobes is 0.063 g/(min X cmH2O X 100 g wet wt), and the initial perimicrovascular pressure is 3.9 cmH2O, rising by 4-7 cmH2O at 1 h. Finally we tested low protein perfusates and found the filtration rate was higher. We calculated an overall reflection coefficient = 0.44, a decrease in the initial perimicrovascular pressure to 1.9 cmH2O and a slightly lower increase after 1 h of edema formation, 2.2-6.6 cmH2O.
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Banco de datos:
MEDLINE
Asunto principal:
Edema Pulmonar
/
Circulación Pulmonar
/
Espacio Extracelular
Límite:
Animals
Idioma:
En
Revista:
J Appl Physiol (1985)
Asunto de la revista:
FISIOLOGIA
Año:
1988
Tipo del documento:
Article