Lung vascular permeability changes in lambs with hyaline membrane disease.
To investigate the mechanism of pulmonary edema in hyaline membrane disease (HMD), lymph from the efferent duct of the mediastinal lymph node was collected in premature lambs before and after delivery by cesarean section. Mean lymph flow in 7 lambs with histologically verified HMD increased progressively over 4 h after delivery to 3 times the fetal value, while lymph flow in 7 lambs without HMD increased to 3.5 times at 1 h and decreased thereafter. At 4 h after birth, lung lymph flow was significantly higher in lambs with HMD than in lambs without HMD (0.70 +/- 0.15 (SEM) vs 0.43 +/- 0.07 ml.h-1.kg-1). Lymph/plasma concentration ratio for small endogenous protein fractions (effective molecular radius, 3.6 and 3.8 nm) was significantly higher in lambs with HMD than in lambs without HMD at 2-4 h. Postmortem extravascular lung water was significantly higher in lambs with HMD (6.1 +/- 0.5 vs 4.3 +/- 0.3 ml/g dry lung weight). It is concluded that lung water is high in lambs with HMD, which appears to be a result both of delayed absorption of fetal lung liquid and increased permeability of the pulmonary exchange vessels.
Sundell
H W
HW
Newborn Lung Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
Grogaard
J
J
Rojas
J
J
Gray
M E
ME
Mohan
P
P
Brigham
K L
KL
D000818:Animals; D001784:Blood Gas Analysis; D001798:Blood Proteins / Q000032:analysis; D002199:Capillary Permeability; D006339:Heart Rate; D006801:Humans; D006819:Hyaline Membrane Disease / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D007231:Infant, Newborn; D008168:Lung / Q000033:anatomy & histology / Q000503:physiopathology*; D008196:Lymph / Q000032:analysis; D009929:Organ Size; D011654:Pulmonary Edema / Q000209:etiology; D012123:Pulmonary Ventilation / Q000502:physiology; D014867:Water / Q000493:pharmacokinetics
D001798:Blood Proteins; D014867:Water