Pulmonary hemodynamics and plasma endothelin-1 during hypoxemia and reoxygenation with room air or 100% oxygen in a piglet model.
The immediate effect on the pulmonary circulation of reoxygenation with either room air or 100% O2 was studied in newborn piglets. Hypoxemia was induced by ventilation with 8% O2 until base excess was <-20 mmol/L or mean arterial blood pressure was <20 mm Hg. Reoxygenation was performed with either room air (n = 9) or 100% O2 (n = 9). Mean pulmonary artery pressure increased during hypoxemia (p = 0.012). After 5 min of reoxygenation, pulmonary artery pressure increased further from 24 +/- 2 mm Hg at the end of hypoxemia to 35 +/- 3 mm Hg (p = 0.0077 versus baseline) in the room air group and from 27 +/- 3 mm Hg at the end of hypoxemia to 30 +/- 2 mm Hg (p = 0.011 versus baseline) in the O2 group (NS between groups). Pulmonary vascular resistance index increased (p = 0.0005) during hypoxemia. During early reoxygenation pulmonary vascular resistance index decreased rapidly to values comparable to baseline within 5 min of reoxygenation in both groups (NS between groups). Plasma endothelin-1 (ET-1) decreased during hypoxemia from 1.5 +/- 0.1 ng/L at baseline to 1.2 +/- 0.1 ng/L at the end of hypoxemia (p = 0.003). After 30 min of reoxygenation plasma ET-1 increased to 1.8 +/- 0.3 and 1.5 +/- 0.2 ng/L in the room air and O2 groups, respectively (p = 0.0077 in each group versus end hypoxemia; NS between groups). We conclude that hypoxemic pulmonary hypertension and plasma ET-1 normalizes as quickly when reoxygenation is performed with room air as with 100% O2 in this hypoxia model with newborn piglets.
Medbø
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Department of Pediatric Research, Institute for Surgical Research, The National Hospital, Oslo, Norway.
Yu
X Q
XQ
Asberg
A
A
Saugstad
O D
OD
D000136:Acid-Base Equilibrium; D000818:Animals; D000831:Animals, Newborn; D004195:Disease Models, Animal; D019332:Endothelin-1 / Q000097:blood*; D006439:Hemodynamics; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000503:physiopathology* / Q000628:therapy; D007231:Infant, Newborn; D010100:Oxygen / Q000097:blood; D010102:Oxygen Inhalation Therapy; D011652:Pulmonary Circulation / Q000502:physiology*; D013552:Swine
D019332:Endothelin-1; D010100:Oxygen