Isoflurane inhibits hypoxic pulmonary vasoconstriction

Journal article


Research Areas

Publication Details

Subtitle: An in vivo fluorescence microscopic study in rabbits
Author list: Sckell A
Publisher: Lippincott, Williams & Wilkins: No Hybrid Open Access
Publication year: 1994
Volume number: 81
Issue number: 6
Start page: 1436
End page: 1444
Number of pages: 9
ISSN: 0003-3022
Languages: English-Great Britain (EN-GB)


Background: Contradictory results have been reported in previous studies
investigating the effect of isoflurane on hypoxic pulmonary
vasoconstriction by indirect approaches. The current study measured the
effects of one-lung ventilation (1LV) and isoflurane 1.5% by direct
visual observation of the pulmonary microcirculation. Methods: Ten New
Zealand White rabbits were anesthetized with intravenous thiopental,
α-chloralose, and piritramid. Arterial, central venous, pulmonary
arterial, left atrial, and airway pressures and cardiac output were
recorded continuously. 1LV was facilitated by a bronchial blocker in the
right main bronchus. A transparent window was implanted into the right
thoracic wall for videofluorescence microscopy of the subpleural
pulmonary microcirculation. After intravenous injection of fluorescein
isothiocyanate-labeled red blood cells, vessel diameters, red blood cell
flux, red blood cell velocity, and dynamic microhematocrit were
measured in pulmonary arterioles and venules during two-lung ventilation
and 1LV during baseline anesthesia and with supplementary isoflurane
1.5%. Results: During intravenous anesthesia, 1LV caused significant
reduction of vessel diameters and red cell flux and velocity and an
increase in microvascular hematocrit in pulmonary arterioles and
venules. The decreases in arteriolar diameters and red blood cell flux
and velocity induced by 1LV were significantly attenuated by isoflurane
as compared with those measured during baseline anesthesia (P = 0.010, P
= 0.029 and P = 0.047). Accordingly, 1LV-induced reduction of venular
red cell flux (P = 0.023) and velocity (P = 0.036) were less pronounced
during isoflurane. Isoflurane caused a significant decrease in arterial
pressure. Venous admixture increased and arterial oxygen tension
decreased significantly during 1LV; the changes were more pronounced
during 1LV with isoflurane 1.5% than during 1LV with baseline
anesthesia. Conclusions: 1LV leads to a marked reduction of
microvascular diameters and blood flow in the hypoxic lung. Isoflurane
1.5% inhibits hypoxic pulmonary vasoconstriction in pulmonary arterioles
and increases regional blood flow in the hypoxic lung.


No matching items found.


No matching items found.

Last updated on 2019-13-08 at 00:15