Pulmonary clearance of 99mTc-DTPA during halothane anaesthesia.
We studied the integrity of the alveolo-capillary barrier during different forms of anaesthesia by measuring the pulmonary clearance of inhaled 99mTc-DTPA. We studied four groups of rabbits. Groups I and II were anaesthetized with nembuthal only and the fractional concentration of inspired oxygen (F1O2) was 0.30 and 1.00, respectively. Groups III and IV were anaesthetized with 1% halothane and F1O2 was 0.30 and 0.99, respectively. 99mTc-DTPA was administered as a fine aerosol and the clearance of the tracer from the lungs was subsequently measured with a gamma camera. The mean half-life of the tracer in the lungs in Groups I-IV was 60, 58, 59 and 26 min, respectively. The rapid pulmonary clearance of 99mTc-DTPA in Group IV indicates that halothane in combination with high oxygen concentration increases the permeability of the alveolo-capillary barrier. This may be due to effects on the pulmonary surfactant system and/or the alveolar epithelium.
Wollmer
P
P
Department of Anaesthesiology, Erasmus University, Rotterdam, The Netherlands.
Schairer
W
W
Bos
J A
JA
Bakker
W
W
Krenning
E P
EP
Lachmann
B
B
D000769:Anesthesia, Inhalation; D000818:Animals; D015824:Blood-Air Barrier / Q000502:physiology*; D006221:Halothane; D010539:Permeability / Q000187:drug effects; D011817:Rabbits; D016284:Technetium Tc 99m Pentetate / Q000493:pharmacokinetics*
D006221:Halothane; D016284:Technetium Tc 99m Pentetate