Pulmonary clearance of 99mTc‐DTPA during halothane anaesthesia

Publisher Website
Google Scholar
Abstract
We studied the integrity of the alveolo‐capillary barrier during different forms of anaesthesia by measuring the pulmonary clearance of inhaled99mTc‐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 F1O2was 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 of99mTc‐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.