Effect of halothane on instantaneous pulmonary capillary blood flow measured by direct intratracheal flow method
Takeda, J.; Iwao, Y.; Hitosugi, Y.; Sekiguchi, H.; Nagano, M.
Masui. Japanese Journal of Anesthesiology 33(9): 953-958
1984
ISSN/ISBN: 0021-4892 PMID: 6512974 Document Number: 238007
Instantaneous pulmonary capillary blood flow [Qc] in 10 patients under halothane anesthesia was estimated by direct intratracheal flow method which measured the flow change due to the uptake of N2O in the airway to pulmonary capillary blood after inhalation of N2O O2 mixture. The flow was measured by connecting an endotracheal tube directly to the highly sensitive flow meter, instead of using body plethysmograph technique. .ovrhdot.Qc max/.hivin.Qc and .ovrhdot.Qc max/SV, which indicate the pulsatility of .ovrhdot.Qc, were: 2.24 .+-. 0.53 and 219 .+-. 63 at 100% O2; 2.03 .+-. 0.40 and 171 .+-. 36 at 0.75% halothane; and 1.82 .+-. 0.29 and 162 .+-. 49 at 1.5% halothane. These indices tended to decrease, but these differences of indices were not statistically significant. As this method is easy to use, without specific training, to hold the respiration and to open the glottis, it is a clinically useful technique to estimate the Qc during anesthesia and respiratory care. Under halothane anesthesia, mean pulmonary capillary blood flow decreased but the effect on pulmonary microcirculation seemed to be slight.