新たに考案した直接気管内流量法によるヒト肺毛細管血流量の測定

抄録

Instantaneous pulmonary capillary blood flow in 14 patients was evaluated by a new device measuring direct intratracheal flow which measured the flow change due to the uptake of N20 by the pulmonary capillary blood by connecting a highly sensitive flow meter directly to the endotracheal tube, instead of using body plethysmograph technique. This method did not need specific training to stop respiration and maintain the glottis open. Instantaneous pulmonary capillary blood flow by this method was found to be bimodal and pulsatile, as described by previous reports.
Indices of “pulsatility” which were Qcmax/Qc, 2.15±0.47, and Qcmax/SV, 212±55, indicated no differences between males and females Qcmax and SV were significantly larger in males than in females and Qc tended to be large in males. Because these two ratios were relative to each other but not to HR, Qc and SV, they were useful indices to estimate the pulsatility of pulmonary capillary blood flow. As this method is simple, it is considered to be a clinically useful technique with wide applications to estimate pulmonary capillary blood flow, particularly during anesthesia and respiratory care.