著者
金田 正徳 竹内 義広 坂井 隆 並河 尚二 湯浅 浩 草川 實
出版者
社団法人 日本呼吸器学会
雑誌
日本胸部疾患学会雑誌 (ISSN:03011542)
巻号頁・発行日
vol.22, no.6, pp.468-473, 1984

Cases of primary lung cancer often have other pulmonary diseases involving the loss of pulmonary function. If a complicating disease is more pronounced in the noncancerous lung, unexpected postoperative respiratory insufficiency may appear. For this reason it is desirous to predict the postoperative lung function preoperatively. In this study the predicted postoperative vital capacity was calculated according to the following formulae from the spirometry data, bronchoscopy, bronchography and lung scintigram using <sup>81m</sup>Kr gas.<br>As for the summation of NNSS, two methods were employed. First was the evaluation of the number of obstructed sub-segmental bronchus by means of bronchoscopy or bronchography. The second method was summation from the count rate of the lung scanning. In younger patients both methods had equal accuracy. However in older patients the latter method had inevitable error, because the assumption for calculating NNSS did not hold in that patient group. We therfore accepted former method for the summation of NNSS.<br>As for the measurement of unilateral vital capacity (or VCc), <sup>81m</sup>Kr lung scintigram which visualizes the actual distribution of ventilation in the lung was useful in comparison with the cumbersome bronchospirometry.<br>To investigate the overall accuracy of our predicting formulae, 16 patients who were alive and cancer free 6 months after surgery were selected. However 5 had to excluded for the study because they had postoperative pulmonary complications which reliably are accompanied by loss of lung function. In the remaining 11 cases the predicted value was within&plusmn;10% deviation of the actually measured value. This accuracy was also acceptable for older patients whose respiratory function was impaired both in cancerous and non-cancerous lung. These formulae were considered to be useful in predicting postoperative lung function and very helpful in deciding surgical indications in cases of severely impaired pulmonary function. However careful management to avoid postoperative lung complications is necessary because the predicted postoperative vital capacity is a final result of the lung function when there are no another function-impairing factor.