Introduction: Three ways of simple calculations (segmental based on 18 segments method, segmental based on 19 segments method and subsegmental method) of predictive postoperative values of forced expiratory volume in one second (FEV1) and diffusion lung capacity for carbon monoxyde (DLCO) are in use during the preoperative survey for patients planned for lung resection as treatment of lung carcinoma as a part of risk assessment. Hypothesis: Segmental calculation method based on 19 segments is better than subsegmental method and segmental calculation method based on 18 segments in prediction of postoperative values of both FEV1 and DLCO one month after lung lobectomy. Materials and methods: Expected postoperative calculated values of FEV1 and DLCO (two segmental and one subsegmental method) of 52 patients undergone lobectomy are related to real postoperative values for same patients one month after surgery. Results: According to univariate analysis, real values of postoperative DLCO correlate most significantly with ppoDLCO calculated by segmental method (18 segments), but real values of postoperative FEV1 correlate most significantly with ppoFEV1 calculated by 19 overall segments segmental method. Data analysis as well showed that preoperative calculated PpoFEV1 and PpoDLCO underestimate real postoperative values of FEV1 and DLCO one month after lobectomy, but it is not statistically significant. Discussion: Same as contemporary guidelines suggest, ppoFEV1 calculation by 19 segments segmental method seems to be the best choice. However, it may be better to calculate PpoDLCO by 18 segments segmental method.
Key words: thoracic surgery, FEV1, DLCO