Submaximal exercise testing and respiratory muscle strength in the evaluation for tolerance of lung resection

Abstract

Exercise test with a treadmill at 2 constant work loads (2 and 4 METs) and measurement of MIP were carried out in 73 patients before lung resection. 69 patients underwent surgery and postoperative cardio-pulmonary complications developed in 16. During the exercise, expiratory gas analysis was performed. VO₂/VE at 4METs seemed to be useful for the evaluation of the exercise performance and was significantly lower in the cases with complications than in those without (P<0.05). MIP was also significantly lower in the cases with complications (P<0.01). The product of FEV_1.0 (ml/m²) by VO₂/VE (%) at4METs was defined as “Oxygen uptake index” (OUI). Exercise capacity and development of complications were correlated with OUI more closely than FEV_1.0 or VO₂/VE at 4METs alone. Postoperative complications developed in 15 out of 29 cases with a predicted OUI of V3300 and MIP of V110cmH₂O, and not in 39 of 40 cases with a predicted OUI of >3300 and/or MIP of >110cmH₂O. Thus, FEV_1.0, VO₂/VE at 4METs, and MIP reflect the potentiality of volume, quality, and power of respiratory system, respectively. Therefore, these 3 parameters are considered to be essential and actually useful in the evaluation for tolerance of lung resection.