ABSTRACT
Cardio-pulmonary responses to a given step-up exercise test were studied in 43 patients who previously received various thoracic operations such as pleural decortication, one or two segmental resections, right or left upper lobectomy, plombage or pneumonectomy. Fourteen control subjects were also studied for comparison. Following a 30 minute rest, the step-up exercise was performed to heights of 20, 30 and 40cm, in that order, for 8 to 10 min. at each height. During the rest and the steady-state exercise period, the expired gas was collected for a period of 5 minutes for the determinations of the minute volume, the O2 consumption and the CO2 Output. Alveolar gas samples were a1so taken following the expired gas collection. The heart rate and blood pressure were also checked during the rest and immediately after each exercise. Various cardio-pulmonary functions of the patient at rest were little different from those of the control, except the heart rate which tended to be higher in the patient than in the control. Although the work capacity of the patient was lower than in the control, most patients were able to complete the required exercise test. However, in carrying out a given exercise load, the patient groups had a greater minute volume, the respiratory rate, the O2 consumption and the CO2 output as compared to the control, indicating that the mechanical efficiency is considerably lowered in the patient. Of various patient groups, the work performance was most limited in the pneumonectomy group while the group with one or two segmental resections was little affected. It is suggested that the patient with one or two segmental resections may be allowed to engage in physical activity up to 700 kg-m/min or more while those with pneumonectomy should not exert themselves above 500 k-gm/min.