[Changes of respiratory function after lung resection--taking notice of changes during exercise test and anaerobic metabolism].
Changes in the following respiratory functions during exercise test were examined before and after surgery in 31 patients undergoing pulmonary resection: VE, VCO2, and VT at a constant VO2 during exercise; and VO2, VCO2, VE and VT at constant loading (watt). At the level of 300 and 500 ml/min of VO2, VCO2 showed no significant difference before and after the operation but when VO2 reached 700 ml/min. VCO2 showed a significant increase from 542.0 +/- 78.3 ml/min to 595.5 +/- 85.2 ml/min postoperatively (p < 0.05). When exercise load was 45 watt, VE showed no significant difference before and after the operation, but when exercise load was 60 watt, VE showed a significant increase from 30.16 +/- 5.38 L/min to 33.89 +/- 4.69 L/min postoperatively (p < 0.005). These results indicated an early acceleration of ventilation in low load postoperatively. With respect to anaerobic metabolism, AT, oxygen uptake to work rate (delta VO2/delta WR), and our proposed index calculated as an area using the cumulative oxygen uptake were compared pre- and postoperatively. The results indicated that AT decreased significantly from 716.0 +/- 190.8 ml/min to 528.4 +/- 150.7 ml/min (p < 0.001), and delta VO2/delta WR also decreased significantly from 13.5 +/- 4.0 ml/min/W to 11.3 +/- 4.2 ml/min/W (p < 0.05). The index calculated as area showed a significant increase from 4070.2 +/- 3468.8 to 5095.3 +/- 3854.5 (p < 0.05). All these findings indicated that anaerobic metabolism increases postoperatively. Accordingly we conclude that postoperative increase of anaerobic metabolism causes postoperative acceleration of ventilation in low load.
Second Department of Surgery, Nippon Medical School, Tokyo, Japan.
Y
Y
Masaki
M
M
Gomibuchi
S
S
Tanaka
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015308:Anaerobic Threshold; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D011013:Pneumonectomy; D011184:Postoperative Period; D012119:Respiration / Q000502:physiology*