Medicine of the Future in America

Lung Mechanics and Gas Exchange During Exercise in Pulmonary Sarcoidosis (8)

In order to determine factors limiting WC to less than 80 percent pred, for each subject data on HRmax, BE, arterial blood gases, P/V-loops at maximal exercise and dyspneic index were analyzed. In the 27 individuals with a low WC, HRmax was 87 percent pred. The fall in BE at maximal exercise, mainly reflecting lactate formation, was, on the average, normal in relation to the work rate. In two subjects, the fall was greater than expected. These results suggest that circulation and aerobic metabolism in general did not limit exercise performance. Nevertheless, in six of the 27 subjects, a high HRmax and a fall in BE indicated circulation to contribute to exercise limitation. The dyspneic index in these patients was 48 percent (range 38 to 55). In contrast, the 21 subjects with a low WC but apparently normal circulation had a dyspneic index of 80 percent (range 50 to 115), indicating ventilation to be the major limiting factor for exercise. In 24 patients, lung function was considered to contribute to a WC less than 80 percent pred. In addition, 16 of the 36 subjects with a WC within the normal range were judged to be slightly limited by their liing function. buy flovent inhaler
The FEVi and VC showed among the lung volumes the closest correlation to working capacity (Table 2).

Table 2—Relations of Different Physiologic Variables to Working Capacity and to PaOt at Maximal Work Load

Relation to WC %Pred n = 56-63 r Relation to PaO, at Max Work, %Pred n = 56-60 r
CstL %pred 0.50 0.34
CdynL at max work %pred 0.69 0.49
Rl %pred -0.52 — 0.33
RfL at max work %pred —0.60 —0.31
TLC %pred 0.50 0.25
VC %pred 0.71 0.49
RV %pred 0.16 -0.13
FEV, %pred 0.74 0.56
FEV,%VC %pred 0.43 0.34
PaO, at rest, sitting %pred 0.22 0.43
PaO, at max work %pred 0.33
This entry was posted in Pulmonary function and tagged gas exchange, lung function, sarcoidosis.
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