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Lung Mechanics and Gas Exchange During Exercise in Pulmonary Sarcoidosis (5)

Lung Mechanics and Gas Exchange During Exercise in Pulmonary Sarcoidosis (5)Predicted Normal Values
Most results are reported in percent predicted values and expressed by percent pred. Reference values refer to the references as: lung volumes and mechanics at rest; RfL, CdynL, Ve, fR, and WresL; Pa02, PaC02, and BE; HRmax, working capacity. buy cipro
Values outside the 95 percent confidence interval for healthy subjects were regarded as abnormal.
Results
Maximal Work Load and Ventilation
The patients had, on the average, a working capacity of 85 percent pred (Table 1). While patients with a WC ^90 percent pred showed a normal minute ventilation (103 ± 16 percent pred) with respect to the maximal load achieved, those with a WC <90 percent pred had an abnormally high ventilation (123 ±22 percent pred, p<0.001). In the latter group of patients, the breathing frequency at maximal work was 37 ± 6.7/ min, ie, significantly higher than the expected rate of 23/min (p<0.001).
Lung Mechanics in All Patients and in Clinical Subgroups
In the entire group of patients, CdynL was reduced and RfL elevated both at rest and exercise, whereas the resistive work of breathing was normal (Table 1). Figure 1 displays typical features of the P/V loop at maximal work load.

Table 1—Physiologic Variables Sitting at Rest and at Maximal Work Load in Sarcoidosis

All Patients n = 54-63 Symptoms Radiographic Stage
Stage 2 n = 21-26 Minor Shrinkage n= 18-20 Stage 3 Moderate-Severe Shrinkage n= 14-16
No n = 16-21 Yes n = 37-42
WCmax, %pred mean 85 94 [*] 81 90 86 76
±SD 23 18 24 26 14 25
CdynL at rest, %pred mean 70§ 87 [*] 63 79 69 58
±SD 35 27 35 41 29 30
CdynL at max work, %pred mean 64 72 60§ 78§[*] 62 [•] 43
±SD 28 19 31 25 28 21
RfL at rest, %pred mean 148 104 [•••] 169 146t 134 165
±SD 86 49 92 100 56 95
RfL at max work, %pred mean 188 118 [*] 223 165 146 [*] 260
±SD 165 41 192 177 69 207
Work of breathing at max work, % pred mean 109 121 104 84[•] 119 126
±SD 54 55 53 30 59 63
PaCO* at rest, kPa mean 4.5§ 4.5 4.4 4.5 4.4 4.5
±SD 0.5 0.6 0.5 0.5 0.5 0.6
FaCO* at max work, kPa mean 4.4 4.4 4.4 4.6 [**] 4.1§ 4.4
±SD 0.6 0.6 0.6 0.5 0.5 0.6
Pa02 at rest, kPa mean 10.9 11.71 [**] 10.5 11.3 11.0 10.1
±SD 1.5 1.6 [*] 1.4 1.3 1.7 1.5
%predmean 86 92 [**] 83 89 86 80
±SD 12 12 11 10 13 12
Pa02 at max work, kPa mean 10.3 10.8 10.1 10.7 10.7 [•] 9.3
±SD 1.6 1.3 1.6 1.2 1.7 1.5
%predmean 84 88 82 87 87
[*] 75
±SD 13 11 13 10 14 12
Pa02 + PaC02 at rest, kPa mean 15.4 16.3 [**] 14.9 15.9 15.4 14.6
±SD 1.4 1.3 1.2 1.2 1.5 1.3
Pa02 + PaCO£ at max work, kPa mean 14.7 15.3 [•] 14.5 5.3 14.8 [*] 13.7
±SD 1.5 1.3 1.5 1.2 1.6 1.2

Figure-1
Figure 1. Two pressure/volume loops at maximal exercise are displayed. The loop to the left is obtained from one of the patients without functional abnormalities and shows moderate pressure changes and a normal tidal volume. The loop to the right shows large pressure changes and a small tidal volume. It was obtained from a patient with pulmonary limitation of her physical performance. Pes, esophageal pressure.

This entry was posted in Pulmonary function and tagged gas exchange, lung function, sarcoidosis.
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