Lung function measured by impulse oscillometry and spirometry following eucapnic voluntary hyperventilation: RESULTS (1)

Lung function measured by impulse oscillometry and spirometry following eucapnic voluntary hyperventilation: RESULTS (1)Baseline lung function
Resting lung function variables obtained using IOS and maximal expiratory flow volume manoeuvres performed by 10 AHR+ and 10 AHR- subjects are presented in Table 2. Mean values for FVC, FEV1, the FEV1 to FVC ratio and FEF25 75 were within normal limits for both groups. The FEV1 values of two AHR+ subjects were 80% or below the values that were predicted. The FEF25 75 values of five AHR+ subjects and two AHR-subjects were 70% or below the predicted values. One subject demonstrated an FEV1 to FVC ratio of 66%. buy levaquin online
No resting spirometric measures were related to post-EVH falls in FEV1. Resting R5 and AX values were significantly correlated with peak post-EVH falls in FEV1 (r=-0.51 and -0.46, respectively; P<0.05). No significant correlations were identified between peak fall in FEV1 and resting Fres or X values (r=-0.30 and 0.41, respectively). Presented in Table 3 are correlation coefficients to post-EVH peak falls in FEV^ as well as baseline cutoff criteria, sensitivity and predictive values for 80% specificity.

TABLE 2 Baseline values for spirometry and impulse oscillometry

FVC FEV1 FEV1/FVC ratio (%) FEF25.75 R5 (cm H2O/lps) Fres (Hz) X (cm H2O/lps) AX (cm H2O/L)
AHR+ subjects1 4.49 (129.0) 2.99 (99.0) 66 1.76 (45.6) 9.29 22.78 -3.12 30.60
2 4.28 (89.0) 3.24 (79.0) 76 2.23 (45.2) 4.31 17.39 -1.56 7.50
3 5.20 (99.1) 4.08 (92.1) 78 3.20 (63.1) 3.83 15.26 -1.63 7.42
4 6.25 (122.6) 5.20 (120.4) 83 5.38 (107.0) 3.81 8.58 -0.68 1.25
5 3.93 (101.0) 3.60 (105.9) 92 4.75 (113.9) 4.3 12.70 -1.41 4.00
6 6.05 (122.0) 4.85 (115.2) 80 4.55 (91.4) 3.22 10.74 -0.96 2.12
7 4.33 (80.2) 3.63 (80.0) 84 3.52 (68.8) 7.14 19.79 -1.65 15.54
8 3.87 (115.2) 3.16 (109.0) 82 3.21 (89.4) 4.15 13.67 -1.53 5.66
9 4.60 (85.2) 3.85 (84.8) 84 3.59 (70.0) 4.20 14.84 -1.41 5.11
10 4.30 (105.9) 3.85 (109.4) 90 4.19 (110.0) 3.57 15.51 -0.70 3.81
Mean 4.73 (104.9) 3.85 (99.5) 81.5 3.64 (80.4) 4.78 15.13 -1.47 8.30
SD 0.835 (17.0) 0.713 (14.9) 7.3 1.121 (25.6) 1.91 4.161 0.689 8.786
AHR- subjects1 5.77 (113.1) 4.35 (100.7) 75 3.28 (65.2) 3.28 8.67 -1.07 1.70
2 4.92 (96.5) 3.91 (90.5) 79 3.17 (63.0) 4.03 15.99 -1.11 5.19
3 6.32 (108.2) 5.68 (116.6) 90 6.70 (127.1) 2.79 8.99 -0.79 1.46
4 4.22 (126.4) 3.68 (126.9) 87 8.31 (218.7) 3.84 11.79 -1.07 3.28
5 4.86 (110.0) 4.06 (111.2) 84 3.82 (93.2) 4.82 15.90 -1.61 6.99
6 4.81 (117.5) 4.10 (121.0) 85 4.93 (126.8) 3.12 7.89 -0.64 0.83
7 4.63 (109.5) 3.93 (112.3) 85 4.02 (101.5) 5.04 13.38 -1.32 4.74
8 6.04 (111.9) 5.01 (125.6) 83 6.81 (139.6) 3.47 13.43 -1.91 5.76
9 5.33 (114.1) 5.32 (114.4) 99 6.03 (116.6) 3.21 13.69 -0.49 1.93
10 6.08 (109.8) 4.68 (103.1) 77 3.70 (72.3) 3.44 9.43 -0.79 1.73
Mean 5.42 (110.0) 4.561 (110.61″) 84.0 4.721 (100.61) 3.69 11.93 -1.08 3.37
SD 0.644 (5.8) 0.649 (10.9) 7.2 1.452 (28.9) 0.779 3.193 0.439 2.282

TABLE 3 Relationship between impulse oscillometry variables and peak falls in forced expiratory volume in 1 s following eucapnic voluntary hyperventilation (EVH)

Variable n Cutoff r Sens Spec (%) (%) PPV (%) NPV (%) TA (%)
Baseline R5 20 4.0 cm H2O/lps -0.51* 60 80 75 67 70
Baseline Fres 20 14 Hz -0.30 60 80 75 67 70
Baseline X 20 -1.30 cm H2O/lps 0.41 70 80 78 73 75
Baseline AX 20 5.5 cm H2O/L -0.46* 60 80 75 67 70
Post-EVH R5 20 6.0 cm H2O/lps -0.74* 80 80 80 80 80
Post-EVH R5 20 50% -0.66* 90 80 82 89 85
(% change) Post-EVH Fres 20 19 Hz -0.70* 80 80 80 80 80
Post-EVH Fres 20 65% -0.47* 50 80 71 62 65
(% change) Post-EVH X 20 -2.0 cm H2O/lps 0.69* 80 80 80 80 80
Post-EVH X 20 90% -0.57* 80 80 80 80 80
(% change) Post-EVH AX 20 12 cm H2O/L -0.73* 90 80 82 89 85
Post-EVH AX 20 300% -0.46* 40 80 67 57 60
(% change)

Category: Lung function

Tags: Airway hyperresponsiveness, Dry air, Eucapnic voluntary hyperpnea, Exercise-induced bronchoconstriction, Forced oscillation