Table 3.
Respiratory parameters at rest (room air) and exactly 1 min after introducing a hypercapnic (FICO2 = 15%; O2 = 21%) or hypoxic gas mixture (FIO2 = 10%; no CO2 added) into the plethysmography chambera
| n | RTN-Control | RTN-Lesion | CBx-Sham | CBx | C1-Control | C1-Lesion |
|---|---|---|---|---|---|---|
| Resting | ||||||
| fR (bpm) | 68 ± 6 | 97 ± 13* | 69 ± 7 | 61 ± 10 | 86 ± 16 | 81 ± 4 |
| VT (ml/100 g) | 0.45 ± 0.1 | 0.22 ± 0.1* | 0.49 ± 0.1 | 0.41 ± 0.1 | 0.34 ± 0.1 | 0.34 ± 0.1 |
| VE (ml/kg/min) | 30.6 ± 4 | 21.1 ± 6* | 34.1 ± 6 | 24.9 ± 5 | 28.3 ± 4 | 28.1 ± 4 |
| Hypercapnia | ||||||
| fR (bpm) | 130 ± 6 | 106 ± 12* | 128 ± 10 | 118 ± 14 | 123 ± 8 | 120 ± 8 |
| VT (ml/100 g) | 0.75 ± 0.1 | 0.32 ± 0.1* | 0.75 ± 0.1 | 0.68 ± 0.1 | 0.63 ± 0.1 | 0.65 ± 0.2 |
| VE (ml/kg/min) | 98.5 ± 15 | 34.7 ± 11* | 96.7 ± 10 | 80.8 ± 15* | 78.6 ± 18 | 77.8 ± 14 |
| Hypoxia | ||||||
| fR (bpm) | 108 ± 6 | 111 ± 17 | 103 ± 13 | 79 ± 11* | 120 ± 10 | 118 ± 11 |
| VT (ml/100 g) | 0.54 ± 0.1 | 0.51 ± 0.2 | 0.63 ± 0.1 | 0.42 ± 0.1* | 0.52 ± 0.1 | 0.62 ± 0.2 |
| VE (ml/kg/min) | 58.8 ± 10 | 55.7 ± 16 | 64.4 ± 13 | 33.0 ± 7* | 62.3 ± 10 | 75.6 ± 19 |
aData are mean ± SD.
*p < 0.0001 for Bonferroni's multiple comparisons between groups in the same condition: resting, hypercapnia, or hypoxia. Only the two-way ANOVA significant differences were described below. RTN-Control versus RTN-Lesion, two-way repeated-measures ANOVA for fR; interaction between RTN-Lesion and hypercapnia, F(1,16) = 95.5, p < 0.0001; lesion effect, F(1,16) = 0.24, p = 0.6248; hypercapnia effect, F(1,16) = 180.4, p < 0.0001; two-way repeated-measures ANOVA for VT; interaction between RTN-Lesion and hypercapnia, F(1,8) = 37,1, p = 0.0003; lesion effect, F(1,8) = 164.5, p < 0.0001; hypercapnia effect, F(1,8) = 62.2, p < 0.0001; two-way repeated-measures ANOVA for VE; interaction between RTN-Lesion and hypercapnia, F(1,8) = 131.7, p < 0.0001; lesion effect, F(1,8) = 258.6, p < 0.0001; hypercapnia effect, F(1,8) = 139.4, p < 0.0001; CBx-Sham versus CBx, two-way repeated-measures ANOVA for fR; interaction between CBx and hypoxia, F(1,12) = 13.1, p = 0.0035; CBx effect, F(1,12) = 10.8, p = 0.0065; hypoxia effect, F(1,12) = 118.1, p < 0.0001; two-way repeated-measures ANOVA for VT; interaction between CBx and hypoxia, F(1,12) = 35.9, p < 0.0001; CBx effect, F(1,12) = 17.6, p = 0.0012; hypoxia effect, F(1,12) = 52.3, p < 0.0001; two-way repeated-measures ANOVA for VE; interaction between CBx and hypoxia, F(1,12) = 34.6, p < 0.0001; CBx effect, F(1,12) = 23.4, p = 0.0004; hypoxia effect, F(1,12) = 103.1, p < 0.0001.