Table 2.
Heart rate variability and respiratory rate prior to (baseline) and after inhalation of the study drugs (T5, T15, T30, T90)
| Salbutamol | Placebo | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Baseline | T5 | T15 | T30 | T90 | T5 | T15 | T30 | T90 | |
| LFnu-HRV | 43.1 ± 16.6 | 61.0 ± 13.5* | 54.7 ± 13.3 | 51 ± 15 | 46.3 ± 15.1 | 55.3 ± 13.4 | 46 ± 11 | 44.2 ± 11.5 | 43.9 ± 16.0 |
| LF-HRV, ms2 | 2128 ± 2638 | 1248 ± 1208 | 741 ± 553 | 448 ± 388 | 1062 ± 1208 | 2564 ± 2257 | 1740 ± 1764 | 1655 ± 1863 | 1782 ± 2585 |
| HFnu-HRV | 56.9 ± 16.5 | 39.0 ± 13.5* | 45.3 ± 13.3 | 49 ± 15 | 53.7 ± 15.1 | 44.7 ± 13.4 | 54 ± 11 | 55.8 ± 11.5 | 56.1 ± 16.0 |
| HF-HRV, ms2 | 3632 ± 6166 | 1094 ± 1633 | 827 ± 913 | 580 ± 784 | 1753 ± 3255 | 2965 ± 4350 | 2841 ± 4133 | 2727 ± 3575 | 2893 ± 5205 |
| LF/HF ratio | 1.3 ± 1.5 | 2.3 ± 1.6* | 1.7 ± 1.3 | 1.6 ± 1.2 | 1.1 ± 0.7 | 1.4 ± 1.1 | 1.1 ± 0.7 | 0.9 ± 0.5 | 0.9 ± 0.5 |
| Respiratory rate min−1 | 15 ± 3 | 15 ± 4 | 16 ± 3 | 16 ± 3 | 15 ± 4 | 15 ± 3 | 12 ± 3 | 14 ± 3 | 15 ± 3 |
*
P < 0.05 for salbutamol compared with baseline. LF-HRV and HF-HRV, low-frequency and high-frequency heart rate variability expressed as normalized units (nu) or absolute values (ms2).