TABLE 2.
Absolute cardiovascular, cerebrovascular and respiratory responses for baseline and during the two recovery periods intervening between the oscillatory lower-body negative pressure (OLBNP) profiles
| Parameter | Baseline | Recovery 1 | Recovery 2 | Main effect P-value |
|---|---|---|---|---|
| Cardiovascular | ||||
| Heart rate (beats min−1) | 63.4 ± 9.5 | 59.8 ± 12.6 | 60.1 ± 12.9 | 0.08 |
| Systolic arterial pressure (mmHg) | 122.5 ± 8.6 | 128.1 ± 13.1* | 127.7 ± 12.7* | 0.03 |
| Diastolic arterial pressure (mmHg) | 67.7 ± 5.3 | 67.3 ± 14.6 | 71.7 ± 4.6 | 0.37 |
| Mean arterial pressure (mmHg) | 87.4 ± 6.3 | 93.0 ± 7.9* | 91.8 ± 7.9* | 0.009 |
| Cerebrovascular | ||||
| ScO2 (%) | 69.2 ± 10.9 | 69.4 ± 11.3 | 69.4 ± 11.5 | 0.95 |
| Deoxygenated haemoglobin (μM) | 13.8 ± 3.8 | 13.9 ± 3.7 | 14.1 ± 3.7 | 0.69 |
| Oxygenated haemoglobin (μM) | 32.9 ± 11.0 | 33.8 ± 12.2 | 33.9 ± 12.3 | 0.36 |
| Systolic MCAv (cm s−1) | 82.0 ± 22.9 | 80.5 ± 20.9 | 80.6 ± 18.8 | 0.46 |
| Diastolic MCAv (cm s−1) | 36.9 ± 8.0 | 37.6 ± 10.0 | 38.0 ± 10.6 | 0.79 |
| Mean MCAv (cm s−1) | 51.2 ± 11.5 | 52.2 ± 13.1 | 52.8 ± 13.4 | 0.66 |
| Peripheral vasculature | ||||
| SmO2 (%) | 70.1 ± 6.3 | 71.8 ± 5.7* | 72.1 ± 6.5* | 0.003 |
| Deoxygenated haemoglobin (μM) | 23.0 ± 6.6 | 22.4 ± 5.7 | 21.9 ± 5.6 | 0.42 |
| Oxygenated haemoglobin (μM) | 55.1 ± 14.5 | 57.6 ± 12.1 | 57.3 ± 12.9 | 0.16 |
| Respiratory | ||||
| etCO2 (mmHg) | 36.7 ± 3.3 | 35.5 ± 5.4 | 33.9 ± 6.7* | 0.07 |
| Respiratory rate (breaths min−1) | 14.7 ± 3.8 | 14.3 ± 3.3 | 15.2 ± 4.0 | 0.30 |
| Blood samples | ||||
| Noradrenaline (pg ml−1) | 477.0 ± 239.2 | 725.9 ± 398.8* | 673.9 ± 324.7 | 0.03 |
Abbreviations: etCO2, end-tidal carbon dioxide; MCAv, middle cerebral artery velocity; ScO , cerebral oxygen saturation; and SmO2 , muscle oxygen saturation. Data were analysed with a linear mixed model for repeated measures followed by Tukey’s post hoc tests. Values are reported as means ± SD.
*
P = 0.004–0.06 versus baseline.