Changes with ambient air versus hyperoxia for all disease groups are shown at end-exercise
| End-exercise | Mean differences (95% CI) with hyperoxia | ||||
| Healthy | PVD | COPD | HFpEF | CHD | |
| IET | |||||
| Work rate W | 13.0 (8.0–19.0)*** | 19.7 (10.5–28.9)*** | 7.9 (3.4–12.3)*** | 5.4 (0.9–9.8)* | 7.0 (−1.3–18.7) |
| SpO2 % | 3.0 (2.1–4.3)*** | 8.0 (3.8–10.9)*** | 3.0 (1.0–6.0)** | 5.0 (3.0–6.4)*** | 4.0 (0.9–7.4)* |
| V′E L·min−1 | 2.0 (−6.0–8.4) | 3.0 (−6.4–9.3) | −0.25 (−2.7–2.1) | 5.8 (−4.2–16.3) | −1.0 (−6.2–4.2) |
| Heart rate bpm | 1.0 (−2–7.7) | 6.0 (−1.9–14.3) | 1.0 (−4.4–5.3) | −9.0 (−36.0–19.2) | 3.0 (−1.7–7.7) |
| V′E/V′CO2 | −1.0 (−5.8–0.3) | −4.7 (−6.8– −2.6)*** | −3.2 (−4.5– −2.0)*** | −3.1 (−4.2– −2.1)*** | −3.0 (−4.6– −1.5)** |
| Arterial lactate mmol·L−1 | NA | 0.5 (−0.1–1.2) | 0.2 (−0.6–0.6) | −0.5 (−1.2–0.3) | NA |
| PaCO2 kPa | NA | 0.7 (0.4–1)*** | 0.5 (0.2–0.7)** | 0.3 (−0.3–0.8) | NA |
| PaO2 kPa | NA | 23.3 (20.1–26.5)*** | 22.1 (20.6–23.6)*** | 15.7 (8.6–22.8)*** | NA |
| SaO2 % | NA | 9.0 (5.9–13.2)*** | 6.6 (5.1–8)*** | 3.3 (0.9–5.7)* | NA |
| Borg CR10 dyspnoea score | −0.9 (−1.5– −0.2)* | −0.6 (−1.2–0.1)*** | 0.0 (−0.7–0.7) | −0.8 (−1.5– −0.1)* | NA |
| Borg CR10 leg score | 0.1 (−0.6–0.9) | 0.5 (−0.8–1.7)*** | 0.4 (−0.4–1.2) | 0.1 (−0.5–0.7) | NA |
| CWRET | |||||
| Endurance time min | 5:45 (4:08–7:20)*** | 11:11 (6:45–15:36)*** | 5:57 (3:27–8:27)*** | 2:24 (0:39–4:10)* | 0:56 (−0:13–4:31) |
| SpO2 % | 3.0 (1.8–5.1)*** | 9.0 (6.1–12.5)*** | 6.0 (3.3–7.8)*** | 5.0 (0.8–9.2)* | 4.0 (1.3–7.0)* |
| V′E L·min−1 | −6.5 (−12.9–0.05) | −5.0 (−12.4–3.8) | −3.4 (−5.8– −0.9)* | −9.6 (−18.3– −0.8) | 0.4 (−5.3–6.2) |
| Heart rate bpm | 2.0 (−2.1–7.1) | −4.0 (−12.4–3.9) | −2.0 (−5.2–1.8) | −1.0 (−6.4–4.1) | −1.0 (−6.7–4.4) |
| V′E/V′CO2 | −0.7 (−1.8–0.2) | −6.0 (−7.9– −4.1)*** | −3.4 (−5.5– −1.3)** | −4.4 (−6.9– −1.9)* | −3.8 (−5.8– −1.7)** |
| Arterial lactate mmol·L−1 | NA | −1.8 (−3.5–0.04) | −1.5 (−2.2– −0.9)*** | −0.7 (−1.8–0.4) | NA |
| PaCO2 kPa | NA | 0.7 (−0.03–0.9) | 0.5 (0.3–0.7)*** | 0.25 (−0.1–0.6) | NA |
| PaO2 kPa | NA | 22.0 (16.6–27.6)*** | 23.1 (21.5–24.7)*** | 23.4 (19.2–27.6)** | NA |
| SaO2 % | NA | 11.7 (8.3–15)*** | 9.7 (5.6–13.8)*** | 6.1 (3–9.2)** | NA |
| Borg CR10 dyspnoea score | −0.3 (−1.2–0.5) | −1.4 (−2.5–0.4)* | −0.9 (−1.5– −0.3)** | −1.3 (−2.1– −0.6)** | NA |
| Borg CR10 leg score | −0.1 (−0.7–0.5) | −0.6 (−1.5–0.3) | −0.5 (−1.2–0.3) | −0.8 (−1.7– −0.1) | NA |
Data are presented as mean differences with 95% confidence intervals. For more details on statistical analyses see the original publications [13–17]. PVD: pulmonary vascular disease with precapillary pulmonary hypertension; COPD: chronic obstructive pulmonary disease; HFpEF: heart failure with preserved ejection fraction with postcapillary pulmonary hypertension; CHD: cyanotic congenital heart disease; IET: incremental exercise test; CWRET: constant work-rate exercise test; NA: not available; SpO2: oxygenation by pulse oximetry; V′E: minute ventilation; bpm: beats per min; V′E/V′CO2: ventilatory equivalent for CO2; PaCO2, PaO2: arterial tension for CO2 and O2; SaO2: arterial oxygen saturation. *: p=0.05; **: p=0.01; ***: p<0.001.