Background
Methods
Interventions
Measurements
Microcirculation assessment
Immunoassays
Statistical analysis
Results
Hemodynamic and blood gas data
t0 | t1 | t2 | p (time)a
| p (interaction)b
| |
---|---|---|---|---|---|
Heart Rate (bpm) | 0.813 | ||||
Hyperoxia
| 70 ± 20 | 71 ± 22 | 77 ± 22##‡
| 0.008 | |
Controls
| 67 ± 19 | 66 ± 19 | 72 ± 25 | 0.086 | |
Mean Arterial Pressure (mmHg) | - | ||||
Hyperoxia
| 86 [70–91] | 87 [81–97] | 83 [72–87]* | 0.008 | |
Controls
| 87 [79–101] | 88 [84–97] | 85 [81–92] | 0.462 | |
Body temperature (°C) | 0.176 | ||||
Hyperoxia
| 36.1 ± 1.1 | 36.3 ± 0.9 | 36.3 ± 1.1* | 0.407 | |
Controls
| 36.7 ± 0.8 | 36.7 ± 0.9 | 37.1 ± 0.8#‡
| 0.010 | |
PaO2 (mmHg) | <0.001 | ||||
Hyperoxia
| 108 ± 35 | 433 ± 109###*** | 111 ± 26‡‡‡
| <0.001 | |
Controls
| 118 ± 33 | 119 ± 28 | 115 ± 33 | 0.622 | |
SaO2 (%) | - | ||||
Hyperoxia
| 99.7 [98.9–100] | 100[100–100]###*** | 99.8 [99.1–100]‡‡
| <0.001 | |
Controls
| 100 [99.6–100] | 99.9 [99.5–100] | 99.8 [99.5–100] | 0.863 | |
PaO2/FiO2 (mmHg) | <0.001 | ||||
Hyperoxia
| 290 ± 93 | 435 ± 111###*** | 287 ± 82‡‡‡
| <0.001 | |
Controls
| 314 ± 108 | 315 ± 93 | 303 ± 99 | 0.330 | |
ScvO2 (%) | - | ||||
Hyperoxia
| 79 [70–83] | 86 [74–90]###
| 76 [72–81]‡‡‡
| <0.001 | |
Controls
| 82 [74–84] | 80 [75–85] | 79 [75–84] | 0.838 | |
pH | 0.696 | ||||
Hyperoxia
| 7.48 ± 0.07 | 7.49 ± 0.07 | 7.48 ± 0.07 | 0.516 | |
Controls
| 7.45 ± 0.06 | 7.45 ± 0.05 | 7.45 ± 0.06 | 0.966 | |
PaCO2 (mmHg) | - | ||||
Hyperoxia
| 38 [36–42] | 39 [34–42] | 39 [36–42] | 0.826 | |
Controls
| 38 [34–42] | 39 [35–43] | 41 [35–42] | 0.145 | |
Base excess (mmol/L) | 0.971 | ||||
Hyperoxia
| 5.0 ± 5.2 | 5.3 ± 5.3 | 5.6 ± 4.9 | 0.430 | |
Controls
| 2.9 ± 3.8 | 3.1 ± 4.1 | 3.3 ± 3.6 | 0.288 | |
Lactate (mmol/L) | - | ||||
Hyperoxia
| 1.1 [0.7–1.5] | 1.2 [1.1–2.0]** | 1.3 [1.0–1.8]* | 0.037 | |
Controls
| 0.9 [0.7–1.2] | 0.9 [0.7–1.2] | 0.9 [0.7–1.2] | 0.616 |
Effects on erythropoiesis
Baseline | 24 h | 48 h | p (time)a
| p (interaction)b
| |
---|---|---|---|---|---|
Erythropoietin (IU/L) | - | ||||
Hyperoxia
| 16.1 [7.4–20.2] | 20.1 [10.7–31.2] | 22.9 [14.1–37.2]#
| 0.022 | |
Controls
| 12.8 [7.3–22.2] | 14.9 [9.2–18.6] | 14.8 [7.9–24.8] | 0.692 | |
Reticulocytes (*103/mm3) | - | ||||
Hyperoxia
| 55.9 [39.4–67.4] | 47.3 [33.1–62.2]##
| 46.2 [29.8–66.2] | 0.010 | |
Controls
| 60.2 [46.3–78.7] | 52.5 [42.9–65.9] | 50.7 [44.1–64.5]#
| 0.027 | |
Hemoglobin (g/dL) | 0.601 | ||||
Hyperoxia
| 10.7 ± 1.4 | 10.2 ± 1.3 | 10.1 ± 1.3#
| 0.013 | |
Controls
| 11.7 ± 2.0 | 11.3 ± 1.8 | 11.3 ± 1.7 | 0.027 | |
Hematocrit (%) | 0.053 | ||||
Hyperoxia
| 32 ± 6 | 31 ± 6 | 30 ± 6#* | 0.029 | |
Controls
| 34 ± 8 | 34 ± 8 | 34 ± 8 | 0.675 |
Effects on the sublingual microcirculation
t0 | t1 | t2 | p (time)a
| p (interaction)b
| |
---|---|---|---|---|---|
TVD small (mm/mm2) | - | ||||
Hyperoxia
| 18.5 [16.5–21.6]** | 16.4 [14.6–21.6]** | 19.3 [18.2–21.3]‡* | 0.035 | |
Controls
| 21.7 [20.0–23.8] | 22.2 [18.8–24.3] | 21.0 [19.8–23.7] | 0.705 | |
TVD medium (mm/mm2) | - | ||||
Hyperoxia
| 0.9 [0.4–1.6] | 0.5 [0.4–0.9]** | 0.7 [0.3–1.3] | 0.268 | |
Controls
| 1.2 [0.8–1.8] | 1.0 [0.7–1.8] | 1.1 [0.6–1.7] | 0.861 | |
PVD small (mm/mm2) | - | ||||
Hyperoxia
| 17.4 [16.3–20.8]** | 15.4 [13.2–20.3]** | 18.4 [17.1–19.9]* | 0.058 | |
Controls
| 20.1 [18.9–22.6] | 21.0 [18.0–23.3] | 20.0 [18.5–22.9] | 0.549 | |
PVD medium (mm/mm2) | 0.178 | ||||
Hyperoxia
| 0.9 ± 0.6 | 0.6 ± 0.5* | 0.8 ± 0.6 | 0.142 | |
Controls
| 1.2 ± 0.6 | 1.2 ± 0.6 | 1.1 ± 0.7 | 0.851 | |
De Backer score (n/mm) | - | ||||
Hyperoxia
| 11.2 [9.9–13.2]** | 9.7 [8.8–13.2]** | 11.8 [10.0–13.4]‡** | 0.019 | |
Controls
| 14.5 [12.0–15.8] | 14.1 [11.6–15.8] | 14.1 [12.7–16] | 0.951 | |
MFI small (AU) | - | ||||
Hyperoxia
| 2.74 [2.50–2.90] | 2.67 [2.50–2.90] | 2.75 [2.52–2.92] | 0.713 | |
Controls
| 2.67 [2.44–2.90] | 2.75 [2.60–3.00] | 2.79 [2.67–2.98] | 0.099 | |
PPV small (%) | 0.223 | ||||
Hyperoxia
| 96 ± 3 | 94 ± 4 | 95 ± 3 | 0.149 | |
Controls
| 94 ± 4 | 95 ± 3 | 95 ± 4 | 0.396 | |
FHI small (AU) | - | ||||
Hyperoxia
| 0.14 [0.08–0.21] | 0.18 [0.09–0.30]* | 0.10 [0.02–0.20] | 0.551 | |
Controls
| 0.09 [0.02–0.19] | 0.09 [0.00–0.18] | 0.09 [0.00–0.18] | 0.290 | |
BFV (μm/s) | 0.631 | ||||
Hyperoxia
| 497 ± 63 | 489 ± 81 | 502 ± 45 | 0.741 | |
Controls
| 520 ± 56 | 519 ± 54 | 531 ± 65 | 0.537 | |
StO2 (%) | 0.655 | ||||
Hyperoxia
| 80 ± 8 | 82 ± 8 | 82 ± 7 | 0.261 | |
Controls
| 81 ± 9 | 81 ± 8 | 82 ± 9 | 0.824 | |
StO2 downslope (%/min) | - | ||||
Hyperoxia
| −7.9 [−9.1, −7.0] | −7.7 [−9.3, −6.8] | −9.4 [−11.0, −7.9]‡
| 0.003 | |
Controls
| −8.1 [−9.7, −6.8] | −7.9 [−10.1, −7.0] | −8.6 [−9.9, −6.9] | 0.212 | |
StO2 upslope (%/min) | - | ||||
Hyperoxia
| 133 [98–243] | 194 [145–274] | 192 [140–244] | 0.101 | |
Controls
| 194 [150–228] | 193 [139–262] | 219 [132–263] | 0.247 | |
StO2 area under the curve (%*min) | 0.284 | ||||
Hyperoxia
| 14.6 ± 8.8 | 18.0 ± 11.8 | 13.2 ± 7.6 | 0.066 | |
Controls
| 20.3 ± 15.1 | 19.8 ± 14.7 | 18.3 ± 13.3 | 0.660 | |
THI (AU) | 0.884 | ||||
Hyperoxia
| 11.0 ± 3.2 | 11.4 ± 3.8 | 11.8 ± 3.2 | 0.374 | |
Controls
| 12.6 ± 2.2 | 12.7 ± 3.5 | 13.0 ± 3.1 | 0.801 |
NIRS variables
NO, ROS and GSH
t0 | t1 | t2 | p (time)a
| p (interaction)b
| |
---|---|---|---|---|---|
Nitrite/nitrate (μM) | 0.378 | ||||
Hyperoxia (n = 12)
| 41 ± 17 | 45 ± 21 | 43 ± 18 | 0.301 | |
Controls (n = 12)
| 51 ± 18 | 55 ± 16 | 59 ± 14 | 0.198 | |
GSH (μM) | - | ||||
Hyperoxia (n = 12)
| 2.21 [2.12–2.28] | 2.17 [2.09–2.25] | 2.24 [2.20–2.39] | 0.114 | |
Controls (n = 12)
| 2.19 [2.12–2.33] | 2.18 [2.15–2.23] | 2.23 [2.17–2.28] | 0.273 | |
ROS (RFU) | - | ||||
Hyperoxia (n = 12)
| 2915 [1196–6537] | 3109 [1348–6961] | 3061 [1261–5841] | 0.046 | |
Controls (n = 12)
| 1773 [1070–3018] | 2024 [1135–3069] | 1841 [1066–3058] | 0.338 |