Table 2. Estimated marginal means, significance of change, and CIs for each variable using multilevel modeling.
| 75 m | 1,300 m | 3,500 m | 4,250 m | 5,300 m | 6,400 m | 7,950 m | 7,950 m+2 L Oxygen | Sig | |
|---|---|---|---|---|---|---|---|---|---|
| Left rSO2 (%) (CI) | 68.77a (65.91–71.63) | 66.00a (64.30–69.70) | 62.62b (59.87–65.37) | 58.94c (55.89–61.99) | 54.16c,d (51.07–57.25) | 49.27d (44.84–53.70) | 41.95e (39.76–44.15) | 62.57a,b,c,e (57.02–68.12) | <0.001 |
| Right rSO2 (%) (CI) | 69.47a (66.74–72.20) | 67.75a (64.57–70.93) | 61.36b (58.88–63.84) | 58.57b,c (55.90–61.24) | 53.98c,d (51.11–56.85) | 50.95d (47.23–54.67) | 39.55e (36.14–42.96) | 61.75b (61.42–62.08) | <0.001 |
| Oxygen content (mLs/100 mLs) (CI) | 18.55a,b (18.08–19.02) | 18.91a (18.44–19.38) | 18.83a (18.25–19.41) | 18.12a,b (17.54–18.70) | 19.02a (18.16–19.89) | 19.29a (17.70–20.87) | 16.81b (15.87–17.76) | 24.27c (23.18–25.37) | <0.001 |
| MCAv (cm/s) (CI) | 59.66 (53.25–66.07) | 56.08 (51.32–60.84) | 62.63 (54.89–70.38) | 60.14 (53.22–67.07) | 66.97 (59.17–74.76) | 66.42 (59.78–73.06) | 62.92 (42.73–83.11) | 49.03 (27.17–70.88) | 0.163 |
| PSV (cm/s) (CI) | 91.32 (82.12–100.51) | 84.34 (76.89–91.80) | 91.73 (82.21–103.24) | 92.39 (81.81–102.96) | 102.75 (91.74–113.75) | 107.10 (96.71–117.48) | 96.15 (63.46–128.84) | 66.70 (15.68–117.73) | 0.116 |
| EDV (cm/s) (CI) | 41.25 (36.96–45.55) | 40.55 (37.42–43.67) | 43.48 (38.34–48.61) | 42.98 (37.62–48.35) | 48.38 (42.37–54.39) | 49.10 (43.45–54.75) | 46.42 (26.56–66.28) | 37.09 (23.25–50.93) | 0.167 |
| Pulsitility index (CI) | 0.85 (0.79–0.90) | 0.81 (0.76–0.86) | 0.78 (0.71–0.84) | 0.82 (0.72–0.92) | 0.82 (0.75–0.89) | 0.87 (0.87–0.97) | 0.83 (0.45–1.2) | 0.71 (0.50–0.91) | 0.213 |
| Resistivity index | 0.54 (0.51–0.57) | 0.54 (0.52–0.56) | 0.52 (0.49–0.55) | 0.53 (0.50–0.56) | 0.53 (0.50–0.56) | 0.54 (0.50–0.57) | 0.52 (0.41–0.64) | 0.47 (0.37–0.57) | 0.410 |
| MCA diameter (mm) | 5.30a (5.01–5.59) | 5.70a,b (5.38–6.02) | 5.51a,c (5.05–5.97) | 5.40a (5.07–5.73) | 5.23a (4.78–5.68) | 6.66b,c,d (6.03–7.30) | 9.34b,e (7.62–11.06) | 6.0a,d,e (5.03–8.02) | 0.003 |
| MCA flow (mL/s) | 13.30a (11.38–15.21) | 14.54a (12.46–16.61) | 15.62a,b (12.53–18.71) | 14.42a (11.75–17.09) | 15.04a,b (11.74–18.34) | 23.68b (18.93–28.43) | 41.16a,b (24.51–57.82) | 15.27a,b (0.64–29.89) | 0.026 |
| Oxygen delivery (mL/s) | 2.47a (2.10–2.85) | 2.74a,b (2.36–3.11) | 2.94a,b (2.34–3.55) | 2.61a (2.12–3.10) | 2.87a,b (2.25–3.50) | 4.69b (3.61–5.78) | 6.98a,b (4.25–9.70) | 3.68a,b (−0.75–8.11) | 0.101 |
CI, confidence interval; EDV, end diastolic velocity; MCA, middle cerebral artery.
Note: altitudes with the same superscript letter do not differ significantly (i.e., they belong to a homogenous subset).