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Table 4 Secondary outcomes

From: The effect of 50% oxygen on PtCO2 in patients with stable COPD, bronchiectasis, and neuromuscular disease or kyphoscoliosis: randomised cross-over trials

 

Neuromuscular disease/

Kyphoscoliosis

Bronchiectasis

COPD

Oxy T = 0

Mean (SD)

N = 18

Air

T = 0

Mean (SD)

N = 20

Estimate (95% CI)

P valuea

Oxy

T = 0

Mean (SD)

N = 24

Air

T = 0

Mean (SD)

N = 23

Estimate (95% CI)

P valuea

Oxy T = 0

Mean (SD)

N = 24b

Air T = 0

Mean (SD)

N = 24b

Estimate (95% CI)

P valuea

Minute ventilation (L/min)

6.8 (2.0)

6.3 (2.0)

0.17 (−0.26 to 0.59)

P = 0.44

7.56 (2.49)

7.13 (1.88)

0.41 (−0.1 to 0.89)

P = 0.09

8.08 (2.72)

8.03 (2.48)

−0.13 (− 0.55 to 0.29)

P = 0.55

Respiratory rate (breaths/minute)

15.7 (5.1)

15.9 (5.6)

−0.01 (− 0.73 to 0.71)

P = 0.98

15.5 (2.9)

14.7 (3.1)

0.4 (−0.4 to 1.2)

P = 0.34

15.4 (5.0)

14.5 (4.4)

−0.3 (−1.0 to 0.3)

P = 0.31

Tidal volume (L)

0.48 (0.21)

0.44 (0.2)

0.004 (−0.024 to 0.033)

P = 0.77

0.50 (0.2)

0.50 (0.15)

0.01 (−0.03 to 0.05)

P = 0.65

0.56 (0.18) c

0.58 (0.17) c

−0.003 (− 0.03 to 0.03)

P = 0.82

Alveolar minute ventilation (L/min)

3.18 (1.28)

2.88 (1.33)

−0.03 (− 0.24 to 0.18)

P = 0.78

3.26 (1.23)

3.10 (1.05)

−0.06 (− 0.26 to − 0.15)

P = 0.58

3.16 (0.94) c

3.15 (0.76) c

−0.21 (− 0.38 to − 0.04)

P = 0.014

Alveolar volume (L)

0.24 (0.15)

0.21 (0.13)

− 0.01 (− 0.023 to 0.01)

P = 0.44

0.22 (0.10)

0.22 (0.09)

−0.02 (− 0.04 to 0.01)

P = 0.14

0.23 (0.10) c

0.24 (0.11) c

− 0.01 (− 0.03 to 0.001)

P = 0.065

ETCO2 (mmHg)

34.1 (2.9)

33.7 (3.4)

−0.20 (−1.0 to 0.60)

P = 0.62

31.8 (3.6)

31.2 (4.4)

−1.0 (− 1.7 to − 0.3)

P = 0.004

29.0 (3.9)

29.2 (4.0)

−1.1 (− 1.7 to − 0.5)

P < 0.001

Volume of dead space (L)

0.24 (0.09)

0.23 (0.08)

0.012 (− 0.004 to 0.027)

P = 0.13

0.28 (0.10)

0.28 (0.07)

0.01 (0.006 to 0.05)

P = 0.011

0.33 (0.09) c

0.33 (0.09) c

0.009 (−0.007 to 0.03)

P = 0.27

VD/VT

0.54 (0.11)

0.56 (0.09)

0.009 (−0.004 to 0.023)

P = 0.17

0.57 (0.06)

0.57 (0.07)

0.03 (0.02 to 0.04)

P < 0.001

0.60 (0.07) c

0.59 (0.09) c

0.023 (0.01 to 0.037)

P < 0.001

Heart rate (beats per minute)

69.7 (13.8)

68.7 (13.3)

0.42 (−1.0 to 1.9)

P = 0.56

73.7 (10.0)

74.9 (11.7)

−1.5 (−2.8 to −0.1)

P = 0.036

71.9 (11.7) c

69.9 (11.8)c

−3.3 (− 4.6 to − 2.1)

P < 0.001

  1. Air Air intervention, COPD Chronic obstructive pulmonary disease, ETCO2 End tidal carbon dioxide, Oxy Oxygen intervention, VD/VT Dead space to tidal volume ratio
  2. aMixed linear model results, oxygen minus air change from T = 0. All models are pooled estimates across all measurement times (10, 20 or 30 min) as the interaction between time point was not significantly different for any of the time points for any of the above outcomes, see Online Supplement for P values. See Online Supplement for data at individual time points and N value details
  3. b Unless otherwise stated
  4. cN = 23