Table 1 Demographic data

Demographic data

 Age (years)

69 (61–71)

65 (63–71)

 BMI

22.19 (21.72–30.9)

24.67 (23.78–26.99)

 Sex (F)

3

5

 FEV1 (L)

0.84 (0.59–1.1)

0.97 (0.7–1.32)

 FEV1 (% predicted) (%)

38 (21–45)

39.8 (39–46)

 FVC (L)

2.3 (1.34–2.6)

2.6 (1.7–3.3)

 FVC (% predicted) (%)

63 (33–105)

82 (63–92)

 FEV1/FVC

48 (32–49)

44 (37–48)

 GOLD stage

3 (3–4)

3 (3–3)

 Pack years smoked

40 (20–60)

40 (39–45)

Baseline observations

 Systolic blood pressure (mmHg)

120 (105–144)

130 (112–139)

 Respiratory rate (breaths/min)

24 (20–28)

29 (26–32)* ( p = 0.0371)

 SpO₂ (%)

91 (90–92)

91 (87–93)

 Heart rate (beats/min)

100 (86–113)

109 (100–116)

Presenting arterial blood gas

 PaO₂ (kPa)

8.67 (8.63–10.57)

7.33 (7.1–8.55)

 PaCO₂ (kPa)

9.18 (8.94–10.31)

9.75 (8.14–9.78)

 pH

7.23 (7.23–7.27)

7.26 (7.25–7.28)

 HCO₃ (mmol/L)

31 (28.2–31.4)

29.5 (28.88–30.64)

Initial NIV settings

 EPAP (cmH₂O)

5 (5–5)

6 (5–6)

 IPAP (cmH₂O)

18 (15–22)

18 (16–20)

 FiO₂ (%)

32 (26–40)

35 (28–40)

Arterial blood gas after 1 h NIV

 PaO₂ (kPa)

8.37 (8.05–8.83)

8.89 (7.9–9.41)

 PaCO₂ (kPa)

9.16 (8.23–10.02)

9.34 (8.49–9.65)

 pH

7.27 (7.24–7.27)

7.27 (7.25–7.27)

 HCO₃ (mmol/L)

29.1 (26.7–30.8)

27.9 (27.7–30.52)

Baseline laboratory investigations

 Leukocytes (× 10⁹/L)

8.9 (6.8–10.4)

9.1 (8.3–11.8)

 Haemoglobin (g/L)

130 (120–136)

151 (143–157)* ( p = 0.0411)

 Platelets (× 10⁹/L)

251 (172–288)

204 (163–308)

 Creatinine (umol/L)

99 (57–136)

77 (69–80)

 Bilirubin (umol/L)

6 (4–6)

7 (5.5–12)

 C-reactive protein (mg/L)

13 (3.5–16)

32 (30–51)* ( p = 0.0199)