Table 2 Primary and secondary study endpoints from baseline to follow-up after the first dose of medication and after 1 week of treatment with morphine or placebo

VAS dyspnea during the last week (cm)

4.3 ± 0.37

4.7 ± 0.53

−1.1 ± 0.33†

−0.35 ± 0.46

VAS dyspnea score during the last hour (cm)

2 [1.6–4]

2.75 [0–6]

0 [− 1–0]

0 [− 3–0]

−1.2 ± 0.6

− 0.2 ± 0.7

VAS cough score during the last hour (cm)

0.5 [0–3]

0 [0–1.7]

0 [−1–0]

0[− 0.7–0] †

0 [− 2–0] †

0[− 0.5–0]

VAS cough score during the last week (cm)

1 [0–3]

1 [0–3]

−0.15 ± 0.24

−0.07 ± 0.34

6MWT distance (m)

338 ± 27

350 ± 30

12 ± 8

1 ± 8

10 ± 9

5 ± 6

PaO2 baseline (kPa)

11 ± 0.7

10 ± 0.7

−0.4 [− 3–0.5]

−0.05 [− 1.1–0.8]

−0.6 [− 1.3–0.9]

−0.2 [− 0.8–1]

PaCO2 baseline (kPa)

5.3 ± 0.3

4.8 ± 0.2

0.1 [−0.1–0.3]

0 [− 0.3–0.05]

0.2 ± 0.1

0.02 ± 0.1

Peripheral saturation (%)

96 ± 0.6

96 ± 0 .7

−1.5 ± 0.7†

−3.1 ± 0.7†

−2 [− 5–1]

−1 [− 2–1]

Borg score before 6MWT

1.8 ± 0.4

2.0 ± 0.6

− 0.1 ± 0.4

−0.2 ± 0.2

−0.7 ± 0.5

−0.2 ± 0.44

Borg score after 6MWT

6.5 ± 0.4

6.7 ± 0.5

0 [0–0]

0 [0–1]*

0.4 ± 0.6

−0.03 ± 0.5

Desaturation during 6MWT (%-points)

−11.5 ± 1.2

−13.0 ± 1.7

0.6 ± 0.6

1.3 ± 1.5

−3 ± 0.8†

− 0.4 ± 1.3

Systolic BP (mmHg)

136 ± 4

134 ± 4

4.6 ± 4.3

−1.0 ± 3.4

1.2 ± 4.9

0.1 ± 2.9

Respiratory rate (/min)

22 ± 1.3

22 ± 1.7

0 [0–2]

2 [0–3]

− 0.8 ± 1.1

2.6 ± 1.1* †

Heart rate (/min)

78 ± 4.0

80 ± 2.5

−1 [− 8–5]

− 6 [− 10--4]*†

−2.1 ± 2.5

−5.2 ± 2.7

FVC (l)

2.0 ± 0.1

2.0 ± 0.1

−0.06 ± 0.03

−0.1 ± 0.06†

−0.1 ± 0.03†

−0.2 ± 0.05†

KBILD score

51 ± 1.7

49 ± 2.9

2.9 ± 1.6

1.6 ± 1.5

Leicester cough score

17 [12–19]

18 [14–20]

1.2 ± 0.4 †

0.2 ± 0.3

GAD7 score

1 [0–5]

0.5 [0–3]

−0.4 ± 0.7

−0.6 ± 0.8