Table 1 Baseline characteristics of the intention to treat population
|  | Intervention group (n = 106) | Control group (n = 105) |
|---|---|---|
Age (years; median (IQR) | 68 (51–79) | 69 (62–79) |
Sex | ||
 Male | 62 (58%) | 46 (44%) |
 Female | 44 (42%) | 59 (56%) |
Smoking status | ||
 Never smoked | 30 (28%) | 25 (24%) |
 Current smoker | 27 (25%) | 12 (11%) |
 Previous smoker | 24 (23%) | 37 (35%) |
 Unknown status | 25 (24%) | 31 (30%) |
Medical history | ||
 Apoplexy | 9 (8%) | 7 (7%) |
 Coronary artery disease | 17 (16%) | 16 (15%) |
 Heart failure | 13 (12%) | 14 (13%) |
 Arterial hypertension | 24 (23%) | 22 (21%) |
 Thromboembolic disease | 11 (10%) | 5 (5%) |
 Chronic obstructive pulmonary disease | 33 (31%) | 32 (30%) |
 Asthma | 6 (6%) | 6 (6%) |
 Other pulmonary or pleural lung disease | 11 (10%) | 9 (9%) |
 Diabetes mellitus | 8 (8%) | 17 (16%) |
 Chronic kidney disease | 8 (8%) | 8 (8%) |
 Other medical disease | 28 (26%) | 36 (34%) |
 Psychiatric disorder | 7 (7%) | 4 (4%) |
Medication at admission | ||
 Β-blockers | 28 (26%) | 23 (22%) |
 Diuretics | 38 (36%) | 49 (47%) |
 Nitrates | 9 (8%) | 14 (13%) |
 Angiotensin-converting-enzyme inhibitor or angiotensin-receptor blocker | 26 (25%) | 38 (36%) |
 Digoxin | 4 (4%) | 5 (5%) |
 Calcium-channel blockers | 16 (15%) | 21 (20%) |
 Aspirin | 16 (15%) | 18 (17%) |
 Inhaled bronchodilators | 39 (37%) | 45 (43%) |
 Inhaled corticosteroids | 21 (20%) | 31 (30%) |
 Oral corticosteroids | 10 (9%) | 17 (16%) |
 Antibiotics | 18 (17%) | 17 (16%) |
 Anticoagulants | 29 (27%) | 36 (34%) |
 Immunosuppressive medication | 5 (5%) | 2 (2%) |
 Other medication | 19 (18%) | 24 (23%) |
Vital signs at admission mean, (min-max) | ||
 Respiratory rate (breaths per min) | 21 (12–44) | 22 (12–40) |
 Saturation (%) | 94 (55–100) | 95 (74–100) |
-  of these patients n received oxygen supply (l/min) | 23 (22%) | 29 (28%) |
o  1–3 l/min n (%) | 15 (65%) | 24 (83%) |
o  4–6 l/min n (%) | 8 (35%) | 4 (14%) |
o   > 6 l/min n (%) | 0 | 1 (3%) |
 Systolic blood pressure (mmHg) | 137 (80–224) | 137 (94–212) |
 Diastolic blood pressure (mmHg) | 78 (32–123) | 78 (47–111) |
 Heart rate (beats per minute) | 90 (52–150) | 86 (40–144) |
 Temperature (°C) | 37.1 (35.2–39.5) | 37.2 (35.0–39.8) |
 Blood glucose | 6.8 (4.1–19.9) | 6.6 (1.0–22.4) |
 Glasgow coma scale scorea | 15 (9–15) | 15 (14–15) |
Patients´ signs and symptoms upon admission | ||
 Cough | 33 (31%) | 43 (41%) |
 Dyspnoea | 90 (85%) | 85 (81%) |
 Chest pain | 28 (26%) | 28 (27%) |
 Respiration rate > 20 breaths per min | 33 (30%) | 30 (29%) |
 Peripheral saturation < 95% | 30 (28%) | 24 (23%) |
 None of the above | 0 | 0 |
Ultrasound examination already performed in ambulance | 0 | 0 |
 Patients severity score upon admissionb | ||
-  I (Red) | 5 (5%) | 1 (1%) |
-  II (Orange) | 29 (27%) | 36 (34%) |
-   | 49 (46%) | 42 (40%) |
-  III (Yellow) -  IV (Green) | 23 (22%) | 27 (26%) |