Table 1. Baseline Characteristics of Patients.
| No. (%) (N = 740) | |
|---|---|
| Age, mean (SD), y | 68.2 (10.9) |
| Age >65 y | 435 (58.8) |
| Women | 274 (37.0) |
| Men | 466 (63.0) |
| BMI, mean (SD) | 25.7 (6.7) |
| Spirometry, mean (SD), No. | 677a |
| FEV1, % predicted | 0.58 (0.96) |
| FEV1/FVC, % | 53.0 (16.7) |
| Active tobacco use, No. | 736 |
| Current active smokers | 263 (38.7) |
| Ex-smokers | 416 (61.3) |
| Pack-year, mean (SD) | 46.4 (26.4) |
| No. | 679 |
| GOLD stages, No.b | 675 |
| I (mild) | 86 (12.7) |
| II (moderate) | 239 (32.3) |
| III (severe) | 259 (38.4) |
| IV (very severe) | 91 (12.3) |
| No. of previous exacerbations in the past year, median (IQR) | 1.0 (0.0-3.0) |
| Venous thromboembolism risk factors | |
| Prolonged immobilization | 133 (18.0) |
| Familial history | 66 (9.5) |
| Cancer in the past 2 y | 59 (8.0) |
| Previous | 55 (7.4) |
| Surgery | 24 (3.3) |
| Trauma | 15 (2.0) |
| Clinical probability of pulmonary embolism (revised Geneva score)c | |
| Low | 139 (18.8) |
| Intermediate | 584 (78.9) |
| High | 17 (2.3) |
| Pulmonary embolism suspectedd | 299 (40.4) |
| Alternative diagnosis to pulmonary embolism more likelye | 567 (76.6) |
| Severity of COPD exacerbation at hospital admission | |
| MRC dyspnea scale during exacerbation, No.f | 725 |
| Normalg | 7 (0.9) |
| Stage | |
| I (dyspnea at strenuous exercise) | 15 (2.0) |
| II (dyspnea at moderate exercise) | 52 (7.0) |
| III (dyspnea at mild exercise) | 88 (11.9) |
| IV (dyspnea during short walk) | 179 (24.2) |
| V (dyspnea at rest) | 384 (51.9) |
| Heart rate >110/min | 158 (21.4) |
| Systolic blood pressure <100 mm Hg | 19 (2.6) |
| Use of accessory inspiratory muscles | 244 (33.0) |
| Expiratory use of abdominal muscles | 150 (20.3) |
| Cyanosis | 59 (8.0) |
| Neurological impairment | 35 (4.7) |
| Bilateral lower limb edema | 118 (15.9) |
| Oxygen therapy required | 401 (54.3) |
Abbreviations: BMI, body mass index, calculated as weight in kilograms divided by height in meters squared; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in the first second of expiration; FVC, forced vital capacity; GOLD, Global Initiative of Chronic Obstructive Lung Disease; IQR, interquartile range; MRC, Medical Research Council.
Spirometry data were not available for 63 patients; however, all of these patients had a previous assessment of COPD by a pulmonologist.
GOLD stages: stage I, FEV1, more than 80% predicted; stage II, 50% FEV1, less than 80% predicted; stage III, 30% FEV1, less than 50% predicted; and stage IV, FEV1 less than 30% predicted.
Revised Geneva score (range, 0-19): low probability (range, 0-3); intermediate probability (range, 4-10); high probability (≥11).
Suspicion of pulmonary embolism was assessed by a senior physician once the patient arrived at the emergency department based on medical history, physical examination, and physician’s judgment and before any diagnostic tests for pulmonary embolism were ordered.
Assessment of an alternative diagnosis to pulmonary embolism more or less likely was performed by a senior physician once the patient arrived at the emergency department based on medical history, physical examination, and physician’s judgment and before any diagnostic tests for pulmonary embolism were ordered.
MRC scale: grade 1, not troubled by breathlessness except on strenuous exercise; grade 2, short of breath when hurrying on a level surface or walking up a slight hill; grade 3, walks slower than most people on a level surface, stops after a mile or so, or stops after 15 minutes walking at own pace; grade 4, stop for breath after walking about 100 yards or after a few minutes on a level surface; and grade 5, too breathless to leave the house or breathless when undressing.
Five patients had productive cough, 1 had tachycardia, and 1 had chest pain.