Table 6. Characteristics of patients with COPD who had Pseudomonas aeruginosa pneumonia and those patients with COPD with pneumonia non-caused by P. aeruginosa.
| Variable | Patients with P. aeruginosa pneumonia [n = 33], n (%) | Patients without P. aeruginosa pneumonia [n = 950], n (%) | p value |
| Demographic data | |||
| Age, median (IQR), years | 74 (68.25–77) | 74 (67–80) | 0.108 |
| >65 years old | 27 (84.4) | 758 (79.8) | 0.524 |
| Male sex | 31 (93.9) | 859 (90.4) | 0.497 |
| Current smoker | 7 (21.2) | 245 (26.0) | 0.066 |
| Ex-smoker | 24 (72.7) | 511 (54.1) | 0.066 |
| Alcohol abuse | 6 (18.2) | 189 (20.1) | 0.499 |
| Influenza vaccine (season) | 22 (81.5) | 605 (71.1) | 0.240 |
| Pneumococcal vaccine, 5 years | 11 (44) | 215 (26.3) | 0.049 |
| Comorbid conditions | |||
| Diabetes mellitus | 9 (27.3) | 207 (21.8) | 0.455 |
| Chronic heart disease | 5 (15.2) | 260 (27.4) | 0.120 |
| Neoplastic disease | 4 (12.1) | 108 (11.4) | 0.894 |
| Chronic renal disease | 1 (3.0) | 66 (6.9) | 0.380 |
| Chronic liver disease | 5 (15.2) | 58 (6.1) | 0.037 |
| Cerebrovascular disease | 2 (6.1) | 67 (7.1) | 0.826 |
| Cognitive deficit (dementia) | 0 (0) | 38 (4.0) | 0.241 |
| Statin use1 | 1 (5.6) | 88 (26.9) | 0.044 |
| Chronic oral steroids | 7 (21.9) | 95 (10.0) | 0.031 |
| Pre-hospital antibiotics | 6 (18.8) | 175 (19.1) | 0.958 |
| Prior antibiotic treatment | 10 (30.3) | 217 (22.8) | 0.342 |
| Prior hospitalization2 | 4 (13.8) | 87 (12.2) | 0.802 |
| Clinical features at presentation | |||
| Fever (≥38.0°C) | 7 (22.6) | 430 (45.7) | 0.011 |
| Acute onset of disease | 11 (33.3) | 435 (45.9) | 0.155 |
| Cough | 31 (93.9) | 828 (87.3) | 0.259 |
| Expectoration | 30 (90.9) | 704 (74.3) | 0.030 |
| Purulent sputum | 25 (83.3) | 525 (63.0) | 0.023 |
| Dyspnea | 29 (87.9) | 736 (77.6) | 0.163 |
| Tachypnea (≥30 breaths·min−1) | 14 (51.9) | 415 (48.4) | 0.726 |
| Pleuritic chest pain | 16 (48.5) | 403 (42.5) | 0.492 |
| Impaired consciousness | 4 (12.1) | 131 (13.8) | 0.781 |
| Septic shock | 4 (12.1) | 63 (6.6) | 0.219 |
| Diarrhea, vomiting | 2 (6.1) | 83 (8.7) | 0.590 |
| Headache | 5 (15.2) | 91 (9.6) | 0.290 |
| Arthromyalgias | 5 (15.2) | 134 (14.1) | 0.869 |
| Laboratory and radiographic findings at presentation | |||
| Respiratory failure (PaO2/FiO2<300 or PaO2<60 mmHg) | 20 (76.9) | 604 (76.2) | 0.929 |
| Multilobar pneumonia | 9 (28.1) | 246 (26.0) | 0.074 |
| Pleural effusion | 3 (9.4) | 131 (13.8) | 0.471 |
| Empyema | 0 (0) | 21 (2.2) | 0.388 |
| High-risk PSI classes3 | 21 (63.6) | 699 (73.8) | 0.193 |
COPD, chronic obstructive pulmonary disease; IQR, interquartile range; PSI, pneumonia severity index.
1
Data available only for 345 patients. 2Data available for 740 patients. 3Patients were stratified into the following risk classes according to the PSI score: low risk (≤90 points, classes I, II, and III) and high risk (>90 points, classes IV and V).