Table 2. Pleural fluid and microbiology characteristics (first thoracentesis).
| Total (n = 79) | Success (n = 64) | Failure (n = 15) | p | ||
| Pleural fluid analysis | |||||
| Frank pus (empyema), n (%) | 52 (66%) | 39 (61%) | 13 (87%) | 0.073 | |
| Protein, g/L (IQR)(†) | 46 (41–50) | 45 (41–50) | 47 (34–48) | 0.534 | |
| LDH, IU/L (IQR)(†) | 4336 (1721–17810) | 3932 (1134–14872) | 17284 (9452–26068) | 0.079 | |
| pH (IQR)(†) | 7.19 (7.0–7.5) | 7.10 (7.0–7.5) | 7.50 (7.15–7.75) | 0.422 | |
| Glucose level, mmol/L (IQR)(†) | 1.0 (0.1–3.8) | 1.0 (0.1–4.1) | 0.6 (0.1–1.1) | 0.716 | |
| Micro-organisms observed on Gram staining, n (%) | 41 (52%) | 28 (44%) | 13 (87%) | 0.003 | |
| Positive culture, n (%) | 36 (46%) | 26 (41%) | 10 (67%) | 0.088 | |
| Positive culture on aerobic atmosphere, n (%) | 25 (32%) | 20 (31%) | 5 (36%) | 0.759 | |
| Positive culture on anaerobic atmosphere, n (%) | 16 (20%) | 11 (17%) | 5 (36%) | 0.036 | |
| Polymicrobial culture, n (%) | 12 (15%) | 8 (12.5%) | 4 (27%) | 0.227 | |
| Microbiological characteristics | |||||
| Positive blood culture, n (%) | 7 (9%) | 5 (8%) | 2 (14%) | 0.612 | |
| Positive pneumococcal urine antigen, n (%) | 7 (37%) | 5 (38.5%) | 2 (33%) | 1.000 | |
| Identified bacteria | |||||
| Anaerobic bacteria, n (%) | 16 (20%) | 11 (17%) | 5 (33%) | 0.171 | |
| Streptococcus milleri, n (%) | 15 (19%) | 12 (19%) | 3 (20%) | 1.000 | |
| Streptococcus pneumoniae, n (%) | 12 (15%) | 9 (14%) | 3 (20%) | 0.689 | |
| Other Streptococcus sp., n (%) | 8 (10%) | 5 (8%) | 3 (20%) | 0.171 | |
| Staphylococcus aureus, n (%) | 3 (4%) | 2 (3%) | 1 (7%) | 0.473 | |
| Gram-negative bacteria, n (%) | 3 (4%) | 2 (3%) | 1 (7%) | 0.473 | |
Quantitative variables are indicated as median (IQR), qualitative variables are indicated as numbers (%). (†) Variables with >10% of missing data.