Baseline characteristics of the 101 patients randomised to the control or procalcitonin group
| Characteristic | Control group | Procalcitonin group |
| Subjects n | 50 | 51 |
| Age yrs (min–max) | 59 (18–83) | 53 (21–88) |
| Male | 37 (74) | 38 (75) |
| Admission category | ||
| Medical | 26 (52) | 27 (53) |
| Emergency surgery | 20 (40) | 23 (45) |
| Elective surgery | 3 (6) | 1 (2) |
| Origin | ||
| Home | 26 (52) | 35 (69) |
| Other institution | 24 (48) | 16 (31) |
| Coexisting illnesses | ||
| Coronary artery disease | 4 (8) | 9 (18) |
| Hypertensive heart disease | 8 (16) | 8 (16) |
| Congestive heart failure | 27 (54) | 21 (41) |
| Renal dysfunction | 7 (14) | 9 (18) |
| Liver disease | 3 (6) | 4 (8) |
| Diabetes mellitus | 13 (26) | 10 (20) |
| Chronic obstructive pulmonary disease | 11 (22) | 8 (16) |
| Neoplastic disease | 5 (10) | 3 (6) |
| Substance abuse | 8 (16) | 5 (10) |
| Reason for mechanical ventilation | ||
| Cardiovascular failure | 16 (32) | 16 (31) |
| Acute respiratory failure | 29 (58) | 24 (47) |
| Trauma | 13 (26) | 20 (39) |
| Neurologic failure | 12 (24) | 18 (35) |
| Sepsis | 15 (30) | 10 (20) |
| Miscellaneous | 4 (8) | 6 (12) |
| Duration of MV before VAP onset days | 6 (4–10) | 6 (3–7) |
| Antimicrobial therapy 14 days before VAP | 41 (82) | 35 (69) |
| Duration of antimicrobial therapy 14 days before VAP days | 5 (1–9.5) | 3 (0–8) |
| Criteria for VAP diagnosis | ||
| Infiltrate on chest radiograph | 50 (100) | 51 (100) |
| Fever ≥38°C | 30 (60) | 26 (51) |
| Leukocytosis or leukopenia | 33 (66) | 32 (63) |
| Purulent tracheal secretions | 28 (56) | 31 (61) |
| CPIS ≥6 | 47 (94) | 43 (84) |
| Fi,O2/Pa,O2<200 | 24 (48) | 25 (50) |
| Shock | 12 (24) | 11 (22) |
| Positive blood cultures within 48 h | 18 (36) | 14 (28) |
| Diagnostic score# | ||
| SAPS II | 45±14 | 42±13 |
| ODIN | 2.3±1.0 | 1.9±0.9 |
| SOFA | 8.2±3.4 | 7.3±3.4 |
| Clinical and laboratorial findings | ||
| Body temperature °C | 38.2±1.2 | 37.9±0.9 |
| Heart rate bpm | 91±23 | 88±18 |
| Mean arterial pressure mmHg | 79±16 | 81±16 |
| Sa,O2 % | 97±3 | 96±4 |
| Pa,O2/Fi,O2 mmHg | 203±97 | 218±114 |
| Leukocyte count μL | 13.3±5.9 | 12.0±6.6 |
| Procalcitonin μg·L−1 | 0.73 (0.21–2.36) | 0.66 (0.22–2.69) |
Data are presented as n (%), median (interquartile range) or mean±sd, unless otherwise stated. MV: medical ventilation; VAP: ventilator-associated pneumonia; CPIS: clinical pulmonary infection score; Fi,O2: inspiratory oxygen fraction; Pa,O2: arterial oxygen tension; SAPS II: simplified acute physiologic score II; ODIN: organ dysfunction and/or infection; SOFA: sepsis-related organ failure assessment; Sa,O2: arterial oxygen saturation. There were no other significant differences between the groups with respect to any other characteristic. Because of rounding; percentages may not sum to 100. The conversion factor for procalcitonin is as follows: μg·L−1 × 0.161: nmol·L−1. #: ODIN p = 0.042.