Table 1. Baseline characteristics and outcome of the 123 patients analyzed.
| Patients | All patients (n = 123) | Bacterial group (n = 19) | Viral group (n = 37) | Unidentified etiology group (n = 67) | p value 1 |
|---|---|---|---|---|---|
| Demographics and underlying diseases | |||||
| Age (years), median (IQR) | 70 (63–80) | 69 (60–75) | 69 (63–75) | 71 (66–81) | 0.2 |
| Sex, male, n (%) | 75 (61) | 13 (68.4) | 18 (48.6) | 44 (65.7) | 0.2 |
| Mc Cabe, median (IQR) | 1 (1–2) | 1 (1–2) | 1 (1–2) | 1 (1–1) | 0.39 |
| Immunocompromized patients, n (%) | 25 (20.3) | 4 (21.1) | 8 (21.6) | 13 (19.4) | 0.95 |
| HIV, n (%) | 1 (0.8) | 0 (0) | 1 (2.7) | 0 (0) | 0.45 |
| Daily corticosteroid therapy, n (%) | 4 (3.3) | 1 (5.3) | 1 (2.7) | 2 (3) | 0.81 |
| Other immunosuppressive therapy, n (%) | 1 (0.8) | 0 (0) | 0 (0) | 1 (1.5) | 0.99 |
| Solid organ transplantation, n (%) | 2 (1.6) | 0 (0) | 1 (2.7) | 1 (1.5) | 0.99 |
| Active cancer, n (%) | 9 (7.3) | 1 (5.3) | 4 (10.8) | 4 (6) | 0.63 |
| Malignant hemopathy, n (%) | 8 (6.5) | 2 (10.5) | 1 (2.7) | 5 (7.5) | 0.42 |
| Active smoker, n (%) | 36 (29.3) | 7 (36.8) | 15 (40.5) | 14 (20.9) | 0.08 |
| Diabetes Mellitus, n (%) | 34 (27.6) | 4 (21) | 13 (35.1) | 17 (25.4) | 0.47 |
| COPD, n (%) | 43 (35) | 5 (26.3) | 19 (51.3) | 19 (28.4) | 0.06 |
| Asthma, n (%) | 8 (6.5) | 0 (0) | 2 (5.4) | 6 (9) | 0.55 |
| Chronic respiratory failure 2, n (%) | 28 (22.8) | 4 (21.5) | 15 (40.5) | 9 (13.4) | 0.008 |
| Ventilatory support at home, n (%) | 21 (17.1) | 5 (26.3) | 6 (16.2) | 10 (14.9) | 0.54 |
| Chronic heart failure 3, n (%) | 30 (23.4) | 4 (21) | 11 (29.7) | 15 (22.4) | 0.71 |
| Antibiotics before ICU admission, n (%) | 66 (53.7) | 8 (42.1) | 20 (54) | 38 (56.7) | 0.54 |
| Characteristics at ICU admission | |||||
| Glasgow coma scale, median (IQR) | 15 (14–15) | 14 (5–15) | 15 (15–15) | 15 (14–15) | 0.052 |
| Temperature (°c), median (IQR) | 37.3 (36.8–38) | 37.2 (36.5–37.7) | 37.2 (37.1–37.5) | 37.3 (36.8–38) | 0.45 |
| Respiratory rate (breath/min), median (IQR) | 24 (20–30) | 28 (20–34) | 22 (19–25) | 25 (21–31) | 0.07 |
| Invasive mechanical ventilation, n (%) | 14 (11.4) | 5 (26.3) | 3 (8.1) | 6 (9) | 0.13 |
| PaO2/FiO2 (mmHg), median (IQR) | 147 (93–236) | 92 (85–177) | 210 (125–276) | 147 (93–230) | 0.01 |
| Lactate (mmol/L), median (IQR) | 1.4 (1–2) | 1.8 (1–2.5) | 1.3 (0.8–1.8) | 1.4 (1.1–2) | 0.12 |
| CRP (mg/L), median (IQR) | 123 (66–219) | 133 (66–320) | 121 (57–191) | 137 (72–205) | 0.67 |
| Procalcitonin (μg/L), median (IQR) | 0.78 (0.28–3.4) | 6.7 (0.51–12) | 0.52 (0.18–1.3) | 0.88 (0.29–3.25) | 0.008 |
| White blood cells (G/L), median (IQR) | 10.6 (7.4–14.4) | 10.1 (5.9–16) | 9 (6.8–11) | 11.7 (8.4–15.3) | 0.027 |
| Neutrophils (G/L), median (IQR) | 8 (6–12.5) | 10 (3.8–14.2) | 8 (4.5–9) | 9 (6–13.5) | 0.47 |
| Lymphocytes (G/L), median (IQR) | 0.7 (0.4–1.3) | 0.4 (0.3–1.3) | 0.9 (0.5–1.3) | 0.7 (0.5–1.2) | 0.08 |
| PSI score, median (IQR) | 121 (89–142) | 131 (91–156) | 116 (84–145) | 118 (89–141) | 0.47 |
| SAPS II score, median (IQR) | 45 (38–62) | 64 (39–80) | 44 (36–51) | 47 (38–62) | 0.1 |
| SOFA score, median (IQR) | 4 (2–7) | 6 (4–11) | 3 (2–6) | 4 (2–6) | 0.013 |
| Vasopressors, n (%) | 38 (30.9) | 11 (57.9) | 12 (32.4) | 25 (37.3) | 0.16 |
| HCAP, n (%) | 20 (16.3) | 1 (5.3) | 7 (18.9) | 12 (17.9) | 0.44 |
| During hospital stay | |||||
| Invasive mechanical ventilation, n (%) | 39 (31.7) | 11 (57.9) | 10 (27) | 18 (26.9) | 0.046 |
| ARDS, n (%) | 17 (13.8) | 7 (36.8) | 3 (8.1) | 7 (10.4) | 0.01 |
| Length of invasive mechanical ventilation (d), median (IQR) | 6 (4–13) | 5 (3–7) | 10 (5–17) | 8 (4–16) | 0.33 |
| Vasopressors, n (%) | 103 (83.7) | 13 (68.4) | 33 (89.2) | 57 (85.1) | 0.1 |
| Renal replacement therapy, n (%) | 13 (10.6) | 2 (10.5) | 4 (10.8) | 7 (10.5) | 1 |
| Outcomes | |||||
| ICU stay (d), median (IQR) | 6 (4–11) | 7 (3–11) | 7 (5–13) | 6 (4–10) | 0.44 |
| Hospital stay (d), median (IQR) | 15 (10–23) | 11 (6–21) | 17 (10–22) | 16 (10–23) | 0.29 |
| ICU mortality, n (%) | 15 (12.2) | 6 (31.6) | 5 (13.5) | 4 (6) | 0.01 |
| Day 28 mortality, n (%) | 21 (17) | 8 (42.1) | 6 (16.2) | 7 (10.5) | 0.009 |
| Hospital mortality, n (%) | 27 (22) | 8 (42.1) | 7 (18.9) | 12 (17.9) | 0.07 |
| One-year mortality, n (%) | 40 (32.5) | 11 (57.9) | 10 (27.0) | 19 (28.4) | 0.046 |
Data are presented as mean (percentage) or as median (interquartile range).
ARDS = Acute respiratory distress syndrome, COPD = Chronic obstructive pulmonary disease, HCAP = Health care-associated pneumonia, HIV = Human immunodeficiency virus, ICU = Intensive care unit, IQR = Interquartile range, PSI = Pneumonia severity index, SAPSII = Simplified acute physiological score, SOFA = Sepsis-related organ failure assessment.
1 between the 3 groups.
2 Chronic respiratory failure was defined as the requirement of long-term oxygen therapy or chronic hypoxemia (defined as chronic arterial oxygen pressure lower than 70mmHg).
3 Chronic heart failure was defined as a physician’s diagnosis in the medical record.