Table 1.
Patients’ characteristics on the day of CT scan
| Parameter | All (N = 42) | Non-recruiters (N = 32) | Recruiters (N = 10) | p |
|---|---|---|---|---|
| Age, median [IQR], years | 63 [58–67] | 64 [58–67] | 65 [58–66] | 0.782 |
| Predicted body weight, median [IQR], kg | 70 [61–73] | 70 [61–71] | 72 [70–75] | 0.102 |
| Body mass index, median [IQR], kg/m2 | 28 [25–31] | 28 [25–31] | 28 [26–29] | > 0.999 |
| Male sex, N (%) | 33 (78.6) | 24 (75.0) | 9 (90.0) | 0.416 |
| Time from symptoms onset, median [IQR], days | 23 [13–28] | 23 [13–29] | 20 [17–25] | 0.631 |
| Time from first confirmed swab, median [IQR], days | 15 [10–23] | 17 [9–24] | 13 [10–20] | 0.738 |
| Time from start of invasive ventilation, median [IQR], days | 9 [4–13] | 9 [4–14] | 7 [3–11] | 0.328 |
| Comorbidities | ||||
| Hypertension, N (%) | 24 (57.1) | 18 (56.3) | 6 (60.0) | > 0.999 |
| Cardiovascular disease, N (%) | 5 (11.9) | 3 (9.4) | 2 (20.0) | 0.577 |
| Smoker, N (%) | 1 (2.4) | 1 (3.1) | 0 (0.0) | > 0.999 |
| Former smoker, N (%) | 5 (11.9) | 5 (15.6) | 0 (0.0) | 0.315 |
| Chronic kidney failure, N (%) | 1 (2.4) | 1 (3.1) | 0 (0.0) | > 0.999 |
| Diabetes, N (%) | 5 (11.9) | 5 (15.6) | 0 (0.0) | 0.315 |
| Obesity, N (%) | 11 (26.2) | 8 (25.0) | 3 (30.0) | > 0.999 |
| Ventilator settings | ||||
| Tidal volume, median [IQR], ml/kg PBW | 7.2 [6.3–7.9] | 7.3 [6.3–8.0] | 6.9 [6.2–7.6] | 0.494 |
| Respiratory rate, median [IQR], 1/min | 19 [17–25] | 18 [16–25] | 22 [19–24] | 0.273 |
| PEEP, median [IQR], cmH2O | 10 [8–12] | 10 [8–12] | 10 [8–13] | 0.988 |
| Plateau pressure, median [IQR], cmH2O | 24 [21–28] | 24 [22–28] | 24 [20–27] | 0.782 |
| FiO2, median [IQR] | 0.60 [0.50–0.70] | 0.68 [0.60–0.70] | 0.55 [0.50–0.65] | 0.138 |
| Respiratory system compliance, median [IQR], ml/cmH2O | 36 [29–50] | 35 [29 –50] | 40 [35–45] | 0.631 |
| Blood gas analysis | ||||
| pH, median [IQR] | 7.43 [7.36–7.48] | 7.42 [7.35–7.47] | 7.46 [7.43–7.49] | 0.052 |
| PaO2, median [IQR], mmHg | 73 [64–91] | 73 [65–92] | 69 [64–86] | 0.475 |
| PaCO2, median [IQR], mmHg | 48 [43–56] | 51 [44–58] | 41 [36–51] | 0.052 |
| PaO2/FiO2, median [IQR], mmHg | 123 [100–160] | 123 [98–155] | 139 [103–205] | 0.494 |
| Lactate, median [IQR], mmol/L | 1.1 [0.8–1.8] | 1.2 [0.8–2.0] | 1.1 [1.0–1.6] | 0.782 |
| Ventilatory ratio | 1.8 [1.5–2.4] | 2.0 [1.5–2.6] | 1.8 [1.6–1.8] | 0.494 |
| Blood analyses | ||||
| D-dimer, median [IQR], ug/L | 1647 [1048–4426] | 1618 [938–4195] | 1754 [1304–4426] | 0.695 |
| C reactive protein, median [IQR], mg/L | 42 [17–108] | 44 [19–110] | 41 [17–60] | 0.531 |
| Procalcitonin, median [IQR], ug/L | 0.21 [0.09–0.97] | 0.25 [0.09–1.44] | 0.21 [0.07–0.33] | 0.423 |
| Interleukin-6, median [IQR], ng/L | 127 [55–387] | 134 [55–339] | 112 [16–453] | 0.873 |
| Creatinine, median [IQR], mg/dL | 0.9 [0.7–1.7] | 0.9 [0.6–1.7] | 1.0 [0.7–1.5] | 0.652 |
| Hemodynamics | ||||
| Heart rate, median [IQR], 1/min | 82 [70–100] | 85 [72–103] | 73 [68–90] | 0.494 |
| Mean arterial pressure, median [IQR], mmHg | 82 [73–93] | 83 [77–102] | 80 [73–85] | 0.551 |
| Ventilator-associated pneumonia, N (%) | 12 (28.6) | 11 (34.3) | 1 (10.0) | 0.233 |
Gas exchange and ventilator settings measured at the clinical PEEP level
IQR interquartile range, PBW predicted body weight, PEEP positive end-expiratory pressure, ICU intensive care unit