Table 1.
Physiological characteristics of the patients—retrospective phase
| General characteristics (n = 201) | |
| Age (mean ± SD) | 61.7 ± 14.5 |
| Sex ratio (F/M) | 62/137 |
| BMI (kg/m2; mean ± SD) | 27 ± 6 |
| SAPS II (mean ± SD) | 51.7 ± 18.8 |
| Chronic respiratory disorder n-(%) | 49 (24.3) |
| Immunodepression n-(%) | 14 (7.1) |
| Admission diagnosis | |
| Respiratory failure n-(%) | 83 (41.1) |
| Cardiovascular failure n-(%) | 56 (27.7) |
| Neurological failure n-(%) | 36 (17.8) |
| Other n-(%) | 27 (13.4) |
| ICU length of stay (day; mean ± SD) | 12.8 ± 14.1 |
| Hospital length of stay (day; mean ± SD) | 28.7 ± 31.4 |
| Overall survival rate n-(%) | 135 (67.8) |
| Respiratory conditions | |
| Respiratory rate (c/min; mean ± SD) | 22 ± 6 |
| SpO2 (%; mean ± SD) | 95 ± 4 |
| PaO2/FIO2 or SpO2/FIO2 (mean ± SD) | 269 ± 126 |
| Invasive MV n-(%) | 128 (63.7) |
| IV sedation n-(%) | 87 (43.3) |
| Paralysing agents n-(%) | 31 (15.4) |
| Tidal volume (mL/kg IBW; mean ± SD) | 7.1 ± 2.0 |
| PEEP (cm H2O; mean ± SD) | 5.3 ± 2.6 |
| FIO2 (%; mean ± SD) | 38 ± 19 |
| Patient/ventilator asynchrony n-(%) | 28 (21.9) |
| Spontaneous breathing n-(%) | 73 (36.3) |
| Standard oxygen | 66 (32.8) |
| Non-invasive ventilation | 7 (3.5) |
| HFNO n-(%) | 5 (2.5) |
| Hemodynamic conditions | |
| Heart rate (b/min; mean ± SD) | 95 ± 22 |
| Mean arterial blood pressure (mmHg; mean ± SD) | 83 ± 16 |
| Lactate (mmol/L; mean ± SD) | 2.8 ± 3.4 |
| Atrial fibrillation | 32 (16.8) |
| Vasopressive agent | 57 (28.4) |
| Hemodynamic instability | 29 (14.4) |
Values are provided as n-(%) or mean ± SD, unless specified otherwise
Respiratory rate is provided as the reference method (chronometric measurement measured over 30 s under spontaneous ventilation or ventilatory rate for patients under ventilatory assistance)
Chronic respiratory disorders are considered for a previous medical history of COPD, OSA and chronic respiratory insufficiency
Oxygenation parameters are provided as PaO2/FIO2 for patients under mechanical ventilation or as SpO2/FIO2 for patients under spontaneous ventilation
Hemodynamic instability was defined as a need for fluid challenge (≥ 500 mL) and/or vasopressive agent increase during the past 2 h of care
BMI, body mass index; SAPS II, Simplified Acute Physiology Score version 2; ICU, intensive care unit; SpO2, pulse oximetry saturation; PaO2, partial pressure of oxygen in arterial blood; FIO2, inspiratory fraction of oxygen; IV, intravenous; PEEP, positive end-expiratory pressure; HFNO, high-flow nasal oxygen