Table 4.
Non-obese patients (n = 44) | Obese patients (n = 29) | p value | |
---|---|---|---|
Demographic characteristics | |||
Age (years) | 60.5 (56–64.5) | 61 (54–64) | 0.78 |
Sex (male) | 35 (79.5%) | 21 (72.4%) | 0.48 |
BMI (kg/m2) | 26.45 (25.35–27.8) | 33.5 (31–35.8) | < 0.001 |
First wave, n (%) | 16 (36) | 7(24) | 0.27 |
Severity scores | |||
SAPS II | 30 (25.5–36) | 29 (25.5–34.5) | 0.60 |
SOFA | 3 (2–4) | 3 (2–4) | 0.95 |
Charlson score | 2 (2–3) | 2 (1–3) | 0.58 |
ICU therapy before ECMO | |||
High-flow nasal O2, n (%) | 38 (86) | 26 (90) | 0.68 |
Duration (days) | 5 (1–7) | 2 (1–6) | 0.08 |
Non-invasive ventilation, n (%) | 18 (41) | 17 (59) | 0.14 |
Duration (days) | 4 (0–6) | 1 (0.5–3) | 0.15 |
Prone positioning, n (%) | 44 (100) | 28 (97) | 0.21 |
Number of sessions | 2 (1–5) | 2 (1.5–4) | 0.88 |
Dexamethasonea, n (%) | 28 (65) | 19 (65.5) | 0.97 |
Time from first symptoms to intubation, days | 11 (7.5–15) | 10 (7–13) | 0.1 |
Time from hospitalization to intubation, days | 5.5 (1–9) | 4 (1–6) | 0.06 |
Time from ICU admission to intubation, days | 4 (1–7) | 2 (0–4) | 0.048 |
Predictive survival scores under ECMO | |||
RESP score | 1 (0–2) | 1 (1–4) | 0.09 |
ECMO net score | 5.5 (4–6) | 4.5 (4–6) | 0.73 |
PRESERVE score | 4 (3–5) | 2 (1–3) | < 0.001 |
SOFA before ECMO | 8 (4–9) | 5 (4–8) | 0.58 |
MV duration before ECMO, days | 7 (3–10.5) | 5 (3–8) | 0.35 |
Time from ICU admission to ECMO, days | 11 (8–14.5) | 9 (4–11) | 0.02 |
Ventilation parameters before ECMO | |||
FiO2 | 100 | 100 | 0.58 |
Plateau pressure, cmH2O | 28 (25–30) | 29 (25–31) | 0.92 |
Positive end-expiratory pressure, cmH2O | 10 (8–12) | 14 (10–15) | < 0.001 |
Driving pressure | 17 (14–20) | 14.5 (12–20) | 0.1 |
Tidal volume, mL/kg predicted bodyweight | 5.7 (5–6,21) | 5.85 (5.6–6.2) | 0.30 |
Respiratory rate, breath per minute | 26 (23–30) | 26.5 (20–30) | 0.83 |
Mechanical power, J/min | 17.7 (14.07–22.22) | 20.3 (17.7–29.7) | 0.06 |
Ventilatory ratio | 2.42 (1.55–2.90) | 2.34 (1.87–2.75) | 0.81 |
Static compliance, mL/cmH2O | 23 (15.5–27.33) | 26.25 (21–39.09) | 0.07 |
Last blood-gas values before ECMO | |||
PaO2/FiO2 ratio | 71.5 (64–84) | 75 (62–81) | 0.93 |
pH | 7.35 (7.26–7.38) | 7.31 (7.26–7.39) | 0.49 |
PaCO2, mmHg | 57.5 (50.5–65.5) | 60 (52–66) | 0.99 |
73 patients were included in this analysis, 3 patients were excluded because of missing data for BMI
Data are expressed as median (interquartiles) or number (percentage, %)
Obesity was defined by a BMI superior or equal to 30 g/m2
Mechanical power (MP) was calculated as follows: MP = 0.098 × tidal volume × respiratory rate × (peak pressure − ½ × driving pressure). Driving pressure was defined as plateau pressure minus positive end-expiratory pressure. Static compliance was defined as tidal volume divided by driving pressure
BMI: body mass index; NSAID: non-steroidal anti-inflammatory drug; ACE: angiotensin converting enzyme; ARB: angiotensin II receptor blockers; SAPS II: Simplified Acute Physiology score; SOFA: Sequential Organ Function; ICU: intensive care unit; ECMO: extra-corporeal membrane oxygenation; MV: mechanical ventilation; O2: oxygen; PaO2: partial pressure of arterial oxygen; FiO2: fraction of Inspired oxygen; PaCO2: partial pressure of arterial carbon dioxide; PaO2/FiO2: ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen; RESP score [17]: Respiratory Extracorporeal Membrane Oxygenation Survival Prediction Score; ECMO net score [18]: score from the Italian ECMO network; PRESERVE score [19]: PRedicting dEath for SEvere ARDS on VV-ECMO score
aPatients receiving dexamethasone 6 mg per day or equivalent dose of corticosteroids