Table 1.

Initial characteristics and outcome of the prone positioned ARDS COVID-19 population (data are expressed as median (interquartile range, IQR) or number (%) as appropriate. After visual assumption of normality, Wilcoxon rank tests were applied for continuous variables. For categorical variables, Fisher’s exact or chi² tests were applied as appropriate)

Variables	n, total available	Total, n(%) or median (IQR) (n = 63)	n, available for ICU survivors (n = 46) *	ICU survivors, n(%) or median (IQR) *	n, available for ICU non-survivors (n = 16)*	ICU non-survivors, n(%) or median (IQR) *	p
Demographic data
Female ratio	63	15 (24%)	46	10 (22%)	16	5 (31%)	0.50
Age (years)	63	64 (56–70)	46	62 (54–69)	16	67 (64–74)	0.045
Weight (kg)	61	89 (75–103)	45	90 (80–103)	15	89 (73–106)	0.68
Body mass index (kg/m²)	61	30 (25–36)	45	30 (26–35)	15	29 (25–46)	0.87
SAPS II	63	42 (31–57)	46	37 (27–57)	16	46 (42–59)	0.030
Medical history
Diabetes mellitus	63	17 (27%)	46	11 (24%)	16	5 (31%)	0.74
Hypertension	63	30 (48%)	46	19 (41%)	16	10 (62%)	0.14
Chronic respiratory disease	63	16 (25%)	46	13 (28%)	16	3 (19%)	0.53
Chronic immunosuppression†	63	5 (8%)	46	2 (4%)	16	3 (19%)	0.10
Chronic Cardiovascular disease	63	16 (25%)	46	12 (26%)	16	3 (19%)	0.74
Chronic kidney disease	63	3 (5%)	46	2 (4%)	16	1 (6%)	1.00
Respiratory parameters
Static compliance (ml/cmH₂O) before first prone positioning	46	33 (23–42)	35	35 (27–44)	11	22 (18–36)	0.036
PaO₂/F_IO₂ ratio before first prone positioning	63	92 (70–117)	46	96 (70–120)	16	86 (64–111)	0.54
Number of prone positioning per patient	63	3 (2–6)	46	3 (2–6)	16	4 (3–8)	0.19
Events in ICU
Vasopressors administered	63	38 (60%)	46	23 (50%)	16	14 (88%)	0.008
VV-ECMO	63	14 (22%)	46	11 (24%)	16	3 (19%)	1.00
Renal replacement therapy	63	8 (13%)	46	4 (9%)	16	4 (25%)	0.19
ICU length of stay (days)	62	19 (14–31)	46	20 (15–32)	16	16 (12–28)	0.24

^*1 patient still in ICU

^†Representing active cancer medical history or chronic immunosuppressor therapies