Table 4.

Factors associated with the occurrence of pressure injuries (univariate logistic regression)

Variables	Patients without pressure injury (n = 60) n/N (%) or med (Q1–Q3)	Patients with at least one pressure injury (n = 21) n/N (%) or med (Q1–Q3)	OR (95% CI)	p
Sex, male	40/60 (67)	18/21 (86)	3.00 (0.88–13.88)	0.081
Age, years	60 (51–68)	58 (52–63)	1.00 (0.96–1.05)	0.91
BMI, kg/m2	30 (27–37)	33 (29–36)	0.99 (0.94–1.01)	0.54
Type 2 diabetes	13/60 (22)	7/21 (33)	1.43 (0.50–3.88)	0.49
History of cardiovascular disease*	7/60 (12)	1/21 (5)	0.38 (0.02–2.32)	0.33
History of respiratory disease**	6/60 (10)	2/21 (10)	0.95 (0.13–4.53)	0.95
SAPS II score	36 (30–48)	39 (33–42)	0.99 (0.95–1.02)	0.43
PaO2/FiO2 ratio before first pronation session, mmHg	82 (68–114)	88 (75–99)	1.00 (0.98–1.01)	0.65
ECMO	12/60 (20)	5/21 (24)	1.25 (0.35–3.96)	0.71
Nitric oxide	25/60 (42)	9/21 (43)	1.05 (0.38–2.86)	0.92
At least one proning session with catecholamines	28/60 (47)	9/21 (43)	0.86 (0.31–2.33)	0.76
Duration of mechanical ventilation, days	14 (9–25)	29 (22–34)	1.01 (1.00–1.02)	0.12
ICU length of stay, days	17 (11–26)	29 (19–34)	1.05 (1.01–1.10)	0.021
Median duration of each proning sessions, h	40 (35–43)	36 (32–40)	0.96 (0.89–1.03)	0.26
Cumulated duration of all proning sessions, days***	3 (2–5)	6 (4–8)	1.33 (1.11–1.63)	0.0015

BMI, Body Mass Index; SAPS II, simplified acute physiology score; ECMO, Extracorporeal Membrane Oxygenation; PaO₂, partial pressure of dioxide in arterial blood; FiO₂, fraction of inspired oxygen; ICU, intensive care unit; PP, prone positioning

***This duration is the added duration of all PP sessions for each patient *chronic heart failure, ischemic heart disease or peripheral arterial disease; **chronic obstructive pulmonary disease or Asthma

Bold formatting of p value indicates a statistically significant value