Table 1. Characteristics of study patients at ICU admission.

Variables	Survivors (n=63)	Nonsurvivors (n=30)	P value
Age, years	58 [40, 67]	62 [52, 71]	0.046
Male gender	35 [56]	22 [73]	0.100
SAPS II	57 [48, 71]	49 [42, 74]	0.399
SOFA score	8 [5, 10]	8 [5, 11]	0.843
Respiratory system	2 [2, 3]	3 [2, 4]	0.045
Nervous system	2 [1, 4]	3 [1, 3]	0.770
Cardiovascular system	0 [1, 4]	0 [0, 4]	0.970
Liver	0 [0, 0]	0 [0, 1]	0.093
Coagulation	0 [0, 0]	0 [0, 1]	0.340
Kidneys	0 [0, 2]	0 [0, 3]	0.940
Comorbidities
Diabetes	16 [25]	9 [30]	0.640
COPD	7 [11]	8 [27]	0.057
Cardiac failure	6 [10]	5 [17]	0.319
Cirrhosis	4 [6]	4 [13]	0.261
Chronic kidney failure	5 [8]	2 [7]	0.828
Immunodeficiency	17 [27]	10 [33]	0.528
Location before ICU admission			0.549
Home	26 [41]	9 [30]
Other wards	25 [40]	15 [50]
Other ICUs	12 [19]	6 [20]
Cause for ICU admission
Acute exacerbation of COPD	4 [6]	2 [7]	0.954
Respiratory acute failure	11 [17]	4 [13]	0.767
Community-acquired pneumonia	9 [14]	6 [20]	0.484
Nosocomial pneumonia	11 [17]	6 [20]	0.767
ARDS	7 [11]	1 [3]	0.430
Cardiac arrest	5 [8]	2 [7]	0.828
Neurologic failure	20 [32]	5 [17]	0.142
Poisoning	5 [8]	0 [0]	0.171
Septic shock	14 [22]	8 [27]	0.637
Cellulitis	3 [5]	3 [10]	0.383
Prior antimicrobial treatment	56 [89]	27 [90]	0.872
Percentage of time spent with hyperoxemia, mean ± SD	44±21	48±23	0.590
Results of blood gases
PaO2, mmHg	116 [85, 173]	112 [80, 172]	0.493
PaO2 >120 mmHg	31 [49]	13 [43]	0.551
PaO2/FiO2	192 [133, 287]	171 [118, 252]	0.410

Data are presented as n [%] or median [interquartile range], unless otherwise indicated. SAPS, simplified acute physiology score; SOFA, sequential organ failure assessment; COPD, chronic obstructive pulmonary disease; ICU, intensive care unit; ARDS, acute respiratory distress syndrome; PaO2, partial pressure of arterial oxygen; FiO₂, fraction of inspired O₂.