Table 2 Baseline characteristics

Percentage of total cohort

100

22

71

5

2

Median (IQR) age, years

76 (64–81)

69 (63–77)

78 (67–82)

66 (54–70)

64

Female sex, n (%)

41 (45)

8 (40)

29 (45)

4 (80)

0 (0)

Hypernatraemia development during hospitalisation, n (%)

58 (63)

20 (100)

35 (54)

1 (20)

2 (100)

SAPS II score^b

49 (41–59)

45 (38–57)

51 (42–59)

31 (20–58)

60

 Plasma sodium, mmol/L

159 (157–161)

157 (156–160)

160 (158–161)

158 (157–159)

157

 Copeptin, pmol/L

51.76 (31.71–78.71)

54.95 (35.01–71.70)

53.19 (34.39–85.95)

3.39 (1.99–3.90)

77.75

 Plasma osmolality, mmol/kg

347.5 (331–371.8)

361.5 (342.2–366.5)

349 (331–382)

346 (340–351)

337

 Urine osmolality, mmol/L

510 (413–647)^c

510 (462–819)

546 (463–647)

249 (216.3–280.8)

284.5

 Urine sodium, mmol/L

60 (28–96.5)

78 (61–107)

49.6 (28.3–102.4)

33 (31–34)

77

 Creatinine, μmol/L

121 (82–177.3)

129.5 (91–188)

119.5 (84.5–173.5)

67.5 (61.8–81.0)

317

 eGFR, ml/min/1.73 m²

45.2 (25.8–66.9)

45.9 (25.2–60.7)

45.0 (26.4–66.6)

97.1 (48.6–110.5)

17.0

 Urea, mmol/L

18.2 (12.5–31.6)

19.8 (15.8–34.3)

18.1 (12.8–30.6)

4 (3.1–3.7)

15.3

 Uric acid, μmol/L

426.5 (306.5–634.8)

403 (323.5–544.5)

472 (304.8–769.5)

282 (263–296.5)

485

 Systolic blood pressure, mmHg

130 (116–143)

130 (120–143)

129 (114–143)

129 (117–138)

112

 Diastolic blood pressure, mmHg

68 (56–80)

65 (51–80)

70 (57–80)

64 (53–78)

58

 Heart rate, beats/minute

90 (80–104)

88 (75–91)

90 (80–109)

88 (77–110)

104

 Temperature, °C

37.7 (36.9–38.2)

37.5 (37.0–38.0)

37.8 (36.9–38.2)

37.8 (37.7–38.0)

37.8

 Glasgow Coma Scale score

13 (9–14)

13 (10–14)

13 (9–14)

14 (13–14)

6

 Hypovolaemic

63 (68)

3 (15)

55 (85)

4 (80)

1 (50)

 Euvolaemic

15 (16)

5 (25)

8 (12)

1 (20)

1 (50)

 Hypervolaemic

14 (15)

12 (60)

2 (3)

0 (0)

0 (0)