Table 1 Comparison of characteristics between elderly and younger patients

Median age (IQR)

56 (46-60)

76 (71-79)

<0.01

Sex (M:F)

27:40

66:42

<0.01

Co-morbidities

Chronic renal failure

11

13

0.15**

Chronic obstructive pulmonary disease

13

25

0.83**

Congestive cardiac failure/Ischemic heart disease/Hypertension

27

69

0.05**

Diabetes mellitus

9

20

0.66**

Physiological variables

Median (IQR)

Median (IQR)

PaO₂ (torr)

93 (67-126)

101 (73.7-172.7)

0.25

PaCO₂(torr)

41 (34-50)

39 (32-49)

0.59

HCO₃ (mmol/L)*

20.56 (4.09)

17.97 (5.38)

<0.01

pH

7.32 (7.25-7.41)

7.29 (7.15-7.37)

0.02

Heart rate

110 (99-128)

105 (88.5-120)

0.02

Systolic blood pressure (mmHg)

120 (95.5-141)

138 (113.5-152)

<0.01

Diastolic blood pressure (mmHg)

65 (51-72)

62 (50-74)

0.77

Mean blood pressure(mmHg)

84 (67-95)

87 (77-98)

0.13

Temperature (degree Celsius)

37.8 (37-38.5)

37.2 (36.5-37.9)

<0.01

Respiratory rate

26 (18.5-32.5)

26 (20-30)

0.28

Number of organs failed on admission

1 (0-2)

1 (0-2)

0.10

Laboratory variables

Sodium (mmol/L)

142 (138.2-145.7)

142 (139-145)

0.71

Potassium (mmol/L)

4.25 (0.84)

4.50 (0.78)

0.04

Urea (mmol/L)

9 (5.2-15.8)

14.5 (9.2-22.5)

<0.01

Creatinine (umol/L)

80.5 (51.7-147.5)

160 (100-250)

<0.01

Bilirubin (umol/L)

14 (8.25-27)

15.5 (8-27.5)

0.93

Albumin (g/L)

28.85 (7.39)

29.27 (5.87)

0.69

Blood sugar (mmol/L)

7.8 (6.1-12.2)

9.4 (6.7-12.2)

0.23

C reactive protein (mg/L)

197.6 (91.4-274.3)

168.7 (62.3-253.5)

0.28

Lactate (mmol/L)

2.1 (1.4-4.3)

2.8 (1.5-6.1)

0.29

White cell count (×10^9/L)

16.2 (11.3-20.9)

15.2 (10.2-24)

0.98

Hematocrit (%)

0.30 (0.26-0.33)

0.31(0.27-0.35)

0.10

Positive culture in the first 24 hours (%)

40.3

44.6

0.62

Scores

APACHE III

57 (41.2-70.2)

77 (58.5-93)

<0.01

APACHE III without age component

48 (36-65)

57.5 (40.2-77.7)

0.03

SAPS II

34.5 (26.7-42)

47 (39-56.5)

<0.01

SAPS II without age component

27 (20-34)

31 (22-41.5)

0.01