Table 1 Baseline characteristics of the study population.

From: Hyperkalemia is associated with short- and mid-term mortalities in critically ill patients in the MIMIC IV database

 

Total (n = 22370)

No Hyperkalemia (n = 18175)

Hyperkalemia (n = 4195)

P value

Demographic variables

 Age (year), Mean ± SD

65.7 ± 16.9

65.7 ± 17.0

65.9 ± 16.7

0.468

 Sex, n (%)

   

< 0.001

 Male

12,609 (56.4)

9989 (55)

2620 (62.5)

 

 Female

9761 (43.6)

8186 (45)

1575 (37.5)

 

Race, n (%)

   

< 0.001

 White

14,121 (63.1)

11,653 (64.1)

2468 (58.8)

 

 Black

1721 (7.7)

1326 (7.3)

395 (9.4)

 

 Asian

620 (2.8)

520 (2.8)

118 (2.8)

 

 Hispanic

718 (3.2)

569 (3.1)

149 (3.6)

 

 American Indian

41 (0.2)

31 (0.2)

10 (0.2)

 

 Others

1106 (4.9)

917 (5)

189 (4.5)

 

 Unknown

4043 (18.1)

3177 (17.5)

866 (20.6)

 

Comorbidities

 Hypertension, n (%)

9992 (44.7)

8429 (46.4)

1563 (37.3)

< 0.001

 Diabetes, n (%)

3217 (14.4)

2435 (13.4)

782 (18.6)

< 0.001

 Heart failure, n (%)

5305 (23.7)

3920 (21.6)

1385 (33.0)

< 0.001

 Myocardial infarction, n (%)

2560 (11.4)

2017 (11.1)

543 (12.9)

< 0.001

 Shock, n (%)

3522 (15.7)

2345 (12.9)

1177 (28.1)

< 0.001

 Sepsis, n (%)

3268 (14.6)

2233 (12.3)

1035 (24.7)

< 0.001

Clinical indices

 Heart rate (beat per minute), Mean ± SD

88.4 ± 21.2

87.6 ± 21.1

91.5 ± 21.0

< 0.001

 MAP (mmHg), Median (IQR)

103.7 (90.0, 118.3)

104.0 (90.3, 118.7)

102.3 (88.0, 117.0)

< 0.001

 SpO2 (%), Mean ± SD

97.5 ± 65.1

97.7 ± 72.2

96.6 ± 4.7

0.303

 LOS (day), Median (IQR)

8.6 (5.7, 14.0)

8.1 (5.5, 12.8)

11.9 (6.9, 20.0)

< 0.001

 ICU stay (day), Median (IQR)

3.8 (2.7, 6.5)

3.6 (2.6, 5.9)

5.0 (3.1, 10.0)

< 0.001

 AKI, n (%)

9067 (40.5)

6326 (34.8)

2741 (65.3)

< 0.001

AKI stage, n (%)

   

< 0.001

 1

552 (62.3)

4366 (69.0)

1286 (46.9)

 

 2

1592 (17.6)

1078 (17.0)

514 (18.8)

 

 3

1823 (20.1)

882 (13.9)

941 (34.3)

 

 KRT, n (%)

819 (3.7)

263 (1.4)

556 (13.3)

< 0.001

Laboratory examinations

 WBC (x109/L), Mean ± SD

12.8 ± 10.1

12.4 ± 8.2

14.5 ± 15.7

< 0.001

 HGB (g/dL), Mean ± SD

10.3 ± 2.4

10.3 ± 2.2

10.1 ± 2.8

0.017

 Creatinine (mg/dL), Mean ± SD

1.2 ± 1.1

1.1 ± 0.9

1.8 ± 1.8

< 0.001

 BUN (mmol/L), Mean ± SD

24.1 ± 20.1

21.8 ± 17.4

34.0 ± 27.2

< 0.001

 Na (mmol/L), Mean ± SD

138.4 ± 4.4

138.6 ± 4.2

137.5 ± 5.1

< 0.001

 CO2 (mmol/L), Mean ± SD

22.7 ± 4.0

23.0 ± 3.8

21.7 ± 4.4

< 0.001

 Cl (mmol/L), Mean ± SD

104.4 ± 6.2

104.6 ± 6.0

103.4 ± 7.0

< 0.001

  1. Abbreviations: AKI, acute kidney injury; BUN, blood urine nitrogen; Cl, chloride; CO2, carbonate; HGB, hemoglobin; IQR, interquartile range; MAP, mean arterial pressure; n, number; Na, sodium; KRT, kidney replacement therapy; SD, standard deviation; WBC, white blood cell.
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