Table 1 Baseline characteristics of the patients according to quartiles of serum iCa levels
iCa levels (mmol/L) | ||||||
|---|---|---|---|---|---|---|
Characteristics | Overall (N=1773) | Q1(iCa<1.07) (N=428) | Q2(1.07≤iCa<1.12) (N=401) | Q3(1.12≤iCa<1.17) (N=436) | Q4(1.17≤iCa) (N=508) | P value |
Age (years) | 71.4(61.7-80.2) | 68.8(57.3-77.8) | 72.1(61.5-81.4) | 72.1(62.6-81.7) | 72.4(64.1-80.6) | <0.001 |
Gender, n | Â | Â | Â | Â | Â | 0.519 |
 Female | 753(42.5%) | 193(45.1%) | 172(42.9%) | 175(40.1%) | 213(41.9%) |  |
 Male | 1020(57.5%) | 235(54.9%) | 229(57.1%) | 261(59.9%) | 295(58.1%) |  |
Race,n | Â | Â | Â | Â | Â | 0.067 |
 White | 1131(63.8%) | 251(58.6%) | 261(65.1%) | 295(67.7%) | 324(63.8%) |  |
 Black | 133(7.5%) | 35(8.2%) | 22(5.5%) | 27(6.2%) | 49(9.6%) |  |
 Asian | 38(2.1%) | 13(3.0%) | 10(2.5%) | 6(1.4%) | 9(1.8%) |  |
 Other | 471(26.6%) | 129(30.1%) | 108(26.9%) | 108(24.8%) | 126(24.8%) |  |
Vital signs | ||||||
 MAP (mmHg) | 85.7(74.0-99.0) | 88.3(75.7-99.8) | 87.3(75.7-100.0) | 83.5(72.0-97.1) | 83.3(73.0-99.3) | 0.003 |
 Respiratory rate(breath/min) | 17.0(15.0-22.0) | 19.0(16.0-24.0) | 17.0(15.0-22.0) | 16.0(14.0-21.0) | 16.0(14.0-20.0) | <0.001 |
Heart rate(beats/min) | 82.0(72.0-95.0) | 86.0(73.0-100.0) | 82.0(72.0-97.0) | 80.0(70.0-93.0) | 80.0(73.0-92.0) | 0.014 |
 Temperature (°C) | 36.7(36.3-37.1) | 36.7(36.4-37.1) | 36.7(36.3-37.1) | 36.6(36.3-37.1) | 36.6(36.2-37.0) | <0.001 |
 SpO2 (%) | 99.0(97.0-100.0) | 99.0(96.0-100.0) | 99.0(96.0-100.0) | 100.0(97.0-100.0) | 100.0(97.0-100) | <0.001 |
Laboratory-based data | ||||||
 Serum-glucose(mg/dL) | 131.0(109.0-167.0) | 143.0(114.0-182.0) | 131.0(110.0-162.0) | 129.0(107.0-159.0) | 127.0(106.0-161.0) | <0.001 |
 Hemoglobin (g/dL) | 10.6(8.9-12.3) | 10.9(9.10-12.4) | 10.6(9.10-12.3) | 10.4(8.68-12.2) | 10.4(8.70-12.1) | 0.025 |
 Platelet (10*9/L) | 182.0(132.0-245.0) | 196.0(137.0-263.0) | 182.0(131.0-251.0) | 175.0(133.0-238.0) | 173.0(129.0-232.0) | 0.025 |
 WBC (10*9/L) | 11.8(8.70-15.6) | 12.5(9.0-16.5) | 12.0(8.8-15.8) | 11.1(8.10-14.8) | 11.8(8.58-15.1) | 0.006 |
 tCa(mg/dL) | 8.4 (7.9-9.0) | 8.0(7.5-8.6) | 8.3(7.9-8.8) | 8.5 (8.1-9.0) | 8.7 (8.3-9.3) | <0.001 |
 Creatinine(mg/dL) | 1.0 (0.7-1.3) | 1.0(0.7-1.7) | 0.9 (0.7-1.3) | 0.9 (0.7-1.2) | 0.9 (0.7-1.2) | 0.004 |
 eGFR(mL/min/1.73 m ) | 79.6(51.5-111.0) | 75.7(46.8-113.0) | 79.6(50.7-109.0) | 79.1(52.7-109.0) | 81.5(54.1-114.0) | 0.234 |
 BUN (mg/dL) | 19.0(13.0-28.0) | 20.5(13.0-34.0) | 18.0(13.0-27.0) | 18.0(14.0-26.0) | 19.0(13.8-27.0) | 0.010 |
 Sodium (mmol/L) | 139.0(136.0-142.0) | 139.0(136.0-141.0) | 139.0(136.0-141.0) | 139.0(136.0-142.0) | 140.0(137.0-142.0) | <0.001 |
 Potassium (mmol/L) | 4.1 (3.8-4.6) | 4.1(3.7-4.5) | 4.1 (3.7-4.5) | 4.2 (3.8-4.6) | 4.2 (3.8-4.6) | 0.001 |
 Chloride (mmol/L) | 106.0(102.0-110.0) | 105.0(101.0-109.0) | 106.0(101.0-109.0) | 106.0(102.0-110.0) | 108.0(104.0-111.0) | <0.001 |
 Magnesium(mg/dL) | 2.0 (1.8-2.3) | 1.9(1.7-2.2) | 2.0 (1.7-2.2) | 2.0 (1.8-2.3) | 2.1 (1.8-2.5) | <0.001 |
 Bicarbonate (mmol/L) | 23.0(20.0-25.0) | 22.0(19.0-24.0) | 22.0(20.0-24.0) | 23.0(21.0-25.0) | 23.0(21.0-25.0) | <0.001 |
 Lactate (mmol/L) | 1.7 (1.2-2.5) | 1.7(1.3-2.8) | 1.7 (1.2-2.5) | 1.6 (1.1-2.3) | 1.8 (1.3-2.6) | 0.003 |
 pH level | 7.4 (7.3-7.4) | 7.4(7.3-7.4) | 7.4 (7.3-7.4) | 7.4 (7.4-7.5) | 7.4(7.3-7.4) | 0.001 |
 Phosphate(mg/dL) | 3.5 (2.9-4.2) | 3.6 (2.9-4.6) | 3.5 (2.9-4.1) | 3.5 (2.9-4.1) | 3.4 (2.8-4.1) | 0.002 |
Comorbidities,n(%) | ||||||
 CAD | 488(27.5%) | 116(27.1%) | 106(26.4%) | 130(29.8%) | 136(26.8%) | 0.666 |
 Congestive heart failure | 546(30.8%) | 136(31.8%) | 129(32.2%) | 139(31.9%) | 142(28.0%) | 0.438 |
 Chronic pulmonary disease | 437(24.6%) | 93(21.7%) | 109(27.2%) | 116(26.6%) | 119(23.4%) | 0.199 |
 Rheumatic disease | 46(2.6%) | 12(2.8%) | 11(2.7%) | 6(1.4%) | 17(3.3%) | 0.283 |
 Liver disease | 120(6.8%) | 42(9.8%) | 25(6.2%) | 29(6.7%) | 24(4.7%) | 0.020 |
 Diabetes | 636(35.9%) | 142(33.2%) | 126(31.4%) | 161(36.9%) | 207(40.7%) | 0.016 |
 Malignancy | 156(8.8%) | 40(9.3%) | 37(9.2%) | 44(10.1%) | 35(6.9%) | 0.325 |
 Hypertension | 959(54.1%) | 208(48.6%) | 222(55.4%) | 242(55.5%) | 287(56.5%) | 0.072 |
 Heart failure | 517(29.2%) | 133(31.1%) | 122(30.4%) | 131(30.0%) | 131(25.8%) | 0.258 |
 Atrial fibrillation | 709(40.0%) | 149(34.8%) | 172(42.9%) | 174(39.9%) | 214(42.1%) | 0.067 |
 Renal failure | 204(11.5%) | 42(9.8%) | 55(13.7%) | 47(10.8%) | 60(11.8%) | 0.334 |
 CKD | 75(4.2%) | 35(8.2%) | 10(2.5%) | 14(3.2%) | 16 3.1%) | <0.001 |
 Hyperlipidemia | 870(49.1%) | 163(38.1%) | 199(49.6%) | 227(52.1%) | 281(55.3%) | <0.001 |
Scoring system | ||||||
 GCS | 15.0(15.0-15.0) | 15.0(15.0-15.0) | 15.0(15.0-15.0) | 15.0(15.0-15.0) | 15.0(15.0-15.0) | 0.297 |
 APS III | 50.0(35.0-71.0) | 58.0(40.0-82.0) | 50.0(35.0-68.0) | 47.0(35.0-66.0) | 46.0(33.0-70.0) | <0.001 |
 SOFA | 2.0 (1.0-4.0) | 2.0 (1.0-4.0) | 2.0 (1. 0-4.0) | 2.00(1.0-4.0) | 2.0 (1. 0-4.0) | 0.351 |
 SIRS | 3.0 (2.0-3.0) | 3.0 (2.0-3.0) | 3.0 (2.0-3.0) | 3.00(2.0-3.0) | 3.0 (2. 0-3.0) | 0.004 |
Treatment information,n(%) | ||||||
 Mechanical ventilation | 262(14.8%) | 80(18.7%) | 67(16.7%) | 53(12.2%) | 62(12.2%) | 0.010 |
 RRT | 123(6.9%) | 62(14.5%) | 18(4.5%) | 21(4.8%) | 22(4.3%) | <0.001 |
 Mechanical thrombectomy | 47(2.7%) | 14(3.3%) | 12(3.0%) | 15(3.4%) | 6(1.2%) | 0.106 |
 Thrombolytic drugs | 288(16.2%) | 92 21.5%) | 64(16.0%) | 64(14.7%) | 68(13.4%) | 0.006 |
 Hospital length of stay,day | 11.9(7.24-19.9) | 13.7(7.97-22.5) | 12.2(7.92-19.7) | 11.9(7.16-20.6) | 10.7(6.6-16.9) | <0.001 |
 ICU length of stay,day | 4.35(2.21-9.09) | 5.84(2.79-11.5) | 4.97(2.31-9.32) | 4.1(2.1-8.2) | 3.86(2.1-7.9) | <0.001 |