Table 1.
Demographic and clinical characteristics of the study population
| Total (n = 1743) | Non-AKI (n = 1150) | AKI (n = 593) | p | |
|---|---|---|---|---|
| Demographics | ||||
| Age, years | 74 (63–82) | 74 (63–82) | 75 (63–84) | 0.069 |
| Male | 687 (51.8) | 496 (50.4) | 191 (55.7) | 0.103 |
| Comorbidities | ||||
| Hypertension | 853 (76.2) | 611 (73.3) | 242 (84.6) | 0.001 |
| Coronary heart disease | 706 (68.5) | 506 (65.1) | 200 (78.7) | 0.001 |
| Diabetes mellitus | 463 (48.7) | 326 (45.5) | 137 (58.5) | 0.001 |
| Hyperlipidaemia | 157 (19.7) | 108 (17.7) | 49 (26.5) | 0.011 |
| COPD | 164 (17.1) | 108 (16.4) | 56 (18.8) | 0.530 |
| CKD | 74 (10.0) | 39 (6.8) | 35 (20.7) | 0.001 |
| Vital signs | ||||
| Heart rate, bpm | 92 (78–112) | 91 (78–110) | 98 (80–117) | 0.003 |
| Systolic blood pressure, mmHg | 138 (120–161) | 138 (120–160) | 140 (120–164) | 0.250 |
| Mean blood pressure, mmHg | 99 (86–114) | 99 (88–114) | 98 (86–116) | 0.677 |
| Laboratory values | ||||
| pH | 7.41 (7.34–7.45) | 7.41 (7.36–7.45) | 7.38 (7.30–7.44) | <0.001 |
| pCO2, mmHg | 36 (30–42) | 36 (31–42) | 34 (28–41) | <0.001 |
| pO2, mmHg | 80 (61–100) | 80 (62–100) | 78 (60–100) | 0.440 |
| Lactate, mmol/L | 1.7 (1.1–2.7) | 1.7 (1.1–2.5) | 1.8 (1.2–3.2) | 0.007 |
| Base excess, mmol/L | −1.8 (−5.7 to 1.7) | −0.9 (−4.0 to 2.5) | −3.9 (−8.2 to −0.4) | <0.001 |
| PaO2/FiO2 ratio, mmHg | 245.8 (186.1–334.8) | 257 (196.2–343.8) | 228.3 (164.2–307.7) | 0.001 |
| Sodium, mmol/L | 138 (135–141) | 138 (135–141) | 137 (134–141) | 0.012 |
| NT-proBNP, pg/mL | 4386 (1048–11635) | 3435 (938–9000) | 7690 (1299–21235) | <0.001 |
| Troponin I, ng/mL | 0.08 (0.03–0.50) | 0.06 (0.03–0.46) | 0.13 (004–0.63) | <0.001 |
| Haemoglobin, g/L | 120 (100–137) | 123 (105–139) | 112 (90–133) | <0.001 |
| ALB, g/L | 36.8 (33.0–40.0) | 37.0 (33.1–40.0) | 36.0 (32.0–40.0) | 0.003 |
| BUN, mg/dL | 8.7 (6.05–14.6) | 7.4 (5.6–10.7) | 12.7 (8.1–21.2) | <0.001 |
| BUN/Cr ratio | 20 (15–26) | 21 (16–27) | 18 (13–24) | <0.001 |
| Cr, mmol/L | 99 (74–165) | 85 (67–115) | 164 (104–292) | <0.001 |
| eGFR, mL/min/1.73 m2 | 47 (26–71) | 57 (39–79) | 27 (16–45) | <0.001 |
| Treatment | ||||
| Invasive MV | 72 (9.3) | 30 (5.1) | 42 (22.3) | 0.001 |
| Inotropic agent | 145 (8.8) | 62 (5.7) | 83 (14.8) | <0.001 |
| Vasodilators* | 593 (79.9) | 422 (71.0) | 129 (70.5) | 0.926 |
| Outcome | ||||
| All-cause 7-day mortality | 98 (7.4) | 37 (3.8) | 61 (18.1) | 0.001 |
| All-cause 30-day mortality | 132 (10.1) | 51 (5.2) | 81 (24.3) | 0.001 |
| In-hospital all-cause mortality | 100 (8.1) | 31 (3.4) | 69 (22.0) | 0.001 |
| Length of hospital stay, days | 12.7 ± 32.2 | 11.64 ± 25.5 | 15.62 ± 46.4 | 0.606 |
| 30-day readmission | 138 (10.8) | 96 (10.1) | 42 (12.7) | 0.217 |
| Cost*, ¥ | 14322 ± 19947 | 12092 ± 15767 | 18510 ± 25622 | 0.030 |
Data are presented as median (25th–75th percentiles), n (%), or mean ± standard deviation.
*Number of patients with data was limited; for reference only.
AKI, acute kidney injury; ALB, serum albumin; BUN, blood urea nitrogen; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; Cr, creatinine; eGFR, estimated glomerular filtration rate; MV, mechanical ventilation; NT-proBNP, N-terminal pro-brain natriuretic peptide; PaO2/FiO2 ratio, ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (oxygenation index); pCO2, partial pressure of carbon dioxide; pO2, partial pressure of oxygen.