Table 2.
Clinical characteristics of the population of patients with and without acute kidney injury
| Variable | All patients | Patients with AKI | Patients without AKI | p value |
|---|---|---|---|---|
| N (%) | 401 (100) | 201 (50.1) | 200 (49.9) | |
| Age | 68 (51 - 79) | 72 (60 - 81) | 64 (45 - 76) | < 0.001 |
| Male | 227 (56.6) | 113 (56.2) | 114 (57) | 0.477 |
| APACHE II | 16 (11 - 22) | 21 (14 - 27) | 13 (9 - 17) | < 0.001 |
| Arterial hypertension | 201 (50.1) | 121 (60.2) | 79 (39.5) | < 0.001 |
| Diabetes mellitus | 74 (18.6) | 48 (23.8) | 26 (13) | 0.004 |
| Cardiopathy | 104 (26.3) | 68 (33.8) | 36 (18) | < 0.001 |
| Heart failure | 56 (14.2) | 41 (20.4) | 15 (7.5) | < 0.001 |
| COPD | 30 (7.6) | 19 (9.4) | 11 (5.5) | 0.091 |
| Stroke | 39 (9.8) | 17 (8.4) | 22 (11) | 0.250 |
| Obesity | 45 (11.4) | 31 (15.4) | 14 (7) | 0.006 |
| Smoking | 109 (27.6) | 56 (27.8) | 52 (26) | 0.423 |
| Peripheral vascular disease | 16 (4.1) | 10 (4.9) | 6 (3) | 0.222 |
| Alcoholism | 37 (9.4) | 12 (5.9) | 25 (12.5) | 0.018 |
| Dyslipidemia | 78 (19.8) | 35 (17.4) | 43 (21.5) | 0.195 |
| Hyperuricemia | 38 (9.7) | 24 (11.9) | 14 (7) | 0.060 |
| Hepatopathy | 17 (4.3) | 6 (2.9) | 11 (5.5) | 0.161 |
| Neoplasia | 80 (20.3) | 38 (18.9) | 42 (21) | 0.363 |
| Chronic kidney disease | 56 (14.1) | 48 (23.8) | 8 (4) | < 0.001 |
| Previous nephrological pathology | 48 (12.2) | 36 (17.9) | 12 (6) | < 0.001 |
| Previous AKI | 63 (16) | 47 (23.4) | 16 (8) | < 0.001 |
| Proteinuria and/or hematuria | 48 (12.2) | 35 (17.4) | 13 (6.5) | 0.001 |
| Prior nephrotoxics | 129 (32.4) | 77 (38.3) | 52 (26) | 0.005 |
| NSAIDs | 34 (8.6) | 19 (9.4) | 15 (7.5) | 0.296 |
| ARA II | 36 (9.1) | 21 (10.4) | 15 (7.5) | 0.191 |
| ACE inhibitors | 48 (12.1) | 28 (13.9) | 20 (10) | 0.141 |
| Contrast media | 33 (8.3) | 22 (10.9) | 11 (5.5) | 0.035 |
| Diuretics | 33 (8.3) | 23 (11.4) | 10 (5) | 0.013 |
| Aminoglucosides | 14 (3.5) | 10 (4.9) | 4 (2) | 0.086 |
| Vancomycin | 7 (1.8) | 6 (2.9) | 1 (0.5) | 0.061 |
| Colistin | 9 (2.3) | 7 (3.4) | 2 (1) | 0.087 |
| Diagnosis on admission | ||||
| Sepsis | 146 (36.4) | 110 (54.7) | 36 (18) | < 0.001 |
| Neurocritical | 65 (16.2) | 15 (7.4) | 50 (25) | < 0.001 |
| Polytrauma | 61 (15.2) | 18 (8.9) | 43 (21.5) | < 0.001 |
| Other | 129 (32.2) | 58 (28.8) | 71 (35.5) | < 0.001 |
| CrS baseline (mg/dL) | 0.88 (0.72 - 1.06) | 1.0 (0.81 - 1.20) | 0.8 (0.67 - 0.92) | < 0.001 |
| CrS admission UTI (mg/dL) | 0.98 (0.73 - 1.62) | 1.6 (1.10 - 2.80) | 0.78 (0.62 - 0.93) | < 0.001 |
| Urea (mg/dL) | 46 (30 - 79) | 77 (46 - 114) | 32 (25 - 45) | < 0.001 |
| Diuresis (mL) | 1300 (800 - 1800) | 950 (400 - 1500) | 1500 (1200 - 1800) | < 0.001 |
| Na+ (meq/L) | 138 (134 - 141) | 138 (133 - 142) | 137 (134 - 140) | 0.513 |
| K+ (meq/L) | 3.9 (3.6 - 4.4) | 4.1 (3.7 - 4.6) | 3.8 (3.5 - 4.1) | < 0.001 |
| Ca++ (mmoL/L) | 1.10 (1.06 - 1.17) | 1.10 (1.03 - 1.15) | 1.12 (1.08 - 1.17) | 0.001 |
| Cl- (meq/L) | 105 (101 - 110) | 106 (101 - 111) | 104 (100 - 109) | 0.012 |
| Glycemia (g/dL) | 1.50 (1.19 - 1.87) | 1.54 (1.20 - 2.03) | 1.50 (1.16 - 1.79) | 0.088 |
| Hemoglobin (g/dL) | 11.0 (9.4 - 12.6) | 10.6 (9.0 - 12.1) | 11.3 (9.9 - 12.9) | 0.001 |
| Platelets (x109/L) | 195 (134 - 259) | 194 (125 - 264) | 198 (145 - 254) | 0.438 |
| Leukocytes (x109/L) | 12.0 (8.7 - 16.1) | 12.6 (8.8 - 18.1) | 11.5 (8.4 - 15.4) | 0.062 |
| Albuminemia (g/dL) | 3.0 (2.6 - 3.5) | 2.9 (2.5 - 3.4) | 3.0 (2.8 - 3.6) | < 0.001 |
| pH | 7.35 (7.29 - 7.40) | 7.32 (7.25 - 7.39) | 7.28 (7.33 - 7.41 | < 0.001 |
| PaO2 (mmHg) | 145 (98 - 215) | 129 (91 - 205) | 161 (109 - 222) | 0.012 |
| PaCO2 (mmHg) | 38 (33 - 44) | 37 (32 - 46) | 39 (34 - 43) | 0.318 |
| HCO3- (meq/L) | 21 (18 - 23) | 19 (16 - 22) | 22 (20 - 24) | < 0.001 |
| Lactate (meq/L) | 2.0 (1.3 - 3.1) | 2.3 (1.6 - 4.9) | 1.7 (1.1 - 2.4) | < 0.001 |
| Mechanical ventilatory assistance | 290 (72.9) | 163 (81.1) | 127 (63.5) | < 0.001 |
| ARDS | 107 (26.9) | 82 (40.8) | 25 (12.5) | < 0.001 |
| Vasopressors/inotropics | 154 (38.6) | 120 (59.7) | 29 (14.5) | < 0.001 |
| Diuretics day 1 | 57 (14.4) | 40 (19.1) | 17 (8.5) | 0.001 |
| Nephrotoxics in ICU | 147 (36.8) | 77 (38.3) | 70 (35) | 0.267 |
| ACE inhibitors | 33 (8.3) | 20 (9.9) | 13 (6.5) | 0.134 |
| ARA II | 4 (1) | 2 (1) | 2 (1) | 0.688 |
| NSAIDs | 77 (19.3) | 29 (14.4) | 48 (24) | 0.011 |
| Contrast medium | 17 (4.3) | 11 (5.4) | 6 (3) | 0.161 |
| Vancomycin | 23 (5.8) | 20 (9.9) | 3 (1.5) | < 0.001 |
| Aminoglucosides | 29 (7.3) | 18 (8.9) | 11 (5.5) | 0.123 |
| Colistin | 23 (5.8) | 18 (8.9) | 5 (2.5) | 0.004 |
| Transfusion | 129 (32.6) | 93 (46.2) | 36 (18) | < 0.001 |
| Diuretics in evolution | 112 (28.3) | 79 (39.3) | 33 (16.5) | < 0.001 |
| ICU mortality | 112 (28.1) | 84 (41.8) | 28 (14) | < 0.001 |
| Hospital mortality | 118 (29.4) | 85 (42.2) | 33 (16.5) | < 0.001 |
AKI - acute kidney injury; APACHE II - Acute Physiology and Chronic Health Evaluation II; COPD - chronic obstructive pulmonary disease; NSAIDs - non-steroidal anti-inflammatory drugs; ARA II - angiotensin II receptor antagonists; ACE inhibitors - inhibitors of angiotensin-converting enzyme; CrS - serum creatinine; ICU - intensive care unit; Na+ - sodium; K+ - potassium; Ca++ - calcium; Cl- chloride; pH - concentration of hydrogen ions; PaO2 - partial arterial oxygen concentration; PaCO2 - partial pressure of carbon dioxide; HcO3 - bicarbonates; ARDS - acute respiratory distress syndrome. Values are expressed as N (%) and the median (interquartile range).