Table 1.
Characteristics of patients without AKI, with transient AKI and with persistent AKIa
| Demographics | No AKI (n = 67) | Transient AKI (n = 54) | Persistent AKI (n = 82) | P valueb |
|---|---|---|---|---|
| Patient characteristics | ||||
| Male gender | 34 (50.7%) | 32 (59.3%) | 56 (68.3%) | 0.15 |
| Age, years | 50 (40 to 60) | 71 (49 to 76) | 66 (56 to 74) | < 0.0001 |
| Weight, kg | 68 (57 to 85) | 75 (64 to 85) | 80 (68 to 89) | 0.006 |
| Knaus score C or D [21] | 21 (31.3%) | 21 (38.9%) | 40 (48.8%) | 0.09 |
| LOD score at ICU admission [19] | 4 (2 to 7) | 6 (5 to 9) | 8 (5 to 9) | < 0.0001 |
| SAPS II score at ICU admission [20] | 35 (27 to 47) | 50 (39 to 62) | 52 (39 to 62) | < 0.0001 |
| Risk factors for AKI | ||||
| Chronic heart failure | 8 (11.9%) | 14 (26.4%) | 18 (22.0%) | 0.15 |
| Chronic kidney diseasec | 1 (1.5%) | 3 (5.6%) | 23 (28.0%) | < 0.0001 |
| Sepsis | 43 (64.2%) | 33 (61.1%) | 61 (74.4%) | 0.12 |
| Aminoglycosides | 8 (11.9%) | 9 (16.7%) | 25 (30.5%) | 0.2 |
| Ionidated contrast agents | 6 (9.0%) | 3 (5.6%) | 9 (11.0%) | 0.55 |
| Organ failure at ICU admission | ||||
| Medical condition | 62 (92.5%) | 51 (94.4%) | 72 (87.8%) | 0.36 |
| Acute respiratory failure | 54 (80.6%) | 39 (72.2%) | 61 (74.4%) | 0.51 |
| Coma | 22 (32.8%) | 24 (44.4%) | 29 (35.4%) | 0.34 |
| Shock | 22 (32.8%) | 28 (51.9%) | 43 (52.4%) | 0.03 |
| Treatments in the ICU | ||||
| Need for vasoactive drugs | 20 (29.9%) | 23 (42.6%) | 43 (52.4%) | 0.02 |
| Mechanical ventilation | 43 (64.2%) | 34 (63.0%) | 52 (63.4%) | 0.99 |
| Noninvasive mechanical ventilation | 21 (31.3%) | 14 (25.9%) | 21 (25.6%) | 0.73 |
| Renal replacement therapy | 4 (6.0%) | 0 | 41 (50.0%) | <0.0001 |
| Diuretics (at admission) | 17 (25.4%) | 18 (33.3%) | 32 (39.0%) | 0.21 |
| Renal function at admission | ||||
| Diuresis, mL/kg/hourd | 0.69 (0.59 to 0.99) | 0.45 (0.32 to 1.11) | 0.40 (0.21 to 0.72) | <0.0001 |
| Plasma urea, mmol/L | 5.4 (3.4 to 7.9) | 13.1 (6.8 to 17.3) | 17.4 (10.9 to 25.1) | <0.0001 |
| Serum creatinine, μmol/L | 68 (59 to 78) | 124 (98 to 164) | 220 (138 to 360) | <0.0001 |
| Urinary indices | ||||
| Urine Na+/urine K+ | 1.8 (0.35 to 1.75) | 1.0 (0.4 to 1.8) | 1.3 (0.5 to 2.4) | 0.01 |
| FeNa, % | 0.5 (0.3 to 1.3) | 0.5 (0.2 to 1.3) | 0.8 (0.4 to 4.0) | 0.004 |
| FeUrea, % | 39 (28 to 40) | 41 (29 to 54) | 32 (22 to 51) | 0.12 |
| U/P urea | 30 (19 to 39) | 16 (9 to 25) | 7 (4 to 14) | <0.0001 |
| U/P creatinine | 83 (52 to 127) | 47 (25 to 76) | 30 (11 to 58) | <0.0001 |
| Outcomes | ||||
| ICU mortality | 7 (11.7%) | 13 (25%) | 37 (48.1%) | 0.0002 |
| Hospital mortality | 14 (20.9%) | 15 (27.8%) | 42 (51.2%) | 0.0003 |
aAKI: acute kidney injury; LOD: Logistic Organ Dysfunction score, which can range from 0 to 22; SAPS II: Simplified Acute Physiology Score version II; FeNa, fractional excretion of sodium ([urine sodium/serum sodium]/[urine creatinine/serum creatinine]) ×100; FeUrea, fractional excretion of urea ([urine urea/serum urea]/[urine creatinine/serum creatinine]) ×100; U/P urea, urine urea/plasma urea; U/P creatinine, urine creatinine/serum creatinine. Data are medians (IQR) or number of patients (%). bP values represent comparisons across the three patient groups. cChronic renal failure was defined as creatinine clearance < 60 mL/minute before ICU admission. dDiuresis represents diuresis per kilogram and per hour during the first six hours following inclusion