Table 1.
Characteristics of included studies
| Study | Country | Design and setting | Total no. of patients (male)/mean age (SD) | Criteria for RRT initiation | RRT modality | Median time of RRT initiation (IQR), h | SOFA scores at administration | ||
|---|---|---|---|---|---|---|---|---|---|
| Early | Delayed | Early | Delayed | ||||||
| Bagshaw [14] | Canada |
Multicenter Mixed population |
2927 (1990) 64.6 + 14.9 |
within 12 h after the onset of KDIGO stage 2 or 3 | Serum potassium ≥ 6 mmol/; pH ≤ 7.2; serum bicarbonate ≤ 12 mmol/L; severe respiratory failure; volume overload; persistent AKI ≥ 72 h | IHD, CRRT | 6.1 [3.9,8.8] | 31.1 [19.0,71.8] | 11.7 + 3.6 |
| Barbar [22] | France |
Multicenter Septic shock population |
488 (296) 69 + 12.2 |
Within 12 h after the onset of failure stage of RIFLE | Serum potassium ≥ 6.5 mmol/; pH ≤ 7.15; severe pulmonary edema refractory to diuretics; no renal function recovery after 48 h | IHD, CRRT | 7.6 [4.4,11.5] | 51.5 [34.6,59.5] | 12.3 + 2.9 |
| Bouman [29] | Netherlands |
Two-center Mixed population |
71 (42) 68.5 + 11.6 |
Within 12 h if urine output < 30 ml/h for 6 h; creatinine clearance of < 20 mL/min | Plasma urea level of > 40 mmol/L; potassium of > 6.5 mmol/L or severe pulmonary edema | LVHF | 7 [5, 10] | 41.8 [21.4,72] | 10.4 ± 2.1 |
| Combes [23] | France |
Multicenter Postcardiac surgery shock |
224 (177) 59.5 ± 15.1 |
Persistent postoperative shock after cardiac surgery | AKI Network stage 3; serum urea > 36 mmol/L; life-threatening hyperkalemia | HVHF, CVVHDF, IHD | NA | NA | 11.8 ± 2.9 |
| Gaudry [20] | France |
Multicenter Mixed population |
619 (409) 66.1 ± 13.9 |
KDIGO stage 3 | Serum potassium > 6 mmol/L; severe pulmonary edema refractory to diuretics; pH < 7.15; serum urea > 40 mmol/L; oliguria > 72 h | IHD, CRRT | 2 [1, 3] | 57 [25,83] | 10.9 ± 3.1 |
| Jamale [28] | India |
Single-center Mixed population |
208 (141) 42.4 ± 15.3 |
Serum urea nitrogen level > 70 mg/dL; creatinine level > 7 mg/dL | Refractory hyperkalemia; volume overload; and acidosis; uremic nausea and anorexia | IHD | NA | NA | 7.9 ± 3.2 |
| Lumlertgul [25] | Thailand |
Multicenter Mixed population |
118 (58) 67.1 ± 15.8 |
AKI (any stage of KDIGO) and no response to furosemide stress test | BUN ≥ 100 mg/dL; serum potassium > 6 mmol/L; serum bicarbonate < 12 mmol/L or pH < 7.15; PaO2/FiO2 ratio < 200; severe pulmonary edema | CVVH, PIRRT, IHD | 2 [1, 3] | 21 [17,49] | 12 ± 3.7 |
| Srisawat [26] | Thailand |
Two-center Mixed population |
40 (22) 66.8 ± 15.9 |
AKI (any stage of RIFLE) | potassium > 6.2 mmol/L; pH < 7.2, severe pulmonary edema refractory to diuretics; persistent oliguria or anuria; serum urea > 40 mg/dL | CRRT | NA | NA | 9.3 ± 3.6 |
| Wald [27] | Canada |
Multicenter Mixed population |
100 (72) 63.1 ± 12.8 |
At least two of the following: twofold increase in serum creatinine from baseline; urine output < 6 mL/kg in the preceding 12 h; whole-blood NGAL ≥ 400 ng/m | Serum potassium > 6.2 mmol/L; serum bicarbonate < 10 mmol/L, severe pulmonary edema; persistent AKI for > 72 h | IHD, CRRT, SLED | 7.4 [6.1,9.6] | 31.6 [22.8,59.5] | 13 ± 2.8 |
| Xia [30] | China | Single-center Sepsis population |
60 (33) 66.4 ± 11.5 |
Sepsis and urinary NGAL ≥ 1310 ng/mL | Serum potassium > 6.5 mmol/L; pH < 7.2; severe pulmonary edema | CRRT | NA | NA | 9.6 ± 3.2 |
| Zarbock [24] | Germany |
Single-center Mixed population |
231 (146) 67 ± 13.1 |
Within 8 h of diagnosis of KDIGO stage 2 | Within 12 h of diagnosis of KDIGO stage 3; or serum urea > 100 mg/dL; serum potassium > 6 mmol/L; serum magnesium > 4 mmol/L; urine < 200 mL per 12 h or anuria; organ edema refractory to diuretics | CRRT, SLED, IHD | 6 [4, 7] | 25.5 [18.8,40.3] | 15.8 ± 2.3 |
AKI acute kidney injury, KDIGO Kidney Disease Improving Global Outcomes classification, RIFLE risk, injury, failure, loss, and end-stage kidney disease classification system, IHD intermittent hemodialysis, CRRT continuous renal replacement therapy, LVHF low-volume hemofiltration, HVHF high-volume hemofiltration, CVVHDF continuous venovenous hemodiafiltration, BUN blood urea nitrogen, CVVH continuous venovenous hemofiltration, PIRRT prolonged intermittent renal replacement therapy, SLED sustained low-efficiency dialysis, NA not available, SD standard deviation