Introduction
Materials and methods
Study population
Data collection
Calculation of delivered and prescribed RRT dose
End points
Statistical analyses
Results
Enrollment and baseline characteristics
All | CRRT | IRRT | Mixed RRT |
P CRRT vs IRRT
|
P (three groups)
| |
---|---|---|---|---|---|---|
n (%) | 471 | 338 (72) | 87 (18) | 46 (10) | ||
Male sex (%) | 67.7 | 66.6 | 70.1 | 71.7 | 0.529 | 0.679 |
Age (years) | 63.6 ± 16.2 | 62.1 ± 16.9 | 68.3 ± 13 | 65.8 ± 14.7 | 0.004 | 0.009 |
Body weight (kg) | 79.3 ± 19.3 | 79.4 ± 19.7 | 77.9 ± 19.6 | 81.4 ± 15 | 0.269 | 0.229 |
ICU admission
| ||||||
SAPS II | 50 ± 18 | 50 ± 17 | 50 ± 19 | 51 ± 21 | 0.508 | 0.788 |
SOFA | 10 ± 4 | 10 ± 3 | 10 ± 3 | 11 ± 4 | 0.703 | 0.012 |
Creatinine (μmol/L) | 99(80 to 150) | 100 (80 to 150) | 106 (80 to 177) | 97 (80 to 115) | 0.277 | 0.278 |
Chronic kidney disease (%) | 56.3 | 55.9 | 55.2 | 60.9 | 0.901 | 0.796 |
Diagnosis
| ||||||
Sepsis (%) | 32.7 | 38.8 | 14.9 | 21.7 | < 0.001 | < 0.001 |
Post-surgical (%) | 29.7 | 21.9 | 51.7 | 45.7 | < 0.001 | < 0.001 |
Admission department
| ||||||
Emergency (%) | 30.4 | 33.4 | 19.5 | 28.3 | 0.012 | 0.040 |
Medicine (%) | 21.0 | 24.0 | 12.6 | 15.2 | 0.022 | 0.041 |
Surgery (%) | 48.6 | 42.6 | 67.8 | 56.5 | < 0.001 | < 0.001 |
Hospital to ICU admission (days) | 1 (0 to 5) | 1 (0 to 4) | 2 (0 to 7) | 1 (0 to 5) | 0.042 | 0.146 |
RRT
| ||||||
ICU admission to start RRT (days) | 3 (1 to 7) | 2 (1 to 7) | 3.5 (1 to 8.5) | 3 (2 to 5) | 0.884 | 0.700 |
RIFLE class at RRT initiation | ||||||
Risk (%) | 11.3 | 12.7 | 5.8 | 10.9 | 0.067 | 0.186 |
Injury (%) | 28.5 | 27.5 | 31.0 | 30.4 | 0.515 | 0.746 |
Failure (%) | 57.3 | 56.8 | 60.9 | 54.3 | 0.489 | 0.759 |
Non-renal indication (%) | 2.8 | 3.0 | 2.3 | 2.2 | 0.740 | 0.920 |
SOFA at RRT initiation | 11 ± 3 | 12 ± 3 | 10 ± 2 | 13 ± 3 | < 0.001 | < 0.001 |
Creatinine at RRT initiation (μmol/L) | 265 (177 to 368) | 274 (177 to 380) | 243 (203 to 301) | 194 (141 to 309) | 0.319 | 0.031 |
Start to end RRT (days) | 3 (2 to 7) | 3 (2 to 6) | 4 (2 to 7) | 13.5 (7 to 26.5) | 0.113 | < 0.001 |
Indication for RRT initiation
| ||||||
Azotaemia | 72.1 | 67.9 | 86.2 | 76.1 | 0.001 | 0.003 |
RIFLE class | 64.4 | 64.9 | 60.9 | 67.4 | 0.495 | 0.715 |
Fluid overload | 58.6 | 61.6 | 51.7 | 50.0 | 0.096 | 0.116 |
Oliguria | 43.6 | 48.1 | 28.7 | 39.1 | 0.001 | 0.004 |
Outcome
| ||||||
ICU mortality (%) | 47.6 | 54.1 | 22.1 | 44.7 | < 0.001 | < 0.001 |
Mechanical ventilation (days) | 10 (3 to 19) | 10 (4 to 19) | 8 (1 to 17) | 16 (11 to 38) | 0.037 | 0.002 |
ICU length of stay (days) | 14 (7 to 27) | 13 (6.5 to 26) | 14 (6 to 23) | 25 (15 to 42) | 0.769 | < 0.001 |
Patient characteristics by RRT dose
CRRT
Less-intensive (< 35 ml/kg/hour) | More-intensive | |||
---|---|---|---|---|
≤ 20 ml/kg/hour | 21 to 34 ml/kg/hour | ≥ 35 ml/kg/hour |
P
| |
n (%) | 61 (18) | 202 (60) | 75 (22) | |
Male sex (%) | 73.8 | 67.8 | 58.1 | 0.139 |
Age (years) | 59.05 ± 19.0 | 63.48 ± 15.9 | 61.01 ± 17.4 | 0.226 |
Body weight (kg) | 91.66 ± 24.4 | 79.70 ± 18.0 | 68.81 ± 12.8 | < 0.001 |
ICU admission
| ||||
SAPS II | 46 ± 19 | 51 ± 17 | 52 ± 16 | 0.030 |
SOFA | 9 ± 4 | 10 ± 3 | 11 ± 4 | 0.030 |
Creatinine (μmol/L) | 106 (88 to 150) | 97 (80 to 150) | 106 (80 to 150) | 0.597 |
Chronic kidney disease (%) | 47.5 | 58.9 | 55.4 | 0.290 |
Diagnosis
| ||||
Sepsis (%) | 31.2 | 40.1 | 40.5 | 0.419 |
Post-surgical (%) | 24.6 | 21.3 | 21.6 | 0.859 |
Admission department
| ||||
Emergency (%) | 36.1 | 35.2 | 25.7 | 0.292 |
Medicine (%) | 16.4 | 23.3 | 32.4 | 0.087 |
Surgery (%) | 47.5 | 41.6 | 41.9 | 0.702 |
Hospital to ICU admission (days) | 0.5 (0 to 4) | 1 (0 to 4) | 1 (0 to 3) | 0.654 |
RRT
| ||||
ICU admission to RRT (days) | 2.5 (2 to 8) | 3 (2 to 7) | 2 (1 to 3) | 0.005 |
RIFLE class at RRT initiation | ||||
Risk (%) | 19.7 | 9.9 | 13.5 | 0.123 |
Injury (%) | 18.0 | 27.7 | 35.1 | 0.086 |
Failure (%) | 55.7 | 59.9 | 50.0 | 0.331 |
Non-renal indication (%) | 6.6 | 2.5 | 1.4 | 0.168 |
SOFA at RRT initiation | 11 ± 3 | 12 ± 3 | 12 ± 3 | 0.068 |
Creatinine at RRT initiation (μmol/L) | 283 (177 to 389) | 283 (194 to 415) | 221 (168 to 327) | 0.052 |
CRRT dose (ml/kg/hour) | 15.4 ± 4.2 | 26.9 ± 4.0 | 44.8 ± 9.4 | < 0.001 |
Start to end RRT (days) | 3 (2 to 6) | 4 (2 to 8) | 2 (1 to 3) | < 0.001 |
Indication for RRT initiation
| ||||
Azotaemia | 65.0 | 70.0 | 63.9 | 0.559 |
RIFLE class | 56.7 | 70.0 | 56.9 | 0.048 |
Fluid overload | 61.7 | 62.5 | 59.7 | 0.917 |
Oliguria | 49.5 | 41.7 | 48.6 | 0.562 |
Outcome
| ||||
ICU mortality (%) | 50.8 | 53.0 | 60.8 | 0.426 |
Mechanical ventilation (days) | 13 (3 to 23) | 12 (5 to 20) | 5 (2.5 to 13) | < 0.001 |
ICU length of stay (days) | 17 (7.5 to 29) | 15 (9 to 27) | 8 (4 to 18) | < 0.001 |
IRRT
Frequency < 6 days/week | Frequency ≥ 6 days/week |
P
| |
---|---|---|---|
n (%) | 31 (36) | 56 (64) | |
Male sex (%) | 71.0 | 69.6 | 0.897 |
Age (years) | 69.13 ± 11.7 | 67.84 ± 13.7 | 0.873 |
Body weight (kg) | 79.52 ± 15.7 | 76.99 ± 21.6 | 0.246 |
ICU admission
| |||
SAPS II | 49 ± 15 | 50 ± 20 | 0.958 |
SOFA | 10 ± 3 | 9 ± 4 | 0.689 |
Creatinine (μmol/L) | 106 (80 to 186) | 106 (80 to 177) | 0.822 |
Chronic kidney disease (%) | 54.8 | 55.4 | 0.963 |
Diagnosis
| |||
Sepsis (%) | 3.2 | 21.4 | 0.023 |
Post-surgical (%) | 64.5 | 44.6 | 0.076 |
Admission department
| |||
Emergency (%) | 12.9 | 23.2 | 0.245 |
Medicine (%) | 12.9 | 12.5 | 0.957 |
Surgery (%) | 74.2 | 64.3 | 0.343 |
Hospital to ICU admission (days) | 3 (0 to 8) | 1 (0 to 6) | 0.322 |
RRT
| |||
ICU admission to RRT (days) | 5 (1 to 11) | 3 (1 to 7) | 0.351 |
RIFLE class at RRT initiation | |||
Risk (%) | 6.5 | 5.4 | 0.834 |
Injury (%) | 41.9 | 25.0 | 0.102 |
Failure (%) | 51.6 | 66.1 | 0.186 |
Non renal indication (%) | 0.0 | 3.6 | 0.287 |
SOFA at RRT initiation | 10 ± 2 | 10 ± 2 | 0.941 |
Creatinine at RRT initiation (μmol/L) | 247 (199 to 296) | 234 (212 to 301) | 0.880 |
Number of sessions per week | 4.5 ± 0.8 | 6.9 ± 0.2 | < 0.001 |
Start to end RRT (days) | 6 (5 to 12) | 3 (1 to 5) | < 0.001 |
Indication for RRT initiation
| |||
Azotaemia | 96.8 | 80.4 | 0.033 |
RIFLE class | 58.1 | 62.5 | 0.685 |
Fluid overload | 41.9 | 57.1 | 0.174 |
Oliguria | 22.6 | 32.1 | 0.345 |
Outcome
| |||
ICU mortality (%) | 19.4 | 23.6 | 0.646 |
Mechanical ventilation (days) | 14 (5 to 21) | 6 (0 to 14) | 0.030 |
ICU length of stay (days) | 18 (13 to 31) | 9.5 (6 to 18) | 0.023 |
Outcomes
CRRT
CRRT | Unadjusted analysis | Covariate adjusted analysis | ||||
---|---|---|---|---|---|---|
OR | 95% CI |
P
| OR | 95% CI |
P
| |
Male sex | 1.47 | 0.91 to 2.37 | 0.097 | 1.86 | 1.11 to 3.12 | 0.019 |
Age (10-year increments) | 1.34 | 1.17 to 1.52 | < 0.001 | 1.42 | 1.22 to 1.64 | < 0.001 |
SOFA at RRT initiation | 1.18 | 1.09 to 1.28 | < 0.001 | 1.20 | 1.10 to 1.30 | < 0.001 |
Creatinine at RRT initiation (μmol/L) | 0.85 | 0.76 to 0.95 | 0.005 | 0.79 | 0.69 to 0.90 | 0.001 |
Downtime | 0.90 | 0.80 to 1.01 | 0.081 | 0.95 | 0.83 to 1.07 | 0.386 |
More-intensive (≥ 35 ml/kg/hour)
| 1.41 | 0.83 to 2.38 | 0.204 | 1.21 | 0.66 to 2.21 | 0.537 |
CRRT dose expressed as | Unadjusted OR with 95% CI | Pvalue | Adjusted OR with 95% CI | Pvalue |
---|---|---|---|---|
Raw value (ml/kg/hour) | 1.00 (0.98 to 1.02) | 0.827 | 0.99 (0.97 to 1.02) | 0.583 |
Increment of 10 ml/kg/hour | 1.05 (0.87 to 1.26) | 0.638 | 0.98 (0.79 to 1.23) | 0.879 |
Literature cut-offs | ||||
≤ 20 ml/kg/hour (ref.) | 1.00 | 1.00 | ||
21 to 34 ml/kg/hour | 1.09 (0.61 to 1.93) | 0.768 | 0.79 (0.40 to 1.55) | 0.492 |
≥ 35 ml/kg/hour | 1.50 (0.76 to 2.98) | 0.245 | 1.00 (0.45 to 2.24) | 0.995 |
Less-intensive (< 35 ml/kg/hour) (ref.) | 1.00 | 1.00 | ||
More-intensive (≥ 35 ml/kg/hour) | 1.41 (0.83 to 2.38) | 0.204 | 1.21 (0.66 to 2.21) | 0.537 |
≤ 20 ml/kg/hour (ref.) | ||||
> 20 ml/kg/hour | 1.19 (0.68 to 2.07) | 0.546 | 0.84 (0.43 to 1.61) | 0.595 |
Tertiles | ||||
1st tertile (≤ 23.5 ml/kg/hour) (ref.) | 1.00 | 1.00 | ||
2nd tertile (23.6 to 30.9 ml/kg/hour) | 0.71 (0.42 to 1.20) | 0.206 | 0.67 (0.37 to 1.23) | 0.196 |
3rd tertile (≥ 31 ml/kg/hour) | 1.32 (0.78 to 2.24) | 0.306 | 1.11 (0.60 to 2.06) | 0.734 |
1st+2nd tertiles (ref.) | ||||
3rd tertile | 1.56 (0.98 to 2.48) | 0.058 | 1.36 (0.79 to 2.32) | 0.268 |
Median | ||||
< Median (ref.) | 1.00 | 1.00 | ||
≥ Median (≥ 27.1 ml/kg/hour) | 0.99 (0.64 to 1.51) | 0.945 | 0.82 (0.49 to 1.35) | 0.433 |
CRRT dose in first 24 hours | ||||
Less-intensive (< 35 ml/kg/hour) (ref.) | 1.00 | 1.00 | ||
More-intensive (≥ 35 ml/kg/hour) | 1.02 (0.65 to 1.62) | 0.918 | 0.96 (0.57 to 1.60) | 0.866 |
CRRT dose in first 48 hours | ||||
Less-intensive (< 35 ml/kg/hour) (ref.) | 1.00 | 1.00 | ||
More-intensive (≥ 35 ml/kg/hour) | 1.08 (0.68 to 1.74) | 0.737 | 1.03 (0.60 to 1.76) | 0.915 |
More-intensive vs less-intensive CRRT dose* | Unadjusted OR* with 95% CI | Pvalue | Adjusted OR* with 95% CI | Pvalue |
---|---|---|---|---|
Patient subgroups
| ||||
Sepsis | 1.64 (0.70 to 3.85) | 0.259 | 1.91 (0.71 to 5.13) | 0.198 |
Non sepsis | 1.27 (0.65 to 2.48) | 0.488 | 0.95 (0.43 to 2.10) | 0.896 |
SAPS II 45 to 60 | 1.03 (0.44 to 2.40) | 0.945 | 0.67 (0.24 to 1.81) | 0.428 |
SAPS II < 45 or > 60 | 1.69 (0.85 to 3.31) | 0.129 | 1.76 (0.80 to 3.86) | 0.159 |
≥ 25 hours of CRRT | 1.06 (0.55 to 2.01) | 0.870 | 1.07 (0.51 to 2.28) | 0.855 |
< 25 hours of CRRT | 1.72 (0.61 to 4.86) | 0.303 | 1.12 (0.34 to 3.73) | 0.854 |
Total | CRRT | |||
---|---|---|---|---|
< 35 ml/kg/hour | ≥ 35 ml/kg/hour |
P
| ||
Length of ICU stay (days) | 13 (6.5 to 26) | 15 (9 to 28) | 8 (4 to 18) | < 0.001 |
Patients who survived | 19 (11 to 32) | 19.5 (12 to 33.5) | 15 (8 to 26) | 0.063 |
Patients who died | 10 (4 to 19) | 12 (6 to 20) | 4.5 (3 to 9.5) | < 0.001 |
Duration of MV (days) | 10 (4 to 19) | 12 (5 to 21) | 5 (2.5 to 13) | < 0.001 |
Patients who survived | 14 (4.5 to 22) | 14 (5 to 24) | 7 (4 to 17) | 0.031 |
Patients who died | 8.5 (3 to 17) | 10 (5 to 18) | 4 (2 to 9.5) | < 0.001 |
IRRT
| ||||
Total
|
Frequency < 6 sessions/week
|
Frequency ≥ 6 sessions/week
|
P
| |
Length of ICU stay (days) | 14 (6.5 to 23) | 18 (15 to 31) | 9.5 (6 to 18) | 0.023 |
Patients who survived | 11 (6 to 20) | 18 (13 to 35) | 8 (5.5 to 14) | 0.008 |
Patients who died | 17 (12 to 23) | 18 (17 to 23) | 15 (12 to 22) | 0.597 |
Duration of MV (days) | 8 (1 to 17) | 14 (5 to 21) | 6 (0 to 14) | 0.030 |
Patients who survived | 5 (0 to 13) | 12 (3 to 24) | 2.5 (0 to 10) | 0.026 |
Patients who died | 17 (11 to 21) | 18 (17 to 21) | 14 (8 to 18) | 0.252 |
IRRT
IRRT | Unadjusted analysis | Covariate adjusted analysis | ||||
---|---|---|---|---|---|---|
OR | 95% CI |
P
| OR | 95% CI |
P
| |
Male sex | 1.28 | 0.37 to 5.12 | 0.674 | 1.38 | 0.42 to 4.58 | 0.598 |
Age (10-year increments) | 1.31 | 0.85 to 2.01 | 0.216 | 1.29 | 0.83 to 2.02 | 0.260 |
RIFLE class | ||||||
Risk (%) | 2.51 | 0.19 to 23.49 | 0.320 | 1.00 | ||
Injury (%) | 2.45 | 0.74 to 7.92 | 0.089 | 1.29 | 0.2 to 8.33 | 0.790 |
Failure (%) | 0.38 | 0.12 to 1.22 | 0.064 | 0.46 | 0.07 to 2.88 | 0.408 |
More-intensive (≥ 6 sessions/week) | 1.29 | 0.43 to 3.82 | 0.646 | 1.50 | 0.48 to 4.67 | 0.482 |
Discussion
Conclusions
Key messages
-
In this observational study, the delivered CRRT dose was markedly lower than 35 ml/kg/hour (median = 27).
-
Alternate day IRRT for critically ill patients was uncommon in the participating centres.
-
After adjustment for multiple variables, there was no beneficial effect of more-intensive RRT dose on ICU survival.
-
Shorter ICU stay and duration of mechanical ventilation were observed in the more-intensive RRT groups.