Introduction
Materials and methods
Study population and methodology
Data handing and statistical analysis
Results
Patient characteristics
No. | Male | Surgical | Sepsis | SAPS 2 | AKI on admission | AKI in ICU | RRT | 28-Day mortality | |
---|---|---|---|---|---|---|---|---|---|
Australia
| 88 | 58% | 57% | 34% | 31 | 11 | 10 | 6 | 15% |
Canada
| 31 | 59% | 25% | 68% | 45 | 13 | 0 | 7 | 22% |
Japan 1
| 16 | 69% | 75% | 19% | 31 | 1 | 2 | 1 | 0% |
Japan 2
| 15 | 40% | 93% | 6% | 25 | 0 | 0 | 0 | 6.3% |
USA
| 34 | 50% | 12% | 32% |
na
| 3 | 1 | 3 | 12% |
Germany
| 35 | 66% | 17% | 37% | 34 | 4 | 5 | 4 | 8.5% |
Italy
| 19 | 74% | 100% | 0% | 29 | 0 | 5 | 0 | 0% |
All
| 239 | 59% | 48% | 34% | 31 | 32 | 22 | 21 | 11% |
All Admissions | Admissions ith AKI-Cr |
P
| Admissions without AKI-Cr | AKI-Cr in ICU |
P
| |
---|---|---|---|---|---|---|
Medical
| 125 | 19 (15%, 9-22%) | 0.45 | 106 | 7 (5.6%, 1.5-10%) | 0.05 |
Surgical
| 114 | 13 (11%, 5-17%) | 101 | 16 (14%, 8-21%) | ||
Sepsis
| 80 | 17 (21%, 12-30%) | 0.015 | 63 | 9 (11%, 4-18%) | 0.35 |
No Sepsis
| 159 | 15 (9.4%, 5-14%) | 143 | 14 (8.8%, 4-13%) |
Oliguria occurring prior to diagnosis of AKI-Cr
Longest duration of oliguria | Days with AKI-Cr next day | Days with no AKI-Cr next day | Sens. | Spec. | PPV | NPV | LR |
P
| RR of AKI-Cr |
---|---|---|---|---|---|---|---|---|---|
None
| 5 | 443 | |||||||
≥1 hr
| 18 | 257 | 0.78 | 0.63 | 0.07 | 0.99 | 2.1 | < 0.0001 | 5.9 |
≥2 hr
| 15 | 194 | 0.65 | 0.72 | 0.07 | 0.98 | 2.4 | 0.0003 | 4.6 |
≥3 hr
| 13 | 125 | 0.57 | 0.82 | 0.09 | 0.98 | 3.2 | < 0.0001 | 5.5 |
≥4 hr
| 12 | 95 | 0.52 | 0.86 | 0.11 | 0.98 | 3.8 | < 0.0001 | 6.3 |
≥5 hr
| 7 | 75 | 0.30 | 0.89 | 0.09 | 0.98 | 2.8 | 0.01 | 3.4 |
≥6 hr
| 5 | 50 | 0.21 | 0.93 | 0.09 | 0.97 | 3.1 | 0.02 | 3.8 |
≥12 hr
| 4 | 9 | 0.17 | 0.99 | 0.31 | 0.97 | 13.5 | 0.0005 | 11.5 |
Ability of oliguria to predict AKI-Cr
Longest duration of oliguria | Days with AKI-Cr next 2 days | Days with no AKI-Cr next 2 days | Sens. | Spec. | PPV | NPV | LR |
P
| RR of AKI |
---|---|---|---|---|---|---|---|---|---|
None
| 9 | 439 | |||||||
≥1 hr
| 26 | 249 | 0.74 | 0.63 | 0.09 | 0.98 | 2.1 | < 0.001 | 4.7 |
≥2 hr
| 22 | 187 | 0.62 | 0.72 | 0.10 | 0.97 | 2.3 | < 0.001 | 4.2 |
≥3 hr
| 18 | 120 | 0.51 | 0.83 | 0.13 | 0.97 | 2.9 | < 0.001 | 4.5 |
≥4 hr
| 17 | 90 | 0.49 | 0.87 | 0.16 | 0.97 | 3.7 | < 0.001 | 5.4 |
≥5 hr
| 10 | 72 | 0.29 | 0.90 | 0.12 | 0.96 | 2.7 | 0.004 | 3.1 |
≥6 hr
| 6 | 49 | 0.17 | 0.93 | 0.11 | 0.96 | 2.4 | 0.04 | 2.5 |
≥12 hr
| 4 | 9 | 0.11 | 0.99 | 0.31 | 0.96 | 8.7 | 0.002 | 7.0 |
Longest duration of oliguria | Days with AKI-Cr next day | Days with no AKI-Cr next day | Sens. | Spec. | PPV | NPV | LR |
P
| RR of AKI-Cr |
---|---|---|---|---|---|---|---|---|---|
None
| 5 | 238 | |||||||
≥1 hr
| 18 | 175 | 0.78 | 0.57 | 0.09 | 0.98 | 1.9 | < 0.001 | 4.5 |
≥2 hr
| 15 | 130 | 0.68 | 0.69 | 0.10 | 0.98 | 2.2 | < 0.001 | 4.3 |
≥3 hr
| 13 | 91 | 0.56 | 0.78 | 0.13 | 0.97 | 2.6 | < 0.001 | 4.2 |
≥4 hr
| 12 | 71 | 0.52 | 0.83 | 0.14 | 0.97 | 3.0 | < 0.001 | 4.6 |
≥5 hr
| 7 | 59 | 0.30 | 0.85 | 0.11 | 0.96 | 2.1 | 0.06 | 2.5 |
≥6 hr
| 5 | 40 | 0.22 | 0.90 | 0.11 | 0.95 | 2.2 | 0.08 | 2.4 |
≥12 hr
| 4 | 8 | 0.17 | 0.98 | 0.33 | 0.96 | 9.0 | 0.002 | 7.4 |
Individual episodes of oliguria and relation to occurrence of AKI-Cr
AKI-Cr | No AKI-Cr |
P
| |
---|---|---|---|
Episodes of oliguria
| 30 | 457 | |
Duration of oliguria
| 3 (1-4) | 2 (1-3.75) | 0.14 |
HR
| 90 (79-100) | 82 (70-95) |
0.02
|
MAP
| 75 (65-80) | 78 (70-87.5) |
0.01
|
CVP
| 11 (10-13) | 9 (7-12) |
0.02
|
On vasopressor or inotrope
| 65% (47-82) | 32% (28-37) |
0.0002
|
Action
| |||
None
| 17% (3-32) | 52% (47-57) |
0.0002
|
Fluid
| 43% (25-62) | 26% (22-30) |
0.05
|
Diuretic
| 47% (28-66) | 26% (22-30) |
0.02
|
Increase/start vasopressor or inotrope
| 17% (3-31) | 24% (17-30) | 0.51 |
Discussion
Statement of key findings
Comparison with previous studies
Significance of study findings
Study strengths and limitations
Future studies
Conclusions
Key messages
-
More patients develop AKI outside the ICU and present with it rather than developing AKI while in ICU.
-
Using oliguria in isolation as a trigger for intervention in ICU might lead to some patients receiving unnecessary intervention and other patients not receiving potentially helpful intervention.
-
Oliguria is relatively frequent in ICU patients and most episodes are not followed by AKI.
-
Oliguria has only a fair predictive ability for subsequent AKI and lacks clinical utility as a test at the observed frequencies of AKI in the ICU.
-
Oliguria accompanied by hemodynamic compromise or increasing vasopressor dose may represent a clinically useful trigger for other early biomarkers of renal injury with the goal of achieving a more accurate and timely identification of patients at risk of AKI.