Background
Methods
Study population and collection of urinary samples
Definition of AKI
Assessment of tryptophan degradation products
Statistical analysis
Results
Early recovery | Late/Non-Recovery |
p
| |
---|---|---|---|
Number | 67 | 25 | |
Age, years (mean ± SD) | 68 ± 14 | 65 ± 15 | NS |
Female gender, n (%) | 19 (28) | 11 (44) | NS |
Hypertension, n (%) | 43 (64) | 15 (60) | NS |
Diabetes, n (%) | 21 (31) | 6 (24) | NS |
Baseline creatinine level, mg/dl (mean ± SD) | 0.97 ± 0.38 | 0.98 ± 0.41 | NS |
Chronic kidney diseasea, n (%) | 19 (28) | 5 (20) | NS |
ICU admission due to | |||
Cardiovascular disease, n (%) | 18 (27) | 5 (20) | NS |
Infection, n (%) | 10 (15) | 6 (24) | NS |
Neurological disease | 5 (7) | 2 (8) | NS |
Liver failure | 1 (1) | 3 (12) | NS |
Kidney failure | 2 (3) | 1 (4) | NS |
Surgery | 31 (46) | 8 (32) | NS |
Time from ICU admission to day 1, days (median (IQR)) | 1 (IQR1-3) | 1 (IQR 1-12) | NS |
Patients with SIRS on day 1, n (%) | 42 (63) | 19 (76) | NS |
Patient with SIRS and infection on day 1, n (%) | 6 (9) | 6 (24) | NS |
APACHE 2 score on admission, (mean ± SD) | 27 ± 7 | 32 ± 7 | < 0.005 |
SOFA scoreb on day 1, (mean ± SD) | 9 ± 4 | 12 ± 4 | < 0.005 |
Patients under vasoactive drugs, n (%) | 42 (63) | 18 (72) | NS |
Invasive ventilation, n (%) | 47 (70) | 20 (80) | NS |
Creatinine on day 1, mg/dl (mean ± SD) | 0.97 ± 0.38 | 0.98 ± 0.41 | NS |
Oliguriac on day 1, n (%) | 7 (10) | 3 (12) | NS |
Hemoglobin on day 1, g/dl (mean ± SD) | 108 ± 16 | 99 ± 20 | < 0.05 |
Thrombocyte count on day 1, x 109/l (mean ± SD) | 188 ± 98 | 130 ± 88 | < 0.05 |
C reactive protein on day 1, mg/l (mean ± SD) | 14 ± 10 | 12 ± 11 | NS |
Early Recovery | Late/Non-Recovery | p-value | |
---|---|---|---|
Number | 67 | 25 | |
Maximum creatinine level, mg/dl (mean ± SD) | 2.0 ± 0.9 | 3.6 ± 2.0 | < 0.0001 |
Minimal eGFR, ml/min (mean ± SD) | 45 ± 25 | 21 ± 9 | < 0.0001 |
RIFLE class, R/I/F | 42/18/7 | 0/6/19 | < 0.0001 |
Duration of AKI, days (mean ± SD) | 3.0 ± 1.8 | 21.5 ± 19.8 | < 0.0001 |
Patients on RRT, n (%) | 2 (3) | 15 (63) | < 0.0001 |
Patients with RBC transfusions, n (%) | 30 (45) | 19 (76) | 0.01 |
Red blood cell transfusions, n (mean ± SD) | 1.4 ± 2.3 | 3.7 ± 4.1 | < 0.001 |
Length of hospital stay, days (mean ± SD) | 34 ± 33 | 50 ± 31 | < 0.005 |
Length of ICU stay, days (mean ± SD) | 18 ± 20 | 31 ± 26 | < 0.01 |
28-day mortality, n (%) | 13 (20) | 11 (46) | < 0.05 |
90-day mortality, n (%) | 25 (34) | 15 (63) | NS |
Urinary excretion of tryptophan metabolites
DAY 1 | DAY 2 | DAY 3 | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
ER | LNR |
p
| ER | LNR |
p
| ER | LNR |
p
| ||
Trp/cr | umol/mmol | 5.51 ± 4.95 | 6.10 ± 6.75 | NS | 9.50 ± 14.91 | 7.28 ± 7.84 | NS | 12.08 ± 10.49 | 6.0 ± 5.6 | < 0.005 |
Kyn/cr | umol/mmol | 2.90 ± 4.87 | 2.94 ± 7.65 | NS | 3.88 ± 5.69 | 4.30 ± 8.80 | NS | 5.60 ± 8.17 | 2.2 ± 4.8 | < 0.0001 |
KynA/cr | umol/mmol | 3.19 ± 3.44 | 7.59 ± 6.81 | < 0.005 | 1.87 ± 1.10 | 9.17 ± 9.67 | < 0.0001 | 2.00 ± 1.28 | 6.51 ± 9.49 | < 0.001 |
3 OH AA/cr | umol/mmol | 1.36 ± 2.86 | 1.04 ± 1.82 | NS | 1.14 ± 1.62 | 0.72 ± 1.04 | NS | 2.02 ± 3.11 | 0.75 ± 0.99 | < 0.05 |
Serotonine/cr | umol/mmol | 0.045 ± 0.075 | 0.053 ± 0.11 | NS | 0.038 ± 0.026 | 0.036 ± 0.041 | NS | 0.045 ± 0.035 | 0.027 ± 0.037 | < 0.005 |
Phenylalanine/cr | umol/mmol | 5.50 ± 5.02 | 9.41 ± 12.84 | NS | 7.56 ± 11.80 | 9.77 ± 12.03 | NS | 8.49 ± 7.55 | 6.73 ± 6.81 | NS |
OH-Trp/cr | umol/mmol | 0.12 ± 0.18 | 0.23 ± 0.72 | NS | 0.11 ± 0.077 | 0.13 ± 0.106 | NS | 0.11 ± 0.068 | 0.11 ± 0.078 | NS |
KynA/Trp | 1.37 ± 2.86 | 2.30 ± 2.73 | < 0.01 | 0.47 ± 0.66 | 1.8 ± 1.8 | < 0.0001 | 0.26 ± 0.20 | 1.33 ± 1.25 | < 0.0001 | |
Kyn/Trp | 0.66 ± 1.24 | 0.34 ± 0.33 | NS | 0.64 ± 1.08 | 0.58 ± 0.93 | NS | 0.73 ± 1.58 | 0.30 ± 0.41 | < 0.05 |
Prognostic performance of tryptophan metabolites
ROC AUC
|
CI 95%
|
Wald χ2
|
P<
| |
---|---|---|---|---|
KynA | 0.72 | 0.59-0.85 | 8.88 | 0.003 |
SOFA score | 0.70 | 0.67-0.83 | 6.75 | 0.01 |
Delta diuresis (day 1 – baseline), ml/h | 0.68 | 0.55-0.81 | 3.84 | 0.05 |
Diuresis, ml/h | 0.63 | 0.51-0.76 | 3.58 | 0.06 |
Delta serum creatinine (day 1 – baseline) | 0.61 | 0.47-0.74 | 2.14 | 0.14 |
Serum creatinine, mg/dL | 0.59 | 0.46-0.72 | 1.38 | 0.24 |