Table 4.
Kynurenine Pathway Activation by Age, Cardiac Arrest Presenting Rhythm, Duration of Cardiac Arrest, and Patient Characteristics
| Variable | TRP, μmol/L | KYN, μmol/L | Ratio of KYN of TRP | KYNA, nmol/L | 3‐HAA, nmol/L |
|---|---|---|---|---|---|
| Admission levels | |||||
| Age, y | |||||
| <59 | 38.4 (31.7 to 49.8) | 2.2 (1.6 to 3.0) | 0.05 (0.04 to 0.08) | 42.3 (21.2 to 80.5) | 23.9 (17.8 to 49.2) |
| 59 to 68 | 39.8 (30.9 to 47.9) | 2.4 (1.7 to 3.2) | 0.06 (0.04 to 0.08) | 50.5 (26.7 to 90.6) | 29.2 (17.8 to 58.5) |
| >68 | 41.1 (28.8 to 51.6) | 3.1 (2.4 to 4.1) | 0.07 (0.06 to 0.1) | 64.6 (37.9 to 100.1) | 29.7 (16.9 to 46.1) |
| P value | 0.849 | <0.0001 | 0.0006 | 0.0298 | 0.5488 |
| Cardiac arrest presenting rhythm | |||||
| Shockable | 42.4 (34.1 to 53.1) | 2.4 (1.7 to 3.2) | 0.06 (0.04 to 0.08) | 57.3 (38.9 to 100.3) | 24.7 (16.9 to 42.0) |
| Nonshockable | 33.1 (24.8 to 42.3) | 2.9 (1.7 to 3.2) | 0.08 (0.06 to 0.12) | 31.6 (15.3 to 82.8) | 33.7 (21.4 to 72.4) |
| P value | 0.0001 | 0.0282 | 0.0001 | 0.0001 | 0.0056 |
| Time to ROSC, min | |||||
| 1 to 15 | 39.8 (30.4 to 51.3) | 2.4 (1.6 to 3.2) | 0.06 (0.04 to 0.09) | 40.8 (23.9 to 77.6) | 22.2 (13.3 to 35.8) |
| 16 to 24 | 40.2 (29.0 to 50.0) | 2.6 (1.8 to 3.9) | 0.06 (0.04 to 0.1) | 54.6 (29.4 to 93.0) | 31.7 (19.8 to 58.6) |
| 25 to 57 | 38.2 (32.0 to 49.8) | 2.6 (2.0 to 3.4) | 0.07 (0.05 to 0.08) | 57.3 (34.9 to 101.2) | 29.8 (18.6 to 59.8) |
| P value | 0.901 | 0.206 | 0.185 | 0.0294 | 0.0046 |
| Lowest 24‐hour systolic blood pressure, mm Hg | |||||
| ≥100 | 42.4 (33.3 to 57.1) | 2.3 (1.7 to 3.1) | 0.05 (0.04 to 0.07) | 34.9 (20.8 to 83.9) | 24.5 (15.0 to 49.3) |
| 70 to 99 | 39.0 (30.8 to 49.6) | 2.5 (1.8 to 3.2) | 0.06 (0.04 to 0.09) | 52.9 (29.3 to 87.0) | 25.8 (17.6 to 44.6) |
| <70 | 36.6 (28.3 to 48.4) | 3.7 (2.9 to 4.7) | 0.1 (0.07 to 0.14) | 90.6 (27.2 to 384.8) | 66.6 (19.5 to 109.2) |
| P value | 0.156 | 0.0002 | <0.0001 | 0.0141 | 0.009 |
| 24‐hour HCO3, mEq/L | |||||
| ≥20 | 39.8 (33.1 to 51.6) | 2.2 (1.7 to 3.0) | 0.05 (0.04 to 0.08) | 45.7 (26.6 to 68.9) | 24.7 (16.1 to 44.6) |
| 15 to 19 | 40.1 (29.1 to 50.0) | 2.6 (2.0 to 3.7) | 0.07 (0.05 to 0.09) | 52.8 (26.6 to 99.7) | 28.3 (18.6 to 44.4) |
| <15 | 33.3 (28.3 to 44.8) | 3.2 (2.9 to 4.3) | 0.1 (0.07 to 0.16) | 95.6 (66.5 to 349.4) | 72.4 (28.9 to 119.8) |
| P value | 0.273 | <0.0001 | <0.0001 | <0.0001 | 0.0001 |
| Outcome at 12 months | |||||
| Good | 39.9 (33.2 to 52.6) | 2.2 (1.7 to 3.0) | 0.05 (0.040 to 0.08) | 49.2 (26.7 to 80.0) | 23.6 (16.5 to 38.3) |
| Poor | 39.0 (29.0 to 48.2) | 2.9 (2.2 to 4.1) | 0.07 (0.06 to 0.1) | 58.7 (28.4 to 100.6) | 33.9 (17.9 to 66.5) |
| P value | 0.1224 | <0.0001 | <0.0001 | 0.046 | 0.002 |
Data are reported as median (interquartile range). 3‐HAA indicates 3‐hydroxyanthranilic acid; KYN, kynurenine; KYNA, kynurenic acid; ROSC, return of spontaneous circulation; TPR, tryptophan.