Table 2. Baseline laboratory values of the study population.
| Variables | Overall N = 99 | Non-AKI N = 41 | AKI N = 58 | AKI stage 1 N = 12 | AKI stage 2 N = 16 | AKI stage 3 N = 29 | p value Non-AKI vs. AKI | p value across AKI stages |
|---|---|---|---|---|---|---|---|---|
| Critical Care Variables | ||||||||
| IMV [n (%)] | 65 (64.3) | 23 (45) | 41 (83.6) | 8 (72.7) | 12 (92.3) | 21 (84) | 0.01 | 0.44 |
| Prone MV [n (%)] | 28 (47.4) | 2 (14) | 26 (57.7) | 6 (75) | 11 (84) | 9 (39) | 0.01 | 0.01 |
| Vasoactive Drugs [n (%)] | 49 (48.5) | 18 (35.2) | 31(63.2) | 6 (75) | 8 (72.7) | 17 (80.9) | 0.01 | 0.85 |
| Laboratory studies | ||||||||
| Creatinine, mg/dL* | 0.98 (0.84–1.51) | 0.87 (0.74–0.99) | 1.23 (0.9–1.72) | 1.02 (0.91–1.56) | 1.13 (0.92–1.5) | 1.51 (0.89–1.9) | 0.01 | 0.55 |
| Nitrogen urea mg/dL* | 18.11 (13.9–26.2) | 14.2 (10.9–20.24) | 23 (16–36.5) | 22.1 (17.0–26.6) | 19.05 (15.5–23.8) | 28.7 (16.1–37.03) | 0.01 | 0.26 |
| Creatinine mg/dL, day 7* | 1.04 (0.71–1.58) | 0.72 (0.62–0.91) | 1.4 (1–1.92) | 1.19 (0.77–1.47) | 1.32 (0.93–1.84) | 1.68 (1.12–2.57) | 0.01 | 0.06 |
| Creatinine, mg/dL on AKI* | 1.62 (1.37–2.06) | NA | 1.62 (1.37–2.06) | 1.31 (1.1–1.48) | 1.52 (1.35–1.79) | 1.93 (1.62–2.99) | NA | 0.01 |
| Maximum Creatinine, mg/dL* | 2.5 (1.71–5.36) | NA | 2.5 (1.71–5.36) | 1.4 (1.18–1.59) | 1.87 (1.56–2.3) | 5.5 (2.99–6.63) | NA | 0.01 |
| CPK, U/I* | 98.8 (60–193.3) | 89.4 (50.4–268.62 | 108.8 (69.1–177.1) | 139.5 (103.0–311.7) | 107.7 (64.7–168.4) | 89 (71.2–174.9) | 0.55 | 0.38 |
| Glucose, mg/dL* | 111.6 (98.2–153) | 101.3 (90.5–111.9) | 124.7 (108.8–184.2) | 127.9 (119.2–237.6) | 112.15 (102–129.4) | 136.5 (110.2–194.7) | 0.01 | 0.07 |
| Uric acid, mg/dL* | 5.17 (4.07–7.58) | 4.52 (3.6–5.9) | 5.7 (4.6–7.3) | 6.3 (5.06–6.9) | 4.9 (3.5–6.7) | 6.27 (4.73–7.58) | 0.01 | 0.26 |
| PaO2/FiO2, mm/Hg* | 194.05 (123.14–238.81) | 211.67 (153–248) | 181.19 (121–228) | 212.5 (146–213) | 194 (146–224) | 172.8 (108–224) | 0.12 | 0.76 |
| Lactate dehydrogenase, UI/L* | 373.1 (235–512.3) | 346.45 (291.3–492.4) | 378 (208–519.7) | 369.9 (263.5–643.3) | 398.2 (296–453.1) | 390.8 (214.6–535.4) | 0.56 | 0.97 |
| C-reactive protein, mg/dL‡ | 17.72 (9.65) | 15.03 (9.3) | 19.57 (9.5) | 21.5 (9.7) | 20.9 (6.6) | 16.8(8.7) | 0.03 | 0.09 |
| D-dimer, μg/ml* | 1.1 (0.7–1.78) | 0.84 (0.6–1.29) | 1.5 (0.83–2.26) | 1.09 (0.79–1.8) | 1.43 (0.88–2.34) | 1.75 (0.97–2.32) | 0.01 | 0.32 |
| Procalcitonin, ng/ml* | 0.2 (0.09–0.58) | 0.18 (0.08–0.3) | 0.25 (0.11–0.71) | 0.22 (0.14–0.67) | 0.26 (0.19–0.46) | 0.24 (0.1–1.2) | 0.01 | 0.85 |
| Troponin, pg/ml* | 4.8 (2.5–12.9) | 3 (2–5.2) | 8 (4.25–38.6) | 8.1 (2.1–55.1) | 12 (7.55–14.8) | 6.05 (4.35–51.2) | 0.01 | 0.82 |
| Albumin, g/dL‡ | 3.44 (0.5) | 3.63 (0.5) | 3.3 (0.46) | 3.56 (0.3) | 3.12 (0.38) | 3.28 (0.52) | 0.01 | 0.02 |
| Hemoglobin, g/dL* | 15.3 (14.4–16.3) | 15.2 (14.6–15.8) | 15.3 (14.4–16.6) | 16.1 (15.1–16.7) | 14.7 (13.3–16.03) | 15.4 (14.8–16.2) | 0.48 | 0.23 |
| Leucocytes, 10x3 mm3* | 8.9 (6.6–11.5) | 8.05 (6.5–11) | 9 (6.7–11.5) | 9.45 (6.3–11.5) | 7.3 (6.38–9.2) | 9.5 (7.25–12.5) | 0.34 | 0.21 |
| Lymphocytes, 10x3 mm3* | 0.8 (0.6–1.2) | 0.9 (0.8–1.33) | 0.7 (0.5–1) | 0.7 (0.48–0.72) | 0.7 (0.5–1.02) | 0.85 (0.5–1.2) | 0.01 | 0.194 |
| Platelets 10x3mm3* | 202 (171–266) | 217.5 (178.5–266.75) | 201 (162–257) | 196.5 (158.25–251.75) | 186 (165.5–267.2) | 201.5 (165–261.25) | 0.34 | 0.85 |
| Platelets/Lymphocytes Index* | 246.25 (173.64–340) | 233.75 (162–264) | 300 (202.2–424) | 317.4 (267.7–460) | 308.1 (234.5–419.9) | 282.7 (176.6–383.4) | 0.01 | 0.45 |
| Platelets/Neutrophils Index* | 29.13 (20.49–41.19) | 34.9 (25.08–44.91) | 27.66 (19–36.5) | 27.1 (19.3–33.04) | 28.8(25.4–39.5) | 26.1 (18.8–36.5) | 0.02 | 0.56 |
| Outcomes | ||||||||
| Mortality (%)* | 44 (44.4) | 6 (14.6) | 38 (65.5) | 3 (25) | 11 (68.7) | 23 (79.3) | 0.01 | 0.01 |
| Days in hospital* | 12 (8.5–23.5) | 9 (8–16) | 14 (9–30) | 14.5 (9.75–32.25) | 13.5 (9–24.75) | 15(9–33) | 0.02 | 0.91 |
| Days to death* | 12 (8.5–23.5) | 7 (4.25–17.25) | 12.5 (9–20) | 9 (8–18) | 13 (9–15) | 12 (8–21) | 0.01 | 0.96 |
| Days to AKI* | 2 (1–9) | NA | 2 (1–9) | 3 (1–9) | 4 (1–10.75) | 2 (1–8) | NA | 0.77 |
| Days on IMV* | 1 (0–1) | 1 (0–1) | 1 (0–1) | 1 (0–1) | 1(0–1) | 1(0–1) | 0.96 | 0.80 |
AKI, acute kidney injury; CPK, creatine phosphokinase; PaO2/FiO2 arterial partial pressure of oxygen/fraction inspired oxygen; IMV, invasive mechanical ventilation; Prone MV, prone mechanical ventilation; vasoactive drugs (norepinephrine and vasopressin on admission). Admission laboratory test results were used unless otherwise specified.
*Data are expressed as medians (interquartile ranges).
‡Data are expressed as means (standard deviation).