Table 2.
Illness Severity and Laboratory Findings of Critically Ill COVID-19 Patients on ICU Day 1
| Characteristic | Maintenance Dialysis Patients (n = 143) | Patients With Non-Dialysis-Dependent CKD (n = 521) | Patients Without Pre-existing CKD (n = 3,600) |
|---|---|---|---|
| Vital signs | |||
| Highest temperature, °C | 37.8 [37.1-38.5] | 37.7 [37.1-38.4] | 38.0 [37.2-38.9] |
| Fever: >38°C | 65 (45%) | 213 (41%) | 1,837 (51%) |
| Lowest systolic BP, mm Hg | 92 [81-108] | 96 [84-112] | 97 [85-110] |
| Highest heart rate, beats/min | 101 [88-119] | 101 [87-116] | 105 [92-121] |
| Highest respiratory rate, breaths/min | 29 [23-35] | 30 [26-36] | 32 [26-38] |
| Severity of illness markers | |||
| Invasive mechanical ventilation | 80 (56%) | 311 (60%) | 2,284 (63%) |
| PEEP, cm H2O | 10 [8-14] | 10 [10-15] | 12 [10-15] |
| Pao2:Fio2 ratio, mm Hg | 164 [101-267] | 125 [79-190] | 122 [83-191] |
| Noninvasive mechanical ventilation | 3 (2%) | 16 (3%) | 86 (2%) |
| High-flow nasal cannula or nonrebreather mask | 29 (20%) | 121 (23%) | 801 (22%) |
| AKI requiring dialysis | — | 27 (5%) | 55 (2%) |
| Renal SOFA scorea | |||
| 0 (creatinine < 1.2 mg/dL) | 0 (0%) | 62 (12%) | 2,347 (65%) |
| 1 (creatinine 1.2-1.9 mg/dL) | 0 (0%) | 168 (32%) | 844 (23%) |
| 2 (creatinine 2.0-3.4 mg/dL) | 0 (0%) | 143 (27%) | 255 (7%) |
| 3 (creatinine 3.5-4.9 mg/dL) | 0 (0%) | 68 (13%) | 71 (2%) |
| 4 (creatinine ≥ 5.0 mg/dL or KRT) | 143 (100%) | 80 (15%) | 83 (2%) |
| Liver SOFA scoreb | |||
| 0 (bilirubin < 1.2 mg/dL) | 132 (92%) | 482 (93%) | 3,253 (90%) |
| 1 (bilirubin 1.2-1.9 mg/dL) | 7 (5%) | 28 (5%) | 251 (7%) |
| ≥ 2 (bilirubin ≥ 2.0 mg/dL) | 4 (3%) | 11 (2%) | 96 (3%) |
| Coagulation SOFA scorec | |||
| 0 (platelet count ≥ 150 K/μL) | 90 (63%) | 408 (78%) | 2,989 (83%) |
| 1 (platelet count 100-149 K/μL) | 37 (26%) | 80 (15%) | 467 (13%) |
| ≥2 (platelet count < 100 K/μL) | 16 (11%) | 33 (6%) | 144 (4%) |
| Vasopressor or inotrope use | 72 (50%) | 219 (42%) | 1,482 (41%) |
| Shockd | 17 (12%) | 75 (14%) | 370 (10%) |
| Coinfections | |||
| Bacterial pneumonia | 24 (17%) | 85 (16%) | 489 (14%) |
| Bacteremia or endocarditis | 11 (8%) | 16 (3%) | 80 (2%) |
| Laboratory findings | |||
| WBC count, ×103/μL | 7.5 [5.7-10.4] | 8.2 [5.8-11.6] | 8.5 [6.1-11.9] |
| Lymphocyte count, ×103/μL | 9.7 [5.4-15.1] | 9.4 [5.7-14.9] | 10.0 [6.0-15.1] |
| Hemoglobin, g/dL | 10.3 [9.0-11.8] | 11.4 [9.5-12.9] | 12.8 [11.4-14.2] |
| Platelet count, ×103/μL | 167 [124-212] | 202 [155-258] | 218 [167-281] |
| Serum creatinine, mg/dL | 7.7 [5.6-10.1] | 2.2 [1.5-3.6] | 1.0 [0.8-1.4] |
| AST, U/L | 46 [30-72] | 48 [33-80] | 54 [36-85] |
| ALT, U/L | 23 [17-40] | 28 [18-47] | 38 [24-62] |
| Bilirubin, mg/dL | 0.6 [0.4-0.7] | 0.5 [0.3-0.8] | 0.6 [0.4-0.8] |
| Lactate, mmol/L | 1.6 [1.0-2.6] | 1.6 [1.0-2.4) | 1.6 [1.1-2.3] |
| CRP, mg/L | 170.0 [73.0-277.7] | 142.4 [84.8-217.5] | 151.0 [81.6-235.7] |
| IL-6, pg/mL | 121.4 [41.3-320.4] | 52.0 [19.0-175.3] | 56.0 [18.0-156.6] |
| Arterial pH | 7.37 [7.28-7.43] | 7.34 [7.26-7.40] | 7.38 [7.30-7.44] |
| Fibrinogen, mg/dL | 542 [369-619] | 588 [442-732] | 614 [491-764] |
| D-Dimer, ng/mL | 1,347 [609-2,623] | 1,385 [670-3,018] | 1,270 [652-3,459] |
| Ferritin, ng/mL | 3,406 [1,795-6,271] | 984 [450-1,981] | 947 [489-1,919] |
| Troponin T, ng/mL | 175 [95-364] | 51 [25-110] | 12 [4-40] |
| Troponin I, ng/mL | 140 [70-330] | 55 [20-170] | 30 [10-110] |
Note: Values are given as number (percent) for categorical variables and as median [interquartile range] for continuous variables. Absolute standardized mean differences comparing the patient groups to one another are presented in Tables S2 to S4. Variables with missing values are presented in Table S13.
Abbreviations: AKI, acute kidney injury; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BP, blood pressure; CKD, chronic kidney disease; COVID-19, coronavirus disease 2019; CRP, C-reactive protein; Fio2, fraction of inspired oxygen; ICU, intensive care unit; IL-6, interleukin 6; KRT, kidney replacement therapy; PEEP, positive end-expiratory pressure; SOFA, Sequential Organ Failure Assessment.
Renal component of the SOFA score was based on the serum creatinine level. Patients who did not have a serum creatinine drawn on ICU day 1 were classified as having renal SOFA score of 0, and patients on KRT were classified as having a renal SOFA score of 4.49
Liver component of the SOFA score. Patients who did not have a serum bilirubin drawn on ICU day 1 were classified as having a liver SOFA score of 0.49
Coagulation component of the SOFA score. Patients who did not have a platelet count drawn on ICU day 1 were classified as having a coagulation SOFA score of 0.49
Shock is defined as the requirement of 2 or more vasopressors or inotropes.