Table 1. Baseline Characteristics in the RICH Trial.
| Characteristic | Regional citrate anticoagulation (n = 300) | Systemic heparin anticoagulation (n = 296) |
|---|---|---|
| Demographics | ||
| Age, mean (SD), y | 67.5 (12.3) | 67.6 (12.5) |
| Weight, mean (SD), kg | 88.2 (26.8) | 87.4 (23.2) |
| Height, mean (SD), cm | 173.0 (8.6) | 173.7 (9.2) |
| Sex, No. (%) | ||
| Men | 206 (68.7) | 207 (69.9) |
| Women | 94 (31.3) | 89 (30.1) |
| Baseline characteristics | ||
| Baseline creatinine, mean (SD), mg/dL | 1.1 (0.3) | 1.2 (0.4) |
| eGFR, mean (SD), mL/min/1.73 m2 | 69.7 (26.1) | 64.8 (21.8) |
| Comorbidities, No. (%) | ||
| Hypertension | 201 (67.4) | 213 (72.2) |
| Chronic kidney disease (eGFR <60 mL/min/1.73 m2) | 113 (37.7) | 135 (46.1) |
| Cardiac arrhythmia | 105 (35.1) | 109 (36.8) |
| Congestive heart failure | 85 (30.4) | 85 (31.4) |
| Diabetes | 79 (26.3) | 100 (33.8) |
| COPD | 43 (14.3) | 53 (17.9) |
| Cirrhosis | 4 (1.3) | 5 (1.7) |
| Source of hospital admission, No. (%) | ||
| Surgical | 225 (75.0) | 228 (77.0) |
| Nonsurgical | 75 (25.0) | 68 (23.0) |
| Reason for admission to ICU, No. (%) | ||
| Cardiac surgery | 75 (25.0) | 80 (27.0) |
| Sepsisa | 56 (18.7) | 53 (17.9) |
| General surgery | 37 (12.3) | 37 (12.5) |
| Vascular surgery | 28 (9.3) | 26 (8.8) |
| Pneumonia/ARDS | 25 (8.3) | 26 (8.8) |
| Trauma | 17 (5.7) | 12 (4.1) |
| Other | 62 (20.7) | 62 (20.9) |
| Clinical measures at randomization, No. (%) | ||
| Mechanical ventilation | 242 (80.7) | 249 (84.1) |
| Receiving vasopressors | 277 (92.6) | 267 (90.5) |
| Creatinine, mean (SD), mg/dL | 2.4 (1.0) | 2.4 (1.2) |
| Oliguriab | 254 (84.7) | 251 (84.8) |
| No oliguria b | 46 (15.3) | 45 (15.2) |
| SOFA score, mean (SD)c | 11.5 (3.0) | 11.5 (3.0) |
| SOFA cardiovascular score, No. (%) | ||
| 0-2b,d | 43 (14.3) | 39 (13.2) |
| 3-4b,d | 257 (85.7) | 257 (86.8) |
| APACHE II, mean (SD)e | 28.4 (6.9) | 28.5 (7.1) |
| Fluid balance, median (IQR), mLf | 4725.0 (1750.0-8400.0) | 4044.0 (1458.0-8142.0) |
| Culture-proven infection | 145 (48.3) | 134 (45.3) |
| Gram positive | 76 (25.3) | 80 (27.0) |
| Gram negative | 89 (29.7) | 73 (24.7) |
| Gram positive and negative | 36 (12.0) | 31 (10.5) |
| Multidrug resistant | 22 (7.3) | 15 (5.1) |
| Fungal infection | 50 (16.7) | 51 (17.2) |
| Indication for CKRT, No./total No. patients with nonmissing data (%) | ||
| KDIGO stage 3g | 189/300 (63.0) | 173/296 (58.4) |
| Clinical indication | 261/300 (87.0) | 260/296 (87.8) |
| Urine output <200 mL/12 h or anuria | 109/173 (63.0) | 101/172 (58.7) |
| Fluid overload with edema | 89/170 (52.4) | 74/168 (44.0) |
| Serum urea >150 mg/dL | 36/174 (20.7) | 45/176 (25.6) |
| Potassium >6 mmol/L | 21/174 (12.1) | 33/176 (18.8) |
| Blood pH <7.15 | 11/173 (6.4) | 11/176 (6.3) |
| Magnesium >9.7 mg/dL | 0/152 (0) | 0/152 (0) |
| Time-based measures, median (IQR) | ||
| Time from randomization to initiation of CKRT | 2.4 (1.2-4.6) | 2.5 (1.0-4.5) |
| Time from ICU admission to CKRT initiation | ||
| All patients | 44.3 (22.3-91.9) | 35.5 (19.6-86.3) |
| Surgical patients | 47.5 (24.8-95.4) | 40.2 (22.4-86.9) |
| Nonsurgical patients | 28.5 (15.8-76.8) | 22.2 (10.7-78.1) |
| Time from operation to CKRT initiation (surgical patients) | 46.7 (24.8-95.6) | 43.0 (25.5-86.9) |
Abbreviations: ARDS, acute respiratory distress syndrome; APACHE II, Acute Physiology and Chronic Health Evaluation Score; CKRT, continuous kidney replacement therapy; COPD, chronic obstructive pulmonary disease; eGFR, estimated glomerular filtration rate; ICU, intensive care unit; IQR, interquartile range; KDIGO, Kidney Disease Improving Global Outcomes; RICH, Regional Citrate vs Systemic Heparin Anticoagulation for Continuous Kidney Replacement Therapy in Critically Ill Patients with Acute Kidney Injury; SOFA, Sequential Organ Failure Assessment.
SI conversion factors: To convert creatinine values to μmol/L, multiply by 88.4; magnesium values to mmol/L, multiply by 0.4114.
According to the Sepsis-3 guidelines.
Stratification variable.
Score that evaluates the degree of organ dysfunction and helps determine the mortality risk of a patient. SOFA score values range from 0 to 24, with higher values indicating highest risk of mortality (SOFA 10-11 indicates 50% mortality).
Cardiovascular SOFA score is the subscore of the SOFA score related to the hemodynamic situation of the patient. Values range from 0 to 4, with higher values indicating greater hemodynamic instability and vasoactive support.
An ICU mortality prediction score with values ranging from 0 to 71. Higher values indicate higher probability of mortality (score 25-29 indicates 55% mortality).
Fluid balance from ICU admission to randomization, irrespective of the underlying condition.
KDIGO stages acute kidney injury in 3 categories, with KDIGO stage 3 being acute kidney injury with the greatest severity.