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Table 1 Baseline characteristics of patients by AKI and RRT status

From: Long-term outcomes in patients who received veno-venous extracorporeal membrane oxygenation and renal replacement therapy: a retrospective cohort study

Characteristica Overall, N = 300a AKI, RRT, N = 178 AKI, no RRT, N = 52 No AKI, N = 70 P-value (all groups)b P-value (AKI vs. no AKI)c
Sex 0.010 0.003
 Male 171 (57%) 109 (61%) 33 (63%) 29 (41%)   
 Female 129 (43%) 69 (39%) 19 (37%) 41 (59%)   
Ethnicityd 0.312 0.121
 White 230 (77%) 138 (78%) 38 (73%) 54 (78%)   
 Black 29 (9.8%) 14 (8.0%) 5 (9.6%) 10 (14%)   
 Asian 27 (9.1%) 16 (9.1%) 6 (12%) 5 (7.2%)   
 Mixed 0 (0%) 0 (0%) 0 (0%) 0 (0%)   
 Other/not-stated 11 (3.7%) 8 (4.5%) 3 (5.8%) 0 (0%)   
Age (years) 44.5 (34.0, 54.2) 48.5 (40.0, 57.0) 39.0 (30.8, 48.0) 41.0 (25.2, 48.0) < 0.001 < 0.001
Weight (kg)d 80.0 (70.0, 100.0) 84.6 (70.0, 102.0) 80.0 (70.0, 102.0) 73.0 (60.0, 85.0) 0.002 < 0.001
BMI (kg/m2)d 27.3 (24.1, 33.4) 27.7 (24.4, 33.8) 28.6 (24.5, 32.6) 25.4 (22.0, 31.1) 0.039 0.013
Diabetes 37 (12%) 26 (15%) 6 (12%) 5 (7.1%) 0.269 0.131
Hypertension 52 (17%) 39 (22%) 5 (9.6%) 8 (11%) 0.039 0.136
Congestive heart failure 8 (2.7%) 6 (3.4%) 1 (1.9%) 1 (1.4%) 0.881 0.686
Coronary artery disease 8 (2.7%) 5 (2.8%) 1 (1.9%) 2 (2.9%) > 0.999 > 0.999
Atrial fibrillation 4 (1.3%) 3 (1.7%) 0 (0%) 1 (1.4%) > 0.999 > 0.999
Peripheral artery disease 1 (0.3%) 1 (0.6%) 0 (0%) 0 (0%) > 0.999 > 0.999
Cerebrovascular accidents (history) 6 (2.0%) 3 (1.7%) 2 (3.8%) 1 (1.4%) 0.523 > 0.999
Chronic lung disease 71 (24%) 34 (19%) 13 (25%) 24 (34%) 0.039 0.017
Chronic liver disease 10 (3.3%) 9 (5.1%) 1 (1.9%) 0 (0%) 0.109 0.124
Any active malignancy within 5 yrs 14 (4.7%) 9 (5.1%) 2 (3.8%) 3 (4.3%) > 0.999 > 0.999
Type of malignancy > 0.999 > 0.999
 Solid tumour 5 (1.7%) 3 (1.7%) 1 (1.9%) 1 (1.4%)   
 Haematologic tumour 9 (3.0%) 6 (3.4%) 1 (1.9%) 2 (2.9%)   
Other immunosuppressive conditions 30 (10%) 22 (12%) 2 (3.8%) 6 (8.6%) 0.178 0.649
Chronic kidney disease (history) 7 (2.3%) 6 (3.4%) 1 (1.9%) 0 (0%) 0.308 0.206
Use of nephrotoxic drugse 78 (26%) 56 (31%) 8 (15%) 14 (20%) 0.029 0.191
SOFA score on day 1 of ICU admission 9.0 (6.0, 12.0) 11.0 (8.0, 14.0) 8.0 (5.0, 9.0) 7.0 (4.0, 8.0) < 0.001 < 0.001
Reason for ECMO support (groups too small) 0.002
 Infection 215 (72%) 143 (80%) 33 (63%) 39 (56%)   
 Immune/inflammation 24 (8.0%) 9 (5.1%) 5 (9.6%) 10 (14%)   
 Asthma or COPD exacerbation 20 (6.7%) 2 (1.1%) 7 (13%) 11 (16%)   
 Trauma 12 (4.0%) 7 (3.9%) 2 (3.8%) 3 (4.3%)   
 Postoperative 2 (0.7%) 1 (0.6%) 1 (1.9%) 0 (0%)   
 Cardiac 8 (2.7%) 6 (3.4%) 1 (1.9%) 1 (1.4%)   
 Others 19 (6.3%) 10 (5.6%) 3 (5.8%) 6 (8.6%)   
ECMO speed (rpm)—initial setting 3,132.5 (2820.0, 3496.2) 3,202.5 (2832.5, 3500.0) 3,145.0 (2828.8, 3586.2) 3,017.5 (2761.2, 3330.0) 0.134 0.047
ECMO duration (days) 9.0 (6.0, 16.0) 10.0 (7.0, 16.0) 8.0 (6.0, 14.0) 8.0 (6.0, 17.8) 0.131 0.389
Baseline serum creatinine (µmol/L) 80 (69, 97) 93 (76, 99) 82 (68, 98) 60 (47, 74) 0.0001 < 0.001
  1. AKI acute kidney injury, BMI body mass index, COPD chronic obstructive lung disease, ECMO extracorporeal membrane oxygenation, ICU intensive care unit, SOFA Sequential Organ Failure Assessment, RRT renal replacement therapy
  2. an (%); median (IQR)
  3. bCategorical variables: Pearson’s Chi-squared test or Fisher’s exact test for small group sizes; continuous variables: Kruskal–Wallis rank sum test
  4. cCategorical variables: Pearson’s Chi-squared test or Fisher’s exact test for small group sizes; continuous variables: Wilcoxon rank sum test
  5. dMissing data: ethnicity (n = 3), weight (n = 15), BMI (n = 45)
  6. eDefined as the receipt of non-steroidal anti-inflammatory drugs, contrast media or nephrotoxic antibiotics (e.g. aminoglycosides, vancomycin, piperacillin–tazobactam, colistin) within 7 days prior to ECMO initiation