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Table 1 Characteristics of patients in the cohort

From: Fluid balance, intradialytic hypotension, and outcomes in critically ill patients undergoing renal replacement therapy: a cohort study

Variable Whole cohort Survivors Non-survivors P value
(n = 492) (n = 241) (n = 251)
Demographics
Age, years 62.9 (16.3) 61.0 (16.6) 64.7 (15.7) 0.01
Male 299 (60.8%) 148 (61.4%) 151 (60.2%) 0.78
Weight, kg (n = 413, 197, 216) 85.2 (24.3) 86.2 (24.4) 84.3 (24.2) 0.43
Comorbidities  
Charlson comorbidity index 2 (1, 3) 2 (1, 3) 2 (1, 4) <0.001
Congestive heart failure 89 (18.1%) 43 (17.8%) 46 (18.3%) 0.89
Liver cirrhosis 20 (4.1%) 4 (1.7%) 16 (6.4%) 0.01
Baseline creatinine, μmol/L (n = 490, 240, 250) 123.5 (86, 206) 136.5 (92, 223) 110 (83, 190) <0.001
Details of ICU admission  
Admission type  
 Medical 241 (49.0%) 115 (47.7%) 126 (50.2%) 0.58
  surgical 251 (51.0%) 126 (52.3%) 125 (49.8%)
  Cardiac surgery 86 (17.5%) 47 (19.5%) 39 (15.5%) 0.25
  Aortic aneurysm repair 29 (5.9%) 19 (7.9%) 10 (4.0%) 0.07
Admission diagnosis (n = 485, 238, 247) <0.001
  Trauma 25 (5.2%) 15 (6.3%) 10 (4.1%)  
  Cardiovascular 198 (40.8%) 106 (44.5%) 92 (37.3%)
  Respiratory 59 (12.2%) 24 (10.1%) 35 (14.2%)
  Gastrointestinal 91 (18.8%) 26 (10.9%) 65 (26.3%)
  Neurological 11 (2.3%) 6 (2.5%) 5 (2.0%)
  Renal 54 (11.1%) 37 (15.6%) 17 (6.9%)
  Other 47 (9.7%) 24 (10.1%) 23 (9.3%)
SOFA on day of ICU admission (n = 347, 164, 183) 12.1 (4.2) 11.6 (4.2) 12.5 (4.1) 0.05
SOFA - cardiovascular on day of ICU admission (n = 341, 161, 180) 3 (1, 4) 3 (1, 4) 3 (1, 4) 0.17
Any vasopressor use on days 1-7 272 (55.3%) 100 (41.5%) 172 (68.5%) <0.001
Details of RRT
SOFA on day RRT commenced (n = 490, 239, 251) 14.2 (4.2) 12.8 (3.9) 15.6 (4.1) <0.001
SOFA - cardiovascular on day RRT commenced (n = 490, 239, 251) 3 (1, 4) 3 (1, 4) 4 (2, 4) <0.001
Days from ICU admission to RRT 2 (1, 5.5) 2 (1, 4) 2 (1, 7) 0.002
Initial RRT modality <0.001
  IHD 212 (43.1%) 129 (53.5%) 83 (33.1%)  
 sLED 61 (12.4%) 31 (12.9%) 30 (12.0%)
  CRRT 219 (44.5%) 81 (33.6%) 138 (55.0%)
Days of RRT 7 (4, 13) 7 (4, 14) 6 (3, 12) 0.015
Mean daily fluid balance, mL 708 (−69, 1805) 413 (−371, 1106) 1134 (242, 2556) <0.001
Positive mean daily fluid balance on days 1-7 353 (71.7%) 151 (62.7%) 202 (80.5%) <0.001
Intradialytic hypotension on any day (n = 490, 240, 250) 428 (87.3%) 194 (80.8%) 234 (93.6%) <0.001
Intradialytic hypotension (% days up to 7) (n = 490, 240, 250) 50.0 (28.6, 80.0) 42.9 (20.0, 66.7) 66.7 (42.9, 100) <0.001
Clinical outcomes  
Days of ICU stay 14 (7, 26.5) 14 (7, 29) 14 (8, 24) 0.75
Days of hospital stay 28 (15.5, 48) 34 (23, 58) 21 (11, 39) <0.001
  1. Dichotomous data are of the form n (%) and continuous data of the form mean (SD) or median (Q1, Q3). The number of patients with data is provided where this differs from the total. P values are based on univariable logistic regression, except for days of ICU and hospital stay, days between ICU admission and RRT, and days of RRT, for which Wilcoxon signed-rank tests are reported. CRRT, continuous renal replacement therapy; ICU, intensive care unit; IHD, intermittent hemodialysis; RRT, renal replacement therapy; SLED, sustained low-efficiency dialysis; SOFA, sequential organ failure assessment score.