College Of Intensive Care Medicine Of Australia And New Zealand
Abstract
OBJECTIVE: To determine if faster blood flow rate (BFR) has an effect on solute maintenance in continuous renal replacement therapy.
DESIGN: Prospective randomised controlled trial. SETTING: 24-bed, single centre, tertiary level intensive care unit.
PARTICIPANTS: Critically ill adults requiring continuous renal replacement therapy (CRRT).
INTERVENTIONS: Patients were randomised to receive one of two BFRs: 150 mL/min or 250 mL/min.
MAIN OUTCOME MEASURES: Changes in urea and creatinine concentrations (percentage change from baseline) and delivered treatment for each 12-hour period were used to assess solute maintenance.
RESULTS: 100 patients were randomised, with 96 completing the study (49 patients, 150 mL/min; 47 patients, 250 mL/min). There were a total of 854 12-hour periods (421 periods, 150 mL/min; 433 periods, 250 mL/ min). Mean hours of treatment per 12 hours was 6.3 hours (standard deviation [SD], 3.7) in the 150 mL/min group, and 6.7 hours (SD, 3.9) in the 250 mL/min group (P = 0.6). There was no difference between the two BFR groups for change in mean urea concentration (150 mL/min group, –0.06%; SD, 0.015; v 250 mL/min group, –0.07%; SD, 0.01; P = 0.42) or change in mean creatinine concentration (150 mL/min, –0.05%; SD, 0.01; v 250 mL/min, –0.08%; SD, 0.01; P = 0.18). Independent variables associated with a reduced percentage change in mean serum urea and creatinine concentrations were low haemoglobin levels (–0.01%; SD, 0.005; P = 0.002; and 0.01%; SD, 0.005; P = 0.006, respectively) and less hours treated (–0.023%; SD, 0.001; P = 0.000; and –0.02%; SD, 0.002; P = 0.001, respectively). No effect for bodyweight was found.
CONCLUSIONS: Faster BFR did not affect solute control in patients receiving CRRT; however, differences in urea and creatinine concentrations were influenced by serum haemoglobin and hours of treatment
