Renal replacement therapy for acute kidney injury in Australian and New Zealand intensive care units: a practice survey

Abstract

Background: There are few published data on the practice of renal replacement therapy (RRT) in Australian and New Zealand intensive care units. These data are essential for designing trials to compare new treatment approaches with "standard care".

Design: A prospective survey of RRT practice in ICUs interested in participating in the Australian and New Zealand Randomised Evaluation of Normal vs. Augmented Level (RENAL) Replacement Therapy in ICU Trial.

Setting and participants: 34 ICUs in Australia and New Zealand.

Outcome measures: Information on choice of therapeutic modality, technique, dose prescription, dose adjustment, technology, and replacement fluid composition before the initiation of the trial.

Results: All ICUs used continuous veno-venous RRT (CRRT) as the therapy of first choice. The most common technique, continuous veno-venous (CVV) haemodiafiltration, was used in 62% (21/34) of ICUs, followed by CVV haemofiltration in 35%, (12/34) and CVV haemodialysis in 3% (1/34). Replacement fluid was given prefilter (pre-dilution) in most cases (94%). Lactate-based replacement fluid or dialysate accounted for 55% of all commercial fluid supplied by pharmacies to participating ICUs, bicarbonate-based fluid for 43% and citrate-based fluid for 2%. In all ICUs, CRRT was prescribed by critical care physicians alone, according to unit policy. The effluent dose varied from 1.5 L/h to 4 L/h, and was not adjusted to body weight in any of the ICUs surveyed. The median (and mode) effluent dose was a fixed regimen of 2 L/h. The most commonly used machine was the Gambro Prisma (38%), followed by the Gambro AK 10 blood module combined with volumetric fluid infusion pumps (29%), and the Kimal Hygieia (18%). The median (and mode) blood flow was 200mL/min. Given the information supplied on pre-dilution rates, the median blood flow, and estimates of haematocrit and body weight based on previous surveys, the "typical" prescribed CRRT urea clearance dose ("standard") before the RENAL trial was estimated to be approximately 25 mL/kg/h.

Conclusions: These findings provide insight into RRT practice in ICUs in Australia and New Zealand, as well as useful data to assess whether the control group in the RENAL trial receives "standard" therapy as delivered in Australian and New Zealand trial centres at the time.