What is the optimal dose for dialysis? This question, too, is plagued by inconclusive research findings. Paganini was the first to raise it formally in patients with acute renal failure; his research team found improved survival with higher doses, but had excluded the sickest and healthiest patients (according to probability of survival) from the study.4 This was followed by two additional studies with results that also seemed to support higher doses.1,5
Then in 2008, in a a similar randomized controlled trial, Tolwani et al6 found no survival benefit with higher versus lower dosing; participants in this study were not excluded based on severity of illness. Also, Tolwani’s research team identified failure to achieve prescribed doses as one factor complicating dose comparison.6
Finally, two large randomized controlled trials were performed to evaluate dosage, one in the US7 and one in Australia and New Zealand.8 Neither research team was able to confirm survival benefits with higher-dose renal replacement therapy, and there were inconsistencies between doses used in the study and standard practice in the US. In fact, the low-dose group received dialysis exceeding what is current practice by more than 30%.
The current prevailing opinion is that we should reach a minimum dose: a Kt/V of 1.2, three times a week, for IHD; or a CRRT dose of 20 mL/kg/h. At this time, higher doses do not confer a clear survival benefit. It remains unknown whether certain patients may benefit from a higher dose. Further research is needed.
Continue reading to find out when to initiate therapy...