Prospert FL, Ruffenach P
Ramped sodium dialysis versus combined ramped sodium and
ramped ultrafiltration dialysis compared to standard sodium
dialysis
Am Soc Nephrol
J Am Soc Nephrol (abstract)
(Sep) 7:1524 1996
The data with regard to the benefits of ramped sodium dialysis (starting
with a sodium of 150-155, for example, and then decreasing to about 135-140
in an exponential or linear fashion, are unclear. There are a number of
abstracts recently reviewed on HDCN (see the
Hemodialysis complications topic area for a listing). Some
studies have combined ramped sodium dialysis with
a non-linear UF rate, whereas others have used a linear UF rate. The role
of non-linear UF has not been clearly apparent in those studies where it
was used. A non-linear UF rate has been shown to be of no
advantage with a fixed dialysate sodium level (Ciccarelli and Zoccali, EDTA
96, Nephrol Dial Transplant 11:A206, 1996, not
reviewed on HDCN).
In this paper, the authors compare ramped sodium dialysis with a linear vs
a ramped UF rate. There were three groups: 140 Na linear UF, 148-138
sodium linear UF, and 148-138 Na, ramped UF (50, 25, 15, and 10% of fluid
removed during hours 1-4, respectively). The design was a crossover trial
in 16 patients, 6 treatments each. The study was small, so few definitive
conclusions could be drawn. Cramps were present in 75% of patients
dialyzed with standard therapy (a very high percentage). Cramps "improved"
in 65% of patients with ramped sodium-linear UF rate, and in 100% of
patients
with ramped sodium-ramped UF rate. Symptomatic hypotension was apparently
reduced (7 episodes standard Rx, 1 episode ramped sodium-linear UF, 0
episodes ramped sodium-ramped UF).
Comment: This study does not shed any particular new light on the
problems. I review it to point out how difficult it is to design such
studies. 1) Larger patient numbers and more hypotensive episodes are
required. 2) The time averaged Na concentration should be similar, or a
kinetic analysis of sodium balance should be done to have similar Na
fluxes. Obviously with a fixed Na of 140, sodium flux is lower than with
148-138. A comparison with probably 143 would be the appropriate control
group. Having said this, I am convinced that ramped sodium dialysis may
help patients with severe cramps, based on personal and research
experience. However, thirst and interdialytic weight gain are increased,
and I believe this form of therapy should be used with caution.
(John T. Daugirdas, M.D., University of Illinois at Chicago)
To go back use the BACK button on your browser.
Otherwise click on the desired link to this article below:
Am Soc Nephrol
Basic hemodialysis :
Complications (acute)