Greenberg S, Shapiro WB, Porush JG
Hemodynamic effects of peritoneovenous shunts in hemodialysis
patients with ascites
Am J Kidney Dis
(Sep) 28:387-394 1996
Peritoneovenous shunts (PVS) have been employed to treat ascites
and increase hemodynamic stability during hemodialysis in ESRD
patients with ascites. In this report, clinical data in 3 such
patients are described and the literature reviewed. Hemodynamic
parameters before and after PVS included: 1. nadir BP 2. number
of intradialytic hypotensive episodes 3. amount of albumin used
to treat hypotension 4. interdialytic weight gain 5. hemodynamic
stability during HD (change in MAP).
PVS placement had dramatic
effects, with the number of hypotensive episodes decreasing from
219 prior to PVS to 0 after PVS, and was associated with
discontinuation of use of albumin to maintain BP. One patient
required replacement of PVS due to infection. When used in
cirrhotic patients, PVS has been shown to increase cardiac output
and suppress the renin angiotensin system. The authors speculate
that improvement after PVS in their patients was due to: 1.
increased mobilization of ascitic fluid into the vascular space
during dialytic ultrafiltration 2. decreased ascitic to vascular
osmotic gradient 3. decreased thirst (due to decreased renin-angiotensin
stimulation during HD) 4.
increased cardiac output.
Comment: Although anecdotal in nature, this report supports the
use of PVS in hemodialysis patients with ascites and symptomatic
hypotension during HD. An increase in ascitic fluid osmolality
during HD, which would tend to result in fluid movement from the
vascular to the third space and predispose to hypotension, has
been demonstrated (Fajardo. ASAIO Trans 34: 617-9, 1988).
Possibly isolated ultrafiltration followed by isovolumic dialysis
would be beneficial in ESRD patients with ascites, since this
would theoretically prevent the development of the ascitic-vascular osmotic
gradient during dialytic
ultrafiltration. Switching patients to CAPD would be another option.
The authors' data do not support the concept that decreased
angiotensin levels and decreased thirst leading to decreased
interdialytic weight gain plays a role in the clinical
improvement seen after PVS, since interdialytic weight gain did
not decrease after the procedure.
(David J. Leehey, M.D., Loyola University at Chicago)