Christopher R. Blagg, MD, Northwest
Kidney Center, Seattle, Washington,
addressed the question, “What Went
Wrong with Hemodialysis in the United
States?” Dr. Blagg stressed that hemodialysis
in the United States has generally
declined in quality over the years. Several
factors appear to have had adverse effects
on the quality of hemodialysis, including
rapid proliferation of dialysis units, many
being established by administrators and
physicians with little experience in
hemodialysis, and oriented toward profit
rather than quality of treatment. Since
reimbursement for dialysis did not
increase over many years, there was an
incentive to look for savings by changing
dialysis practices. Salaries of personnel
constituted the lion’s share of dialysis
costs, so shortening of dialysis time to
decrease employment time became a
common way of decreasing expenses. This
practice was supported by the National
Cooperative Dialysis Study, which reported
that the time of dialysis was unimportant
as long as patients achieved Kt/V of
0.9 – 1.0 per dialysis with a three-times
weekly schedule. Only recently, have several
publications from the US and other
countries, stressed the need for longer
dialysis and higher Kt/V. The development
of continuous quality improvement programs
and emphasis on the HCFA
Core Indicators have resulted in some
improvement.
In addition to the general decline in
quality of treatment, the best hemodialysis
method associated with the best out-comes,
home hemodialysis, has declined
steadily since the start of the Medicare
ESRD Program in 1973. There were multiple
reasons for this decline. The most
important seemed to be (1) inadequate
payment for home hemodialysis;
(2) change of demographics, with more
elderly patients without helpers and suit-able
home circumstances coming to
hemodialysis; (3) lack of hemodialysis
machines designed specifically for home
hemodialysis; and (4) availability of peritoneal
dialysis, which was easier to learn
and perform at home. However, recent
years have seen a revival of interest in
home hemodialysis as a treatment option.
The most important developments are
adoption of more-frequent, daily or nightly
protocols, and the development of
“user-friendlier” dialysis equipment.
In the late 1960s and early 1970s in
the majority of hemodialysis patients,
blood pressure was controlled by gentle
ultrafiltration or by increasing dialysis frequency.
Only 5% – 10% of patients
required blood pressure medications. The
situation dramatically changed after the
introduction of short dialyses, when the
prevalence of hypertension increased to as
high as 60% – 90% in various studies.
Whereas, in the general population, hypertension
is unequivocally considered a risk
factor for cardiovascular morbidity and
mortality, in the mid-1990s, several retrospective
analyses of mortality in relation
to blood pressure control found better survival
in hemodialysis patients with higher
blood pressure. In contrast, others reported
increased mortality in hemodialysis
patients with higher blood pressure.
Mahmoud Salem, MD, University of
Mississippi, Jackson, Mississippi, under-took
a task to answer the question, “Is
High Blood Pressure Good or Bad in
Patients on Conventional Hemodialysis?”
A thorough review of papers related to this
topic revealed that most articles from the
US, including reports of the United States
Renal Data System, disclose better survival
in patients with higher blood pressure or
no influence of blood pressure on mortality.
On the contrary, several papers from
Japan and France, where longer duration
of hemodialysis sessions is practiced,
report better survival in patients with better
blood pressure control. Several papers
found J (or U)-curve patterns with
increased mortality in patients with very
high and very low blood pressures. Dr.
Salem concluded that, in conventional
dialysis, there is no definite answer
whether lowering blood pressure improves
survival. There is no question that rapid
lowering of blood pressure should be
avoided. Patients over 50 years old may
need higher blood pressure to preserve
adequate tissue perfusion.
There are a few centers that retained
the method of treatment prevailing in the
1970s, namely, three weekly hemodialysis
sessions of 8 hours duration. Based on the
experience of the Centre de Rein Artificiel
de Tassin in France, Bernard Charra, MD,
presented data supporting the title of his
talk, “Blood Pressure Controlled by Gentle
Ultrafiltration Improves Survival in
Hemodialysis Patients.” Cardiovascular
mortality is higher in patients with both
high and low blood pressure, creating the
“U-curve” phenomenon. Low blood pressure
befalls patients with frail hearts.
Because mortality related to low blood
pressure occurs early, and that related to
high blood pressure is not apparent until
after 5 – 7 years, studies based on short-term
observations may be misleading.
Dr. Charra discussed a vicious cycle
created by short dialysis with a high
ultrafiltration rate leading to poor blood
pressure control. What is the mechanism?
The high ultrafiltration rate, which exceeds
the refilling rate, causes hypovolemia
during dialysis, hypotension, and several
reactions from patients and hemodialysis
personnel: patients request shortening of
the dialysis duration, blaming the length
of dialysis for their symptoms; nurses
infuse normal or hypertonic saline to
combat hypotension; physicians increase
target weight and/or sodium
concentration in dialysis solution. All
these maneuvers increase interdialytic
weight gains, which lead to further
increases in ultrafiltration rates. And the
vicious cycle continues. High blood
pressure predialysis necessitates the use
of blood pressure medications, which
aggravate hypotensive episodes. As a
consequence, blood pressure is not
properly controlled. On the contrary,
gentle ultrafiltration allows achievement
of good blood pressure control without
hypotensive episodes. It is necessary to
lower target weight very gradually after
dialysis initiation and remember that
there is a lag in blood pressure response
of 1 – 2 months.
Thus, the ultimate answer to the
question, “What Went Wrong with
Hemodialysis in the United States?,” is that
dialysis duration has been unjustifiably
shortened based on false assumptions that
dialysis duration in a three-times weekly
schedule does not influence survival, and
Kt/V less than or equal to 1.0 per treatment
is sufficient for adequate dialysis.
