HEMODIALYSIS ADEQUACY
Laurie Vinci RN, BSN, CNN
September 17, 2011
OBJECTIVES
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Identify adequacy of dialysis and it’s
components
Discuss K-DOQI Guidelines for
hemodialysis adequacy
Discuss nursing interventions to achieve
adequate dialysis
Definition: Hemodialysis Adequacy
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The delivered dose of hemodialysis that will
optimize the survival and well-being of the
patient
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Numerous studies have demonstrated a
correlation between the delivered dose of
hemodialysis and patient mortality and
morbidity
Components of Hemodialysis
Adequacy
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Delivered dose of hemodialysis (HD) should be
measured at regular intervals no less than monthly
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Two components of HD adequacy:
1) Urea Kinetic Modeling (Kt/V)
2) Urea Reduction Ratio (URR)
NKF-KDOQI, 2006, CPG 2
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Kt/V (Dose of Dialysis)
K = Urea clearance through dialysis
t = Time of dialysis in minutes
V = Volume of urea in proportion to
volume of body water
Urea Reduction Ratio (URR)
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Difference between pre and post BUN
Statistically significant predictor of mortality
URR = PRE BUN- POST BUN X 100
PRE BUN
Methods for Dialysis BUN
Blood Sampling
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Pre/Post dialysis blood samples must be from
same session
Avoid dilution of pre BUN sample (with
heparin/saline)
NKF-KDOQI, 2006, CPG 3
SLOW FLOW/STOP PUMP
METHOD
AT COMPLETION OF DIALYSIS:
1) Turn dialysate flow off, decrease UFR to 50 ml/min, lowest
TMP or off
2) Decrease BFR to 100 ml/min for 15 seconds
A) Slow Flow: After 15 seconds, leaving blood pump at
100 ml/min, draw BUN sample from port on arterial line. Stop
blood pump and terminate treatment per unit protocol.
OR
B) Stop Pump: After 15 seconds, stop pump, clamp arterial
and venous blood lines, draw BUN sample from arterial needle
tubing, then terminate treatment per unit protocol
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Minimally adequate HD
HD treatment 3 x week
Kt/V 1.2 or URR 65%
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Target dose of HD
Kt/V 1.3 or URR 70%
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NKF-KDOQI, 2006, CPG 4
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Dose of dialysis should not be based solely
on the URR and/or Kt/V. Other factors
need to be included:
1) Potassium removal
2) Correction of acidosis
3) Sufficient protein/caloric intake to prevent
malnutrition
4) Longer time for fluid removal
Control of Volume and Blood
Pressure
Blood pressure control improves patient outcomes
UF should be optimized with a goal to render the
patient euvolemic and normotensive
 Restrict Na intake to 2 gms/24 hrs
 Increasing positive Na+ balance by “Na profiling” or
using a high dialysate Na+ concentration should be
avoided
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NKF-KDOQI, 2006, CPG 5
Strategies to Minimize
Hypotensive Symptoms
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Avoid excessive UF
Slow the UF rate
Perform isolated UF (SUF)
Manipulate Na levels (modeling)
Decrease dialysate temperature from 37C to 34-35C
(need MD order)
Administer midodrine pre dialysis (MD order)
Manage Hemoglobin
Optimize patient behavior through education
Interventions: Evaluate elements of HD
treatments that may compromise urea
clearance
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Assess for access recirculation
Verify flow of blood through the access (especially if
loop graft)
Inadequate blood flow from the access resulting in
decreased blood flows
Dialyzer blood leak on day Kt/V and/or BUN drawn
Inefficient dialyzer
DFR set too low
Inadequate coagulation
Inadequate dialyzer reprocessing
Review Treatment Documentation on day of
Kt/V and URR
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Review prescribed treatment vs. actual
treatment parameters
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Review Blood Flow Rate and Dialysate Flow
Rate
Assess for Lab and Blood
Sampling Errors
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Lab errors
Dilution of pre BUN with N/S or heparin
Drawing pre BUN after HD initiated
Drawing post BUN before HD completed or
drawing sample late (>3 mins. after
completion)
Blood lines or needles reversed
Assess Reductions in Treatment
Times
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Treatment
5 Minutes
Week
15 Minutes
Month
65 Minutes
(1.08 Hours)
Year
780 Minutes
(13 Hours/0.54 Days)
10 Minutes
30 Minutes
130 Minutes
(2.17 Hours)
1,560 Minutes
(26 Hours/1.08 Days)
15 Minutes
45 Minutes
195 Minutes
(3.25 Hours)
2,340 Minutes
(39 Hours/1.63 Days)
20 Minutes
60 Minutes
(1 Hour)
260 Minutes
(4.33 Hours)
3,120 Minutes
(52 Hours/2.17 Days)
25 Minutes
75 Minutes
(1.25 Hours)
325 Minutes
(5.42 Hours)
3,900 Minutes
(65 Hours/2.71 Days)
30 Minutes
90 Minutes
(1.5 Hours)
390 Minutes
(6.5 Hours)
4,680 Minutes
(78 Hours/3.25 Days)
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