Vascular Access and the
conditions of coverage.
What you must do
Speaker’s Disclosure
A t l B
Anatole
Besarab,
b MD
Dr. Anatole Besarab
has
h relevant
l
t fifinancial
i l
relationships
p with commercial
interests in VascAlert.
Director of Clinical Research,
Di i i off N
Division
Nephrology
h l
and
dH
Hypertension,
t
i
Henry Ford Hospital.
Clinical Professor of Medicine,
Medicine
Wayne State University School of Medicine,
Detroit Michigan
NKF Co-Chair VA WG
•
•
•
•
•
AB 1/19/2009
Conditions of Coverage
New regulations in effect now that will change how dialysis
facilities need to comply with Medicare rules for providing
dialysis treatments.
Although portions of the current dialysis payment process
is bundled, like the composite rate (the definition of
composite is "made up of disparate or separate parts or
elements.
The composite now includes vascular access monitoring
and surveillance. More money will not be paid for these
services
The payer, Centers for Medicare & Medicaid Services
(CMS), expects caregivers to adhere to certain standards
and outcomes
CMS plans to move from a 5% sampling of dialysis patient
data to collecting 100% of data from more than 350,000
patients each year. Not clear whether this will include
vascular access reporting on all patients but inspectors will
be looking
Conditions of Coverage
•
•
The dialysis facility must measure, analyze, and track
quality indicators or other aspects of performance that
the facility
f
adopts or develops that reflect
f
processes off
care and facility operations.
operations.
These performance components must influence or relate
t the
to
th desired
d i d outcomes
t
or b
be th
the outcomes
t
th
themselves.
l
The program must include, but not be limited to, the
following:
–
(i) Adequacy
Ad
off dialysis.
di l i
– (ii) Nutritional status.
– (iii) Mineral metabolism and renal bone disease.
– (iv) Anemia management.
– (v) Vascular access.
– (vi) Medical injuries and medical errors
quality assessment (section 494.110)
AB 1/19/2009
AB 1/19/2009
The Problem
Why The Problem
• Appropriate care requires constant attention
•
•
t the
to
th maintenance
i t
off vascular
l access
patency and function.
Practice patterns can contribute to patient
morbidity and mortality, as well as costs.
The USRDS reported that HD access failure
q
cause of
was the most frequent
hospitalization for pts with CKD Stage 5.
Why are these statements important?
Conditions of Coverage
Monitoring
g is not an option
p
• The interdisciplinary team must provide vascular
access monitoring and appropriate, timely
referrals
f
l to achieve
hi
and
d sustain
i vascular
l access.
• The
Th patient’s
ti t’ vascular
l access mustt b
be
monitored to prevent access failure, including
monitoring
o to g o
of a
arteriovenous
te o e ous g
grafts
a ts a
and
d fistulae
stu ae
for symptoms of stenosis.
Section 494.90, page 596
• Consistent
and ongoing
surveillance is lacking at many
clinics.
• Trending programs are not
consistently utilized at the clinic
level.
Conditions of Coverage
Surveillance is not an options
• For patients with grafts and fistulas, the
medical
di l record
d should
h ld show
h
– evidence of periodic monitoring and
surveillance of the vascular access for
stenosis and signs of impending failure
– documentation of the monitoring and
surveillance
ill
may be
b on the
th dialysis
di l i ttreatment
t
t
record, progress notes, or on a separate log.
– A member of the facility
y staff must review the
vascular access monitoring/surveillance
documentation to identify adverse trends and
take action if indicated
AB 1/19/2009
AB 1/19/2009
Definitions: K/DOQI
Q & CMS
• Monitoring:
Ph i l examination
Physical
i i off the
h vascular
l access ffor
abnormal pathology.
Assessment of clinical abnormalities during
treatment or after treatment.
Paid
a d for
o in the
t e co
composite
pos te for
o d
dialysis
a ys s
• Surveillance:
Evaluation of the vascular access by
means of specifically designed tests using
special
p
instrumentation.
Not reimbursable
AB 1/19/2009
Monitoring Vs. Surveillance
•
•
In clinical trials, "monitoring" is defined and then
carried out (as in M. Allon's or R. Lindsay's studies) per
protocol.
protocol Thus when a surveillance
surveillance, whether pressure
or access flow" is added, it is difficult with the small
sample sizes to see an additional effect. To complicate
matters all studies showed ability to detect more
matters,
problems but no benefit from the additional procedures.
On the other hand, in clinical practice, monitoring is
frequently not done "properly"
properly or the staff is not
adequately trained (there are few nurses in most
dialysis units clinically trained to examine grafts or
fistulas).
fistulas) Thus when surveillance is added and data is
consistently analyzed, the practioner notices the
reduction in catheters, unexpected thrombosis, etc and
becomes a believer.
AB 1/19/2009
Added Benefits of Surveillance
over Monitoring
M i i
• CMS has accepted that there is added"
added
benefit of surveillance in proactively
managing
g g and p
preventing
g access
dysfunction.
– Despite the dichotomy of beliefs as to its
added value
– Absence of adequate RCT data to its
effectiveness
• This dichotomy of beliefs results from two
phenomenon.
phenomenon
AB 1/19/2009
Purpose of Access
M i i /S
Monitoring/Surveillance
ill
! Detection of stenosis
! Detection of stenosis which is hemohemodynamically significant and is at a
“stage” where it is amenable to
interventions and which, if left untreated,
would p
produce thrombosis within xx
weeks/months.
AB 1/19/2009
Rationale for
Monitoring/Surveillance
(Why do it?)
Patency
y of Grafts w/wo p
prior
Thrombosis
N
Mean patency
of 6 studies
without
thrombosis
Mean patency
of 6 studies
following prior
thrombosis
1299
3 mo
76.6
6 mo
56.0
12 mo
35.0
•
1878
47 7
47.7
32 5
32.5
This difference in patency use increases the
risk of catheter use
AB 1/19/2009
Monitoring/Surveillance
g
(Why do it?)
• You must do it. Inspectors will be
•
•
• Keep permanent vascular access open
• Improve Kt/V from missed treatments or
checking on you
You really
y have no choice.
It is in the best interest of the patient
•
•
q
dialyzer
y
blood flow
inadequate
Minimize (avoid) temporary or tunneled
catheter use
Improve QoL: patient and staff
Maximize chair utilization
AB 04/05/2008
Monitoring: Standard Method for
Access assessment
Access
• Clinical Evaluation byy “experienced”
p
staff
– Documented Physical examination (visual
assessment, assessing the pulse, listening for a
bruit) at multiple segments of the vascular access.
Done at least monthly! Preferably weekly
– Evaluation of unexplained (confirmed) decrease in
Kt/V (not explained by inappropriately low blood
pump flow
fl
or shortened
h t
d titime).
) M
Monthy!
th !
– Assessment of treatment issues: difficulties in
cannulation, prolonged bleeding from needle sites
after
ft needle
dl withdrawal,
ithd
l presence off aneurysms or
strictures and notification of responsible physicians.
Reported each time!
AB 01/19/2009
AB 01/20/2009
Efficacy of Monitoring in
D
Detecting
i Stenosis
S
i in
i Grafts
G f
Year
Vein
Artery
No Noise ,
No Needles
Monitoring:
Direction of flow; absence or presence of
thrill
Aneurysms/pseudoaneurysms
Graft
PPV
1996
106
92
Cayco
1998
68
97
Robbins
1998
38
89
Maya
2004
334
69
Robbins
2006
151
70
697
76.5
Total/
Mean
Occlusion
site
Presence of a stricture
N
Safa
Rotation of needles
AB 1/19/2009
05/11/08 AB
Clin. Exam in AVF
Comparison
Technique
q
28 patients with malfunctioning AVF
– Sensitivity 50%, specificity 100% for inflow lesions
– Sensitivity
y 38%,, specificity
p
y 43% for outflow stenosis
•
142 consecutive patients with
AVF referred for dysfunction
Clinical
– Sensitivity 85%, specificity
71% for inflow lesions
Examination
– Sensitivity 92%, specificity
86%
for outflow stenosis
Is
•
84 patients with AVF, 54% radiocephalic, evaluated by PE, and
G d
Good
Doppler.
PPV
Clinical Monitoring
Clin Eval
Static/Derived VPR
Is
70
70--76%
92%
Pretty
Good
Flow
Dilution
Ultrasound
U
t asou d
•
Pretty
Examiners
by Doppler, 66% by PE,
– 59% of AVF hadThese
a 50% stenosis
Are Not In
Our
– Sensitivity 96%
96%, specificity
76%
76%,
PPV 86%
86%, NPV 93% for PE
with Doppler as standard
Dialysis centers
93%
80%
1. Thompsen MB, Stenport G. Acta Chir Scand 1985:151:133-137
2. Asif et al CJASN 2007;2:1191-94
AB 1/19/2009
2. Campos RP, et al Semin Dial 2008, Feb 1 [epub ahead of print]
AB 1/19/2009
Surveillance
Optimizing Stenosis detection
! Detection of stenosis which is hemohemodynamically significant and is at a
“stage”
stage where it is amenable to
interventions and which, if left untreated,
would
ld produce
d
thrombosis
h
b i within
i hi xx
weeks/months.
• Which method?
–Ease of test
–Technical cost
–Labor cost
–Data Collection and review
What surveillance test do I use
and what criteria determine
referral for action?
AB 1/19/2009
Surveillance of Vascular Access
AB 1/19/2009
Intra Access Pressures: Keep the
contrasts
co t asts
The vascular access is a tube. In a tube
1.0
Pressure gradient = Flow/ Resistance
or
Q = !P / R
0.8
In a Graft !P = 50
50--60 mm Hg . You can feel a pulse
In an AVF !P = 10
10--30 mm Hg. There is no pulse
Hemodynamic Assessment by a particular method
•
•
Anatomic/Functional (Flow) Imaging
–
Angiography
–
Doppler, MRI
06
0.6
Arterial
Cannulation
Sit
Site
Venous
Cannulation
Site
0.5
0.4
0.2
–
Static ((direct or indirect).
) The important
p
P is the p
pressure in the access.
–
Dynamic venous pressure is discredited. Is affected by the needle.
01
0.1
Native Fistula
0
Artery
A
Access
Fl
Flow Measurements
M
t
–
Graft
0.7
Access
Pressure
Ratio
0.3
Venous (+/(+/-Arterial) Pressure Measurements
Do not use. It does not work
•
Pressure Profiles Within Normal
Grafts and Native Fistulas
0.9
Art. Section
Ven. Section
Vein
Vascular Access
Indicator dilution, conductivity dialysance
AB 1/19/2009
04/01/03 AB
Static Pressure from the Dialysis Machine
Static Arterial and Venous Access Pressures
1 Turn the blood pump off
1.
off.
VDP = 220
mmHg
2. Clamp the tubing between dialyzer and
venous drip chamber.
PDC
MediSystems Access Alert
Gauge 0-120
mm Hg
3. Read venous drip chamber pressure
(VDP) 30 seconds after stopping flow.
4. Determine in cm the height difference
between the arm of the chair and drip
chamber (!H).
5. Corrected VP = ((3.4 + 0.35
!H)+VDP0
D
Deemed
d too
t
expensive, $4/week
6. Measure mean arterial pressure
7. Calculate
VAPR =
Vein
Venous
e ous
Corrected Ven Access Pressure
Arterial
MAP
Artery
All together 13 crucial steps = short cuts
= junk in = junk out
AB 1/19/2009
AB 1/19/2009
Access Pressure Ratios and Flow
On-line Vascular Access Database
G ft
Graft
New Access in 73 y/o Diabetic Male
Angioplasty
1
0.8
Clotted left forearm loop graft
g
stenosis.
1)) Intragraft
2) Stenosis at venous anastomosis
3) Cephalic vein stenosis
1000
800
0.75
A
Access
Pressure 0.6
Ratio 0.5
Arterial
Venous
600
0.4
400
0.2
200
Flow
ml/min
0
0 1
2
3
4
5
6
7
8
9 10 11 12 13 14
Time (weeks)
04/01 Beserab
AB 1/19/2009
Thrombectomy
Th
There
is
i no one
“unique”
unique value of flow
or pressure that “fits”
fits
all p
possible
combinations of arterial
and vein ratios
Access Pressure Ratios and Flow
51 y/o
/ ffemale,
l 5 PTFE arm grafts
ft placed
l
d in
i previous
i
2 yrs
with 11 salvage procedures
0.70
PTA
0.60
0.50
Static
pressure0.40
ratio 0.30
0.20
0.10
0.00
93.00
93.50
Flow Technologies Available
94.00
Year
AB 1/19/2009
2000
1800
1600
1400
1200
1000
800
600
400
200
0
95.00
PTA
94.50
Doppler
Intraaccess
Fl
Flow
(ml/min)
AB 1/19/2009
Access Flow Measurement
Flow
– Utrasound Flow dilution (Transonics
(Transonics))
– Crit
Crit--Line II ((HemaMetrics
HemaMetrics))
))
– CritLine III TQA (HemaMetrics
(HemaMetrics))
– Glucose infusion
– FMC Ionic dialysance
Access Flow =
770 ml/min
Qb = 281 ml/min
Access Flow =
780 ml/min
Time
Kecn
0:15
AF 0:22
0:45
1:15
1:45
2:15
2:45
222
112
230
223
218
214
210
Mean
219
Time
04/07/08 AB
Krivitski KI 48:244-250, 1995
AB 1/19/2009
Gotch ASAIO J 1999; 45:139 -146
Reverso™ Flow Reversing
I t
Interconnector
t from
f
Medisystems
M di t
Predicting Graft Thrombosis (ROC Curves)
From Paulson W: Sem Dial 14(3):175
14(3):175-80
80
1.00
sis
no
ste
a
³Q
0.60
Qa
Sens
sitivity
0.80
0.40
0 20
0.20
0.00
0.00
May ell al:
M
l KI 52
52:1656,
1656 1997
Neyra el al: KI 54:1714, 1998
0.20
0.40
0.60
0.80
1.00
False Positive Rate
AB 1/19/2009
ROC Curves for VAPRT in Grafts
1
AB 1/19/2009
VAPRT Statistics for Fistulas
0.0
0.45
0.8
0.2
0.4
VAPRT Test Results
03
0.3
0.55
0 - 3 Months
0 - 6 Months
Sensitivity (%)
83
86
Specificity (%)
93
94
Positive Predictive Value (%)
67
65
Negative Predictive Value (%)
98
98
False Positive Rate (%)
17
14
False Negative Rate (%)
7
6
0.5
0.6
True 0.6
Positive
Rate
Area Under the Curve = 0.82
0.4
0.8
0.2
Y = 7.685 - (0.6832 e –31.1982 X) - (7.0007 e –0.0459 X )
r2 = 0.995
1.0
0
0
02
0.2
04
0.4
06
0.6
08
0.8
1
False Positive Rate
AB 1/19/2009
AB 1/19/2009
Advantages
g of Vasc Alert
Increasing
Venous Access
Pressure Ratio
• Uses routinely collected dialysis data
• Does not require dialysis staff time for data
collection
• Measurements are made “passively” during
each dialysis
y
session
• The database is on-line, just click and the
Avg. Tx Blood
Flow 421 ± 56
ml/min
Decreasing
Avg. Tx Blood
Flow 371 ± 44
ml/min
patient’s
i
’ access data
d
is
i available
il bl
• Must be able to electronically transmit the
data to a file server for analysis
AB 1/19/2009
K/DOQI G
id li 4
Guideline
Treatment of Stenoses
Stenoses should be treated if:
•Clinical or physiologic
y
abnormality
+
Anatomic abnormality
> 50% diameter
• decreased access blood flow
(<600ml/min in grafts, 500 in AVF,
or a decrease in flow))
• elevated intra-access venous
pressure
• abnormal physical exam
490 ml/min
SVPR =0.78
• prolonged bleeding
anatomic lesion without a physiologic effect that is not
•An
decreased dialysis dose (Kt/V)
•progressing
recirculation should be left alone: PTA is not innocuous
AB 1/19/2009
Besarab’s Rules for Evaluating
Efficacy of Surveillance
• The surveillance technique is relatively
unimportant
i
t t as long
l
as it iis ““cheap”,
h
” easily
il
available, assesses hemodynamics reproducibly
and detects stenoses with sufficient accuracy.
accuracy The
following caveats should be kept in mind
– Not all detected stenoses are amenable to
angioplasty:
– Not every
y lesion needs to be fixed. If a lesion is
hemodynamically stable, access provides
adequate Kt/V, leave it alone !!!!
Anatole Besarab,M.D. Director of Clinical Research Division of Nephrology & Hypertension, Henry Ford Health System, Co
Co--chair
Vascular Access 2006 KDOQI Work Group
A Simpleton's Guide to
Access Maintenance
Besarab’s Rules for
Evaluating Efficacy of
Surveillance
! Find the hemodynamically significant stenoses
• Do not Mix and Match: Keep the contrasts
•
among patients
ti t
Prolongation of access survival is not the
key. Avoidance of thrombosis is! (The
patient does better if procedures are
elective and not emergent).
! Find them all
! Fix all that need fixing
! Check to make sure they are fixed
!
!
Pull back pressures
Fl
Flow
velocity
l it wires
i
! Know when to abandon the access
elements for success!
Anatole Besarab,M.D. Director of Clinical Research Division of Nephrology & Hypertension, Henry Ford Health System, Co
Co--chair Vas
Vascular
cular Access
2006 KDOQI Work Group
Dysfunctional
y
PTFE Hemodialysis
y Graft
Dialysis Thrombotic Events
(Data for 2 years)
Events/pt-yr
0.80
Y = 0.773 - 0.144 • X
0.70
Basilic vein
" T +PTA =C
R = 0.981
P < 0.05
0 05
0 60
0.60
PTFE graft
ft
0.50
0.40
0.30
0.20
0.10
0.00
Control
Two venous stenoses
AB 1/19/2009
AB 1/19/2009
Period 1
Period 2
Period 3
Am I insane I Biannual
keep getting
the same result.
Periods
Done it 5 times now at 3 different
institutions; p = 25 =1/32 ~0.03
Stenosis Surveillance Decreases
Catheter Use and Hospitalization
Access Surveillance Improves
Outcomes
# per pattient year
•
•
*P < .01
0.6
0.5
Conclusions
– Only stenoses showing progressive change should be
treated
0 57
0.57
0.5
•
0.44
0.4
0.3
*
0 32
0.32
0.2
•
0
Hospitalization
Qa
Catheter Use
Ultrasound
Is this not we
want:
catheterWD;
useJASN
and hospitalization?
Dossabhoy
NR,
Ramlower
SJ, Paulson
(Abs) 2003 14:54A
Th k You
Thank
Y
When Intervention is done, All lesions must be
treated
– Need better tools to evaluate which lesions to fix and the
success of the PTA at the time of intervention
0.2
0.18
0.1
Control
Surveillance does work
Access Databases in real
real--time must become part of
access management
We need adequately powered RCT that do not
“stack the deck” against surveillance