Transcript Hemodialysis Access and Management

Chronic Kidney Disease and Dialysis
Patient Care –
What the Generalist Should Know
Nephrology Topic Review
Clarian Arnett Hospital
Lafayette Medical Education Foundation
January 18, 2011
Stephen R. Ash, MD, FACP
Clarian Arnett Health
Director of Dialysis, Wellbound
Director of R&D
Ash Access Technology and HemoCleanse, Inc.
Lafayette, IN
Role of Primary Physicians in Treatment of
CKD Patients and Preparing for Dialysis
• Identify patients with CKD
• Identify causes of kidney disease (diabetes,
hypertension, obstruction, hyperuricemia, infections,
obstruction, medications)
• Treat the primary disease and prolong renal function,
for example using ACE/ARB in diabetics with CKD
• Refer to Nephrology at CKD Stage 3 (GFR=30-60
ml/min/1.73M2)
• Observe for signs of uremia
• Help to determine with patient, family and
Nephrologist whether dialysis is indicated
• Preserve arm veins for hemodialysis access
• Expect and support access procedures at stage 4-5
(GFR<20 ml/min/1.73M2)
• Avoid damage to fistula or graft in arm
• Monitor graft and fistula function, report abnormalities
1. Dialysis Options and How They
Work
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Peritoneal dialysis
Hemodialysis
CVVHD
NxStage Home Dialysis Therapy
Dialysis=Diffusion
Nighttime cyclers decrease the number of daytime
exchanges needed.
The Hemodialysis Blood Side
System
Fresenius K-Machine
NxStage Therapy System
2. Symptoms of Renal Failure (Uremia)
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Gastritis: nausea, vomiting, gastritis, anorexia
Fluid Overload, CHF: shortness of breath, orthopnea
Encephalopathy: confusion, sleepiness, coma
Neuropathy: itching, weakness
Pericarditis: chest pain, shortness of breath
3. Physical
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Signs of Renal
Failure
Vomiting
Edema
CHF, Rales
Confusion, Coma
Bleeding
Decreased urine output (sometimes)
Hypertension
Diminished inflammatory response and signs of infection
4. Laboratory
Values in Renal
Failure
• Creatinine elevation (normal is 0.6-1.4)
• GFR decrease by MDRD or CG (normal for 70 year old of 70 kg is
70)
• BUN increase (normal up to 22)
• Phos increase (normal up to 4.5)
• Potassium increase (normal up to 5.5)
• Hemoglobin decrease (normal lower limit 13)
• Bicarbonate decrease (normal lower limit 24)
• Hundreds of other chemical and hormonal changes
5. Medical
Therapy of Chronic
Renal Failure
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Potassium (bicarbonate, glucose & insulin, saline, β-agonists, Kayexelate,
calcium, stop various meds)
Phosphorus (calcium acetate, calcium carbonate, Renvela, Fosrenol)
Urea (diet restriction, exclude GI bleed)
Optimize GFR (fluid load, fluid decrease, improve blood pressure, stop
various meds)
Avoid nephrotoxic meds (nsaids, ACE, iodinated contrast agents)
Avoid or adjust other toxic meds (MRA contrast, Reglan, Digoxin,
Amiodarone, Lovenox, etc).
6. When
do we start dialysis
in CKD? Which Type?
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Clearance
– GFR < 15 ml/min for non-diabetics (MDRD)
– GFR < 25 ml/min for diabetics
– Downward trend in GFR
– Upward trend in uremic toxins
Symptoms
Quality and length of expected life
Home patient potential: good patient historically, family support and partner, mobility,
interest and capability
– PD, especially for heart failure, diabetes, provides several years of support
– Short daily Hemo: capability and interest
– Overnight Hemo 8 hours every other night also possible
In-center patient potential
– Must tolerate surgery or procedures for vascular access device
– Must tolerate rapid fluid shifts and heart strain
– Must cooperate with medical regimen
– Transportation must be available for three treatments per week
Stages of Chronic Kidney Disease
Description
eGFR (ml/min/1.73m2)
I
“Normal” Renal function
>90
II
“Mild” Renal Dysfunction
60-89
III
“Moderate” Renal Dysfunction
30-59
IV
“Severe” Renal Dysfunction
15-29
V
“End-Stage” Renal Disease
<15
Stage
7. Requirements for Hemodialysis
Access
• Blood flow rate of 400 ml/min for 4 hours treatment,
without blockage
• Blood flow rate in vicinity of access (like catheter or
needle) must be at least 800 ml/min
• Minimal infection risk
• Low risk of bleeding
• No tubes through the skin if possible
• Longevity in years, not months
Types of Hemodialysis Access
• AV Fistula
• AV Graft
• Tunneled Internal Jugular dialysis Catheter
Scribner Shunt-1960
Short History of Hemodialysis Access after
Scribner Shunt:
AV Fistula
Original Cimino-Brescia Fistula; side-by-side
Other types of fistulas
Finding Veins-Sometimes Easy,
Sometimes Hard
Vein Mapping to Find Suitable
Veins and Arteries
Fistula Problems-Stenosis
Note enlargement of radial artery-to provide a liter per
minute blood flow
Signs of Venous Stenosis in
Vascular Access
Physical Exam..Detects Inflow
Problems and Outflow Problems
Aneurysms are Weakened Areas, not Able
to Receive More Needlesticks
But, 30-50% of fistulas don’t work in the first
place….
AV Grafts
ArterioVenous Grafts
Can Teflon be a Blood Vessel?
Grafts Become Covered by Body Tissues,
Sometimes Too Much Tissue
And Stenosis Near the Connection
of the Graft and Vein
Infection is Rare, Redness is
Common
Pseudoaneurysms are Near
Blowouts
Tunneled Permanent Central Venous
Catheters for Dialysis
The Third Choice
But as CMS Reports: We have a
Continuing Dependence on CVCs…
BFRs w/ Vascular Accesses
Dacron Cuff is under the skin
Tips are at the entry to the heart
Wardrobe Requirements
Natalie Cole, 2009
Did you notice this first?
Exact placement is sometimes
difficult…
Vein entry is with Ultrasound
Problems Include Clotting
And Fibrous Sheathing
Catheter Sheaths
develop at point of
contact to vein or
atrial wall…
Fibro-Epithelial (Fibrin) Sheath
L IJ
CVC
FibroEpithelial
Sheath
SVC
RA
Courtesy, Arif Asif
KDOQI
2007
Risky!
Exchange?
Balloon sheath?
Brush?
30 minutes?
Overnight?
Can catheter outcomes be improved? For
sheathing, new catheter designs might help…
Centros
Tips form
a flat
plane;
ports are
held in
middle of
vein
CentrosTM: Preferred Placement in SVC
art
ven
art
ven
The catheter tips are positioned in the lower third of the SVC rather
than in the atrium…
Centros™: A Self Centering Catheter
tip
tip
Pacemaker
leads
The ports are held in the middle of the SVC and away from the vein
wall. These CT’s were performed after 4 months of catheter use.
CentrosTM: Preliminary Study Results
Average Flow at -200 Arterial Pressure, Centros(TM) Catheters
(+/- Standard Deviation)
500
ml/min
400
300
200
100
0
0
1
2
3
4
w eeks
5
6
7
Standard Catheters
P < 0.05 (n=120)
Flow rate of the CentrosTM Catheters was 400 ml/min, constant over time
(7 weeks) and higher than with current Dual Lumen tunneled dialysis catheters.
Infection in Tunneled CVC for
Dialysis
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Incidence of 1-5/1000 patient days, or 3-15% of patients per month (higher
in non-tunneled catheters)
Serious consequences, systemic and metastatic infections
Highly costly
Requires long-term systemic antibiotics and usually antibacterial catheter
lock to resolve
For Staph Aureus or Pseudomonas organisms catheter must be
removed/replaced
Prophylactic antibiotic or antiseptic locks can diminish incidence but have
their own problems