Transcript Technical Aspects of Hemodialysis

Technical Aspects of
Hemodialysis
Saramma Mathew, RN,BSN,CNN
Renal Educator
Hackensack University Medical Center, Hackensack, NJ
Anatomy
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Two Kidneys
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Two Ureters

One bladder
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One Urethra
Nephron

Nephron –functional
unit of the kidney
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Filter the waste
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Kidney has lot of
blood vesselscapillaries
Kidney Physiology
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Glomerulus- ball of
capillaries
Bowman’s capsule
Selectively
permeable
Glomerular
Filtration
Tubule
Functions of Kidneys

Excretory Functions:


Gets rid of waste
Endocrine functions:
Hormones
 EPO
 Calcitriol

Principles of dialysis
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Solutions:
Solvent
 Solute
 Semi permeable membrane
 Ultra filtration

First Principle of HD - Diffusion
Solutes move from a
region of higher
concentration to a
region of lower
concentration until
concentration is
equal on either side.
Factors affecting diffusion

Concentration gradients:

Molecular weight of the solutes:

Temperature
Factors affecting Diffusion
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Membrane permeability:
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Surface area of the membrane:
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Flow geometry:
2nd Principle of HD - Osmosis
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Osmosis is the movement
of solvent through the
semi permeable
membrane from an area
of lower concentration to
an area of higher
concentration.

Ultra filtration:
Adequacy of Dialysis
Formula for Urea Reduction Rate
Pre Dial BUN
-
Post Dial BUN
________________________ x100
Pre Dialysis BUN
=
URR Calculation
Adequacy - Kt/V
K= Dialyzer clearance
 T= Length of dialysis time (in minutes)
 V= Urea distribution volume in millimeters.
 Kt/V must be greater than 1.2
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Adequacy

UKM – Urea Kinetic Modeling

Provides More Accuracy

Measures Protein levels
Machine alarms

PRIORITY ALARMS
Air detector alarm
 Blood leak detector
 Arterial pressure –high/low alarm
 Venous pressure high/low alarm

Technical Complications

POTENTIAL PROBLEMS
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Air in Bloodlines:
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Blood loss:
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Clotting in extracorporeal circuit.
Complications: POTENTIAL PROBLEMS
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Dialyzer membrane leak:
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Hemolysis:
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Power failure:
Heparin – Purposes in HD

Function: to prevent
clotting
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Sensitivity:
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Inadequate Heparin
Heparin Protocols
2.
Heparin free
Strength of Heparin
3.
Administering heparin:
1.
o
o
o
o
Systemic
Continuous infusion
Intermittent
Low-dose “tight “ heparinization