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Technical Aspects of Hemodialysis. Saramma Mathew, RN,BSN,CNN Renal Educator Hackensack University Medical Center, Hackensack, NJ. Anatomy. Two Kidneys Two Ureters One bladder One Urethra. Nephron. Nephron –functional unit of the kidney Filter the waste
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Technical Aspects of Hemodialysis Saramma Mathew, RN,BSN,CNN Renal Educator Hackensack University Medical Center, Hackensack, NJ
Anatomy • Two Kidneys • Two Ureters • One bladder • One Urethra
Nephron • Nephron –functional unit of the kidney • Filter the waste • Kidney has lot of blood vessels-capillaries
Kidney Physiology • 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 • 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 • Membrane permeability: • Surface area of the membrane: • Flow geometry:
2nd Principle of HD - Osmosis • 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
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 • Air in Bloodlines: • Blood loss: • Clotting in extracorporeal circuit.
Complications: POTENTIAL PROBLEMS • Dialyzer membrane leak: • Hemolysis: • Power failure:
Heparin – Purposes in HD • Function: to prevent clotting • Sensitivity: • Inadequate Heparin
Heparin Protocols • Heparin free • Strength of Heparin • Administering heparin: • Systemic • Continuous infusion • Intermittent • Low-dose “tight “ heparinization