DIALYSIS Dr. Frank Edwin

CAUSES OF RENAL FAILURE 􀂃 Diabetes 􀂃 Untreated high blood pressure 􀂃 Inflammation 􀂃 Heredity 􀂃 Chronic infection 􀂃 Obstruction 􀂃 Accidents

1.Renal Failure Diagnosis Symptoms: Anorexia, Nausea, Vomiting, Oliguria ? Precipitating factors Signs: Anaemia, Hypertension, Fluid Overload etc Biochemistry: Blood Urea >7mmol/l Creatinine >120umol/l Electrolytes: Rising K+ Creatinine Clearance (GFR <<120ml/l) Urine: Proteinuria May be Acute or Chronic Acute – Reversible or Irreversible

2. Treatment Options No Treatment Monitoring & Predialysis Dialysis Control symptoms Preserve Residual Renal Function Control rising BP (Antihypertensives) Control Renal Bone Disease (Ca2+, Vit D) Prevent/Treat Anaemias (Erythropoietin, Blood) Dialysis Renal Transplantation

Dialysis Definition Artificial process that partially replaces renal function Removes waste products from blood by diffusion (toxin clearance) Removes excess water by ultrafiltration (maintenance of fluid balance) Wastes and water pass into a special liquid – dialysis fluid or dialysate

Types Haemodialysis (HD) Peritoneal Dialysis (PD) They work on similar principles: Movement of solute or water across a semipermeable membrane (dialysis membrane)

Diffusion Movement of solute Across semipermeable membrane From region of high concentration to one of low concentration

Ultrafiltration Made possible by osmosis Movement of water Across semipermeable membrane From low osmolality to high osmolality Osmolality – number of osmotically active particles in a unit (litre) of solvent

The process of diffusion 1. 2 The process of diffusion 1.                                                2.                                                 Blood cells are too big to pass through the dialysis membrane,  but body wastes begin to diffuse (pass) into the dialysis solution. 3.                                                 Diffusion is complete. Body wastes have diffused through the membrane,  and now there are equal amounts of waste in both the blood and the  dialysis solution.

The process of ultrafiltration in PD 11. 2 2 The process of ultrafiltration in PD 11.                                                 2 2.                                                  Blood cells are too big to pass through the semi-permeable membrane,  but water in the blood is drawn into the dialysis fluid by the glucose. 3.                                                  Ultrafiltration is complete. Water has been drawn through the peritoneum by the glucose in the dialysis fluid  by the glucose in the dialysis fluid. There is now extra water in the dialysis  fluid which need to be changed.

Haemodialysis Dialysis process occurs outside the body in a machine The dialysis membrane is an artificial one: Dialyser The dialyser removes the excess fluid and wastes from the blood and returns the filtered blood to the body Haemodialysis needs to be performed three times a week Each session lasts 3-6 hrs

AV Fistula

Vascular Access Catheter

PD Access Done under LA or GA

Problems with HD Rapid changes in BP Fluid overload fainting, vomiting, cramps, chest pain, irritability, fatigue, temporary loss of vision Fluid overload esp in between sessions Fluid restrictions more stringent with HD than PD Hyperkalaemia Loss of independence Problems with access poor quality, blockage etc. Infection (vascular access catheters) Pain with needles Bleeding from the fistula during or after dialysis Infections during sessions; exit site infections; blood-borne viruses e.g. Hepatitis, HIV

SODIUM Regulates blood volume and pressure Avoid salt Use Alternate food seasonings: lemon and limes, spices, seafood seasoning, Italian seasoning, vinegars, peppers

FLUIDS Healthy kidneys remove fluids as urine Check for fluid and sodium retention Need to restrict fluid intake

LAB MONITORING Haemoglobin Albumin Calcium Phosphorus GFR (24 hour urine) Sodium Potassium Urea Creatinine