DIALYSIS Dr. Frank Edwin 1. Renal Failure Diagnosis

DIALYSIS Dr. Frank Edwin

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 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

Selection for HD/PD Clinical condition Lifestyle Patient competence/hygiene (PD - high risk of infection) Affordability / Availability

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. 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

Requirements for HD Good access to patients circulation Good cardiovascular status (dramatic changes in BP may occur)

Performing HD HD may be carried out: In a HD Unit At a Minimal Care / Self-Care Centre At Home

HD Unit Specially designed Renal Unit within a hospital Patients must travel to the Unit 3x a week Patients are unable to move around while on dialysis; may chat, read, watch TV or eat Nursing staff prepare equipment, insert the needles and supervise the sessions

Minimal / Self-Care Dialysis Patients take a more active role Patients prepare the dialysis machine, insert the needles, adjust pump speeds and machine settings and chart their progress under the supervision of dialysis staff Patients must travel to the unit 3x / week Patients need to be on a fixed schedule

Home Haemodialysis Use of machines set up at home Machines have many safety devices inbuilt Thorough patient training Requires the help of a partner at home every time Suitability is assessed by the haemodialysis team Ideal for patients who value their independence and need to fit in their treatment around a busy schedule

HD Access 2 types of access for HD: Must provide good flow Reliable access A fistula: arterio-venous (AV) Vascular Access Catheter

AV Fistula

AV Fistula

Vascular Access Catheter

AV Fistula Access Matures in about 6 weeks Ensure good working order Avoid tight clothing or wrist watch on fistula arm Assess fistula daily; notify immediately if not working Avoid BP cuff on fistula arm Avoid blood sampling on fistula arm (except daily HD Rx) Avoid sleeping on fistula arm Grafts (synthetic) may be used to create an AV fistula

Vascular Access Catheter Double lumen plastic tube May be placed in Jugular, Subclavian or Femoral vein May be temporary or permanent Temporary – awaiting fistula or maturation Permanent – poor vessels for fistula creation e.g. children and diabetics Catheters must be kept clean, dry and dressed to prevent infection

Effects of HD on Lifestyle Flexibility: Difficult to fit in with school, work esp if unit is far from home. Home HD offers more flexibility Travel: Necessity to book in advance with HD unit of places of travel Responsibility & Independence: Home HD allows the greatest degree of independence Sexual Activity: Anxiety of living with renal failure affects relationship with partner Sport & Exercise: Can exercise and participate in most sports Body Image: Esp with fistula; patient can be very self conscious about it

Problems with HD Rapid changes in BP 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 esp in between sessions 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

Peritoneal Dialysis (PD) Uses natural membrane (peritoneum) for dialysis Access is by PD catheter, a soft plastic tube Catheter and dialysis fluid may be hidden under clothing Suitability Excludes patients with prior peritoneal scarring e.g. peritonitis, laparotomy Excludes patients unable to care for self

Addendum to Principles (PD) Fluid across the membrane faster than solutes; therefore longer dwell times are needed for solute transfer Protein loss in PD fluid is significant ~ 8-9g/day Protein loss ↑s during peritonitis PD patients require adequate daily protein averaging 1.2 – 1.5g/kg/day Other substances lost in the dialysate Amino acids, water soluble vitamins, some medications and hormones Calcium and dextrose are absorbed from the dialysate fluid into the circulation

Addendum to Principles (PD) Standard dialysis solution contains: Na+ – 132 mEq/l Cl- – 96 -102 mEq/l Ca2+ – 2.5 – 3.5 mEq/l Mg2+ – 0.5 -1.5 mEq/l Dialysis solution buffer: Sodium lactate Pure HCo3- HCo3- /Lactate combinations Lactate is absorbed and converted to HCo3- by the liver Dextrose solution strengths: 1.5%, 2.5%, 4.25%

Types Continuous Ambulatory Peritoneal Dialysis (CAPD) Automated peritoneal Dialysis (APD)

CAPD Dialysis takes place 24hrs a day, 7 days a week Patient is not attached to a machine for treatment Exchanges are usually carried out by patient after training by a CAPD nurse Most patients need 3-5 exchanges a day i.e. 4-6 hour intervals (Dwell time) 30 mins per exchange May use 2-3 litres of fluid in abdomen No needles are used Less dietary and fluid restriction

CAPD Exchange

APD Uses a home based machine to perform exchanges Overnight treatment whilst patient sleeps The APD machine controls the timing of exchanges, drains the used solution and fills the peritoneal cavity with new solution Simple procedure for the patient to perform Requires about 8-10 hrs Machines are portable, with in-built safety features and requires electricity to operate

PD Access Done under LA or GA

DIET Why is diet important? Managing the diet can slow renal disease The need for dialysis can be delayed The diet affects how patients feel

CONTROLLING YOUR DIET Foods to control are those containing: Protein Potassium Sodium Phosphorous Fluid

PROTEINS Animal protein Dairy (milk, cheese) Meat (steak, pork) Poultry (chicken, turkey) Eggs Plant protein Vegetables Breads Cereals

MAJOR SOURCES OF POTASSIUM Milk Potatoes Bananas Oranges Dried Fruit Legumes Nuts Salt substitute Chocolate

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

PHOSPHOROUS Phosphorus is a mineral which combines with calcium to keep bones and teeth strong Too little calcium and too much phosphorus Need to control the phosphorus in the diet Need to take a phosphate binder or a calcium supplement

VITAMINS Folic acid Iron supplements Do not take OTC’s without consulting the doctor.

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

Lifestyle Changes with PD Flexibility Can be performed almost anywhere Least impact on work / school life (esp APD) Travel Dialysis supplies can be delivered to most parts of the world; travel more flexible. APD machines are portable; will fit into a car boot, can be carried by train/air Responsibility Requires more responsibility from patient but more independence

Lifestyle Changes with PD Sports/Exercise Most are possible Advice on swimming, lifting, contact sports Sexual Activity May affect relations based on patient anxiety Delivery & Storage of Supplies Home delivery and storage A month’s supplies – 40 boxes; space to store Specially recruited and trained delivery staff

Problems with Treatment Monotomy of treatment The treatment never goes away against days off with HD Body Image Problems Esp with a permanent catheter Abdominal stretching Fluid Overload Much less a problem than with HD Dehydration Less common than fluid overload Abdominal Discomfort Bloated feeling

Problems with Treatment Poor drainage Common problem esp with new patients Fibrin plug Catheter displacement Leakage Fluid may leak around catheter exit site. (May leak into scrotum) Stop PD temporarily Resite catheter (use new one) Infections Exit site infections Tunnel infection peritonitis

Problems with Treatment Hernia Aggravation of pre-existing herniae (repair) Evolution of new herniae Declining effectiveness of the peritoneum e.g. repeated infection Effect of glucose in the dialysis fluid

Comparison of Dialysis Treatment Options