hemodialysis machine12 (2)
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Kidney FunctionCalcium Balance Vitamin DActivation Recovery of Bicarbonate Sodium Removal Bone Structure Metabolic End Products Cardiac Activity
Regulation of Blood PH Blood Pressure Blood Formation Removal of Urea ,Creatinine etc .Potassium Balance Water BalanceErythropoietin Synthesis
Need Dialysis is a treatment for people in the later stage of kidney failure (chronic renal insufficiency). This treatment cleans the blood and removes wastes and excess fluid from the body, which are normally removed by healthy kidneys. Sometimes dialysis is a temporary treatment (acute). However, when the loss of kidney function is permanent, as in end-stage kidney failure, dialysis is required on a regular basis (chronic). The only other treatment for kidney failure is a kidney transplant.
There are two types of dialysis: hemodialysis and peritoneal dialysis. In hemodialysis, blood is passed through an artificial kidney (hemodialyzer) to clean it. Peritoneal dialysis uses a filtering process similar to hemodialysis, but the blood is cleaned inside the body rather than in a machine.
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.
DiffusionDiffusion/dialysis the movement of solutes from a compartment in which they are in high concentration to one in which they are in lower concentration along an electrochemical gradient. An electrolyte solution runs countercurrent to blood flowing on the other side of a semipermeable (small pore) filter. Small molecules such as urea move along the concentration gradient into the dialysate fluid. Larger molecules are poorly removed by this process. Solute removal is directly proportional to the dialysate flow rate.
By controlling the chemicals in the dialysate, the dialysis machine controls this transfer of solutes according to the doctor's prescription. Dialysis machines control the chemicals in the dialysate by mixing dialysis fluid concentrates, which are strong versions of the chemicals, (acetate or sodium bicarbonate plus acetic acid based solutions) with purified water
www.health.bcu.ac.uk Small molecules (less than 68 000 molecular weight) are removed from the blood by using the high blood pressure to squeeze the molecules from the glomerulus to the Bowmans capsule.The small molecules include:WaterGlucoseUreaSodium ChlorideAmino acids and small proteins
UltrafiltrationUltrafiltration, also referred to as convection, is fluid flow through the membrane, forced by a difference in pressure on the two sides of the dialyzer (pressure gradient). This controls the patient's weight loss over the course of the treatment. This is very effective in removal of fluid and middle-sized molecules, which are thought to cause uremia
UltrafiltrationWhile earlier dialysis machines either controlled dialysate pressure or the pressure difference across the membrane in order to achieve ultrafiltration. Modern dialysis machines are generally volumetric, meaning they control the volume of fluid removed from the patient directly and allowing dialysate pressure to change as it will in order to achieve the prescribed weight loss.
OsmosisOsmosisis the net movement of water across a selectively permeable membrane driven by a difference in the amounts of solute on the two sides of the membrane. In dialysis, this refers not to water movement across the hemodialyzer membrane, but across cell membranes within the body-either from within the red cells to the blood plasma, or from within cells of the various tissues in the body (like muscles) to interstitial fluid (the fluid in between cells)
Thin material separates the compartmentsBlood and dialysate flow in opposite directionsDialysate drains the wastes out of the bloodClean blood is returned to the body
Dialyzer Characteristics 1- Biocompatibility( how much a membrane is compatible with human body ) 2- Membrane Surface Area 3- Molecular Weight ( the solute size that can pass through the membrane ).4- Ultrafiltration Coefficient 5- Clearance ( the rate of solute removal )
Dialysis solution, also known as dialysate, is the fluid in the dialyzer that helps remove wastes and extra fluid from the blood, as well as regulate blood pH and proper level of the ion concentrations. It contains chemicals in low concentrations.
Blood is pumped with the peristaltic pump through the capillaries, the dialyzing solution is flowing around the capillaries in opposite direction.
Dialysis Solution (Dialysate) FunctionFluid in the dialyzer that contains chemicals in low concentrations . This solution are : Bicarbonate and Acetate .Functions :-1-Remove the wastes and extra fluid from the blood2-Regulate blood PH and proper level of the ion concentration .
Components for Hemodialysis machine-Single patient hemodialysis systems can be divided into three major components :-1- dialysate delivery system.
2- The extracorporeal blood-delivery circuit .
3- The dialyzer .
Components for Hemodialysis machine
How Dialysis Work
Hemodialysis Machine Parts
Parameters monitoring in Hemodialysis Machine 1- Blood Flow .2-Dialysate Flow.3- Dialysate Temperature.4- Conductivity .5- Venous and Arterial pressure.6-Blood in dialysate leaks.7- Patient blood pressure.
When the air detector senses air it will trigger audible and visual alarms, stop the blood pump and clamp the venous blood tubing to keep air from getting into the patients bloodstream.
UltrafiltrationDialysis machine causes hydraulic pressureThere is higher pressure in blood compartment than in the dialysate compartmentThis forces water and any other molecules small enough to pass through the membrane to evacuate the blood.
Single Patient Dialysate Delivary System
Volumetric UF Control System
The extracorporeal blood-delivery circuit