Schematic representation of dialysis system

1. General Reassessment

Acute or chronic dialysis prescription should be reviewed. evaluated. and carried out accurately to obtain the maximal efficiency for dialysis. The patient's physiologic status is assessed to ascertain the necessity of adjusting any dialysis orders.  All machine parameters are assessed to ensure that the prescribed procedure is correctly implemented. The goal is to initiate and terminate the dialysis procedure safely and comfortably with no or minimal complications.

2.Rinsing and priming

Technical and nursing personnel have a great responsibility to assure proper and safe connections, flow paths, and overall adequacy and safety of the system.

Adherence to the manufacturer's procedure for rinsing is mandatory.

Importance of rinsing and priming :       

1Rinsing and priming the dialyzer assure adequate removal of allergens (e.g. ethylene oxide ) and reduction of the incidence of anaphylactic membrane reactions         

2.Microbubbles are also removed when the venous end of the dialyzer pointed upward.

The dialyzer should be used within 5-10 minutes to avoid leaching of residual ethylene oxide or other leachable allergens into the rinsing fluid.

Dialyzer should be rerinsed briefly immediately prior to dialysis if more than 10 minutes has elapsed.

3. Patient Monitoring Predialysis:  (See its Tip)

Weight , Pulse Rate , B.P.Laying   & Standing  Temperature, Fluid status, Blood investigations and Vascular access patency and freedom from infection

4.Obtaining vascular access

Poor vascular access is a limiting factor to patient survival on hemodilysis. Therefore great care must be taken to maintain adequate vascular access.

·        Percutaneous venous cannula ( Femoral,  Subclavian,  Jugular )

      Residual heparin or clot is first aspirated from both catheter lumen

      Check the patency of each lumen by irrigating with a saline filled syringe.

      Heparin loading dose is administered in the venous limb and flushed with saline.

      Initiate dialysis after 3 minutes

·        AV fistula and graft: (see the previous tip; Using permanent vascular access)

      Heparin loading dose is administered in the venous needle and flushed with saline.

      Initiate dialysis after 3 minutes

5.Initiatting dialysis

·        Set the blood flow rate at 50 then 100 ml/minute, untill the blood fills the blood circuit.

·        The Priming fluid in the lines and dialyzer is disposed of to drain until the blood reaches the venous air trap. In unstable patient the priming fluid is usually given to the patient t maintain the blood volume.

·        Increase the blood flow rate to the desired level after the circuit is filled with blood (150-250 in acute cases).

·        Initiate the dialysis solution flow and adjust the TMP.

6.Alarms ( See the previous tip )

Blood circuit

Arterial pressure

Venous pressure

Air detector

Dialysis solution circuit

Conductivity

Temperature

Blood leak

7. Patient monitoring During Dialysis (see its Tip)

Pulse rate , BP every 30 to 60 minutes in chronic dialysis, but at least every 15 minutes in acute dialysis, Food & Fluid intake, Complications during dialysis and any particular observations.

8. Termination of dialysis

a. Saline rinse: The blood is returned by pumping sterile normal saline into the arterial side until the blood is displaced.  After the bubble trap the fluid should be very pale pink in color (to assure that the patient has lost the least amount of red cells).

b. Saline-Air rinse: The blood is forced by pumping a small amount of saline into the arterial line, then the line is opened to allow air into the circuit to push the saline and blood. Again the fluid entering the patient should be very pale pink in color.

c. Air-Saline rinse: It begins with an infusion of air to displace the blood until it reaches the end of the dialyzer. At this point the saline is pumped into the arterial line to displace the air.  At the same time the air is allowed to escape at the level of venous chamber while the saline is being infused to the patient. It is effective, but air embolism is a potential risk.

NB: I- Constant visual monitoring of venous line is required to avoid air infusion into the

           patient in b and c methods.

      II- Hollow fiber dialyzer are rinsed by saline rinse method because complete removal

           of blood by air from tiny diameter of hollow fiber is difficult.

9. Patient monitoring Postdialysis    (see its tip)

Weight  ,  Pulse Rate  , BP Laying &Standing ,Temperature, Blood investigations and Vascular access patency. All patients parameters and any unusual occurrences should be documented on patient's file.

10. Equipment care

The care of dialysis machine is the responsibility of the staff and  of the biomedical technicians. Scheduled maintenance recommended by the manufacturer should followed meticulously for the safe and efficient function of the equipment.