Procedure: Ending and Deaccessing Dialysis Treatment

Ensure that patient and health care provider safety standards are met during this procedure including:

  • Risk assessment and appropriate PPE
  • 4 Moments of Hand Hygiene
  • Procedural Safety Pause is performed
  • Two patient identification
  • Safe patient handling practices
  • Biomedical waste disposal policies
  • Sharps handling

INDEX

  1. Dons PPE and Hand Hygiene
  2. Performs Saline Flush
  3. Retransfuses Blood
  4. Accesses Catheter
  5. Prevents Blood Exposure
  6. Blocks Catheter
  7. Adds Medication Label
  8. Disposes of Circuit
  9. Documents
  10. Catheter Disconnection Checklist

Equipment Required:

  • Appropriate PPE—always include a mask with a face shield
    Sterile dressing tray (the dressing tray includes the sterile drapes and a place to inject blood for clot inspection).
  • 2 pair non sterile gloves
  • 2 large (1.5 mL) chlorhexidine 2% swabs (without alcohol) (use 4 wipes if catheter or clamps are visibly soiled.
  • 2 empty 3 mL syringes
  • 2 - 4 10 mL NS syringes
  • 1 Sterile 4X4 gauze
  • Non-sterile gauze (for clot assessment)
  • 2 preloaded syringes of 4% Sodium Citrate blocking solution 
  • 2 Luer-lock needleless access caps, primed with citrate
  • Red medication label
  • Gauze and tape (to cover limbs)
  • Yellow Biohazard Waste Bucket

Printable Checklist for Accessing a Dialysis Catheter

Printable Checklist for Deaccessing a Dialysis Catheter

Note:

If CRRT treatment is being terminated electively, prepare sterile field and equipment required to access and block the dialysis catheter prior to starting.

At the end of a treatment, blood that is contained within the CRRT circuit is retransfused to the patient. This is done by drawing saline into the access limb (instead of blood) until the blood has been returned into the return limb of the catheter. To facilitate prompt retransfusion when necessary, a bag of normal saline  with a standard IV tubing set is connected between the access limb and access tubing via a 3-way stopcock and left in situ with the stopcock turned off to the saline. This is called a "rescue line". 

The entire circuit (including heater set) contains ~216 ml of volume (189 ml for filter and tubing and 27 ml in TheraMax heater bag). To retransfuse, the stopcock of the rescue line is opened to the saline infusion and circuit (closed to the access limb). Saline will be pulled into the circuit and returned to the access limb until ~216 ml of blood has been returned (blood reaching the return side will appear dilute).

When evaluating haemoglobin changes in a patient on CRRT, the timing of the treatment should always be considered (e.g., haemoglobin may drop after initiation of treatment or if the filter clots without retransfusion). It is always better to retransfuse early than to allow the filter to clot completely.

SALINE FLUSH

At any time during a treatment, a saline flush can be performed. This is accomplished using the same process described for retransfusion. Saline is drawn into the access limb until clear fluid is observed passing through the filter. A volume of 50 – 100 ml of saline is sufficient to evaluate the filter. Observe the filter as the the saline moves from bottom to top of filter. 

The volume of saline administered can be calculated by assessing the blood flow rate and duration that the saline is open. For example, if the blood flow is set at 200 ml/min, a 15 second flush will provide a 50 ml saline bolus. This can be removed over the next hour by increasing the fluid removal rate by 50 ml/hr (or 25 ml X 2 hours). To retransfuse, the blood flow can be reduced to 216 ml/minute and the saline flush opened for one full minute. 

PROCEDURE

 1.

Don PPE and Hand Hygiene

Perform hand hygiene, don appropriate PPE including mask with face shield.

2.

Saline Flush

Keep clamps on saline infusion tubing open (roller clamp and slide clamp). Turn saline off and on by the stopcock to facilitate rapid intervention if needed.

Determine blood flow rate and measure duration of flush in seconds. Adjust if desired to make volume calculation easier (e.g., 200 ml/hr for 30 seconds).

When ready to flush, turn stopcock "closed" to the access lumen and open between the saline and dialysis circuit.  Saline will be drawn in to the circuit instead of blood.

Watch as the saline reaches the filter. Blood in the filter will clear, allowing for visible inspection of the amount of clotting.

Close the clamp when sufficient flushing has occurred.

Adjust the fluid removal for the next hour to remove the volume of the saline flush.

Saline will be drawn into the access side of the circuit upon starting blood return. By keeping the IV clamps open, saline flushing can be performed quickly by a single stopcock adjustment.

Safety Note: The saline rescue line always stays with the ACCESS TUBING (not the access limb).  Normally, the stopcock will sit between the access limb and access tubing.  If the lines are reversed (the return limb is used to access the patient's blood), the access tubing will be connected to the return limb.  The rescue line stays with the access tubing to sit between the return limb of the catheter and the access tubing of the circuit when the lines are reversed.

A rescue line should never be placed between the return tubing and the limb being used to return blood (usually blue). Should the stopcock connection leak, blood could be pulled from the patient and into the bed at up to 300 ml/min.  As long as there is any resistance in the return end (generating a pressure of +10 mmHg or more), a "return disconnect" alarm would be suppressed.

3.

End Treatment

Inspect return side of circuit for signs of clotting. Open up the flow of saline in the rescue line and pull saline until ~216 ml has been delivered. Turning the blood flow to 216 ml and leaving the flush open for one minute makes the process simple.  

Once a sufficient volume of saline has been administered, clamp the saline flush and choose "Stop" and "End Treatment". 

There is an auto-return feature available that will guide you to add a spike to a bag of saline and connect the access limb to the spike.  The rescue line process is preferred due to speed and simplicity

The auto-return feature can also be used if non-urgent retransfusion is required.

4.

 

Accesses Catheter

Prepare equipment and access catheter as per CCTC procedure for Accessing a Temporary Double Lumen Dialysis Catheter.

Check for clots and flush vigorously as per procedure.

5.

Prevents Blood Exposure

As soon as each end of the circuit is disconnected, drop the end of the CRRT tubing into the biohazardous waste bin or connect.

6.

Blocks Catheter

Obtain two syringes of 4% citrate solution (for catheter blocking) and two needleless access cap. Connect each syringe to one access cap and prime the cap with citrate.

Attach the needleless access cap and infuse a volume equal to the limb volume plus 0.1 ml into each of the lumens.

For citrate, up to 2.5 ml can be injected into each limb without concern over administration into the patient (2 ml is the usual flush).

If heparin is being used to block a line, limit the volume to exactly the limb volume plus 0.1 ml.

If TPA is being used to block a line, the limb volume plus 0.3 ml should be ordered.

The overage volume is used to ensure that the drug reaches the end of the catheter.  For heparin, it is important to avoid additional administration to prevent systemic heparinization.

7.

Adds a Medication Label

Wrap the ends of the limbs with gauze net and add a completed medication sticker to identify citrate solution

 8.

Disposes of Circuit

Ensure all CRRT lines are clamped, then unload CRRT filter and tubing from the machine. Dispose set and any other supplies with blood exposure in the yellow biohazardous waste bucket.

Do not place non-blood contaminated products in the biohazardous container (such as Hemosol or saline bags).

9.

Documents Blood Return

Document whether blood was successfully retransfused or lost within a clotted filter.

Record the volume of blood that was returned (if blood was successfully retransfused, the volume of blood that was returned is the same as the volume lost at the time of therapy initiation).

Developed: November 30, 2017, Reviewed: January 22, 2022
Brenda Morgan CNS CCTC

REFERENCES

LHSC Renal Program Procedures