Procedure: CRRT Saline Flush, Ending Treatment 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. Don PPE and Hand Hygiene
2. Rescue Line and Saline Flush
3. End Treatment/Retransfuse Blood
4. Access Catheter
5. Prevent Blood Exposure
6. Block Catheter
7. Add Medication Label
8. Dispose of Circuit
9. Document
10. Printable Checklist for Deaccessing a Dialysis Catheter

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) 
• 2 empty 10 mL syringes
• 2 - 4 10 mL NS syringes (extra saline syringes may be needed if there is visible blood on the catheter limbs or clamps)
• 1 Sterile 4X4 gauze
• Non-sterile gauze (for clot assessment)
• 2 preloaded syringes of 4% Sodium Citrate blocking solution 
• 2 dead-end Luer-lock caps
• 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

Ending a Treatment

Nurses determine when to end a treatment. Termination of a treatment is done when there are signs of imminent clotting, spontaneous machine shutdown, decrease in filter efficiency or the need to transport the patient off of the unit. Filter efficiency is evaluated Q 12 H by calculating an ultrafiltration urea/serum urea ratio.  Perfect clearance of urea is identified by a ratio of 1.0 (the serum urea is equal to the ultrafiltration urea indicating 100% clearance of urea).  If the ultrafiltration urea:serum urea ratio drops to below 0.80, the filter should be changed to optimize efficiency of clearance. 

If the treatment does not require termination for any of these reasons, it will be routinely changed at ~72 hours.  The machine will prompt the nurse to end the treatment at 72 hours and a yellow light will illuminate. You can continue beyond ~72 hours until a more convenient time by selecting override (we do not generally extend by more than a couple of hours.  

Retransfusion 

At the end of a treatment, blood that is contained within the CRRT circuit is retransfused to the patient.  This is done in CCTC by drawing saline into the access limb of the catheter (instead of blood), until all of the blood has been returned into the return limb of the catheter.

In CCTC, we do not retransfuse using the on-screen procedure that instructs you to spike a saline bag. Instead, we keep a 1 L bag of 0.9 % sodium chloride connected to the access limb. This is called a "rescue line".  

When using the TherMax heater, the filter, tubing and heater set contains a total volume of ~217 mL. When retransfusing the patient at the end of a treatment, strive to administer ~217 mL of saline.  Additional volume will make the patient more positive.
 

Saline Flush

The same rescue line can be used to administer a bolus of saline, or to flush the tubing for the purpose of inspecting the filter for clotting. 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. The volume of a saline flush can be determined by evaluating the blood flow rate and duration of saline flush.

Haemoglobin Changes

When evaluating haemoglobin changes in a patient on CRRT, consider the Hb in relation to the start and stop times of a CRRT treatment.  Haemoglobin may drop after initiation of treatment due to dilution with saline.  If the filter clots and retransfusion of blood cannot be performed, a hemoglobin drop may occur due to blood lost in the circuit.

Safety Note

The saline rescue line always stays with the ACCESS TUBING (not the access limb).  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 of the patient's catheter.  The rescue line stays with the CRRT circuit access tubing; never add stopcocks or extra connections to the return tubing.  Should a stopcock or connection leak at this point, 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.

1. 

Include Face Shield with PPE

Include a face shield with PPE.

Rescue Line and Saline Bolus

Figures 1.0 and 2.0 show a rescue line added to the access tubing of a CRRT circuit.  Figure 1.0 shows the position of the clamps during treatment (open to the patient and access tubing, closed to the rescue line).  Figure 2.0 shows the position of the clamps for saline flushing/retransfusion (closed to patient, open to saline flush and access limb of circuit).

1. Inspect return side of circuit for signs of clotting.
2. A volume of 50 – 125 ml of saline is sufficient to evaluate the filter. 
3. Examine the blood flow and determine the duration of time needed to deliver the desired bolus.  For example, if the blood flow is reduced to 200 mL/min (to make the math easy), a 15 second flush will provide a 50 ml saline bolus. A 30 second flush at 250 mL/min will deliver 125 mL.
4. Simultaneously open the rescue line as you clamp the access limb of the patient's catheter.
5. Leave open for the desired duration of time.
6. At the end of the time period, choose "Stop" on the machine.
7. Clamp the rescue line and reopen the clamp on the access limb of the catheter.
8. Select "Resume Treatment" from the screen.
9. Record the saline bolus volume in the intake section of the fluid balance record.

End Treatment

1. If CRRT treatment is being terminated electively, prepare sterile field and equipment required to access and block the dialysis catheter prior to starting. See Procedure for Accessing a Dialysis Catheter.
2. Inspect return side of circuit for signs of clotting.
3. Turn the blood flow to 217 ml/min. 
4. Simultaneously open the rescue line as you clamp the access limb of the patient's catheter.
5. Leave open for exactly 1 minute, then hit "Stop" on the machine.
6. Clamp the rescue line
7. Select "End Treatment" and follow the online steps to disconnect the circuit.

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.

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

Prevent 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.

7.

Add a Medication Label

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

 8.

Dispose 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.

Document Blood Return

Document the time treatment ended in the CRRT Navigation Bar. Record whether blood was successfully retransfused or lost within a clotted filter.

Do not record the volume of blood returned in the intake section of the fluid balance record at end-of-treatment; we do not record the priming bolus at the start of the treatment - this is considered net neutral at temination (this is a unit specific procedure). 

Document any saline flush volume in the intake section of the Intake Section of the Fluid Balance record of the EHR.