Connect the Circuit
Confirms Blood Flow Rates
Set the flow rate as per orders. Set initial blood flow rate to 250 ml/min and fluid removal to 0 ml/hour. The PrisMax will ramp up to this speed as tolerated. Fluid removal can be started once patient has stabilized.
Adds Saline Flush
Rescue Line: Prime a bag of normal saline with regular IV tubing. Place a stopcock on the end with the saline infusion connected at 90 degrees to the flow (to reduce flow restriction, the access limb and access tubing should be in a straight line. Leave the stopcock off to the saline with any clamps on the IV tubing open (this allows for rapid flushing/return of blood if needed).
If the return limb is going to be used as the access (lines are reversed), the rescue line stays with the access tubing. If the saline line is opened and stopcock closed to the catheter limb, the CRRT machine will pull saline at the set blood flow rate (e.g., 250 ml/min). Blood can be retransfused at this rate in less than one minute. A smaller volume can be used to check for clots - observe as the saline moves up through the filter. To identify saline volume, time the duration that the saline line is open (e.g., 30 seconds at 250 ml/min would be a saline bolus of 125 ml).
A rescue line should never be added to the return tubing. If the stopcock became disconnected, this could result in blood being pulled from the patient and returned into the bed at up to 250 ml/min. The stopcock could create enough resistance to prevent a "return disconnect alarm". A return disconnect alarm will be activated if the return pressure falls below a pressure of +10 mmHg.
Connect the circuit to the catheter as follows:
Follow the on screen instructions for connecting the effluent tubing to the effluent bag and return tubing to the Y connection of the priming solution.
Bring clamp both limbs of the Y connector.
Bring the clamp on the access and return tubing close to the end for ease of access. Clamp the access and return tubing.
Check to ensure all other clamps (including the PBP) are open before proceeding.
Bring the priming bag with access and return tubing still connected to the Y connector to the bedside.
Heparin Bolus:
If a heparin bolus has been ordered (for heparin filter anticoagulation prescription), administer the bolus directly into the access limb (red) just prior to connecting the circuit as follows (the volume of heparin must be less than the volume of the catheter). This technique ensures that the first blood to hit the filter will be heparinized, but prevents the patient from receiving a direct heparin bolus.
- Clamp the access limb of the catheter
- Attach the heparin containing syringe to the access limb (red) of the dialysis catheter (e.g., 5,000 in 0.2 ml)
- Open the access limb clamp.
- Inject the heparin into the access limb.
- Reclamp the access limb.
Confirm Circuit Connections:
- Connect the rescue line stopcock/saline infusion to the access (red) end of the CRRT circuit.
- Connect the limb of the patient catheter that is being used for access (red line unless lines are reversed) to the rescue line stopcock. If lines are reversed, ensure that the rescue line remains connected to the access tubing (not the return tubing).
- Connect the return limb (blue) of the patient catheter to the return (blue) end of the CRRT circuit.
Ensure all clamps are open before starting treatment:
- Open the access and return clamps on the catheter.
- Close the stopcock on the rescue line "off" to the saline infusion.
- Open the roller clamp of the saline infusion.
- Ensure that all clamps in the CRRT circuit are open - double check the clamp on the PBP line (close to access connection), effluent line and all infusions.
Initiates Treatment:
- Initiate treatment following on screen prompts
- Observe catheter connections for blood leak
- Monitor circuit closely for leakage or air bubbles and be prepared to raise the deaeration chamber level quickly to prevent air in return alarm
NOTES:
If treatment is started with lower blood flow rates, the access pressure will be too low (i.e., less negative). As blood flow increases, the access pressure becomes more negative (more “suck” is required to pull the larger blood flow volume). If the access pressure is less negative than minus 10, the CRRT machine will interpret this as a disconnected access limb and generate an alarm. To avoid access disconnection alarms, escalate the blood flow rate quickly during initiation of treatment. Starting at 250 mL/min will usually prevent this from happening.
If pump pressures permit, increase the blood flow rate as quickly as possible to 300 mL/min (as tolerated). Higher blood flow rates can reduce filter clotting by shortening the duration of time that blood remains in the filter. Blood flow rates must be increased as quickly as possible for maximum clotting reduction benefit. Access and return pressures will increase as blood flow rate increases - once blood flow is stable, these pressures should also stabilize.
Once the circuit is connected, all clamps should remain open. Any time that a high priority alarm is activated, the blood pump automatically stops and the blood flow circuit closes (safe mode).
If therapy is initiated with any clamps closed, the CRRT machine will immediately alarm and shut down. Repeated alarms during initiation may lead to treatment failure/shut down.
|