This module will review the Basic Components of CRRT
The following tools are vital components to perform CRRT: Well functioning vascular access A CRRT System - the Prismaflex Hemofilter/disposables used with the Prismaflex System. Dialysate and/or replacement solutions (PrismaSate and PrismaSol) A blood/fluid warmer compatible with the Prismaflex In this module you will learn about each of the treatment components.
A patient will need a veno-venous double lumen catheter or two single lumen venous catheters. One side of the lumen will deliver blood from the patient to the filter, and the other lumen will return the blood back from the filter to the patient. There are three access locations that are most commonly used, each with advantages and disadvantages. The internal jugular vein allows for ease of catheter insertion. Femoral vein is ideal when a patient is immobilized, and is also considered an easy site for insertion. Subclavian vein has a high risk of pneumo/hemothorax and is associated with central stenosis.
Here are some important considerations when using Vascular Access Catheter for CRRT: <read slide>
Anticoagulant may be required to ensure circuit patency by preventing clotting and optimal clearance. Typical anticoagulants used are heparin, various types of citrate protocols, or no heparinization. Sometimes only saline flushes of the circuit are employed, though this technique doesn’t prevent clotting from occurring.
During CRRT, room temperature dialysate and/or replacement solutions enter the extracorporeal circuit. The blood can become cooled as heat is lost to the atmosphere through the blood tubing set. The Prismaflex warmer is designed to prevent heat loss, minimize calorie loss and essentially enhance patient comfort.
What makes the Prismaflex hemofilters unique? Gambro’s Prismaflex sets are pre-connected and color-coded for ease of set loading. The set comes with a pre-connected effluent bag that is also used as a prime collection bag. The effluent bag has a port for draining the effluent and/or collection of effluent samples. The bag hooks on the side of the Prismaflex machine make handling of the solution and effluent bags easy. Latex has been identified as a source of allergic reactions. Eliminating latex in these products reduces this risk.
Additional features of the Prismaflex hemofilter sets include: Single set for all therapy modalities, as well as multiple sites for replacement solution infusion, integrated PBP line and high flow lines that eliminate nuisance pressure alarms. Clear plastic covered blood/fluid pumps for easy visibility of the pump segments and early detection of any blood/fluid leaks. Electrostatic Discharger Ring – grounds the blood circuit so that ECG artifact associated with peristaltic pumps is minimized. Integrated barcode reader to determine the correct set for the therapy prescribed and for automatic alarm limit setting.
To monitor access, filter and effluent pressures in the system, the Prismaflex set uses pressure pods with no blood-air interface to decrease clotting. The patented deaeration system contains a unique chamber with a spinning cylinder that removes air by propelling bubbles upwards during its operation. Use of a post-replacement fluid layer (~200cc/hr), eliminates the blood/air interface and reduces clot formation. A semi-automatic air removal procedure eliminates the need for disposables such as syringes and needles. This system also monitors the blood return pressure.
Except for M60, all the Prismaflex filter sets allow maximum solution flows (up to 8L/hr) handled by the Prismaflex System with the reduced risk of clotting. For higher blood flows, it is recommended to use HF1400. Notice that the HF1400 requires a minimum BFR of 100ml/min and a minimum priming rinse volume of 2L. The blood volumes in these sets are slightly larger than the blood volumes of the same set for the Prisma. Prismaflex sets are designed with a larger inner diameter tubing to accommodate the higher blood flow rates associated with optimized CRRT dosing.
Solutions in CRRT are used as dialysate or replacement depending on the mode of therapy, as we have learned in the previous slides. Solutions used in CRRT must contain a buffer to normalize the acid base balance. The purpose of buffers in CRRT are: To balance the ongoing endogenous acid production in the body Treat underlying metabolic acidosis To replace bicarbonate that is lost in the ultrafiltrate during the treatment Gambro was the first manufacturer to commercialize a bicarbonate-based dialysate and replacement fluid in one 5-liter bag.
These are two types of solutions available from Gambro. There are 6 different PrismaSate formulas with 5 different PrismaSol formulas. The Prismasate solution is used exclusively as dialysate and the PrismaSol solution is used as replacement.
Review Prismasate formulas
Review Prismasol Formulas
This graphic explains how easy it is to prepare PrismaSate/PrismaSol solution for use. Break the red frangible pin between the two compartments. Transfer the fluid from compartment A to compartment B. Rinse the fluid back into compartment A and then back into compartment B twice. Gently shake compartment B so that all components are mixed together. The dialysate line may be connected to either of the two access ports. If the luer access is used, remove the cap and connect the male luer lock on the dialysate line to the female luer receptor on the bag; tighten. Using thumb and forefinger, break the blue frangible pin at its base, and move it back and forth. Do not use a tool. Verify that the pin is completely separated and that fluid is flowing freely. The pin will remain in the luer port during treatment. If the injection port is used, first remove the snap-off cap. Then introduce the spike through the rubber septum. Verify that the fluid is flowing freely.
The Prisma ® System was the first fully integrated system for automated extracorporeal blood therapy, continuous fluid management, and therapeutic plasma exchange and the Prismaflex System is the next generation device. This overview will introduce you to the Prismaflex System for CRRT.
I’ve reviewed all the components needed to perform a CRRT procedure except for the machine itself. Now I’ll proceed with the machine overview. The Prismaflex Control Unit can be divided into three functional parts or “sub-units” that are interrelated … (read slide).
The communication unit is where the operator receives information and communicates with the system. This is the heart of the machine. The communication unit consists of a “touch screen” display and status lights.
The interactive display of the communication unit is your command center. The display is a 12 inch full-color touch screen which provides step by step instructions to guide you through all the machine’s operations, a s you can see in this example. During treatment, the same detailed instructions appear for alarms and ending the treatment. On-screen instructions reduce your reliance on quick reference cards and other sources of instruction that might not be readily available when you need it. The contents of the display depend on the operations at the moment. Prismaflex’s screens contain softkeys which, when pressed, send commands to the control unit. You will get to practice this during the hands-on segment of today’s training.
The status lights at the top of the machine give a general indication of the machine’s state of operation. Green light signifies normal treatment conditions. Yellow light reflects a Caution/Advisory alarm, such as a bag is empty and the operator needs to change the bag. Red is Warning/Malfunction and is the highest priority and needs immediate intervention because patient safety may be compromised.
The Prismaflex Control Unit consists of the pumps, the pressure monitoring system and the important safety features of the machine. It performs the following functions: • Loads and primes the Prismaflex set automatically. • Pumps blood through the blood flowpath of the Prismaflex set. • Delivers anticoagulant solution into the blood flowpath. • Controls fluid removal from the patient. • Pumps sterile anticoagulant/infusion solution into the blood access line with the pre-blood pump (PBP). • Pumps sterile replacement fluid and/or sterile dialysate. Pumps effluent. • Monitors the system and alerts the operator to abnormal situations through alarms.
The Prismaflex pumps control the flow of fluid in the hemofilter set and consists of five pumps: - Blood pump pulls blood from the patient and pushes it through the blood side of the hemofilter and back to the patient (up to 450ml/min); - Effluent pump controls patient fluid removal and removes used dialysate, replacement fluid and PBP fluid, pushing all into the effluent bag. (up to a total of 10L/hr); - Replacement pump(s) infuse fluid into the blood compartment (up to 8L/hr); - Dialysate pump infuses dialysate into the fluid compartment of the hemofilter (up to 8L/hr); - PBP infuses fluid into the blood circuit before the filter (up to 4L/hr but not exceeding the blood flow rate); - Syringe pump infuses fluid, such as an anticoagulant, into the blood compartment after the blood pump, but before the blood enters the hemofilter. - The pinch valves direct the flow of solutions from replacement and dialysate scales to either pre, post, or pre and post filter infusion(s) depending on the mode of therapy chosen. We will talk more about this during the set-up and operation.
The Prismaflex Control Unit has an integral pressure monitoring system that provides noninvasive assessment of the access, filter, return and effluent pressures. Pressure monitoring provides notification to the operator of abnormal pressure conditions, such as extremely negative or positive pressure in any segment of the blood lines or effluent line. Pressure monitoring also provides data needed by Prismaflex software to calculate other vital pressure conditions, such as transmembrane pressure (TMP) and filter pressure drop ( Δ Pressure Drop).
There are two types of pressure monitoring on the Prismaflex: the pressure pod system which is used to measure access, filter and effluent; and the drip chamber pressure monitor for the return. The pod system consists of the pressure pods included in the filter set, the pressure sensor housing on the front of the machine and the pressure sensor located inside the machine. Each pressure sensor housing holds the corresponding pressure pod of the Prismaflex set and provides a connection between the pod and an internal pressure sensor. This provides non-invasive pressure monitoring of the access line, filter, and effluent line. There are no air-blood interfaces. The pressure monitor for the return is made up of: • Deaeration chamber, located on the return line of the set. • Chamber monitor line. An integral part of the deaeration chamber, this line provides a connection between the top portion of the deaeration chamber and the return pressure port on the control unit. • Return pressure port. The front panel of the control unit has a luer-lock port located on the upper right (see Figure 1.1 on page 1-5 in Operator Manual).
The Prismaflex flow control unit contains the safety feature components of the machine such as: Blood Leak Detector- Continuously monitors the effluent line for the presence of red blood cells, indicating a leak in the filter membrane. Bar Code Reader – Identifies the Prismaflex Filter set and sets the operating limits accordingly ECG Discharger Ring– Grounds the blood circuit and minimizes ECG artifacts caused by the static generated by blood pump rotations. Air Bubble Detector - Continuously monitors the return line for air bubbles. Return Line Clamp- Occlusive clamp closes during all Warning and Malfunction alarms, when power is off, and during some self-tests to prevent blood and/or air from passing to the patient. Deaeration Chamber Holder - Secures the deaeration chamber of the filter set.
The Prismaflex System contains a procedure that allows for semi-automated removal of air bubbles in the circuit. Since an air pocket exists at the top of the deaeration chamber, an air/blood interface is unavoidable. To minimize clot formation in the chamber, a patented design allows creation of a post replacement fluid layer on top of the blood to eliminate the air/blood interface and to minimize clot formation.
This chart contains a summary of all the maximum flow rates available on each pump during the various CRRT modalities.
The Prismaflex’s fluid control unit is comprised of the scales and scale hook assemblies that serve each fluid pump (effluent, PBP, replacement and dialysate). Each scale continuously monitors the weight of each individual bag it is holding. Weight measurement is used to precisely control ultrafiltration and patient fluid removal. The scales are color coded for safety and align with the color-coding of the hemofilter set.
Four high-precision scales have been ergonomically designed to facilitate bag handling. Each scale slides out and the scale hook assembly/carrying bar are removeable to ensure an ergonomic and convenient method for bag changing. This will be demonstrated during set-up and practiced during the hands-on segment of training. The three independent infusion scales allow the use of different fluid compositions. Sudden bag movements are filtered by the software to avoid nuisance alarms.
PrismaFlex ® STEPP
Basic Components in CRRT Hemofilter CRRT Solutions Blood Warmer Vascular access Anticoagulation CRRT System
Flow Control Unit – Pumps Effluent Pre Blood Pump Replacement Blood Syringe Dialysate Pinch Valves
Flow Control Unit Pressure Monitoring Effluent Filter Return Access
Pressure Monitoring Pressure Pods Prismaflex® Operator’s Manual Chapter 4-p52 Pressure Pod System Return Pressure Monitor Pressure Port Monitor Line Deaeration Chamber To Software Pressure Sensor Air side Bloodline Diaphragm Pressure Pod Fluid side Front Panel
Safety Components Blood Leak Detector Air Bubble Detector Return Line Clamp Deaeration Chamber Holder Bar Code Reader ECG Discharger Ring