FAQ - Nursing Considerations

What is the usual blood flow rate for TPE using the Plasmafo?

The blood flow rate for TPE is considerably lower than for hemodialysis. TPE can best be accomplished at rates of 100 to 150 ml/min.

How much volume is exchanged?

The amount of plasma removed from a patient in TPE is based on the plasma volume (PV). Most TPE procedures exchange 1 to 1.5 PV of the patient. The PV is a calculated value, such as:

PV = Total Blood Volume x (1.0 - .hematocrit)

Total blood volume may be estimated by the use of a Nomogram or by multiplying the weight of a patient by 65 ml/kg.

What are the usual plasma exchange rates using the Plasmaflo™?

In general, the plasma removal rate and the fluid replacement rate are the same. The plasma exchange rate is between 1/5th and 2/5th of the blood flow rate. The plasma exchange rate should be limited, depending on the transmembrane pressure of the filter.

What coagulation parameter is followed to assess the need for fresh frozen plasma replacement?

The two tests used are the Prothrombin Time (PT) and the fibrinogen level. Those centers that use PT feel that the PT must be elevated more than 2 or 3 seconds above the control before FFP should be considered. Since fibrinogen is removed during TPE, other centers will follow fibrinogen levels. They feel that a fibrinogen level of less than 125 mg/dl is an indication for FFP replacement.

What is the extracorporeal volume (ECV)?

The ECV is less than 200 ml's. The tubeset contains approximately 125 ml's and the Plasmaflo™ volume is 65 ml's.

Is systemic anticoagulation necessary?

Heparin anticoagulation is used. Since heparin is a protein-bound drug, some of the administered heparin will be removed with the plasma. It is recommended that activated clotting times be maintained at about 2 to 2 1/2 times baseline.

How much time does it take to complete a TPE treatment using the Plasmaflo™?

The procedure time depends on a number of factors. The vascular access, patient's hemodynamic stability, patient's hematocrit, blood flow rate and plasma flow rate all contribute to the length of the treatment. Treatments are prescribed in volumes of plasma to be exchanged. Generally, a four liter exchange will take about two-and-a-half (2 1/2) hours.

What is the Patient-To-Nurse ratio for TPE?

Patients who need TPE may be critically ill. Additionally, the procedure requires careful attention to operating details and patient management. We recommend that the patient: nurse ratio is 1:1, similar to acute hemodialysis treatments.

What are some of the potential complications of performing TPE?

Hypotension secondary to inadequate fluid replacement or medication removal
Dehydration secondary to inadequate fluid replacement
Electrolyte imbalance secondary to improper electrolyte replacement
Infection
Hemorrhage
Hemolysis
Chills
Dizziness
Vasovegal & anaphylactic reactions
Allergic reaction to the solution used to replace the plasma
Air embolism

Why are nephrology nurses on the forefront of performing therapeutic plasma exchange?

The nephrology nurse's role in TPE has evolved naturally. The expertise with extracorporeal circulation has always been in the domain of nephrology. Nephrology nurses are recognized experts on systemic anticoagulation of whole blood, and have been skilled in the maintenance and monitoring of sophisticated equipment and technology for decades.

For the nephrology nurse, what are the benefits of becoming involved in therapeutic plasma exchange?

TPE allows the nurse to utilize existing skills in a new and similar manner and offers a comfortable alternative to hemodialysis. Unlike patients with chronic renal failure, patients who need TPE generally return to normal activities of daily living, providing a new sense of job satisfaction to the nephrology nurse.

Note: Please read the device instructions and consult with a physician to assess all possible complications.