Feasibility, Efficacy, and Safety of Peripheral Venous Access for Chronic Double-Filtration Plasmapheresis with Regional Citrate Anticoagulation

INTRODUCTION

Peripheral venous access (PVA) is recommended as a first-line vascular approach for therapeutic plasmapheresis with centrifugation methods but not filtration, which usually requires high blood flow. We evaluated the feasibility, efficacy, and safety of double-filtration plasmapheresis (DFPP) with PVA, using ultrasound guidance and regional citrate anticoagulation (RCA), i.e., PVA-RCA-DFPP in patients undergoing chronic DFPP. Secondly, we assessed the number of central venous catheters (CVCs) avoided.

METHODS

A single-center retrospective study evaluated 22 adult patients on chronic DFPP to perform PVA-RCA-DFPP. They were classified into 3 groups: successful (i.e., completion of sessions with PVA), primary failure (i.e., no sessions completed), secondary failure (i.e., ≥1 session with PVA completed but secondary return with CVC or arteriovenous fistula).

RESULTS

Among the 22 patients included (64% men), 7 patients (32%) were classified as primary failures (2 patient refusals, 5 inadequate PVAs), 1 patient (5%) as a secondary failure (due to uncomfortable venipunctures), and 14 patients (64%) as successful. In the successful group including 12 patients treated for chronic inflammatory demyelinating polyneuropathy (CIDP) and 2 patients for familial hypercholesterolemia (FH) (2 patients), 116 sessions were performed, with a median treated plasma volume of 4.3 L [IQR 3.6-4.6] (45 mL/kg) for a median duration of 134 min [IQR 122-144], and a median blood flow of 94 mL/min [IQR 87-103]. For the CIDP group, 90% of sessions achieved a plasma volume >1 TPV, and for the FH group 91% of sessions achieved an LDLc reduction >60%. Eleven sessions out of 116 (9%) were interrupted, mostly due to PVA dysfunction (5/11) and circuit clotting (4/11). Session interruptions decreased significantly between each patient's first and following sessions (29% to 7%, p = 0.009).

CONCLUSION

Chronic PVA-RCA-DFPP can be performed safely and efficiently, avoiding the use of CVCs.

Comprehensive guide to managing a chronic automated red cell exchange program in sickle cell disease

Sickle cell disease (SCD) is associated with significant morbidity and mortality, and limits both the quality and quantity of life. Transfusion therapy, specifically automated red cell exchange (aRCE), plays a key role in management of SCD and is beneficial for certain indications in the chronic, outpatient setting. The approach to maintain a successful chronic aRCE program for SCD is multifaceted. This review will highlight important considerations including indications for aRCE, patient selection, transfusion medicine pearls, vascular access needs, complications of therapy, aRCE prescription, and therapy optimization. Moreover, the importance of a multidisciplinary approach with frequent communication between the services involved cannot be overstated. Ultimately, the underlying goal of a chronic RCE program is to improve the quality of life and longevity of patients with SCD.

Therapeutic plasma exchange in patients with severe obesity (BMI >40): A survey of practices in the United States

BACKGROUND

The prevalence of obesity in the United States is estimated at 42.4% and expected to increase over the next decade. Therefore, understanding how to best perform certain medical procedures on severely obese (SO) patients is a necessity. This study presents results on the current methods of performing therapeutic plasma exchange (TPE) on SO patients. This paper aims to contribute to the existing literature by providing new insights into calculating plasma volume (PV) for TPE in SO patients.

METHODS

Blood Bank/Apheresis Directors at all institutions with pathology residency and/or blood banking/transfusion medicine fellowship programs were asked to complete a 5-question online survey about their institutional policies regarding TPE in SO patients. Survey data were analyzed to determine if institutions have policies in place to calculate PV in SO patients.

RESULTS

Out of the 144 institutions contacted, 45 (31%) completed the survey. Nine (20%) institutions had a policy to calculate PV differently for SO patients, 7 (16%) reported a specific body mass index (BMI) above which they alter PV calculation, and 7 (16%) reported a maximum volume exchanged in SO patients.

CONCLUSION

A minority of responding institutions had specific policies in place to calculate PV for TPE in SO patients. Practice patterns for calculating PV for TPE in SO patients varied, with some institutions adjusting PV calculations and others setting a maximum volume to be exchanged regardless of BMI. These findings highlight the need for establishing a clear method of calculating PV in SO patients.

Physiological role of plasma and its components and the clinical implications of different methods of apheresis: A narrative review

Nowadays, therapeutic plasmapheresis (TP) is accepted as part of the treatment for specific groups of diseases. The availability of different methods, including double filtration and adsorption, increases selectivity for the removal of substances. However, the use of these techniques requires a thorough understanding of the characteristics and components of plasma. By considering pivotal papers from several databases, the aim of this narrative review is to describe the characteristics of plasma related to apheresis techniques. We have tried to cover the clinical implications including physiology, estimation of plasma volume, viscosity, and a description of its components including the size, volume of distribution, and half-lives of the different substances to be removed or maintained depending on the clinical situation and applied apheresis technique. Applying this knowledge will help us to choose the right method and dosage and improve the efficacy of the procedure by preventing or addressing any complications.

Red Blood Cells: Exchange, Transfuse, or Deplete

Erythrocytapheresis, red blood cell (RBC) depletion, and RBC exchange transfusions are apheresis techniques used to rapidly lower the circulating RBC mass or to exchange the patient erythrocyte mass with donor RBC. Automated RBC exchange is performed using an apheresis device, while manual RBC exchange is based on sequential phlebotomies and isovolemic replacement. Compared to simple RBC transfusions, RBC exchange offers several advantages, e.g., a lower risk for iron accumulation and efficient control of pathological erythrocyte populations. Disadvantages are the higher costs of the procedure, the increased use of donor RBC, and the requirement of apheresis devices and trained hospital staff. The most frequent indication for RBC exchange is sickle cell disease (SCD). RBC exchange transfusions are standard treatment in SCD patients with a history of or a risk for acute stroke and are clinical options for other acute complications of SCD. The most common indication for RBC depletion is the removal of donor RBC from the bone marrow grafts in major ABO-incompatible allogeneic hematopoietic stem cell transplantation to avoid immediate hemolysis. Rare indications for RBC exchange are severe infections with intraerythrocytic pathogens such as malaria or babesiosis and severe erythrocytosis or hereditary hemochromatosis where the aim is to rapidly decrease RBC populations or the iron content. However, only few high-quality studies are available looking at the efficacy of RBC exchange in the different disease entities, and treatment is often based on low levels of evidence and should therefore be decided in close collaboration with a transfusion medicine specialist.