Tina S. Ipe

Ultrasound-guided peripheral venous access for therapeutic apheresis procedures reduces need for central venous catheters.

Therapeutic and donor apheresis requires adequate vascular access to achieve inlet flow rates of ∼50—100 mL/min. While central dialysis‐type venous catheters can usually provide such access, their use includes several associated risks. Some of these risks can be avoided or diminished if adequate peripheral venous access can be established. Some patients have adequate peripheral veins for apheresis that cannot be readily identified visually or by palpation. We hypothesized that ultrasound‐guided peripheral venous access would benefit such patients and would lead to placement of fewer central venous catheters. The technique of ultrasound‐guided peripheral access for apheresis has been in use at Houston Methodist Hospital since 2012. We performed a prospective review of patients undergoing inpatient and outpatient apheresis at Houston Methodist Hospital from July 1, 2015 to September 30, 2015, to assess its benefit. During this time, we performed 831 procedures on 186 patients, including 787 therapeutic plasma exchanges, three red blood cell exchanges, 41 peripheral stem cell collections. Ultrasound‐guided vascular access was used for 68 procedures (8% of all procedures), including 62 therapeutic plasma exchanges, 4 peripheral stem cell collections, and 2 red blood cell changes. Use of ultrasound‐guided peripheral access prevented the placement of central venous catheters in 37 (20%) patients, demonstrating its utility in a busy transfusion service.

Critical updates in the 7th edition of the American society for apheresis guidelines

The 7th edition of the American Society for Apheresis (ASFA) guidelines was composed by an international physicians committee, and includes 14 new diseases, and 2 new indications for diseases described in the former guidelines. Several indications have either changed names or were excluded from this edition. The guidelines are developed after taking into account documented evidence, either supporting or negating use of apheresis technology in the treatment of diseases. Based on this evidence, the committee revises, updates and includes or excludes disease entities/indications in the guidelines. This article describes the revisions to the 7th edition of the ASFA guidelines, in a comprehensive manner.

The management of anticoagulation in patients undergoing therapeutic plasma exchange: A concise review

We surveyed multiple apheresis centers represented by the authors for their clinical approach to the management of anticoagulation issues during therapeutic plasma exchange (TPE). We present the results of their practices and a review of the pertinent literature. As plasma is removed during TPE, replacement with all or partial non‐plasma‐containing fluids (eg, 5% albumin) may lead to significant changes in hemostasis. These changes are amplified in patients who are receiving anticoagulation. We discuss various anticoagulants as well as the monitoring and adjustment of anticoagulation before, during, and after TPE. No single guideline can be applied, but rather, patients must be monitored individually, taking into account their often complex clinical conditions and medication profiles.

The utility of therapeutic plasma exchange for amphotericin B overdose

Medication error is a preventable cause of morbidity and death in the inpatient population. We describe a patient with an antifungal overdose treated with therapeutic plasma exchange (TPE). The patient was diagnosed with cryptococcal meningitis and received an acute overdose of amphotericin B deoxycholate instead of the prescribed liposomal amphotericin B. Consequently, the patient developed clinical symptoms including tremors, hypertension, visual hallucinations, vertigo, fever, and acute renal failure. A series of four TPEs was emergently initiated, resulting in complete resolution of most symptoms.

Vascular access for therapeutic plasma exchange: VASCULAR ACCESS FOR TPE

Therapeutic plasma exchange is an apheresis modality in which plasma is separated from the blood cellular components ex vivo, discarded, and replaced with an isosmotic fluid (most commonly 5% albumin) to maintain appropriate oncotic pressure in the patient. Therapeutic plasma exchange is used in the treatment of many diseases and indications. The recent seventh edition of the American Society for Apheresis guidelines indicates approximately 72 diseases and 116 indications for which therapeutic plasma exchange may be effective. One of the critical aspects for the successful performance of therapeutic plasma exchange is appropriate vascular access to provide high blood flow for the collection and return phases of the procedure, especially because most patients who need therapeutic plasma exchange will require more than one treatment over days to weeks. This article provides an overview of the characteristics of therapeutic plasma exchange, the clinical diseases and indications that may be treated with therapeutic plasma exchange, and the different types of vascular access employed, with their advantages and disadvantages. The latter may include peripheral venous access and intravascular or implantable access devices, such as arteriovenous grafts and fistulas, central venous catheters, and central venous catheters tunneled with ports.

Ultrasound view of vein collapse during therapeutic apheresis performed with peripheral access: THERAPEUTIC APHERESIS VEIN COLLAPSE

Therapeutic apheresis requires adequate vascular access to achieve inlet flow rates of approximately 50 to 100 mL/min. While dialysis-type central venous catheters can usually provide such access, their use includes several associated risks. Some of these risks can be mitigated if peripheral venous access can be established. We have found that ultrasound guidance is helpful in establishing and maintaining such access. Inadequate peripheral vascular access often results in “low inlet pressure” (LIP) alarms on the apheresis machine. Prior to the use of ultrasound, efforts to investigate and correct LIP alarms often resulted in “blind” repositioning of the access needle. This approach can increase the risk of patient or donor injury. The clip demonstrates what we have found is a common cause of LIP alarms: vein collapse at the tip of the access needle. Video Clip S1 was taken during the investigation of repeated LIP alarms in two outpatients undergoing therapeutic plasma exchange (TPE) for myasthenia gravis at a rate of 50 mL/min, the slowest recommended rate. The clip demonstrates that even at that slow rate, the access vein would collapse under the negative pressure created by the apheresis machine. Animations are included to provide visualization of the collapse associated with pump start/stop and alarms. REPRESENTATIVE STATIONARY PICTURE. [Color figure can be viewed at wileyonlinelibrary.com]

Therapeutic and Donor Apheresis

Abstract Apheresis machines separate whole blood into cellular and plasma fractions. This allows for therapeutic interventions through removal of pathologic substances from these fractions (e.g., therapeutic plasma exchange to remove acetylcholine receptor antibodies in patients with myasthenia gravis) or by isolation and treatment of a specific blood component (e.g., collection and photoactivation of WBCs to induce immunomodulation by extracorporeal photopheresis). Apheresis procedures are also used to collect blood products for transfusion and hematopoietic progenitor cells for transplant. This chapter focuses on the basic principles of apheresis procedures, indications for therapeutic apheresis that are supported by evidence-based guidelines, and the management of adverse events associated with these procedures.

An extremely rare splice site mutation in the gene encoding complement factor I in a patient with atypical hemolytic uremic syndrome

Atypical hemolytic uremic syndrome (aHUS) is a rare disease characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney failure. The disease is difficult to diagnose due to its similarity with other hematologic disorders, such as thrombotic thrombocytopenic purpura (TTP). However, genetic mutations are found in 50–70% of patients with aHUS and can be useful in its diagnosis.

Therapeutic Plasma Exchange for Potential Human Leukocyte Antigen Antibody-Mediated Rejection in Liver Transplant Patients

The objective of this study was to systemically examine the effect of serum biotin on five thyroid function assays (thyroidstimulating hormone [TSH], free T4, free T3, total T4, and total T3) across three immunoassay platforms. Two clinical labs participated in the study. Lab A measures TSH, free T4, free T3, and total T4 on the Siemens Dimension Vista 1500 and total T3 on the Siemens Centaur. Lab B uses the Roche Cobas e602 platform to measure these five assays. All assays on the Roche Cobas, the total T3 assay on the Siemens Centaur, and the TSH, free T4, and free T3 assays on the Siemens Vista utilize biotin. The Vista total T4 and the Centaur total T3 assays do not use biotin, and were included as controls. The five assays in Lab A were evaluated using two levels of analytes (normal level and higher level) with free biotin spiked in at 11 concentrations ranging from 1.25 mg/L to 1,280 mg/L. The five assays in Lab B were evaluated using only one level of analytes (the normal level). In Lab A, total T3 and total T4 remained consistent regardless of biotin levels. TSH, free T4, and free T3, however, were significantly altered (>10% change) at 320 mg/L, 320 mg/L, and 160 mg/L of biotin, respectively for both levels of analytes. In Lab B, TSH, total T4, free T4, total T3, and free T3 were significantly altered (>10% change) at 80 mg/L, 1,280 mg/L, 320 mg/L, 80 mg/L, and 320 mg/L of biotin, respectively. Higher levels of biotin falsely increased results with the competitive free T4, free T3, total T4 and total T3 assays, and decreased results with the sandwich TSH assays. In conclusion, this in vitro study illustrated that biotin can cause interference in assays (eg, TSH and other thyroid hormone tests) that incorporate biotinylated components. This is clinically relevant as any patient taking biotin supplementation who receives a thyroid panel could end up with aberrant results that could not only be confusing but also misleading. Further studies are warranted to see if this panel of thyroid test is affected by in vivo biotin supplementation. AJCP / MEETING ABSTRACTS