Eric Salazar

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.

Improving Positive Blood Culture Removal Time Significantly Decreases Total Processing Time

CONTEXT Timely processing of blood cultures with positive results, including Gram staining and notification of clinicians, is a critical function of the clinical microbiology laboratory. Analysis of processing time in our laboratory revealed opportunities to enhance workflow efficiency. We found that the average time from positive blood culture result to removal of the bottle for processing (positive-to-removal [PR] time) was inadequate for our rapid pathogen identification program. OBJECTIVE To determine whether increased vigilance about PR time and prioritization of laboratory resources would decrease PR time and total processing time. DESIGN We performed a retrospective analysis of blood culture PR time 7 months before and 7 months after an in-service meeting during which the importance of PR time was emphasized, and corrective measures were implemented. RESULTS Before the in-service meeting, the average PR time for 5057 samples was 38 minutes, with an aggregate time of 192,251 minutes. Unexpectedly, we discovered that only 51.8% (2617 of 5057) of the positive blood cultures were removed in less than 10 minutes. After the in-service meeting, for 5293 samples, the average PR time improved to 8 minutes, the aggregate time improved to 44,630 minutes, and 84.5% (4470 of 5293) of the positive blood cultures were removed in less than 10 minutes. These improvements reduced the time to telephone notification of the Gram stain results to a caregiver by 46.7% (from 105 minutes to 56 minutes). CONCLUSIONS Increased awareness of barriers to rapid pathogen identification and interventions for improving performance time significantly enhanced care of patients with bloodstream infections.

Impact of intraoperative factor concentrates on blood product transfusions during orthotopic liver transplantation

Major bleeding in orthotopic liver transplantation is associated with significant morbidity and mortality. Limited literature exists regarding comparative effectiveness of prothrombin complex concentrate and fibrinogen concentrate during orthotopic liver transplantation on blood product utilization.

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.

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 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