Membrane-based therapeutic plasma exchange: Proposed techniques for preventing filter failure.

BACKGROUND AND OBJECTIVES: Therapeutic plasma exchange (TPE) is commonly performed using membrane-based TPE (mTPE) and is prone to filter failure. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We report on 46 patients, with a total of 321 mTPE treatments using the NxStage machine. This was a retrospective study with an aim to evaluate the effect of heparin, pre-filter saline dilution and the impact of total plasma volume exchanged (< 3 L vs. ≥3 L) on the rate of filter failure. Primary outcome was the overall rate of filter failure. Secondary outcomes included factors that may have indirectly influenced the rate of filter failure, including hematocrit, platelet count, replacement fluid (Fresh Frozen Plasma vs. albumin), and access type. RESULTS: We found that treatments that received both pre-filter heparin and saline had a statistically significant decrease in filter failure rate as compared to those that received neither (28.6% vs. 5.3%, P = .001), and compared to the treatments that received pre-filter heparin alone (14.2% vs. 5.3%, P = .015). In treatments that received both pre-filter heparin and saline predilution, we noted a significantly higher filter failure rate when the plasma volume exchanged was ≥3 L as compared to those that had <3 L exchanged (12.2% vs. 0.9%, P = .001). CONCLUSIONS: Rate of filter failure in mTPE can be reduced by implementing several therapeutic interventions including pre-filter heparin and pre-filter saline solution. These interventions were not associated with any clinically significant adverse events. Despite the above-mentioned interventions, large plasma volume exchanges of ≥3 L can negatively impact filter life.

Therapeutic plasma exchange as adjunct therapy for bullous pemphigoid.

Bullous pemphigoid (BP) is a rare autoimmune blistering disease caused by pathogenic antibodies which deposit into the dermo-epidermal junction. We present a case of bullous pemphigoid in a young female refractory to initial therapy with immunosuppressives and steroids who experienced significant improvement in blister burden after a course of adjunct therapeutic plasma exchange (TPE). This case report provides valuable insight into the benefit of utilizing TPE for BP and provides treatment specifics regarding use of TPE in a patient with BP.

Impact of prefilter dilution on IgG removal in membrane-based therapeutic plasma exchange.

INTRODUCTION: Previous studies have demonstrated that a "one plasma volume exchange" would result in an estimated 63% decline in pretreatment IgG levels. We evaluated the use of prefilter dilution with normal saline as a method to prevent filter failure without decreasing the efficiency of IgG removal. METHODS: Twenty-one treatment sessions were analyzed and all received prefilter dilution with normal saline. Primary outcome was to determine whether prefilter dilution resulted in decreased treatment efficiency in removing the targeted IgG. Secondary outcome was filter failure in conjunction with the combined use of prefilter heparin and saline infusions. RESULTS: All 21 treatments (100%) received prefilter dilution with saline solution and 19/21 (90.47%) also received prefilter heparin (bolus and/or hourly infusion). We demonstrated a 60%-70% decline in pretreatment IgG levels. CONCLUSION: Prefilter dilution during membrane-based therapeutic plasma exchange based treatment did not result in a demonstrable decrease in efficiency of IgG removal while maintaining filter patency.

Membrane-based therapeutic plasma exchange: Hemodynamics and operational characteristics leading to procedure failure.

BACKGROUND AND OBJECTIVES: Therapeutic plasma exchange (TPE) is a blood purification treatment capable of removing large molecular weight substances from plasma. It is commonly used for the removal of circulating pathogenic immunoglobulins presumed to be the cause of many autoimmune diseases. TPE can be performed with a membrane-based system (mTPE) or a centrifugal-based system (cTPE). When plasma separation is performed with a membrane, filter clotting can lead to longer treatment time, higher cost and can negatively impact patient satisfaction. In this study, we examine the operational characteristics that might influence filter life. DESIGN, SETTING, PARTICIPANTS, & MEASURES: We report on 24 patients, with a total of 135 mTPE treatments in a single tertiary care academic center using the NxStage machine. The study focuses on treatment specific parameters that may lead to procedure failure. The main parameters of interest were transmembrane pressure (TMP) and the filtration fraction as displayed on the machine (FFd) compared to the calculated filtration fraction (FFc). Primary outcome was to measure whether TMP, FFc, and FFd influenced filter survival. Secondary outcomes included factors that might have indirectly resulted in filter failure, including hematocrit (Hct), platelet count, heparin use, and intra-treatment calcium administration. RESULTS: In this study, we demonstrated that machine displayed filtration fractions (FFd) were lower than FFc and this difference was significantly larger in TPE sessions that experienced a clotting event (7.58 vs 6.22, P = .031). TPE sessions that clotted had a higher mean TMP (57.48 mmHg vs 44.43 mmHg, P = .001) and clotting events tended to have a lower mean blood flow rate (175.83 mL/min vs 189.55 mL/min, P = .002). In TPE sessions that received prefilter calcium administration, a higher mean dose of calcium gluconate was found in the sessions that experienced clotting (3.27 g vs 2.70 g, P = .013). Patients who experienced at least one clotting event were noted to be heavier than those patients without any clotting events (91.52 kg vs 72.15 kg, P = .040). Prefilter heparin administration was not associated with a lower incidence of filter clotting. We did not find a statistically significant difference in clotting events based upon type of intravenous access, pretreatment hematocrit, or pretreatment platelet counts. CONCLUSION: Among patients undergoing mTPE, machine FFd on the NxStage system are consistently lower than FFc. Treatments where there was a greater difference between displayed and FFc had a greater likelihood of filter clotting. Treatments with higher TMP were associated with failed treatments. Prefilter calcium administration during treatment was associated with increased filter clotting. Lower blood flow rates and higher patient weight were also associated with increased filter clotting. Prefilter heparin administration did not reduce the incidence of filter clotting.

Diabetic nephropathy in pregnancy: Report of two cases progressing to end-stage renal disease within one year postpartum.

BACKGROUND: Diabetes mellitus is a leading cause of nephropathy and end-stage renal disease. However, diabetic nephropathy during pregnancy in patients with normal glomerular filtration rate and subsequent progression to end-stage renal disease has not been well studied. CASES: This report presents two patients with poorly controlled type 1 diabetes mellitus who had diabetic nephropathy with preserved estimated glomerular filtration rate (Case 1: 117 mL/min/1.73m2; Case 2: 79 mL/min/1.73m2) and shared a similar clinical course, with glomerular filtration rates decreasing by approximately one-half during pregnancy and progression to end-stage renal disease within the first year postpartum. Both women had a long history of type 1 diabetes: 18 years and 24 years for case 1 and case 2 respectively. The first patient's course of pregnancy was complicated by difficult-to-control blood glucose and hypertension with subsequent preeclampsia. The second patient's course of pregnancy was complicated by difficult-to-control blood sugars and preterm labor resulting in classical cesarean delivery at 24 weeks. Both patients had renal biopsies shortly after delivery as their renal function continued to worsen postpartum. Both kidney biopsies demonstrated advanced diabetic nephropathy changes and ultimately required chronic renal replacement therapy within 7-9 months postpartum. CONCLUSION: Comprehensive family planning discussions with women who have diabetic nephropathy should include the risks of renal disease progression, even in those patients with preserved renal function at the time of conception.

An apparatus for rapid and nondestructive comparison of masks and respirators.

The SARS-CoV-2 global pandemic has produced widespread shortages of certified air-filtering personal protection equipment and an acute need for rapid evaluation of breathability and filtration efficiency of proposed alternative solutions. Here, we describe experimental efforts to nondestructively quantify three vital characteristics of mask approaches: breathability, material filtration effectiveness, and sensitivity to fit. We focus on protection against aqueous aerosols >0.3 µm using off-the-shelf particle, flow, and pressure sensors, permitting rapid comparative evaluation of these three properties. We present and discuss both the pressure drop and the particle penetration as a function of flow to permit comparison of relative protection for a set of proposed filter and mask designs. The design considerations of the testing apparatus can be reproduced by university laboratories and medical facilities and used for rapid local quality control of respirator masks that are of uncertified origin, monitoring the long-term effects of various disinfection schemes and evaluating improvised products not designed or marketed for filtration.

Life-threatening hypertriglyceridemia-induced pancreatitis related to alectinib successfully treated by plasmapheresis: A review of the literature on metabolic toxicities associated with anaplastic lymphoma kinase inhibitors.

INTRODUCTION: Actionable mutations are tested as standard of care for all new metastatic non-small cell lung cancers. Tumors harboring an anaplastic lymphoma kinase mutation respond to tyrosine kinase inhibitors targeting anaplastic lymphoma kinase pathway. Patients are monitored for common adverse effects, although we occasionally encounter unexpected side effects. CASE REPORT: A 52-year-old male presented with a right hilar lung mass, and workup revealed a stage IIIA adenocarcinoma. He underwent treatment with concurrent chemoradiation; however, disease recurred one year later with a right hilar mass and contralateral mediastinal lymphadenopathy, biopsy of which resulted positive for adenocarcinoma. Molecular analysis showed anaplastic lymphoma kinase rearrangement and alectinib was started. Six months into therapy, he presented with hematochezia, nausea, and epigastric pain and was diagnosed with acute pancreatitis. Triglyceride level resulted above the measurable level at >5680mg/dL, thought to be the inciting event of pancreatitis.Management and outcome: Despite treatment with intravenous hydration, insulin infusion, and antibiotics, he decompensated with development of respiratory failure, shock requiring intensive care. Therapeutic plasmapheresis was initiated due to persistently elevated triglyceride. Following the third plasmapheresis, triglyceride level decreased to 359 mg/dL. With aggressive multidisciplinary management, he made a complete recovery. Follow-up imaging studies at three and six months show a stable mass-like abnormality in the right hilum without evidence of disease progression. DISCUSSION: Prior to starting alectinib, our patient's triglyceride level was 420 mg/dL. While he consumed alcohol, he had no other traditional risk factor. To our knowledge, this is the first reported case of hypertriglyceridemia-induced acute pancreatitis related to treatment with an anaplastic lymphoma kinase inhibitor.