Treatment of high-risk, refractory acquired methemoglobinemia with automated red blood cell exchange

Off with the blues: Therapeutic plasma exchange in a case of copper sulphate poisoning

CuSO4 (Copper sulphate) poisoning though rare, is associated with high mortality. It involves multiple organ systems and if not dealt with promptly can lead to death. Supportive care and chelation therapy along with TPE (therapeutic plasma exchange), whole blood exchange or red cell exchange can be employed in management. We report such a case where swift clinical improvement was seen after TPE.

2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, β-adrenergic receptor antagonists (also known as β-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

Cationic Pollutant Removal from Aqueous Solution Using Reduced Graphene Oxide

Reduced graphene oxide (rGO) is one of the most well-known graphene derivatives, which, due to its outstanding physical and chemical properties as well as its oxygen content, has been used for wastewater treatment technologies. Particularly, extra functionalized rGO is widely preferred for treating wastewater containing dyes or heavy metals. Nevertheless, the use of non-extra functionalized (pristine) rGO for the removal of cationic pollutants is not explored in detail or is ambiguous. Herein, pristine rGO—prepared by an eco-friendly protocol—is used for the removal of cationic pollutants from water, i.e., methylene blue (MB) and mercury-(II) (Hg-(II)). This work includes the eco-friendly synthesis process and related spectroscopical and morphological characterization. Most importantly, the investigated rGO shows an adsorption capacity of 121.95 mg g⁻¹ for MB and 109.49 mg g⁻¹ for Hg (II) at 298 K. A record adsorption time of 30 min was found for MB and 20 min for Hg (II) with an efficiency of about 89% and 73%, respectively. The capture of tested cationic pollutants on rGO exhibits a mixed physisorption–chemisorption process. The present work, therefore, presents new findings for cationic pollutant adsorbent materials based on oxidized graphenes, providing a new perspective for removing MB molecules and Hg(II) ions.

Recommendations for diagnosis and treatment of methemoglobinemia

Methemoglobinemia is a rare disorder associated with oxidization of divalent ferro‐iron of hemoglobin (Hb) to ferri‐iron of methemoglobin (MetHb). Methemoglobinemia can result from either inherited or acquired processes. Acquired forms are the most common, mainly due to the exposure to substances that cause oxidation of the Hb both directly or indirectly. Inherited forms are due either to autosomal recessive variants in the CYB5R3 gene or to autosomal dominant variants in the globin genes, collectively known as HbM disease. Our recommendations are based on a systematic literature search. A series of questions regarding the key signs and symptoms, the methods for diagnosis, the clinical management in neonatal/childhood/adulthood period, and the therapeutic approach of methemoglobinemia were formulated and the relative recommendations were produced. An agreement was obtained using a Delphi‐like approach and the experts panel reached a final consensus >75% of agreement for all the questions.

Writing scientific case reports for top-line journals

The venerable clinical case report has been largely reduced to the status of commodity in the present age of dedicated case report journals. Top-line clinical journals may discourage or even refuse to accept clinical case reports due to their potential adverse effect on the impact factor of the journal. But while the traditional clinical case report, that presents a case history and attempts to extrapolate a lesson from it, may have fallen out of favor, there remains a need for astute clinical observations that serve to stimulate the generation of hypotheses and may lead, ultimately, to medical breakthroughs. Clinicians are very much capable of employing scientific reasoning when approaching an unusual clinical situation. By remaining up to date with the literature, and determining, at the outset of the case, what lessons may be learned from it, they can formulate a scientific approach, using clinical methods, to result in meaningful contributions to the literature in top-line journals.

The Adsorption of Methylene Blue on Eco-Friendly Reduced Graphene Oxide

Recently, green-prepared oxidized graphenes have attracted huge interest in water purification and wastewater treatment. Herein, reduced graphene oxide (rGO) was prepared by a scalable and eco-friendly method, and its potential use for the removal of methylene blue (MB) from water systems, was explored. The present work includes the green protocol to produce rGO and respective spectroscopical and morphological characterizations, as well as several kinetics, isotherms, and thermodynamic analyses to successfully demonstrate the adsorption of MB. The pseudo-second-order model was appropriated to describe the adsorption kinetics of MB onto rGO, suggesting an equilibrium time of 30 min. Otherwise, the Langmuir model was more suitable to describe the adsorption isotherms, indicating a maximum adsorption capacity of 121.95 mg g^-1 at 298 K. In addition, kinetics and thermodynamic analyses demonstrated that the adsorption of MB onto rGO can be treated as a mixed physisorption-chemisorption process described by H-bonding, electrostatic, and π - π interactions. These results show the potential of green-prepared rGO to remove cationic dyes from wastewater systems.

Recent advances in transmission-blocking drugs for malaria elimination

The scientific community worldwide has realized that malaria elimination will not be possible without development of safe and effective transmission-blocking interventions. Primaquine, the only WHO recommended transmission-blocking drug, is not extensively utilized because of the toxicity issues in G6PD deficient individuals. Therefore, there is an urgent need to develop novel therapeutic interventions that can target malaria parasites and effectively block transmission. But at first, it is imperative to unravel the existing portfolio of transmission-blocking drugs. This review highlights transmission-blocking potential of current antimalarial drugs and drugs that are in various stages of clinical development. The collective analysis of the relationships between the structure and the activity of transmission-blocking drugs is expected to help in the design of new transmission-blocking antimalarials.

Use of Cellular and Plasma Apheresis in the Critically Ill Patient: Part II: Clinical Indications and Applications

Apheresis is the process of separating the blood and removing or manipulating a cellular or plasma component for therapeutic benefit. Such procedures may be indicated in the critical care setting as primary or adjunctive therapy for certain hematologic, neurologic, renal, and autoimmune/rheumatologic disorders. In part I of this series, the technical aspects of apheresis were described and the physiologic rationale and clinical considerations were discussed. This review highlights the pathophysiologic basis, specific clinical indications, and treatment parameters for disorders that more commonly require management in the intensive care unit. The choice of plasma or cellular apheresis in these cases is guided by wellaccepted, evidence-based clinical treatment guidelines. For some disorders, such as liver failure, severe sepsis, and multiple-organ dysfunction syndrome, apheresis treatment approaches remain experimental. Ongoing studies are investigating the potential utility of conventional plasma exchange, ex vivo plasma manipulation, and newer technologies for these and other disorders in severely ill patients.

A Pale Baby With Blue Blood

A previously healthy 9-month-old boy presented to the emergency department with sudden onset of pallor and reduced activity. A detailed history and initial blood tests revealed the diagnosis of oxidant stress-induced hemolysis caused by glucose-6-phosphate dehydrogenase deficiency. However, the child also had a second diagnosis that was revealed with additional testing. This case is described to illustrate the dual diagnosis and management guidelines for both potentially serious conditions.

Parameter optimization for nitrate removal from water using activated carbon and composite of activated carbon and Fe2O3 nanoparticles

Composite of activated carbon and Fe₂O₃ nanoparticles was synthesized as a novel adsorbent for nitrate removal.

Evaluation and management of acquired methemoglobinemia associated with topical benzocaine use

Benzocaine is a widely used topical oropharyngeal anesthetic and has been reported to cause methemoglobinemia. We discuss benzocaine-induced methemoglobinemia and review the causes, presentation, and management of this serious complication. Treatment with methylene blue will result in reversal of methemoglobinemia and clinical recovery in most cases but needs to be used at appropriate doses in carefully selected individuals. Physicians who perform procedures involving the application of benzocaine for topical anesthesia need to rapidly identify and treat methemoglobinemia to avoid significant associated morbidity and mortality.

Rasburicase causing severe oxidative hemolysis and methemoglobinemia in a patient with previously unrecognized glucose-6-phosphate dehydrogenase deficiency

Rasburicase is frequently used in tumor lysis syndrome (TLS). Although it is very well tolerated, it can cause severe oxidative hemolytic anemia and methemoglobinemia in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. We report another case of rasburicase-induced methemoglobinemia in a patient with previously unrecognized G6PD deficiency and review the cases of methemoglobinemia and oxidative hemolysis reported in the literature to date. Patients from ethnicities in which G6PD deficiency is prevalent at high risk of TLS should be screened for G6PD deficiency prior to administration of rasburicase where practical. Asymptomatic decrease in oxygen saturation by oximetry and cyanosis are signs of methemoglobinemia; patients recover with conservative measures including supplemental oxygen and packed red cell transfusion.

Influence of organic matter and solute concentration on nitrate sorption in batch and diffusion-cell experiments

Nitrate sorption potentials of three surface soils (soils-1-3) were evaluated under different solute concentrations, i.e. 1-100 mg L(-1). Batch and diffusion-cell adsorption experiments were conducted to delineate the diffusion property and maximum specific nitrate adsorption capacity (MSNAC) of the soils. Ho's pseudo-second order model well fitted the batch adsorption kinetics data (R(2)>0.99). Subsequently, the MSNAC was estimated using Langmuir and Freundlich isotherms; however, the best-fit was obtained with Langmuir isotherm. Interestingly, the batch adsorption experiments over-estimated the MSNAC of the soils compared with the diffusion-cell tests. On the other hand, a proportionate increase in the MSNAC was observed with the increase in soil organic matter content (OM) under the batch and diffusion-cell tests. Therefore, increasing the soil OM by the application of natural compost could stop nitrate leaching from agricultural fields and also increase the fertility of soil.

Free heme and the polymerization of sickle cell hemoglobin

In search of novel control parameters for the polymerization of sickle cell hemoglobin (HbS), the primary pathogenic event of sickle cell anemia, we explore the role of free heme, which may be excessively released in sickle erythrocytes. We show that the concentration of free heme in HbS solutions typically used in the laboratory is 0.02-0.04 mole heme/mole HbS. We show that dialysis of small molecules out of HbS solutions arrests HbS polymerization. The addition of 100-260 μM of free heme to dialyzed HbS solutions leads to rates of nucleation and polymer fiber growth faster by two orders of magnitude than before dialysis. Toward an understanding of the mechanism of nucleation enhancement by heme, we show that free heme at a concentration of 66 μM increases by two orders of magnitude the volume of the metastable clusters of dense HbS liquid, the locations where HbS polymer nuclei form. These results suggest that spikes of the free heme concentration in the erythrocytes of sickle cell anemia patients may be a significant factor in the complexity of the clinical manifestations of sickle cell anemia. The prevention of free heme accumulation in the erythrocyte cytosol may be a novel avenue to sickle cell therapy.

Cytapheresis in the treatment of cell-affected blood disorders and abnormalities

This report presents our experience with cytaphereses performed in treatment of 476 patients. Leukapheresis was used in management of 68 patients with hyperleukocytosis leukostasis (WBC > or = 150 x 10(9)L(-1)). Average decrease in cell count after treatment was 73.3%. Plateletapheresis for 32 patients (platelets > or = 1500 x 10(9)L(-1)) was applied in order to prevent the thrombotic-hemorrhagic syndrome and resulted in a moderate platelet count reduction (84.3%). Erythrocytaphereses performed in treatment of 376 patients by manual or automated technique resulted in a rapid blood viscosity drop (42.4+/-7.1%). Patients with red blood cell exchanges (severe malaria and autoimmune hemolytic crisis) were in life-threatening situations and resulted in a prompt reduction of parasitized or antibody-coated RBCs and anemia correction. This study indicates that "conventional" TCs resulted in considerable cytoreduction only in patients with especially high cell count. This effect was not associated with bone marrow remission. The best clinical effect and long-term benefits were obtained using RBCX and antimalarial drugs in malaria patients who have had high-level parasitized-RBCs with multiorgan dysfunction.

Methylene blue for diagnosis of displaced atrial lines

Methylene blue (aniline violet, tetra-methylthionine chloride) has several important uses in clinical medicine, including diagnosis of displaced central lines. After cardiac surgery, three infants with suspected displacement of direct atrial lines were given methylene blue. After injection of the dye into the atrial lines, bluish discolouration was identified in their chest drainage. Use of methylene blue in small amounts appears to be a safe and effective way of diagnosing extravasation of fluid from displaced central lines.

Long-term therapeutic plasma exchange in the outpatient setting using an implantable central venous access device

We presented the results of our prospective trial of the Bard CathLink 20 in outpatient therapeutic plasma exchange in May 2000. Since the close of that study, three of the original subjects and one additional subject have received continuous outpatient treatment using the device. We report herein on its long-term use. Four patients with demyelinating polyneuropathy underwent outpatient plasma exchange of 1-1 1/4 plasma volumes using Bard CathLink 20 venous access devices for up to 2 1/2 years. Treatment schedules varied according to the status of the patient's neuropathy. Four men (age 59, 60, 76, 79) underwent 55, 56, 38, and 41 plasma exchanges over 18.5, 18, 20, and 38.5 months, respectively, all in the outpatient setting. Ninety-one percent were completed in <150 min (mean 120 +/- 28 min) with 3,783 +/- 314 ml of plasma removed. Mean access flow rates were approximately 70 +/- 11 ml/min. Plasma flow rates were approximately 38 +/- 6 ml/min. (During our original 6-month prospective trial, access and plasma flow rates were approximately 54 and 32 ml/min, respectively). There were no adverse effects resulting from use of the CathLink and no hospitalizations were needed for plasma exchange. Pressure alarms were infrequent. Access and plasma flow rates achieved with the CathLink 20 have increased by about 30 and 16%, respectively, with long-term use. The conclusion from our prospective trial of this device, that it could conveniently be used for long-term outpatient plasma exchange, is supported by our follow-up experience.

A nephrology based mobile extracorporeal therapy service

BACKGROUND

Therapeutic apheresis (TA) is an essential part of the medical community services in any metropolitan area. We discuss the background, development, and maintenance of a TA program.

RESULTS

A successful program has immediate response, knowledgeable nurses and physicians, and ongoing continuing quality initiatives. Nurses should ultimately be trained to be a Hemapheresis Practitioner (HP).

CONCLUSION

A metropolitan-wide TA program was successfully initiated and maintained with proper physician and nursing input using our guidelines.

Prospective investigation of a subcutaneous, implantable central venous access device for therapeutic plasma exchange in adults with neurological disorders

Standard alternatives to antecubital access for long-term therapeutic plasma exchange, including percutaneous polyurethane or tunneled silicone catheters, are associated with complications and inconvenience for the patient. We have investigated the Bard CathLink 20, a subcutaneously implantable central venous access device, as an alternative for outpatient plasma exchange. The CathLink 20 consists of a funnel-shaped titanium port connected to a soft polyurethane-derived catheter and is accessed percutaneously using an 18-gauge catheter-over-needle Angiocath. Six patients with paraproteinemic polyneuropathies underwent 64 outpatient plasma exchanges using the CathLink 20 for access, 31 using 2 CathLink 20's (draw and return), 20 using a single CathLink 20 as the draw site and 13 using a single CathLink 20 as the return site. Mean (+/- SD) plasma removed was 3,680 +/- 551 ml in 115.2 +/- 25.3 min. Apheresis personnel were able to access the ports in 1.23 +/- 0.6 attempts per port per procedure. Six of 70 planned procedures were aborted: 3 because of failure of an antecubital access site and 3 because of catheter occlusion resolved using a thrombolytic agent. Whole blood flow rate was approximately 54 ml/min, and plasma flow rate was about 32 ml/min for 135 min. Access pressures were stable at -150 to -200 torr (P = 0.1395). Return line pressures varied between 90 and 130 torr (P = 0.0147). No patient required hospitalization during the study. Though not optimized for apheresis, the CathLink 20 provides a reasonable option for chronic apheresis patients who lack adequate peripheral venous access.

Methemoglobinemia after topical anesthesia with lidocaine and benzocaine for a difficult intubation

Methemoglobinemia is an uncommon cause of cyanosis; however, rapid diagnosis is critical to avoid potentially fatal consequences. Several local anesthetics can precipitate methemoglobinemia in susceptible patients. This case report of acute methemoglobinemia occurred during fiberoptic intubation in an awake patient without a past medical history of adverse reactions to local anesthetics.

Therapeutic plasma exchange and cytapheresis in pediatric patients

Pediatric therapeutic apheresis is reviewed including what it is, how it is performed and indications for its use. Pediatric patients are special, and the unique needs for replacement fluids and attention to access, anticoagulation, volume shifts and hypothermia are stressed. While all indications cannot be addressed, the procedures most commonly performed are reviewed. These include erythrocytapheresis, leukaphereses and plasma exchanges. A table details the strength of evidence supporting the use of apheresis procedures for many of these indications.