The Effect of Calcium Chloride in Treating Hyperkalemia Due to Acute Digoxin Toxicity in a Porcine Model

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.

Recent Progresses in Non-Dialysis Chronic Kidney Disease Patients with Hyperkalemia: Outcomes and Therapeutic Strategies

Chronic kidney disease (CKD) affects about 10% of the world's population. Hyperkalemia is a life-threatening complication in patients with CKD, as it is associated with adverse cardiovascular and kidney outcomes. There are still many challenges and questions to address to improve the currently available therapeutic strategies to treat hyperkalemia, such as how to approach the emergency management of hyperkalemia. In recent years, in addition to novel oral potassium binders, great progress has been made in the application of novel kidney protective strategies, such as mineralocorticoid receptor antagonists and sodium-glucose cotransporter 2 inhibitors (SGLT2i) in hyperkalemia therapy. This review will discuss the recent advances from clinical trials in the effective management of hyperkalemia in non-dialysis CKD patients, enhancing the knowledge of physicians and internists concerning these newer agents and providing a helpful reference for clinical practice.

Pharmacological treatment of cardiac glycoside poisoning

Cardiac glycosides are an important cause of poisoning, reflecting their widespread clinical usage and presence in natural sources. Poisoning can manifest as varying degrees of toxicity. Predominant clinical features include gastrointestinal signs, bradycardia and heart block. Death occurs from ventricular fibrillation or tachycardia. A wide range of treatments have been used, the more common including activated charcoal, atropine, β-adrenoceptor agonists, temporary pacing, anti-digoxin Fab and magnesium, and more novel agents include fructose-1,6-diphosphate (clinical trial in progress) and anticalin. However, even in the case of those treatments that have been in use for decades, there is debate regarding their efficacy, the indications and dosage that optimizes outcomes. This contributes to variability in use across the world. Another factor influencing usage is access. Barriers to access include the requirement for transfer to a specialized centre (for example, to receive temporary pacing) or financial resources (for example, anti-digoxin Fab in resource poor countries). Recent data suggest that existing methods for calculating the dose of anti-digoxin Fab in digoxin poisoning overstate the dose required, and that its efficacy may be minimal in patients with chronic digoxin poisoning. Cheaper and effective medicines are required, in particular for the treatment of yellow oleander poisoning which is problematic in resource poor countries.

Pharmacotherapy of pediatric advanced life support and toxicological emergencies

Guidelines for pediatric advanced life support have been available for nearly a quarter of a century. Recommendations for the pharmacological management of pediatric cardiac arrest have changed over these years. Several important differences have been observed between adult advanced cardiac life support and pediatric advanced life support that must be recognized when children require resuscitation, such as the cause of the arrest, age-specific monitoring parameters, weight-based medication dosing, and obstacles in obtaining venous access. To make matters more complicated, differences also exist across neonatal and pediatric age spectrums. In addition, some toxicological emergencies commonly occurring in children require pharmacological management with agents that have a unique mechanism of action for cardiac support.

Mortal hyperkalemia disturbances in rats are NO-system related. The life saving effect of pentadecapeptide BPC 157

We demonstrate the full counteracting ability of stable gastric pentadecapeptide BPC 157 against KCl-overdose (intraperitoneal (i), intragastric (ii), in vitro (iii)), NO-system related. (i) We demonstrated potential (/kg) of: BPC 157 (10ng, 10μg ip, complete counteraction), l-arginine (100mg ip, attenuation) vs. L-NAME (5mg ip, deadly aggravation), given alone and/or combined, before or after intraperitoneal KCl-solution application (9mEq/kg). Therapy was confronted with promptly unrelenting hyperkalemia (>12mmol/L), arrhythmias (and muscular weakness, hypertension, low pressure in lower esophageal and pyloric sphincter) with an ultimate and a regularly inevitable lethal outcome within 30min. Previously, we established BPC 157-NO-system interaction; now, a huge life-saving potential. Given 30min before KCl, all BPC 157 regimens regained sinus rhythm, had less prolongation of QRS, and had no asystolic pause. BPC 157 therapy, given 10min after KCl-application, starts the rescue within 5-10min, completely restoring normal sinus rhythm at 1h. Likewise, other hyperkalemia-disturbances (muscular weakness, hypertension, low sphincteric pressure) were also counteracted. Accordingly with NO-system relation, deadly aggravation by L-NAME: l-arginine brings the values to the control levels while BPC 157 always completely nullified lesions, markedly below those of controls. Combined with l-arginine, BPC 157 exhibited no additive effect. (ii) Intragastric KCl-solution application (27mEq/kg) - (hyperkalemia 7mmol/L): severe stomach mucosal lesions, sphincter failure and peaked T waves were fully counteracted by intragastric BPC 157 (10ng, 10μg) application, given 30min before or 10min after KCl. (iii). In HEK293 cells, hyperkalemic conditions (18.6mM potassium concentrations), BPC 157 directly affects potassium conductance, counteracting the effect on membrane potential and depolarizations caused by hyperkalemic conditions.

Cardiac glycoside toxicity: more than 200 years and counting

Digitalis toxicity produces a toxidrome characterized by gastrointestinal, neurologic, electrolyte, and nonspecific cardiac manifestations. Chronic toxicity remains much more difficult to recognize compared with an acute presentation because of the nonspecific manifestations; therefore, serum glycoside levels are essential for diagnosis in this population. The mainstay of management continues to be rapid toxidrome identification followed by digoxin-specific antibody fragment therapy with supportive care. Several controversies still remain, including therapy for patients dependent on hemodialysis, appropriateness of calcium therapy for hyperkalemia, ideal agents for arrhythmia therapy, and the potential utility of plasmapheresis for removal of bound digoxin-antibody fragment complexes.

Toxic bradycardias in the critically ill poisoned patient

Cardiovascular drugs are a common cause of poisoning, and toxic bradycardias can be refractory to standard ACLS protocols. It is important to consider appropriate antidotes and adjunctive therapies in the care of the poisoned patient in order to maximize outcomes. While rigorous studies are lacking in regards to treatment of toxic bradycardias, there are small studies and case reports to help guide clinicians' choices in caring for the poisoned patient. Antidotes, pressor support, and extracorporeal therapy are some of the treatment options for the care of these patients. It is important to make informed therapeutic decisions with an understanding of the available evidence, and consultation with a toxicologist and/or regional Poison Control Center should be considered early in the course of treatment.

Management of yellow oleander poisoning

BACKGROUND

Poisoning due to deliberate self-harm with the seeds of yellow oleander (Thevetia peruviana) results in significant morbidity and mortality each year in South Asia. Yellow oleander seeds contain highly toxic cardiac glycosides including thevetins A and B and neriifolin. A wide variety of bradyarrhythmias and tachyarrhythmias occur following ingestion. Important epidemiological and clinical differences exist between poisoning due to yellow oleander and digoxin; yellow oleander poisoning is commonly seen in younger patients without preexisting illness or comorbidity. Assessment and initial management. Initial assessment and management is similar to other poisonings. No definite criteria are available for risk stratification. Continuous ECG monitoring for at least 24 h is necessary to detect arrhythmias; longer monitoring is appropriate in patients with severe poisoning. Supportive care. Correction of dehydration with normal saline is necessary, and antiemetics are used to control severe vomiting. Electrolytes. Hypokalemia worsens toxicity due to digitalis glycosides, and hyperkalemia is life-threatening. Both must be corrected. Hyperkalemia is due to extracellular shift of potassium rather than an increase in total body potassium and is best treated with insulin-dextrose infusion. Intravenous calcium increases the risk of cardiac arrhythmias and is not recommended in treating hyperkalemia. Oral or rectal administration of sodium polystyrene sulfonate resin may result in hypokalemia when used together with digoxin-specific antibody fragments. Unlike digoxin toxicity, serum magnesium concentrations are less likely to be affected in yellow oleander poisoning. The effect of magnesium concentrations on toxicity and outcome is not known. Hypomagnesaemia should be corrected as it can worsen cardiac glycoside toxicity. Gastric decontamination. The place of emesis induction and gastric lavage has not been investigated, although they are used in practice. Gastric decontamination by the use of single dose and multiple doses of activated charcoal has been evaluated in two randomized controlled trials, with contradictory results. Methodological differences (severity of poisoning in recruited patients, duration of treatment, compliance) between the two trials, together with differences in mortality rates in control groups, have led to much controversy. No firm recommendation for or against the use of multiple doses of activated charcoal can be made at present, and further studies are needed. Single-dose activated charcoal is probably beneficial. Activated charcoal is clearly safe. Arrhythmia management. Bradyarrhythmias are commonly managed with atropine, isoprenaline, and temporary cardiac pacing in severe cases, although without trial evidence of survival benefit, or adequate evaluation of possible risks. Accelerating the heart rate with atropine or beta-adrenergic agents theoretically increases the risk of tachyarrhythmias, and it has been claimed that atropine increases tachyarrhythmic deaths. Further studies are required. Tachyarrhythmias have a poor prognosis and are more difficult to treat. Lidocaine is the preferred antiarrhythmic; the role of intravenous magnesium is uncertain. Digoxin-specific antibody fragments. Digoxin-specific antibody fragments are effective in reverting life-threatening cardiac arrhythmias; prospective observational studies show a beneficial effect on mortality. High cost and lack of availability limit the widespread use of digoxin-specific antibody fragments in developing countries.

CONCLUSIONS

Digoxin-specific antibody fragments remain the only proven therapy for yellow oleander poisoning. Further studies are needed to determine the place of activated charcoal, the benefits or risks of atropine and isoprenaline, the place and choice of antiarrhythmics, and the effect of intravenous magnesium in yellow oleander poisoning.

Case files of the medical toxicology fellowship of the California poison control system-San Francisco: calcium plus digoxin-more taboo than toxic?

A 68 year old woman with a history of diabetes mellitus presented to the emergency department after experiencing several days of nausea and vomiting. Recorded vital signs included: blood pressure 98/32 mm Hg, heart rate 69 bpm, "normal" respirations, and no fever. Her initial ECG revealed peaked T waves and regular rhythm with no visible P waves. Initial serum electrolytes were notable for a potassium level of 7.7 mmol/L, and a creatinine level of 9.6 mg/dL (849 micromol/L). She was unable to provide a list of her current medications or other medical history. There was no old chart immediately available for comparison.

Metaraminol (Aramine) in the management of a significant amlodipine overdose

OBJECTIVE

To report a patient with a significant amlodipine self-poisoning who failed to clinically respond to conventional treatment and was managed with metaraminol (Aramine).

PATIENT

A 43-year old male presenting after ingestion of 560 mg amlodipine, who failed to respond clinically to treatment with fluid resuscitation, calcium salts, glucagon and norepinephrine/epinephrine inotropic support.

MAIN RESULTS

Following a loading bolus of 2 mg and intravenous infusion (83 microg/min) of metaraminol (Aramine) there was improvement in his blood pressure, cardiac output and urine output.

CONCLUSIONS

This is the first case report of the beneficial use of metaraminol (aramine) in the management of significant amlodipine poisoning unresponsive to conventional therapy.