Controversies in Management of Hyperkalemia.

BACKGROUND: Hyperkalemia is a common electrolyte disorder that can result in morbidity and mortality if not managed appropriately. OBJECTIVES: This review evaluates the classic treatments of hyperkalemia and discusses controversies and new medications for management. DISCUSSION: Potassium (K+) plays a key role in determining the transmembrane potentials of "excitable membranes" present in nerve and muscle cells. K+ is the predominant intracellular cation, and clinical deterioration typically ensues when patients develop sufficiently marked elevation in extracellular fluid concentrations of K+ (hyperkalemia). Hyperkalemia is usually detected via serum clinical laboratory measurement. The most severe effect of hyperkalemia includes various cardiac dysrhythmias, which may result in cardiac arrest and death. Treatment includes measures to "stabilize" cardiac membranes, to shift K+ from extracellular to intracellular stores, and to promote K+ excretion. Calcium gluconate 10% dosed 10 mL intravenously should be provided for membrane stabilization, unless the patient is in cardiac arrest, in which case 10 mL calcium chloride is warranted. Beta-agonists and intravenous insulin should be given, and some experts recommend the use of synthetic short-acting insulins rather than regular insulin. Dextrose should also be administered, as indicated by initial and serial serum glucose measurements. Dialysis is the most efficient means to enable removal of excess K+. Loop and thiazide diuretics can also be useful. Sodium polystyrene sulfonate is not efficacious. New medications to promote gastrointestinal K+ excretion, which include patiromer and sodium zirconium cyclosilicate, hold promise. CONCLUSIONS: Hyperkalemia can be deadly, and treatment requires specific measures including membrane stabilization, cellular shift, and excretion.

Emergency medicine considerations in atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is an abnormal heart rhythm which may lead to stroke, heart failure, and death. Emergency physicians play a role in diagnosing AF, managing symptoms, and lessening complications from this dysrhythmia. OBJECTIVE: This review evaluates recent literature and addresses ED considerations in the management of AF. DISCUSSION: Emergency physicians should first assess patient clinical stability and evaluate and treat reversible causes. Immediate cardioversion is indicated in the hemodynamically unstable patient. The American Heart Association/American College of Cardiology, the European Society of Cardiology, and the Canadian Cardiovascular Society provide recommendations for management of AF. If hemodynamically stable, rate or rhythm control are options for management of AF. Physicians may opt for rate control with medications, with beta blockers and calcium channel blockers the predominant medications utilized in the ED. Patients with intact left ventricular function should be rate controlled to <110 beats per minute. Rhythm control is an option for patients who possess longer life expectancy and those with AF onset <48 h before presentation, anticoagulated for 3-4 weeks, or with transesophageal echocardiography demonstrating no intracardiac thrombus. Direct oral anticoagulants are a safe and reliable option for anticoagulation. Clinical judgment regarding disposition is recommended, but literature supports discharging stable patients who do not have certain comorbidities. CONCLUSION: Proper diagnosis and treatment of AF is essential to reduce complications. Treatment and overall management of AF include rate or rhythm control, cardioversion, anticoagulation, and admission versus discharge. This review discusses ED considerations regarding AF management.