A 62-year-old man with type 2 diabetes mellitus and hypertension presents to the emergency department with generalized weakness and palpitations. Over the past 2 days, he reports reduced oral intake and intermittent nausea. On examination, his blood pressure is 100/60 mm Hg, heart rate 98 bpm, and he appears mildly dehydrated. His medications include lisinopril 10 mg daily and metformin; he denies use of potassium supplements or potassium-sparing diuretics. Laboratory studies reveal serum potassium 6.2 mEq/L, creatinine 2.1 mg/dL (baseline 1.0 mg/dL), arterial blood gas pH 7.18, and bicarbonate 15 mEq/L. ECG shows peaked T waves. Considering this patient’s clinical presentation and laboratory findings, which of the following pathophysiological mechanisms is MOST likely the primary contributor to his current hyperkalemia?

A 68-year-old man presents to the ICU with peaked T-waves on ECG and a serum potassium of 6.8 mEq/L. His history is significant for Stage 4 chronic kidney disease (CKD) secondary to diabetic nephropathy, type 2 diabetes mellitus (T2DM), heart failure with reduced ejection fraction (HFrEF) managed with lisinopril and spironolactone, and chronic obstructive pulmonary disease (COPD). Which underlying disease is the primary contributor to his acute hyperkalemia by directly impairing potassium excretion?

A 62-year-old female is admitted to the critical care unit on a non-rebreather mask for severe weakness and altered mental status. She has a central venous catheter for rapid fluid and electrolyte repletion. Initial labs show serum potassium 1.9 mEq/L (normal 3.5–5.0 mEq/L) and magnesium 1.5 mg/dL (normal 1.7–2.2 mg/dL). ECG reveals prominent U waves and flattened T waves. She has hypertension and heart failure, and was recently prescribed a loop diuretic plus potassium chloride 20 mEq daily. Her daughter reports that her mother often struggles to pick up prescriptions due to lack of transportation and has been rationing medications because of financial concerns.

Considering the patient’s severe hypokalemia and clinical context, which social determinant of health is the MOST critical precipitating risk factor contributing to her current presentation?

Critically ill patients in the intensive care unit frequently develop disturbances in serum potassium levels. Based on epidemiologic studies in this population, which of the following potassium disturbances is most commonly observed?

A 65-year-old man with end-stage renal disease on hemodialysis presents to the ICU after missing his last dialysis session. He reports progressive muscle weakness. Vital signs are stable. An ECG shows widened QRS complexes and decreased P-wave amplitude. Laboratory studies reveal serum potassium of 6.9 mEq/L (reference 3.5–5.0 mEq/L). Based on this presentation, which of the following sets of clinical and ECG findings is most consistent with his electrolyte imbalance?

A 62-year-old man with end-stage renal disease on thrice-weekly hemodialysis presents to the ICU with profound muscle weakness. His serum potassium is 7.8 mmol/L and ECG shows peaked T waves, prolonged PR interval, and widened QRS complexes. What is the most appropriate INITIAL management step?

A 62-year-old man with a history of COPD reports three days of significant nausea and vomiting with decreased oral intake. Laboratory studies show severe hypokalemia (serum potassium 2.4 mEq/L), metabolic alkalosis (pH 7.53, bicarbonate 34 mEq/L), and elevated urinary potassium excretion (spot urine potassium 55 mEq/L). He uses an albuterol inhaler at home but denies diuretic use. What is the most likely primary cause of his hypokalemia?

A 68-year-old man with stage 4 chronic kidney disease (CKD) and heart failure with reduced ejection fraction (HFrEF) is admitted to the ICU for sepsis. His home medications include spironolactone, lisinopril, and furosemide. During hospitalization, he develops persistent hyperkalemia (serum potassium 5.8 mEq/L) despite dietary potassium restriction. The clinical team is considering long-term potassium management strategies upon discharge. Given his comorbidities and the need to balance acquisition costs with monitoring and adverse event burdens, which of the following potassium management strategies is MOST appropriate to prioritize for this patient?

A 58-year-old man with end-stage renal disease on hemodialysis presents with muscle weakness. His serum potassium is 7.1 mEq/L, and ECG shows peaked T waves with a widened QRS complex. Which of the following represents the most appropriate prioritized pharmacotherapy plan for immediate management of his hyperkalemia?

A 62-year-old man with severe sepsis is admitted to the ICU and develops AKI after aggressive fluid resuscitation. His serum potassium is 2.8 mEq/L while on a norepinephrine infusion for septic shock. Considering the expanded volume of distribution and impaired renal clearance in critical illness, which potassium replacement strategy best ensures safe and effective correction of his hypokalemia?