Why is hypokalemia dangerous?
- Symptoms can manifest below a K of 3.0 mEq/L, with severe symptoms (muscle weakness, rhabdomyolysis, respiratory weakness, ileus, nausea/vomiting, and arrhythmias) not usually developing until K <2.5 mEq/L
- In patients with cirrhosis, hypokalemia is associated with worsening hepatic encephalopathy
- In patients with structural heart disease, heart failure or taking antiarrhythmics, they are also at higher risk for arrhythmias with hypokalemia
- In patients with myocardial infarction, hypokalemia is associated with increased frequency of ventricular arrhythmias and death
Why not just replete everyone?
- Increased nursing and physician workload
- Increased cost
- Patient discomfort and GI upset from PO repletion options
- Burning and pain from IV repletion options
- Hyperkalemia carries significant risk as well if patients are over-repleted or develop AKI
What should we aim for in the inpatient setting?
- K of 3.5-4.0 mEq/L for patients with cirrhosis and heart disease (MI, HF, arrhythmias)
- K of 3.0-3.5 mEq/L is likely safe for all other patients who are asymptomatic
- Exceptions include patients who are significantly total body potassium depleted (DKA, severe malnutrition, etc.)
References and More Reading:https://twitter.com/tony_breu/status/1092539740287631367
Hypokalemia in acute medical patients: risk factors and prognosis
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Why do we administer potassium to a goal of ≥4.0 mEq/L?As an intern, potassium (oral or IV) was likely my most common order. How did this become a key part of inpatient providers' days?
Let's have a look at potassium and find out why we "replete".
— Tony Breu (@tony_breu) February 4, 2019