What are the initial potassium supplementation orders for a patient with severe hypokalemia (potassium level of 2.6 mEq/L) who has already received 40 mEq of potassium (potassium) orally (PO) and 20 mEq intravenously (IV) in the emergency department (ED)?

Management of Severe Hypokalemia (2.6 mEq/L) for Hospital Admission

For a patient with severe hypokalemia (2.6 mEq/L) who has already received 40 mEq PO and 20 mEq IV in the ED, administer 10 mEq/hour IV potassium chloride continuously with a maximum of 200 mEq in 24 hours, while monitoring serum potassium levels every 4-6 hours.

Initial Assessment of Severity

This patient has severe hypokalemia (K+ <3.0 mEq/L) which requires immediate attention due to risks of:

• Cardiac arrhythmias
• Neuromuscular dysfunction
• Increased mortality

Inpatient Potassium Replacement Protocol

IV Potassium Administration:

• Concentration: Do not exceed 80-100 mEq/L for peripheral IV administration 1
• Rate: 10 mEq/hour via calibrated infusion device 2
• Maximum daily dose: 200 mEq over 24 hours for patients with K+ >2.5 mEq/L 2
• Route: Central line preferred for higher concentrations; peripheral IV acceptable at lower concentrations 2

Monitoring Requirements:

• Check serum potassium every 4-6 hours until stable
• Continuous cardiac monitoring
• Monitor renal function with each potassium check
• Assess for symptoms of hypo/hyperkalemia

Special Considerations

Rate Adjustment for Severe Cases:

• For patients with K+ <2.0 mEq/L or with ECG changes/muscle paralysis, rates up to 40 mEq/hour may be used with continuous ECG monitoring 2
• Since this patient has K+ of 2.6 mEq/L, standard replacement rate (10 mEq/hour) is appropriate

Oral Supplementation:

• Once IV replacement is established and the patient is stable, add oral potassium supplements (40-80 mEq/day divided into 2-3 doses)
• Oral replacement is preferred when feasible, except in cases with ECG changes, neurologic symptoms, or non-functioning bowel 3

Precautions and Contraindications

• Mandatory infusion pump: Always use a calibrated infusion device 2
• Avoid rapid correction: Rapid potassium administration can cause fatal arrhythmias
• Verify renal function: Ensure adequate urine output before aggressive replacement
• Avoid potassium-sparing diuretics: Until potassium levels normalize 4

Follow-up Orders

1. Recheck serum potassium 4-6 hours after initiating therapy
2. Adjust infusion rate based on repeated measurements
3. Investigate underlying cause of hypokalemia while treating
4. Document ECG findings before and during treatment
5. Consider magnesium level assessment and replacement if indicated

Common Pitfalls to Avoid

• Underestimating total body potassium deficit: Serum K+ of 2.6 mEq/L may represent a total body deficit of 300-400 mEq 3
• Overcorrection: Can lead to hyperkalemia, especially in patients with renal impairment
• Inadequate monitoring: Failure to check potassium levels frequently during replacement
• Peripheral IV infiltration: Can cause tissue necrosis with concentrated potassium solutions

By following this protocol, you can safely manage this patient's severe hypokalemia until the hospitalist assumes care in the morning.