Clinical Conundrum: can albuterol as delivered by metered dose inhalers (MDI) replaced nebulized therapy for the treatment of hyperkalemia?
Background:
Given the push to avoid nebulized therapy during the COVID-19 pandemic, the question has been posed: Can albuterol as delivered by metered dose inhalers (MDI) replace nebulized therapy for the treatment of hyperkalemia?
Normally, hyperkalemia in adults is treated with: 10 mg albuterol nebulized therapy (1). While there is no data specific to nebulized albuterol deposition, it is widely agreed that approximately 10% of a nebulized dose reaches the lung (2).
Answer:
Therefore, we would aim for ~1 mg dose of albuterol as delivered by MDI (90 mcg/actuation). A study from 2017 showed approximately 40% of albuterol as delivered by MDI reaches the lung (3). However, this can be improved by 40-60% through use of a spacer. Therefore, approximately 60 mcg of every 90 mcg actuation will reach the lungs, and ~16 actuations will be needed. The process can be streamlined by delivering four actuations into the spacer before the patient inhales (4).
Bottom Line:
The suggested treatment dose for hyperkalemia using a MDI plus spacer instead of nebulization is four, 4-actuation doses as delivered by a spacer for a total of 16 actuations.
Notably, a study using 1200 mcg of albuterol (delivered by MDI with a spacer in 17 patients with CKD) found a reduction in serum potassium of ~0.4 mEq/L over 60 minutes; however, >50% of included patients saw an initial rise in serum potassium by 0.1-0.15 mEq/L in the first minute, demonstrating the need for pre-treatment with calcium to stabilize the myocardium (5).
Written By:
Joanne C. Routsolias, PharmD, RN, BCPS
Clinical PharmD Specialist - Emergency Medicine/Toxicology
Cook County Health
References:
1. J Am Soc Nephrol. 1998;9(8):1535-1543
2. Am Rev Respir Dis. 1991;143:727–37.
3. J Aerosol Med Pulm Drug Deliv. 2017;30(4):256-266
4. Thorax 1984;39:935-941
5. Chest 1999;115:617-622