PGY1 Pharmacy resident University of Kentucky Lexington, Kentucky, United States
Introduction: Our MICU utilizes an electrolyte replacement protocol (ERP) to direct electrolyte dosing. Replacement is guided by serum levels alone and includes no patient specific factors that should inform appropriate dosing. This is of particular concern with magnesium given a literature showing ICU patients frequently have significant deficits despite normal serum levels with well-defined risk factors such as diabetes.
Magnesium plays a critical role in supporting cardiac electrophysiology. ICU patients are routinely at increased risk for arrhythmias (structural heart disease, septic shock, QTc prolonging medications, etc.). Failure to identify and replace significant magnesium deficits could increase their risk for developing life threatening arrhythmias.
Our performance improvement goal was to develop and pilot a checklist our critical care pharmacists could use to quickly identify patients requiring more aggressive magnesium replacement than the ERP would provide.
Methods: We created a Do/Confirm checklist focusing on 2 sets of risk factors. • Risk factors for having significant magnesium deficits. • Risk factors for developing arrhythmias.
We retrospectively assessed the frequency of risk factors for hypomagnesemia in patients admitted to our MICU from March 1, 2021 - May 31, 2021.
We defined diabetic patients prescribed outpatient diuretics as a high-risk population for having significant deficits. Within this cohort we looked at admission Mg levels as well as the prevalence of an acute or chronic cardiac diagnoses and exposure to QTc prolonging medications.
Results: 32 of 364 patients (9%) met the high-risk criteria. 88% had normal magnesium levels. 75% had documented cardiac diagnoses and 25% received at least one QTc prolonging medication. Despite multiple risk factors, only 13% of the high-risk cohort would have received any replacement by ERP. Applying our checklist would suggest additional repletion for at least 85% of patients in the high-risk cohort.
Conclusions: We have demonstrated that a checklist can be used to identify patients in the ICU who may require more aggressive magnesium supplementation than the ERP will provide. Our next steps include surveying clinical pharmacists and prospectively collecting new data to evaluate the utility of the checklist in practice.
