Implementing and assessing an evidence-based electrolyte dosing order form in the medical ICU

The purpose of this study was to evaluate the efficacy, safety, and nursing acceptability of a nursing initiated, evidence-based order form to replace potassium, magnesium, and phosphate in the MICU.

This retrospective study compared patients receiving electrolyte replacement with the order form to matched historical control patients receiving traditional electrolyte replacement (no order form). The primary outcomes were absolute change in serum concentrations and the proportion of doses achieving normal serum concentrations. Other outcomes were adverse events as documented in the medical record and nursing acceptability as assessed by survey.

The 2 groups (12 in each group) were similar. The order form and control groups received 36 and 62 potassium doses, 14 and 48 magnesium doses, and 34 and 13 phosphorus doses, respectively. Doses of all three electrolytes were significantly larger with the order form. Absolute changes in potassium, magnesium, and phosphorus serum concentrations for the order form group and control group were 0.36+/-0.42 versus 0.11+/-0.43 mmol/l (p<0.01), 0.56+/-0.69 versus 0.13+/-0.40 mequiv./l (p=0.07), and 0.53+/-0.82 versus 0.66+/-0.83 mg/dl (p=0.63), respectively. Normal serum concentrations achieved for each electrolyte replacement dose in the order form group and control group were 72% versus 18% (p<0.001), 86% versus 21% (p<0.001), and 47% versus 62% (p=0.57), respectively. No adverse events occurred. The nursing survey showed satisfaction and comfort using the order form.

The use of the order form provided greater efficiency for replacing potassium and magnesium but not phosphorus without increasing the occurrence of adverse events. The order form was well received by nursing staff.