Protocol-driven vs. physician-driven electrolyte replacement in adult critically ill patients

The intensive care unit is a dynamic environment, where high numbers of patients cared for by health care workers of different experiences and backgrounds might result in great variability in patient care. Protocol-driven interventions may facilitate timely and uniform care of common problems, like electrolyte disturbances. We prospectively compared protocol-driven (PRD) vs. physician-driven (PHD) electrolyte replacement in adult critically ill patients.

In the first month of the two-month study, potassium, magnesium, and phosphate levels were checked by a physician before ordering replacement (PHD replacement period). Over the second month, ICU nurses proceeded with replacement according to the protocol (PRD replacement period). We collected demographic data, admission diagnosis, number of potassium, magnesium, and phosphate levels done per day, number of low levels per day, number of replacements per day, time between availability of results to ordering replacement, time to starting replacement, post-replacement levels, serum creatinine, replacement dose, arrhythmias and replacement route.

During the PHD replacement period, 43 patients meeting the inclusion criteria were admitted to the ICU, while 44 were admitted during the PRD month. The mean time (minutes) from identifying results to replacement of potassium, phosphate and magnesium was significantly longer with PHD replacement compared with PRD replacement (161, 187, and 189 minutes vs. 19, 26, and 19 minutes) (P<0.0001). The number of replacements needed and not given was also significantly lower in the PRD replacement period compared with the PHD replacement period (2, 4, and 0 compared with 9, 6 and 0) (P<0.05). No patients had high post-replacement serum concentrations of potassium, phosphate or magnesium.

This study shows that a protocol-driven replacement strategy for potassium, magnesium and phosphate is more efficient and as safe as a physician-driven replacement strategy.