Intravenous Potassium Phosphate Protocol Evaluation for Electrolyte Repletion in the SICU

Introduction: The Cleveland Clinic Surgical Intensive Care Unit (SICU) updated its electrolyte repletion protocol to incorporate intravenous (IV) potassium phosphate for simultaneous potassium and phosphate replacement. The electronic medical record limits replacement based upon a single value, thus the current design uses the potassium value to guide dose selection, when both potassium and phosphorus are low. The purpose of this evaluation was to assess the protocol’s utilization, effectiveness in achieving target electrolyte levels, and safety.


Methods: A retrospective evaluation was conducted for 84 administrations of IV potassium phosphate between April 1 and May 30, 2024. Protocol eligibility, compliance, time to administration, and post-repletion laboratory values were assessed. Effectiveness was defined as achieving serum potassium (4-5 mEq/L) and phosphorus (3.5-4.5 mg/dL) target levels per protocol.


Results: Of 84 administrations, 72 (92.9%) were eligible for protocol-guided use. Protocol compliance was 61.9%, with reasons for non-compliance including: incorrect drug selection (6%), dosing errors (16.7%), and missing labs (78.6%). The average time from lab result to administration was 3.33 hours.

Serum potassium levels reached goal in 51.9% of cases, while phosphorus goal was achieved in 30.4% of cases. Hyperkalemia occurred in only 1.2% of cases. Nearly half (46.9%) of patients remained hypokalemic after repletion. When the phosphorus goal was adjusted to 3.0 – 4.5 mg/dL, phosphorus goal attainment significantly improved from 30.4% to 51.9%.


Conclusions: The current IV potassium phosphate protocol demonstrates suboptimal efficacy and modest compliance, with a low risk of over-correction to supratherapeutic levels. Reducing the phosphorus goal range to 3-4.5 mg/dL and adjusting the protocol to guide dosing based on phosphate instead of potassium may improve target achievement.