Background The protocol for the safe use of intravenous potassium chloride, which was revised and approved by the Pharmacy and Therapeutics Committee and Patient Safety and Risk Management Committee, was implemented in our 1,500-bed hospital on May 30, 2012. It defines the best recommendations for the safe prescription, storage, dispensing, substitution policy, preparation and administration of concentrated and diluted potassium solutions with the aim of improving patients’ safety and ensuring the maximum efficiency and clinical applicability.

Concentrated (10 mmol/10 mL) ampoules were removed from patient care areas and replaced with standard commercial premixed diluted solutions, except in critical care and emergency areas. These were authorised to store and prepare solutions using ampoules, in which case it is necessary to carry out independent double-checking during its preparation and prior to its administration. The other care areas cannot have concentrated ampoules, and when a solution that is not commercially available is required for a patient, the pharmacy department (PD) has to prepare and dispense it on an individual basis.

Purpose To quantify and evaluate the nonstandard potassium solutions prepared by the PD following implementation of the protocol.

Materials and methods Retrospective study of the solutions prepared in the PD over a one-year period (June 2012–May 2013). Variables: 1) care unit and clinical indication, 2) type and volume of fluid and potassium concentration, 3) number of solutions prepared and 4) period of time.

Results 212 solutions (1.5% of the total number of intravenous mixtures prepared during the study period) were prepared for 63 patients. 40% were for 14 medical, 16% for 9 oncological and 14% for 7 surgical patients who required fluids for maintenance with higher potassium concentrations (sodium chloride 0.9% and glucose 5%/sodium chloride 0.3%: 60–80 mmol/1000 mL and 30–60 mmol/500 mL; glucose 5%/sodium chloride 0.18%: 20–40 mmol/500 mL) than those commercially available (40 mmol/1000 mL) or using fluids that are not commercially available with potassium (sodium chloride 0.18%: 10–20 mmol/500 mL) for a mean period of 2.6, 1.6 and 1.3 days, respectively. 23% were required for 21 paediatric patients with different volumes and concentrations of potassium according to their anthropometric and clinical characteristics for 1.2 days, and the other 7% for 12 cardiac patients who required a concentrated solution at specific moments (sodium chloride 0.9%: 20–40 mmol/250 mL) after being transferred from the intensive care unit.

Conclusions Centralising the preparation of nonstandard potassium solutions in the PD for non-authorised care areas is an important patient safety practice that is feasible in our current structure.

It would be convenient for the PD and the medical team of non-authorised care units to standardise the prescription and preparation of solutions for selected patients and for certain types of fluids and potassium concentrations.

No conflict of interest.