Background Local reactions related to intravenous administration of potassium chloride occur in up to 25% of patients. Given that hypokalaemia is common in hospitalised patients, it is important that intravenous potassium replacement be carried out with a minimal chance of infusion failure caused by phlebitis, extravasation or patient refusal due to intolerability.

Purpose To measure the relationship between intravenous potassium preparation concentrations and duration of infusion with severity of pain.

Material and methods The study was conducted in a tertiary hospital for a period of 1 month. A sample of 150 prescriptions were selected randomly from patients who presented to the pharmacy. 5 prescriptions were selected daily. The patient was eligible to be included if he/she could be interviewed. The intravenous cannula was inserted at least 1 hour before the start of the potassium chloride infusion, and all sites were inspected before the first infusion to ensure that there was no obvious pre-existing local pain. In order to assess the patient’s pain, a numeric rating scale (NRS) ranging from 1 (no pain) to 10 (worst pain) was used to rate pain at the infusion site. The pharmacist asked patients to rate the severity of pain at the infusion site using the NRS before the start and at the end of each infusion.

Results Mean patient age was 48.27 years. The average potassium level prior to infusion was 3.17 mmol/L. There was no pre-existing local pain, tenderness or phlebitis at the site of the infusion, and pain scores before the start of the infusions were 0 (no pain) for all patients. The study showed that the association between the concentration and pain was strong (p=0.048). The lowest infusion rate was 20 mL/hour and the highest was 250 mL/hour with an average of 105.25 mL/hour. The study showed that the association between the infusion rate and pain was week (p=0.062).

Conclusion The association between potassium chloride intravenous concentration with severity of the pain was established. The study showed the importance of initiation of a policy for standardisation of potassium concentrations as well as guidelines for treatment of hypokalaemia.

No conflict of interest