Authors (including presenting author) :
Chan CC, Wong MH
Affiliation :
Department of Pharmacy, Queen Mary Hospital
Introduction :
A vast number of parenteral nutrition (PN) are being compounded by Aseptic Unit of Pharmacy every day. These compounded PN are often made up of over 10 types of ingredients and thus prone to human errors during the prescribing, dispensing and administration process. Magnesium overdose is one of the common error that can cause serious outcomes. Besides, Physicians may not know the omsolarity value and glucose concentration of compounded PN solutions and the current PN dispensing program also lacks such critical information which is essential to determine whether it is safe to be infused peripherally with minimal risk of line-related events. Such values can only be estimated using a formula or calculated manually if needed. In addition, the program cannot provide the total calorie of the PN.
Objectives :
(1) To minimize the risk of magnesium overdose; (2) To provide total calorie, overall osmolarity and glucose concentration of the PN solution; (3) To ensure all peripherally administered compounded PN meet the safety criteria on osmolarity and glucose concentration; (4) To reduce the need of manual calculation.
Methodology :
An excel program was designed to calculate the overall osmolarity and glucose concentration of the PN solution by inputting the volume of each ingredient. The calculator would display whether the PN solution is safe to be infused peripherally. If it is beyond safety limit, the calculator would then advise ways to manage. A label containing the above information would be generated and affixed to the dispensing record of PN solution for physicians’ and nurses’ reference. Besides, the calculator has a threshold value for magnesium dosage, above which an alert message would be prompted and no label can be generated, thus preventing inadvertent overdose during prescribing and dispensing.
Result & Outcome :
The medication safety of compound PN is now secured by ensuring appropriate magnesium dosage, osmolarity and glucose concentration. No medication incident involving magnesium overdose and inappropriate osmolarity or glucose concentration for peripheral infusion occurred after implementation of the calculator. The calculator saves time for manual calculation, provides reference for pharmacy staff to adjust the PN regimen according to the target calorie, osmolarity or glucose concentration, and facilitates communication between pharmacists and physicians on dosage adjustment through instant feedback from the calculator.
