Introduction Glucose and electrolyte bags are prepared in many neonatal units to provide maintenance fluid, calories, sodium and potassium in the first few days of life. As part of a safer injectables alert1 workstream in South Central Strategic Health Authority it was identified that the bags are prepared by nursing staff in the ward environment against a prescription. This is a complex process with inherent risks including calculation and measurement errors.
Aim To measure the concentration of sodium and potassium in ward prepared infusions and compare with the prescription.
Method Neonatal pharmacists across 12 units were asked to send used bags of glucose and electrolyte solution to Wessex Laboratories. Details of the infusion were sent to the investigator. The laboratory measured the concentration of electrolytes in each bag using atomic absorption spectrophotometry (Perkin-Elmer AA400). The results from the analysis were then compared with the expected value according to the prescription.
Results A total of 45 tests were carried out from 27 bags from 7 centres, 27 (60%) sodium and 18 (40%) potassium. The mean variation between ordered and measured electrolyte was +2.4% (95% CI −2.8 to +7.6%). The measured concentration was within the acceptable limits of 90–110% in 38 (84%) tests. Deviation outside these limits were seen in 7 (16%) tests (four sodium and three potassium). These tests were all taken from solutions in burettes rather than bags.
Discussion We found that 16% (7) of the tests deviated by more than 10% either above or below the prescribed concentration. To the authors knowledge this is the first study of the variability in concentration of this type of infusion although other studies have shown variable results.2–4 Where tests were outside the limits no harm resulted from these discrepancies the use of the burette system is under review.
Conclusions/Recommendations Pharmacists should be aware that errors can occur in the preparation of these infusions and to take this into account when assessing the patient.
Consideration should be given to the development of stock bags in a similar way to parenteral nutrition.
Consideration should be given to simplify both the prescribing and preparation process with the use of proformas.
Further work to test more samples and other drugs is planned.