The effect of concentration, reconstitution solution and pH on the stability of a remifentanil hydrochloride and propofol admixture for simultaneous co-infusion.

BACKGROUND: There are scenarios where pre-mixing and infusing analgesic and anaesthetic agents as a single intravenous (IV) solution is highly desirable; however, it is important to ensure the agents are compatible when mixed. As such, the long-term stability of a remifentanil-propofol mixture, and means of improving this, were assessed across a range of remifentanil concentrations, diluents, and time points. METHODS: Remifentanil was reconstituted with ultrapure water, 0.9% saline, 20% saline, or 8.4% sodium bicarbonate solution (the latter two chosen for their pH characteristics, rather than their use in pharmaceutical reconstitution) and then mixed with propofol (1%) or further diluted with water to derive concentrations of 10-50 µg mL- 1. Remifentanil and propofol concentrations were determined initially and then periodically for up to 24 h using high performance liquid chromatography (HPLC). Mass spectrometry (MS) was used to detect degradation products in solutions containing 30 µg mL- 1 of remifentanil. Statistical analysis was performed using ANOVA and Student's t-test, with a significance value of 0.05. RESULTS: Isolated remifentanil (pH < 4) and propofol (pH 7.35) did not degrade significantly when reconstituted with water or saline solution over 24 h, while remifentanil reconstituted with sodium bicarbonate degraded significantly (P < 0.001, pH 8.65). Mixing with propofol substantially increased the pH of the mixture and resulted in significant remifentanil degradation for all reconstitution solutions used, while propofol remained stable (pH 6.50). The amount of degradation product detected in samples containing isolated remifentanil and a mixture of the drugs was proportional to the remifentanil degradation observed. CONCLUSIONS: Remifentanil stability is affected by both the reconstitution solution used and when mixed with propofol, with pH appearing to be a contributing factor to degradation. If the pH of the solution and concentration of remifentanil are correctly controlled, e.g. through the use of a more acidic diluent, an admixture of remifentanil and propofol may be useful clinically.

Support needs of supply nurses in rural and remote Queensland.

OBJECTIVE: The aim of this report is to discuss a needs analysis conducted with rural and remote nurses in Queensland undertaking supply of medications in public hospitals without a pharmacist. DESIGN: Survey questionnaire. METHODS: A questionnaire was faxed to 65 Queensland Health rural and remote hospitals using supply nurses. It contained six closed questions regarding previously identified medication 'supply' issues, and three open questions to determine additional information. RESULTS: Of the surveys, 42 (65%) were returned. Major areas of interest included a safety checklist for medication supply (90%, 38/42), more information on medication labelling requirements (83%, 35/42) and timing of medications with regard to food (86%, 36/42). Requirements for patient counselling, increased access to consumer medication information (CMI) (76%, 32/42), and resources regarding doses, indications, interactions and adverse effects also rated highly (73%, 31/42). Thirty-three supply nurses highlighted at least one issue in the open questions: more information on the legal requirements of repackaging medications (39%, 13/42), increased access to CMI and counselling tools (36%, 12/42) and an efficient stock control system (30%, 10/42). CONCLUSIONS: This report highlights the need to broaden current support services available to nurses undertaking the supply of medications. It is vital that support programs, and the laws and guidelines related to supplying medications in rural and remote hospitals, support health care professionals providing quality use of medicines (QUM) and reflect the realities of rural and remote health care.