Abstract
Objective
To quantify the variability in the concentration of drug infusions prepared on an intensive care unit and establish whether there was a relationship between the quality of syringe labeling and drug preparation.
Design
Audit carried out over 3 weeks in May 2006 and completed in May 2007.
Setting
The adult neurosciences critical care unit of a UK university teaching hospital.
Interventions
Daily collections of discarded syringes containing midazolam, insulin, norepinephrine, dopamine, potassium or magnesium.
Measurements and results
Residual solutions in the syringes were sampled and the concentrations measured. Syringe labels were inspected and awarded a score for labeling quality based on an 11-point scale. A total of 149 syringes were analyzed. Six of the magnesium syringes contained 4–5 times too much Mg2+, presumably because of confusion about converting millimoles to grams. The majority of the other infusions differed from the expected concentration by more than 10%. Magnesium infusions were least likely to be properly labeled (p = 0.012), and there was a positive correlation between quality of syringe labeling and drug preparation (p = 0.002). After the introduction of a new electrolyte prescription chart, magnesium and potassium preparation significantly improved but there was still substantial variability.
Conclusions
These findings present a strong argument for the use of pre-prepared syringes or standardized drug preparation and labeling systems. They also highlight once again the difficulties healthcare professionals encounter when dealing with different ways of expressing drug concentrations.
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References
Wheeler SJ, Wheeler DW (2005) Medication errors in anaesthesia and critical care. Anaesthesia 60:257–273
Valentin A, Capuzzo M, Guidet B, Moreno RP, Dolanski L, Bauer P, Metnitz PH (2006) Patient safety in intensive care: results from the multinational Sentinel Events Evaluation (SEE) study. Intensive Care Med 32:1591–1598
Osmon S, Harris CB, Dunagan WC, Prentice D, Fraser VJ, Kollef MH (2004) Reporting of medical errors: an intensive care unit experience. Crit Care Med 32:727–733
Calabrese AD, Erstad BL, Brandl K, Barletta JE, Kane SL, Sherman DS (2001) Medication administration errors in adult patients in the ICU. Intensive Care Med 27:1592–1598
Tissot E, Cornette C, Demoly P, Jacquet M, Barale F, Capellier G (1999) Medication errors at the administration stage in an intensive care unit. Intensive Care Med 25:353–359
Kopp BJ, Erstad BL, Allen ME, Theodorou AA, Priestley G (2006) Medication errors and adverse drug events in an intensive care unit: Direct observation approach for detection. Crit Care Med 34:415–425
van den Bemt PMLA, Fijn R, van der Voort PHJ, Gossen AA, Egberts TCG, Brouwers JRBJ (2002) Frequency and determinants of drug administration errors in the intensive care unit. Crit Care Med 30:846–850
Rothschild JM, Landrigan CP, Cronin JW, Kaushal R, Lockley SW, Burdick E, Stone PH, Lilly CM, Katz JT, Czeisler CA, Bates DW (2005) The Critical Care Safety Study: The incidence and nature of adverse events and serious medical errors in intensive care. Crit Care Med 33:1694–1700
Fraind DB, Slagle JM, Tubbesing VA, Hughes SA, Weinger MB (2002) Reengineering intravenous drug and fluid administration processes in the operating room. Step one: task analysis of existing processes. Anesthesiology 97:139–147
Herout PM, Erstad BL (2004) Medication errors involving continuously infused medications in a surgical intensive care unit. Crit Care Med 32:428–432
Webster CS, Merry AF, Larsson L, McGrath KA, Weller J (2001) The frequency and nature of drug administration error during anaesthesia. Anaesth Intensive Care 29:494–500
Allen EM, Van Boerum DH, Olsen AF, Dean JM (1995) Difference between the measured and ordered dose of catecholamine infusions. Ann Pharmacother 29:1095–1100
Parshuram CS, Ng GYT, Ho TKL, Klein J, Moore AM, Bohn D, Koren G (2003) Discrepancies between ordered and delivered concentrations of opiate infusions in critical care. Crit Care Med 31:2483–2487
Ferner RE, Langford NJ, Anton C, Hutchings A, Bateman DN, Routledge PA (2001) Random and systematic medication errors in routine clinical practice: a multicentre study of infusions, using acetylcysteine as an example. Br J Clin Pharmacol 52:573–577
Andersen L, Dinesen B, Jorgensen PN, Poulsen F, Roder ME (1993) Enzyme immunoassay for intact human insulin in serum or plasma. Clin Chem 39:578–582
Connerty HV, Lau HSC, Briggs AR (1971) Spectrophotometric determination of magnesium by use of methylthymolblue. Clin Chem 17:661
Frant MS, Ross JW Jr (1970) Potassium ion specific electrode with high selectivity for potassium over sodium. Science 167:987–988
Hartwick RA, Brown PR (1980) The use of high pressure liquid chromatography in clinical chemistry and biomedical research. Adv Clin Chem 21:25–99
Lehmann B, Boulieu R (1995) Determination of midazolam and its unconjugated 1-hydroxy metabolite in human plasma by high-performance liquid chromatography. J Chromatogr B Biomed Appl 674:138–142
United States Pharmacopeial Convention (1999) United States Pharmacopeia. Stationery Office Books, Rockville, MD, pp 1131–1132
Wheeler DW, Remoundos DD, Whittlestone KD, Palmer MI, Wheeler SJ, Ringrose TR, Menon DK (2004) Doctors' confusion over ratios and percentages in drug solutions: the case for standard labelling. J R Soc Med 97:380–383
Scrimshire JA (1989) Safe use of lignocaine. BMJ 298:1494
Rolfe S, Harper NJ (1995) Ability of hospital doctors to calculate drug doses. BMJ 310:1173–1174
Oldridge GJ, Gray KM, McDermott LM, Kirkpatrick CM (2004) Pilot study to determine the ability of health-care professionals to undertake drug dose calculations. Intern Med J 34:316–319
Wheeler DW, Wheeler SJ, Ringrose TR (2007) Factors influencing doctors' ability to calculate drug doses correctly. Int J Clin Pract 61:189–194
Wheeler DW, Carter JJ, Murray LJ, Degnan BA, Dunling CP, Salvador R, Menon DK, Gupta AK (2008) The effect of drug concentration expression on epinephrine dosing errors: a randomized trial. Ann Intern Med 148:11–14
Drew D, Schumann D (1986) Homogeneity of potassium chloride in small volume intravenous containers. Nurs Res 35:325–329
Thompson WL, Feer TD (1980) Incomplete mixing of drugs in intravenous infusions. Crit Care Med 8:603–607
Tonner PH, Weiler N, Paris A, Scholz J (2003) Sedation and analgesia in the intensive care unit. Curr Opin Anaesthesiol 16:113–121
Klem SA, Farrington JM, Leff RD (1993) Influence of infusion pump operation and flow rate on hemodynamic stability during epinephrine infusion. Crit Care Med 21:1213–1217
Weiss M, Neff T, Gerber A, Fischer J (2000) Impact of infusion line compliance on syringe pump performance. Paediatr Anaesth 10:595–599
United States Pharmacopeial Convention: USP 797 (2007) United States Pharmacopeia. Stationery Office Books, Rockville, MD
Merry AF, Webster CS, Connell H (2007) A new infusion syringe label system designed to reduce task complexity during drug preparation. Anaesthesia 62:486–491
Acknowledgements
The study was funded by the Association of Anaesthetists of Great Britain and Ireland, which had no role in study design, in collection, analysis, and interpretation of data, in the writing of the report, or in the decision to submit the paper for publication. We are indebted to David Robb and Alison Gray for designing and refining the new electrolyte prescription chart.
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Wheeler, D.W., Degnan, B.A., Sehmi, J.S. et al. Variability in the concentrations of intravenous drug infusions prepared in a critical care unit. Intensive Care Med 34, 1441–1447 (2008). https://doi.org/10.1007/s00134-008-1113-9
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DOI: https://doi.org/10.1007/s00134-008-1113-9