• Daniel W Wheeler, Joseph J Carter, Louise J Murray, Beverley A Degnan, Colin P Dunling, Raymond Salvador, David K Menon, and Arun K Gupta.
• Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom. dww21@cam.ac.uk
• Ann. Intern. Med. 2008 Jan 1;148(1):11-4.

BackgroundThe expression of drug concentration as a ratio may cause dosing errors.ObjectiveTo examine the effect of ratio expressions on drug administration.DesignRandomized, blinded, controlled study.SettingSimulation center in an urban hospital.Participants28 physicians.InterventionParticipants managed a simulated pediatric acute anaphylaxis scenario by using epinephrine ampules labeled with mass concentration (1 mg in 1 mL) or a ratio (1 mL of a 1:1000 solution).MeasurementsThe amount of epinephrine given and the time taken to administer it.ResultsCompared with providers using ampules with mass concentration labels, those using ratio labels gave more epinephrine (adjusted mean dose, 213 microg above target [95% CI, 76.4 to 350.1 microg]; P = 0.003), and took longer to do so (adjusted mean delay, 91 seconds, [CI, 61.0 to 122.1 seconds]; P < or = 0.0001).LimitationsPerformance in simulated scenarios may not reflect clinical practice. In reality, ampule labels provide both expressions of concentration.ConclusionThe use of ratios to express drug concentration may be a source of drug administration error. Patient safety might be improved by expressing drug concentrations exclusively as mass concentration.

17 keywords...

hide…