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Medline ® Abstract for Reference 55

of 'Anaphylaxis: Emergency treatment'

55
TI
The effect of drug concentration expression on epinephrine dosing errors: a randomized trial.
AU
Wheeler DW, Carter JJ, Murray LJ, Degnan BA, Dunling CP, Salvador R, Menon DK, Gupta AK
SO
Ann Intern Med. 2008;148(1):11.
 
BACKGROUND: The expression of drug concentration as a ratio may cause dosing errors.
OBJECTIVE: To examine the effect of ratio expressions on drug administration.
DESIGN: Randomized, blinded, controlled study.
SETTING: Simulation center in an urban hospital.
PARTICIPANTS: 28 physicians.
INTERVENTION: Participants 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).
MEASUREMENTS: The amount of epinephrine given and the time taken to administer it.
RESULTS: Compared 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).
LIMITATIONS: Performance in simulated scenarios may not reflect clinical practice. In reality, ampule labels provide both expressions of concentration.
CONCLUSION: The 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.
AD
Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom. dww21@cam.ac.uk
PMID