A Simplified Gentamicin Dosing Chart is Quicker and More Accurate for Nurse Verification than the BNFc

Eileen H J Wong ¹, Zoe Taylor ², John Thompson ³ and David Tuthill ^2*

¹ Cardiff University School of Medicine, United Kingdom
² Children's Hospital for Wales, Cardiff and Vale NHS Trust, United Kingdom
³ Cardiff University, United Kingdom

^* To whom correspondence should be addressed. E-mail: david.tuthill{at}cardiffandvale.wales.nhs.uk.

Accepted 17 June 2008

Abstract

Background: At least 5% of all paediatric admissions are complicated by a medication error. Nurses can prevent some errors by correctly verifying prescriptions before administering drugs. To do so successfully requires adequate drug calculation skills and familiarity with the BNFc. We wished to explore whether a newly devised chart would improve their dose calculation ability and thus potentially reduce doctors’ prescription errors.

Aims: To explore nurses’ ability to calculate doses of gentamicin for neonates and children using a new simple dosing chart compared to the BNFc.

Methods: Two gentamicin dosing charts (paediatric and neonatal) were devised by a multidisciplinary group to simplify dose calculation and selection of frequency. These charts were compared with the BNFc using 4 questions (2 neonatal; 2 paediatric) asking ward nurses to correctly calculate gentamicin doses in their work environment. Answers were scored for both the correct dosage and frequency.

Results: 51 nurses participated. Only 11 nurses(22%) answered all 4 questions correctly. A higher proportion correctly answered both the dosage and frequency questions simultaneously when using the chart compared to the BNFc: paediatric questions 100%(51/51 chart) cf 80%(41/51 BNFc) [OR 0.20] and neonatal questions 55%(28/51 chart) cf 35%(18/51 BNFc) [OR 0.2]. Errors when using the BNFc were due to selection of the wrong regimen (23%), wrong frequency (17%) and one 10-fold dosing error. When using the chart, there were no dosing errors made, only frequency errors for the neonatal regimen.

Conclusion: The chart was more reliable, quicker and may be useful for patient safety. Revising the format of BNFc may be beneficial for nurses.