Gaze S E, Paediatric Pharmacist, Lewisham Hospital, London, UK

Objectives: To determine the proportion of patients:
  • receiving the recommended dose of gentamicin (based on the most appropriate guideline)
  • having 1st blood levels of gentamicin measured and recorded at the correct date/time
  •  having all details completed on Green Stickers (used to document levels on drug charts for patients on TDM drugs)

Method: A data collection form was designed and used to capture data on all gentamicin prescribing and monitoring activity on the neonatal and paediatric wards at Lewisham Hospital over a 4 week period. Data collected included: age, weight, dose, gentamicin levels, time when levels were taken and details completed on the Green Sticker.

Results: 50 patients were identified as having received gentamicin on the neonatal and paediatric wards during the study period.

Figure 1: No of patients who received correct dose of gentamicin and had levels checked at correct time

Ward No of patients Correct dose 1st level measured at correct time
NICU 35 35 (100%) 33 (94%)
CSW 10 6 (60%) 8 (80%)
CMW 4 4 (100%) 3 (75%)
PICU 1 1 (100%) 1 (100%)

[NICU = Neonatal Intensive Care Unit; CSW = Children's Surgical Ward; CMW = Children's Medical Ward, PICU = Paediatric Intensive Care Unit]

4/50 (8%) of patients received 7mg/kg daily (as per BNF-C) instead of 6mg/kg daily (as per local paediatric formulary).

If all levels had been taken and documented appropriately, there should have been a total of 90 green stickers attached and completed in full on the patients' drug charts. 59/90 (65%) green stickers were attached to the patients' drug charts.

31 gentamicin levels were measured and available to view on the computer that were not recorded on the drug charts.

Of the 59 stickers that were attached to drug charts, there were 101 errors in terms of missing information.

Figure 2: Missing details on Green Sticker

Missing details No of errors Percentage of errors
Name of drug 41 41%
Time level due 22 22%
Time level taken 18 18%
Level 2 2%
Action 8 8%
Signed / dated 10 10%

8/59 (14%) of green stickers were completed in full.

Conclusion: There is confusion over whether 6mg/kg or 7mg/kg once daily is indicated for general medical and surgical paediatric patients. Since 7mg/kg gentamicin is a safe and effective dose, I would recommend prescribing this dose for all children (not neonates) unless they have specific conditions such as cystic fibrosis, endocarditis or renal impairment.

There is also confusion about when the first trough level of gentamicin should be checked. I would recommend checking gentamicin levels before the second dose is due, to ensure that the drug is being eliminated appropriately.

This audit demonstrated that completion of Green Stickers is poor. Further education is needed to explain the importance of completing the stickers in full, so that levels can be interpreted appropriately.

References: 1. Sleight E. Gentamicin Use in NICU. July 2008. Via Trust intranet. 2. Guy's and St. Thomas ' Paediatric Formulary 2005. Seventh Edition. 3. Daman C. Febrile Neutropenia Guidelines. August 2008. Via Trust intranet 4. Shankar A. Once Daily Gentamicin Guideline for Cystic Fibrosis. March 2008. Via Trust intranet. 5. BNF for children. July 2008.