The study was not performed in a temperaturecontrolled room , meaning that variations in ambient temperature could account for some of the variations in the dead-space measurements . This study was conducted during the first Covid-19 lockdown in the UK , so access to a temperature-controlled room was not possible and , as previously stated , this more accurately reflects the typical UK veterinary practice environment .
The viscosity of injection solutions has been shown to increase liquid adherence to equipment such as needles and syringes [ 13 ] , further increasing drug wastage . As this study used only water for injection , it is probable that the volume of drug lost from actual CDs will be greater than those reported here .
Finally , this study included only two brands of syringe and one brand of needle . Cambruzzi and Macfarlane [ 9 ] reported additional variation from some manufacturers , so practices should consider conducting audits of their own equipment to establish local recommendations for accurate CDR wastage volumes .
Conclusion
The use of accurate discard volumes in the CDR is essential for accurate record keeping , to reduce the occurrence of unaccounted discrepancies in the stock balance .
Notably , there was a significant difference between the dead-space volumes of 1 ml , 3 ml and 5 – 20 ml syringes . The study found that the size of the needle gauge with larger syringes was irrelevant . However , the choice of needle gauge in combination with 1 ml syringes can impact discard volumes and result in additional loss of drugs . A 23G needle or smaller should be used for drawing up CDs to minimise drug wastage .
This study has highlighted concerns about the use of 0.05 ml as a standard discard volume , and suggests that discard volumes should be based on the equipment in use at the individual practice . For simplicity , the first author ’ s practice has implemented a recommendation that , where possible , a 1 ml syringe combined with a 25G needle is used to withdraw CDs and a discard volume of 0.08 ml is recorded in the CDR . A clinical audit is planned to evaluate the impact of this protocol on record accuracy .
Assessment of learning
1 . A standard dead-space discard volume of 0.05 ml will ensure accurate controlled drug records .
a ) True b ) False
2 . Needle gauge significantly affects the deadspace discard volume for which syringe size ?
a ) 1 ml b ) 3 ml c ) 5 ml d ) 10 ml
3 . What does the term ‘ diversion ’ refer to in relation to controlled-drug supply ?
a ) The use of controlled drugs prescribed for an animal by the animal ' s owner .
b ) The acquisition of controlled drugs prior to delivery to the intended recipient .
c ) Supplying a different controlled drug from the one originally prescribed .
d ) The transfer of a prescribed drug from the individual to whom it is prescribed to another person .
4 . How much of a discrepancy in controlled drug records is tolerated by the Veterinary Medicines Directorate when auditing records ?
a ) Up to 5 % b ) Up to 10 % c ) Up to 15 % d ) Up to 20 %
1 . b ) False 2 . a ) 1 ml 3 . d ) The transfer of a prescribed drug from the individual to whom it is prescribed to another person . 4 . b ) Up to 10 %
Answers
28 Veterinary Nursing Journal