Does local anaesthetic reduce pain in rubber ring castration of neonatal lambs?

Abstract

PICO Question In lambs less than 7 days old undergoing castration with rubber rings does administration of local anaesthetic compared to no local anaesthetic result in a reduction of pain-related behaviours? Clinical bottom line Category of research Treatment. Number and type of study designs reviewed Six studies were appraised; all were controlled clinical or field trials. Strength of evidence Moderate. Outcomes reported Local anaesthetic administered to lambs castrated with rubber rings resulted in the demonstration of fewer pain related behaviours and also diminished the increases in plasma cortisol in the immediate post-castration period when compared to lambs castrated without local anaesthetic. Local anaesthetic administered at least 15 minutes before rubber ring castration may significantly reduce behavioural signs of pain and plasma cortisol changes. Conclusion In lambs less than 7 days old undergoing castration with rubber rings, local anaesthetic reduces markers of pain when compared to lambs castrated without local anaesthetic. How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.

Keywords

• analgesia
• castration
• lambs
• local anaesthesia
• local anaesthetic
• pain
• rubber rings