Anaesthesia and Post-operative Analgesia following Experimental Surgery in Laboratory Rodents: Are we Making Progress?

Abstract

Current attitudes to the use of animals in biomedical research require that any pain or distress should be minimised. This can often be achieved by the use of appropriate anaesthetic and analgesic regimens. There, is however, little information on the peri-operative regimens used. A literature review was conducted to estimate how commonly analgesics are administered to laboratory rodents, the most widely used species of laboratory animals, and to assess the anaesthetic regimens employed. Studies describing potentially painful experimental procedures involving rodents were identified from peer-reviewed journals published from 1990 to 1992 and from 2000 to 2002. In papers published between 2000 and 2002, if analgesic administration was not specified, the institutional veterinary surgeons or authors of the papers were contacted by e-mail to obtain additional information on analgesic use. From 1992 to 2002, there was an increase in the reported prevalence of analgesic administration to laboratory rodents from 2.7% to 19.8%. Although the use of analgesics has increased over the past ten years, the overall level of post-operative pain relief for laboratory rodents is still low. Anaesthetic methodology changed markedly between the two time-periods sampled. Notably, there was an increase in the use of isoflurane and of injectable anaesthetic combinations such as ketamine/xylazine, whereas the use of ether and methoxyflurane decreased.

Assessment of post-laparotomy pain in laboratory mice by telemetric recording of heart rate and heart rate variability

“…Mice are also increasingly used in complex investigations requiring additional surgical intervention. Doubtless, post-operative pain relief following surgical procedures such as laparotomy would seem to be necessary, but is often omitted as documented in a recent survey [1]. A reason given for withholding analgesics from laboratory rodents is that no signs of pain were observed and therefore analgesics were considered to be unnecessary.…”

Laboratory Animal Science: A Resource to Improve the Quality of Science

“…The effects of pain on experimental results are well described but often neglected; only 20% of papers currently report analgesic treatment (Richardson and Flecknell 2005). Much evidence suggests the identification of pain assessment and treatment as a principle of efficient management.…”

Prophylactic use of antimicrobials in surgical pig models; a literature review (2012‐2014)

“…Twenty-six of 34 articles gaining an AAUI of 5 did so by not reporting antimicrobial use when antimicrobials were not recommended. In studies analysing the reported versus actual use of analgesic drugs in laboratory animals, follow-up interviews with corresponding authors revealed that reported analgesic use closely corresponded with the actuality (Richardson and Flecknell 2005). If the same is true in this review then a tendency to good practice is revealed.…”

“…However, a recent study examining analgesic use in laboratory animals found little difference between the reported and actual administration frequency of analgesics when the latter were determined by contacting corresponding authors (Richardson and Flecknell 2005). On this basis, it is assumed that reported and actual levels of antimicrobial use are similar.…”