Contemporary topics in laboratory animal science / American Association for Laboratory Animal Science
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Contemp Top Lab Anim Sci · Mar 2003
Acetaminophen as a postsurgical analgesic in rats: a practical solution to neophobia.
Acetaminophen administration is gaining popularity as a postsurgical analgesic in many rodent labs despite reports that animals may consume suboptimal doses as a result of taste neophobia. The present study evaluated the presence, duration, and extent of acetaminophen neophobia in adult male and female rats (Long Evans) with the intent of developing a protocol for administration of this analgesic in the rodent surgery lab. After a 7-day baseline period in which average water consumption, food consumption, and body weight were established for 32 rats (20 females and 12 males), cherry-flavored acetaminophen was administered (6 mg/ml) in the animals' water bottles for an additional 7 days. ⋯ Female animals displayed normal to elevated fluid consumption on all days of drug exposure. Both male and female animals, however, decreased their food intake after drug exposure and subsequently lost weight. Recommendations for the oral administration of acetaminophen as a postsurgical analgesic are discussed.
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Contemp Top Lab Anim Sci · Mar 2003
Comparative StudyComparison of three commercially available activated charcoal canisters for passive scavenging of waste isoflurane during conventional rodent anesthesia.
Chronic, low-level exposure to waste anesthetic gases has been linked to increased incidences of neurologic and reproductive dysfunction, hepatic and renal toxicity, and neoplasia in humans. We have shown previously that one brand of activated charcoal canister (F/Air) used for passive scavenging of halogenated gases does not completely remove isoflurane during anesthetic protocols used in conventional laboratory animal facilities. For the present study, we compared the scavenging capacities of three commercially available canister brands (Breath Fresh, EnviroPure, F/Air) using the same protocol. ⋯ Failure (defined as an isoflurane efflux of > or = 100 ppm) occurred in 42% of Breath Fresh units but 0% for the other brands. In a subsequent experiment (n = 6/brand), all Breath Fresh and F/Air but no EnviroPure canisters had at least one reading of > or = 5 ppm by the time they gained 30 g. These data indicate that marked variability in gas-scavenging capacity exists between different brands of commercially available activated charcoal canisters and suggest that trace levels of waste isoflurane may occur in high-throughput laboratory animal anesthesia rooms unless canister exhaust also is captured.
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Contemp Top Lab Anim Sci · Nov 2002
Pain evaluation and response to buprenorphine in rats subjected to sham middle cerebral artery occlusion.
Appropriate and efficacious use of analgesics in rodents must be balanced judiciously between animal needs and research objectives. A concern in many studies is that analgesia will confound experimental outcome or interpretation. Accordingly, determining whether rats subjected to surgical protocols show evidence of pain is important if we are to provide rational postoperative analgesia without compromising experimental objectives. ⋯ Postoperatively, all treatment groups showed elevated assessment scores relative to baseline values. Buprenorphine at the tested doses did not markedly reduce total assessment scores postoperatively relative to those in vehicle-treated animals. Further evaluation of rodent postoperative pain and response to analgesia is needed if we are to formulate a sound scientific approach to animal management in protocols requiring surgical manipulations.
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Contemp Top Lab Anim Sci · Mar 2002
Atmospheric waste isoflurane concentrations using conventional equipment and rat anesthesia protocols.
Chronic, low-level exposure of health care professionals to waste anesthetic gases has been linked to increased incidences of neurologic and reproductive dysfunction, hepatic and renal toxicity, and neoplasia. The present study assessed the potential for waste anesthetic gas exposure to researchers administering isoflurane to rats by using standard delivery systems and conventional anesthesia protocols. Well-maintained bench-top precision isoflurane vaporizers were equipped with two circuits (a nonrebreathing one hooked to a modified Bain facemask, and the other to an induction box) attached to commercially available, activated charcoal canisters (passive gas scavenging). ⋯ The background isoflurane level rose to 0.5 ppm after 75 min of continuous bench-top operation in a room with 22 air exchanges hourly but did not escalate if the anesthesia unit--or at least the gas-scavenging canister--was placed in a fume hood, or if the system was used in a room with 42 hourly air changes. Isoflurane efflux via the exhaust ports exceeded 5 ppm in 31% of gas-scavenging canisters that had not reached their maximum use life (as defined by the manufacturer's specifications); in a parallel prospective study, isoflurane was emitted from 88% of canisters by the time that they had reached 50% of their specified lifespan. These data indicate that (1) isoflurane emissions likely will occur at trace levels in laboratory animal facilities even when well-maintained precision isoflurane vaporizers equipped with conventional activated charcoal (passive) gas-scavenging units are used and (2) exposure to anesthetic pollution can be mitigated substantially by selecting low-flow anesthesia regimens, improving gas-scavenging practices, and optimizing the configurations of the delivery system and work area.
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Contemp Top Lab Anim Sci · May 2001
Medetomidine-ketamine anesthesia in red-eared slider turtles (Trachemys scripta elegans).
This study evaluated the effects of high and low dosages of medetomidine-ketamine in red-eared slider turtles (Trachemys scripta elegans) and the reversibility of the anesthesia with atipamezole. Thirty healthy adult turtles were assigned randomly to one of two dosage groups. The lower dosage group received 0.1 mg medetomidine/kg body weight intramuscularly (i.m.) combined with 5 mg ketamine/kg i.m. ⋯ Heart rate and cloacal temperatures remained stable throughout the entire procedure for both groups. Atipamezole was administered i.m. at five times the dose of medetomidine (0.5 mg/kg i.m. or 1 mg/kg i.m.) 60 min after the medetomidine-ketamine was administered. All of the turtles were swimming 60 min after atipamezole administration.