The effects of lidocaine-prilocaine cream on responses to intravenous catheter placement in cats sedated with dexmedetomidine and either methadone or nalbuphine.

Objective: To compare the reaction to cephalic intravenous (IV) catheter placement with or without lidocaine-prilocaine cream in cats sedated with dexmedetomidine and methadone or nalbuphine.

Study Design: Prospective, randomized, blind study.

Animals: A group of 24 female mixed breed cats.

Methods: Cats were randomly allocated to one of the two sedation protocols: dexmedetomidine (0.01 mg kg) and methadone (0.3 mg kg; DEXMET) or dexmedetomidine (0.01 mg kg) and nalbuphine (0.3 mg kg; DEXNALB). Sedation was scored 30 minutes later using a visual analog scale. Subsequently, a 2 × 3.5 cm area of the antebrachium over the cephalic vein was clipped, and half the cats within each protocol were randomly assigned for topical lidocaine-prilocaine cream (treatment), whereas no cream was applied to other cats (control). After 20 minutes, an attempt was made to place a 24 gauge catheter into the cephalic vein and the reaction of the cats to this procedure was scored using a numeric scale 0-3. Sedation and catheterization reaction scores were compared between sedation protocols and whether cats were administered lidocaine-prilocaine cream or not using the Friedman test followed by the Bonferroni procedure. A p value < 0.05 was considered significant.

Results: Sedation scores were not different between sedation protocols or between treatment and control cats within each protocol. All cats administered lidocaine-prilocaine cream showed no reaction to IV catheter placement. Among the control cats, no response was observed in one cat in DEXNALB. Catheterization reaction score was lower in the treatment cats in both the sedation protocols when compared with their respective controls.

Conclusions And Clinical Relevance: Lidocaine-prilocaine cream applied for 20 minutes abolished the reaction to catheterization in cats sedated with dexmedetomidine and nalbuphine or methadone. Facilitation of IV catheter placement occurred within 20 minutes of lidocaine-prilocaine application.