Cardiovascular tolerance of intravenous lidocaine in broiler chickens (Gallus gallus domesticus) anesthetized with isoflurane. (July 2015)

• Record Type: Journal Article
• Authors: Brandão, João; da Cunha, Anderson F; Pypendop, Bruno; Stout, Rhett; Nevarez, Javier; Tully, Thomas N
• Is Part Of: Veterinary anaesthesia and analgesia. Volume 42:Number 4(2015:Jul.)
• Page Start: 442
• Page End: 448
• Publication Date: 2015-07
• Subjects: avian -- bird -- lidocaine -- local anesthesia -- Ross-708 -- toxicity; Veterinary anesthesia -- Periodicals; 636.089
• DOI: 10.1111/vaa.12226
• Languages: English
• ISSNs: 1467-2987

Abstract

Abstract: Objective: To determine the cardiovascular effects of lidocaine infused intravenously (IV) in broiler chickens. Study design: Two phase study: Phase 1, randomized up-and-down study to determine effective dose 50 (ED50 ) for lidocaine; Phase 2, prospective randomized study to determine the cardiovascular effects of lidocaine. Animals: Seventeen Ross-708 broiler chickens ( Gallus gallus domesticus ) [11 chickens (Phase 1) and 6 chickens (Phase 2)], weighing 2.6–4.3 kg. Methods: After induction of anesthesia with isoflurane and placement of monitoring equipment including invasive blood pressure, chickens were administered lidocaine IV. During Phase 1, using an up-and-down design, each animal received a variable dose selected based on the response of the previous animal. During Phase 2, each animal was administered 6 mg kg −1 of lidocaine IV over 2 minutes. Clinically irrelevant cardiovascular effects were defined as a relative decrease of heart rate (HR) and mean blood pressure (MAP) <30% subsequent to IV lidocaine administration. The ED50 was defined as the dose rate that would cause clinically irrelevant cardiovascular depression in 50% of the population. Results: During Phase 1, using an up-and-down study design ( n = 11), the ED50 of lidocaine was determined to be 6.30 mg kg −1 and 6.22 mg kg −1 (95% confidence interval, 5.30–7.13 mg kg −1 ), when calculated by Dixon's up-and-down method, and logistic regression, respectively. During Phase 2, following infusion of lidocaine (6 mg kg −1 ), no clinically relevant effects on HR or MAP were detected in any animal. Conclusions and clinical relevance: Previous reports state that the dose of lidocaine used in birds should be =4 mg kg −1 . In this study, 6 mg kg −1 of lidocaine injected IV was not associated with adverse cardiovascular effects. These results suggest that the dose of 4 mg kg −1 can be exceeded, at least in chickens, and opens the possibility of other therapeutic uses for lidocaine in birds.