Analgesic effects of maxillary and inferior alveolar nerve blocks in cats undergoing dental extractions

Abstract

The aim of this study was to evaluate the analgesic effects of maxillary and/or inferior alveolar nerve blocks with lidocaine and bupivacaine in cats undergoing dental extractions. Twenty-nine cats were enrolled. Using an adapted composite pain scale, cats were pain scored before the dental procedure and 30 mins, and 1, 2 and 4 h after isoflurane disconnection. Cats were sedated with buprenorphine (20 µg/kg), medetomidine (10 µg/kg) and acepromazine (20 µg/kg) intramuscularly. Anaesthesia was induced using alfaxalone (1-2 mg/kg) intravenously and maintained with isoflurane in oxygen. Each cat was randomly assigned to receive maxillary and/or inferior alveolar nerve blocks or no nerve blocks prior to dental extractions. Each nerve block was performed using lidocaine (0.25 mg/kg) and bupivacaine (0.25 mg/kg). Heart rate, systolic arterial blood pressure, respiratory rate, end tidal carbon dioxide and isoflurane vaporiser settings were recorded 5 mins before and after the dental extractions, and the difference calculated. Group mean differences (mean ± SD) for heart rate (-9.7 ± 10.6 vs 7.6 ± 9.5 beats/min [nerve block vs control group, respectively], P <0.0001), systolic arterial blood pressure (-10.33 ± 18.44 vs 5.21 ± 15.23 mmHg, P = 0.02) and vaporiser settings (-0.2 ± 0.2 vs 0.1 ± 0.4, P = 0.023) were significantly different between groups. The control group had higher postoperative pain scores (median [interquartile range]) at 2 h (3 [1.75-4.00] vs 1 [0-2], P = 0.008) and 4 h (4 [2-6] vs 2 [1-2], P = 0.006) after the dental extractions. Maxillary and inferior alveolar nerve blocks with lidocaine and bupivacaine administered prior to dental extractions resulted in a reduction in heart rate and blood pressure while allowing for a reduction in isoflurane. Cats receiving nerve blocks had lower postoperative pain scores than the group without nerve blocks.

Pain behaviors before and after treatment of oral disease in cats using video assessment: a prospective, blinded, randomized clinical trial

“…Some studies have evaluated oral pain when comparing the efficacy of different analgesic treatments in dogs and cats [13,14]. In the current study, the CMPS-F was used for pain assessment.…”

An extended release local anaesthetic: potential for future use in veterinary surgical patients?

“…; Aguiar et al . ). However, the duration of analgesia using these techniques is also limited due to the duration of action of the currently available formulations, as shown nicely in experimental studies (Trumpatori et al .…”

Local and regional anaesthesia in dogs and cats: Overview of concepts and drugs (Part 1)

“…When used as part of a multimodal protocol, both intraoperative nociceptive indicators (e.g. heart rate, respiratory rate and blood pressure changes at the time of a nociceptive stimulus) and postoperative pain scores are lower in patients receiving local/regional anaesthesia along with systemically administered analgesics when compared to patients receiving systemically administered analgesics alone (Aguiar, Chebroux, Martinez-Taboada, & Leece, 2015;Benito et al, 2016;Carpenter, Wilson, & Evans, 2004;Mosing, Reich, & Moens, 2010;Myrna, Bentley, & Smith, 2010;Perez et al, 2013;Savvas et al, 2008;Yilmaz et al, 2014).…”

“…Another advantage of intraoperative anti-nociception is improved anaesthetic safety because the inhalant dose, or minimum alveolar concentration (MAC), required to produce a surgical plane of anaesthesia is decreased in patients receiving local/regional blocks as part of a multimodal analgesic protocol (Aguiar et al, 2015;Kona-Boun, Cuvelliez, & Troncy, 2006;McMillan, Seymour, & Brearley, 2012;Mosing et al, 2010;Perez et al, 2013;Snyder & Snyder, 2013).…”