Clinical Assessment of an Ipsilateral Cervical Spinal Nerve Block for Prosthetic Laryngoplasty in Anesthetized Horses.

Tate B Morris,Jonathan M Lumsden,Victoria Locke,Samuel D A Hurcombe,Sophia Sommerauer,Colin I Dunlop

doi:10.3389/fvets.2020.00284

Abstract

The nociceptive blockade of locoregional anesthesia prior to surgical stimulation can decrease anesthetic agent requirement and thereby potential dose-dependent side effects. The use of an ipsilateral second and third cervical spinal nerve locoregional anesthetic block for prosthetic laryngoplasty in the anesthetized horses has yet to be described. Anesthetic records of 20 horses receiving locoregional anesthesia prior to laryngoplasty were reviewed and compared to 20 horses of a similar patient cohort not receiving locoregional anesthesia. Non-blocked horses were 11 times more likely to require adjunct anesthetic treatment during surgical stimulation (P = 0.03) and were 7.4 times more likely to receive partial intravenous anesthesia in addition to inhalant anesthesia (P = 0.01). No horse in the blocked group received additional sedation/analgesia compared to the majority of non-blocked horses (75%) based on the anesthetist's perception of anesthetic quality and early recovery movement. No difference in recovery quality was observed between groups (P > 0.99). Cervical spinal nerve locoregional anesthesia appears well-tolerated and useful in reducing cumulative anesthetic agent requirement and may decrease the need for additional sedation/analgesia in horses undergoing anesthetized prosthetic laryngoplasty.

Highlights

According to a significant multicenter inquiry, more than 58% of perioperative fatalities in “noncolic” horses are due to either perianesthetic cardiovascular failure or musculoskeletal injury sustained during anesthetic recovery [1]
Eleven blocked horses were excluded from analysis on the basis of the C2–C3 block administered by alternate anesthetists (6/11), laryngoplasty performed by an alternate surgeon (1/11), incomplete data (2/11), a volume >10 mL 0.5% bupivacaine HCl administered (1/11), and administration of the C2–C3 block at the conclusion of surgery (1/11)
Results of our study found that the use of a C2–C3 ipsilateral locoregional block was associated with a reduced intraoperative adjunctive anesthetic requirement

Summary

Introduction

According to a significant multicenter inquiry, more than 58% of perioperative fatalities in “noncolic” horses are due to either perianesthetic cardiovascular failure or musculoskeletal injury sustained during anesthetic recovery [1]. Modification of the anesthetic or sedative type and amount used is one such way, because all may promote or enhance anesthesia, but they are not without potential deleterious effects. The volatile anesthetics isoflurane and halothane have been shown to produce dose-dependent cardiopulmonary depression [2], whereas intravenous anesthetic drugs such as the N-methyl-D-aspartate-receptor antagonist ketamine can result in detrimental excitation or ataxia during recovery [3]. Used α2-adrenergic receptor agonists produce dose-dependent cardiovascular depression, decreased gastrointestinal. C2–C3 Block for Anesthetized Laryngoplasty motility, and ataxia [4], and opioids can have central nervous system stimulatory effects, as well as decrease gastrointestinal motility [4]. By combining multiple agents at smaller doses, adverse dose-dependent effects may be mitigated

Methods

Results

Conclusion