Continuous Rate Infusion of Ketamine Hydrochloride and Dexmedetomidine for Maintenance of Anesthesia during Laryngotracheal Surgery in New Zealand White Rabbits (Oryctolagus cuniculus)

Assessment of a Combination of Tiletamine/Zolazepam, Ketamine, and Dexmedetomidine for Anesthesia of Swine (Sus domesticus)

This study investigated the induction of anesthesia in swine by injection of tiletamine/zolazepam and ketamine in combination with either dexmedetomidine (TKD) or xylazine (TKX). We hypothesized that TKD would accelerate anesthesia onset and prolong recovery as compared TKX in swine undergoing a noninvasive radiographic procedure. A randomized crossover experiment was performed on 6 healthy, intact, male miniature swine undergoing radiographic examination. Swine were randomly assigned to one of 2 groups: 1) 5mg/kg tiletamine/zolazepam, 2.5mg/kg ketamine, and 0.0125mg/kg dexmedetomidine (TKD) or 2) 5mg/kg tiletamine/zolazepam, 2.5mg/kg ketamine, and 2.5mg/kg xylazine (TKX). Either TKD or TKX was administered intramuscularly at 0.05mL/kg to provide anesthesia for a 45-min radiographic procedure. At 45min after drug administration, atipamezole was administered. During anesthesia, swine were monitored for duration parameters (time to sternal recumbency [onset of anesthesia], lateral recumbency, loss of palpebral reflex, return of the palpebral reflex, and return to sternal recumbency [onset of recovery]) and physiologic parameters (heart rate, %SpO₂, noninvasive blood pressure, and body temperature). Duration and physiologic parameters did not differ between groups at any time point. The results indicate TKD and TKX provide comparable general anesthesia in swine undergoing a radiographic examination.

Sedation and Anesthesia in Exotic Animal Critical Care

Sedation and anesthesia of exotic animals in inherently challenging, but often facilitates the best care for patients. Critical illness or injury adds on another layer of complexity to their management for obtaining diagnostics and providing treatments. This article serves to review some of the more recent literature of sedation and anesthesia within exotics practice, bringing to light some nuances and considerations for when those patients are critically ill or injured.

Dexmedetomidine Effectively Sedates Asian Elephants (Elephas maximus)

Simple Summary

Sedation in standing procedures is commonly performed in elephants. To successfully and safely initiate standing in elephants, chemical restraint drugs should provide sufficient sedation with minimal complications (i.e., recumbency, significant physiologic alterations, and prolonged recovery). This study investigated the sedative effects of dexmedetomidine in Asian elephants. Results suggest dexmedetomidine 1–2 µg/kg provides effective sedation. However, we suggest a single intramuscular dexmedetomidine injection of 2 µg/kg for approximately 70 min of sedation. This is the first study to demonstrate dexmedetomidine use in Asian elephants.

Abstract

This study investigated the sedative effects of dexmedetomidine in Asian elephants. We hypothesized that 2 µg/kg dexmedetomidine would provide sufficient standing sedation. A crossover design study was performed in three Asian elephants. Each elephant was assigned to 1 of 3 treatment groups—1 (D1), 1.5 (D1.5) or 2 (D2) µg/kg dexmedetomidine (intramuscular injection, IM) with a two-week ‘washout period’ between doses. Elephants were monitored for 120 min. At 120 min (Ta), atipamezole was administered IM. Sedation and responsiveness scores were evaluated. Physiological parameters (pulse rate, respiratory rate, and %SpO₂) and clinical observations were monitored during the study and for 3 days post drug administration. D2 provided the longest sedation (approximately 70 min), compared to D1 and D1.5. After Ta, each elephant’s sedative stage lessened within 10–15 min without complications. No significant abnormal clinical observations were noted throughout and during the 3-days post study period. These data suggest that a single 2 µg/kg IM dexmedetomidine injection provides sufficient standing sedation for approximately 70 min in Asian elephants.

Numerical and experimental investigations on vocal fold approximation in healthy and simulated unilateral vocal fold paralysis

We have developed a novel surgical/computational model for the investigation of unilateral vocal fold paralysis (UVFP) which will be used to inform future in silico approaches to improve surgical outcomes in type I thyroplasty. Healthy phonation (HP) was achieved using cricothyroid suture approximation on both sides of the larynx to generate symmetrical vocal fold closure. Following high-speed videoendoscopy (HSV) capture, sutures on the right side of the larynx were removed, partially releasing tension unilaterally and generating asymmetric vocal fold closure characteristic of UVFP (sUVFP condition). HSV revealed symmetric vibration in HP, while in sUVFP the sutured side demonstrated a higher frequency (10 - 11%). For the computational model, ex vivo magnetic resonance imaging (MRI) scans were captured at three configurations: non-approximated (NA), HP, and sUVFP. A finite-element method (FEM) model was built, in which cartilage displacements from the MRI images were used to prescribe the adduction and the vocal fold deformation was simulated before the eigenmode calculation. The results showed that the frequency comparison between the two sides were consistent with observations from HSV. This alignment between the surgical and computational models supports the future application of these methods for the investigation of treatment for UVFP.