Use of a continuous, local infusion of bupivacaine for postoperative analgesia in dogs undergoing total ear canal ablation

Loco-Regional Anaesthesia during Standing Laparoscopic Ovariectomy in Equids: A Systematic Review (2003-2023) of the Literature

Laparoscopic ovariectomy is generally performed with equids in the standing position, with the animals heavily sedated and restrained in stocks. This procedure may be quite painful, and it is essential first to manage intraoperative pain to complete the surgery, respecting the animal's welfare and, at the same time, ensuring the safety of the operators. Laparoscopy requires multiple small incisions to introduce the instruments, with one to two incisions enlarged sufficiently to remove the ovary. The surgical procedure must be associated with effective pain control, usually obtained with loco-regional anaesthesia, mesovarian injection, mesovaric or ovarian topical anaesthesia, and epidural anaesthesia. This systematic review aims to discuss articles published from 2003 to 2023 on treating loco-regional anaesthesia in standing laparoscopic ovariectomy in association with an evaluation of pain. The literature review was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines on three databases (NCBI-PubMed, Web of Science, and SciVerse Scopus). Despite the collected papers numbering 36, we identified only five eligible papers, demonstrating that few studies are performed in order to evaluate the quality of analgesia with loco-regional anaesthesia in standing laparoscopic ovariectomy in equids. The authors of this systematic review agree that the association of injectable and epidural anaesthesia is the best solution to manage intraoperative pain in standing laparoscopic ovariectomy in equids.

Description of postoperative complications and bacterial contamination of wound soaker catheters used to administer postoperative local analgesia after mastectomy in 11 dogs: case series

Mastectomy is a common and painful procedure in dogs. Wound soaker catheters (WSC) are frequently used to reduce postoperative pain, including pain after mastectomy. The objectives of this case series were to describe the use of WSC for owner administration of postoperative local analgesia in dogs with mammary tumors treated surgically, to identify complications associated with WSC and to determine the frequency of bacterial colonization of the catheters. Twelve WSC were placed in 11 dogs during mastectomy surgery, left in place for three days, protected by a dressing and successfully managed by owners at home. No postoperative antibiotics were administered. No complications were identified in any cases. No bacterial growth was identified on bacteriological analysis of the twelve WSC. These results suggest that the use of WSC is a safe alternative for postoperative analgesia administration following mastectomy in dogs. Future studies comparing dogs with or without WSC with a larger number of dogs are needed to further evaluate efficacy and complications.

Use of wound infusion catheters for delivery of local anesthetic following standing partial ostectomy of thoracolumbar vertebral spinous processes in horses is not associated with increased surgical site infections

Background

Wound infusion catheters (WICs) have been used in humans and some veterinary species for post-operative local anesthetic administration following a variety of surgical procedures, aiming to reduce post-operative analgesia requirements and improve patient comfort. Benefit in reduction in pain, post-operative analgesia requirements and length of hospital stay are well documented in humans, but use of WICs may not have been widely adopted in veterinary species due to the concern of increased complications, such as dehiscence or surgical site infection (SSI), creating a barrier to their use. This study aimed to evaluate the use of WICs in horses undergoing standing partial ostectomy surgeries, document complications and investigate if the incidence of SSI was equivalent between those horses that did and did not have a WIC.

Methods

Clinical records were searched between January 2010-December 2023 for horses undergoing standing partial ostectomy surgery of thoracolumbar vertebral spinous processes at one institution. Population variables (age, breed, bodyweight), placement of a WIC or not, post-operative complications, analgesia protocols and surgical time were recorded. Horses received up to 0.1 mg kg-1 bupivacaine (0.5 mg mL-1) every 6-8 h via the WIC where one was placed. To compare SSI complication incidence between using or not using a WIC, a proportional independent equivalence test was used.

Results

There were 64 horses included in the final analysis with a WIC placed in 29/64 horses (45.3%) and 35/64 (54.7%) having no WIC placed at surgery. Incidence of short-term SSI was 11.4% (no WIC used) and 13.8% (WIC used), respectively. The difference in proportion of SSI between the presence or absence of a WIC was not significant [-0.024 (90% CI -0.181; 0.133); p = 0.94].

Conclusion

The incidence of SSIs was equivalent between groups whether a WIC was used or not. WICs should be considered as part of a multi-modal analgesic approach in the post-operative period. Further research into local anesthetic dosing and its impact on rescue analgesia requirements and pain-scores is warranted.

Use of wound infusion catheters for postoperative local anaesthetic administration in cats

OBJECTIVES

The present study aimed to document the use of the wound infusion catheter (WIC) following a variety of surgical procedures in cats, investigating complications and risk factors associated with catheter placement or local anaesthetic (LA) administration.

METHODS

A retrospective, multicentric study was performed. Medical databases of eight veterinary referral hospitals from 2010 to 2021 were searched to identify records of cats where WICs were used. Information regarding signalment, type of surgery, size and type of WIC placed, and LA protocol used, as well as postoperative complications, were retrieved.

RESULTS

One hundred and sixty-six cases fulfilled the inclusion criteria. Feline injection site sarcoma resection was the most common surgery. Overall complications were identified in 22/166 cats (13.2%). Thirteen cats (7.8%) experienced wound-related complications, whereas nine cats (5.4%) experienced drug-delivery complications. The only factor associated with an increased risk of complications was the amount of a single dose of LA delivered through the catheter (P <0.001). An amount higher than 2.5 ml of LA delivered at each administration was associated with an increased risk of complications. All complications were minor and self-limiting.

CONCLUSIONS AND RELEVANCE

WICs were used for a large variety of surgical procedures with different protocols of LA administration as part of a multimodal analgesic plan in cats. The risk of complications was relatively low and self-limiting, suggesting its safe use in cats. Further prospective studies are required to evaluate efficacy of postoperative analgesia and to determine the suitable protocol for WIC handling and maintenance.

Liposomal bupivacaine is both safe and effective when administered via local infiltration at surgical site and mesovarium for laparoscopic ovariectomy in mares

BACKGROUND

Liposomal local anaesthetic solutions may provide extended-duration analgesia postoperatively but have not been assessed following intra-peritoneal local infiltration in any species.

OBJECTIVES

To evaluate two doses of 1.33% liposomal bupivacaine (LB) versus 0.75% bupivacaine HCL (BHCl) for analgesia following laparoscopic ovariectomy in mares.

STUDY DESIGN

Prospective cohort study.

METHODS

Fifteen healthy Quarter Horse mares (age 2-20 years) with normal bilateral ovarian palpation and appearance were enrolled. Horses were restrained in standing stocks and administered an α-2 agonist, butorphanol, and flunixin meglumine, followed by a variable rate infusion of sedation with α-2 agonists. Bilateral paralumbar fossa ovariectomies were performed. Treatment with either 30 ml 0.75% BHCl followed by 20 or 40 ml LB 13.3% (LB20 and LB40) volume expanded with saline to 80 ml total (n = 6/group) or 80 ml BHCl alone (n = 3, BCHL) was infused around incision sites and each mesovarium (LB or BHCl) prior to ovariectomy. Horses were monitored for 72 h by physical examination, algometry, and pain scoring (composite pain scale by Bussieres et al., Horse Grimace Scale). Abdominocentesis with peritoneal fluid analysis was performed at 72 h.

RESULTS

Analgesia achieved with all treatment protocols allowed completion of ovariectomy procedures. Pressure algometry scores were lower in BHCl-treated horses versus both LB groups overall. Pain scores were improved with LB-treated horses in a dose-dependent fashion (Horse Grimace Scale scores LB40 < LB20 < BHCL; composite pain scale scores LB40 < BHCL, LB20 < BHCL, BHCL, and LB20 did not differ). Peritoneal fluid total protein was lower in LB40 versus LB20 and BHCL horses. No complications from LB administration were appreciated.

MAIN LIMITATIONS

Small patient sample size, lack of follow-up past 72 h or histopathology.

CONCLUSIONS

Analgesia duration was extended and pain scores improved postoperatively with LB versus BHCl in a dose-dependent fashion. Further clinical evaluation of extended-duration local anaesthetics in horses for improved postoperative pain management is warranted.

Scoping review of quality of anesthetic induction and recovery scales used for dogs

OBJECTIVE

To compare, describe and assess the level of validation of all instruments measuring quality of induction and recovery from anesthesia in dogs.

DATABASES USED

A search was performed using the electronic database PubMed to find articles containing an induction quality scale, a recovery quality scale or both in dogs. Articles not directly accessible through PubMed were obtained through the Auburn University Library website and Google Scholar. The phrases 'induction scoring systems dogs', 'recovery scoring systems dogs', 'anesthetic induction score dogs', and 'anesthetic recovery score dogs' were used for searches using the 'best match search' function. The time frame searched was from 1980 to May 2020. The search was conducted from March 2020 to May 2020.

CONCLUSIONS

A thoroughly tested and validated scale for measuring the quality of induction and recovery does not exist in the current veterinary literature. A large disagreement exists between studies on the use of induction and recovery scales, and many have reported inconsistent results with current instruments. It is recommended that an induction and recovery scale intended for wide-scale use be constructed and tested extensively for psychometric validation and reliability.

Effects of fentanyl-lidocaine-ketamine versus sufentanil-lidocaine-ketamine on the isoflurane requirements in dogs undergoing total ear canal ablation and lateral bulla osteotomy

OBJECTIVE

To compare the isoflurane-sparing effects of sufentanil-lidocaine-ketamine (SLK) and fentanyl-lidocaine-ketamine (FLK) infusions in dogs undergoing total ear canal ablation and lateral bulla osteotomy (TECA-LBO).

STUDY DESIGN

Randomized blinded clinical study.

ANIMALS

A group of 20 client-owned dogs undergoing TECA-LBO.

METHODS

Intravenous (IV) administration of lidocaine (3 mg kg^-1) and ketamine (0.6 mg kg^-1) with fentanyl (5.4 μg kg^-1; n = 10; FLK group) or sufentanil (0.72 μg kg^-1; n = 10; SLK group) was immediately followed by the corresponding constant rate infusion (CRI) (lidocaine 3 mg kg^-1 hour^-1; ketamine 0.6 mg kg^-1 hour^-1; either fentanyl 5.4 μg kg^-1 hour^-1 or sufentanil 0.72 μg kg^-1 hour^-1). Anaesthesia was induced with propofol 3-5 mg kg^-1 IV and was maintained with isoflurane. End-tidal isoflurane concentration (Fe'Iso) was decreased in 0.2% steps every 15 minutes until spontaneous movements were observed (treated with propofol 1 mg kg^-1 IV) or an increase of > 30% in heart rate or mean arterial pressure from baseline occurred (treated with rescue fentanyl or sufentanil). Quality of recovery and pain were assessed at extubation using the short-form Glasgow Composite Pain Scale (SF-GCPS), Colorado State University Canine Acute Pain scale (CSU-CAP), and visual analogue scale (VAS). Data were analysed with analysis of variance, t tests, Fisher test and Spearman coefficient (p < 0.05).

RESULTS

Fe'Iso decreased significantly in SLK group (45%; p = 0.0006) but not in FLK (15%; p = 0.1135) (p = 0.0136). SLK group had lower scores for recovery quality (p = 0.0204), SF-GCPS (p = 0.0071) and CSU-CAP (p = 0.0273) than FLK at extubation. Intraoperative rescue analgesia and VAS were not significantly different between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Compared with FLK infusion, CRI of SLK at these doses decreased isoflurane requirements, decreased pain scores and improved recovery quality at extubation in dogs undergoing TECA-LBO.

Description of a new approach for great auricular and auriculotemporal nerve blocks: A cadaveric study in foxes and dogs

Otitis externa is a painful condition that may require surgical intervention in dogs. A balanced analgesia protocol should combine systemic analgesic agents and local anaesthesia techniques. The aim of the study was to find anatomical landmarks for the great auricular and the auriculotemporal nerves that transmit nociceptive information from the ear pinna and to develop the optimal technique for a nerve block. The study consisted of two phases. In phase I, one fox cadaver was used for dissection and anatomical localization of the auricular nerves to derive landmarks for needle insertion. Eight fox cadavers were subsequently used to evaluate the accuracy of the technique by injecting methylene blue bilaterally. In phase II findings from phase I were applied in four Beagle canine cadavers. A block was deemed successful if more than 0.6 cm of the nerve's length was stained. Successful great auricular nerve block was achieved by inserting the needle superficially along the wing of the atlas with the needle pointing towards the jugular groove. For the auriculotemporal nerve block the needle was inserted perpendicular to the skin at the caudal lateral border of the zygomatic arch, close to the temporal process. The overall success rate was 24 out of 24 (100%) and 22 out of 24 (91%) for the great auricular and the auriculotemporal nerves, respectively, while the facial nerve was stained on three occasions. Our results suggest that it is feasible to achieve a block of the auricular nerves, based on anatomical landmarks, without concurrently affecting the facial nerve.

Variability of performance of wound infusion catheters

OBJECTIVE

To compare the distribution of flow from two commercial and one handmade multihole wound infusion catheters.

STUDY DESIGN

Open label experimental measurement of flow distribution in a bench top apparatus of handmade (n = 10) and two commercial (n = 10 each) wound infusion catheters with 5-6'' (12-15.2 cm) long diffusion surfaces.

METHODS

The distribution of 6 mL of distilled water injected at three different injection speeds (0.5, 5, and 120 minutes) through individual triangular pieces of felt cloth fitted over six contiguous regions of the diffusion surface of each catheter was measured in triplicate.

RESULTS

The distribution of flow through the six regions was significantly more uniform at the two faster injection speeds. Ninety two per cent of the 120 minute infusion trials resulted in one or more regions producing negligible flow (<5% of total output), and in 16% of the 120 minute trials all the flow came from just one or two regions.

CONCLUSIONS

Constant-rate infusions of 3 mL hour(-1) provide erratic distribution of flow from wound infusion catheters in a bench top apparatus. Commercial catheters did not outperform handmade catheters.

CLINICAL RELEVANCE

Uneven distribution of flow at low infusion speeds may contribute to inconsistent or unsatisfactory pain relief in patients treated with continuous wound infusions of local anesthetics.

Analgesic management of an eight-year-old Springer Spaniel after amputation of a thoracic limb

Analgesic agents were administered perioperatively to an eight-year-old Springer Spaniel undergoing amputation of its right thoracic limb. The amputation was carried out due to a painful, infiltrative and poorly differentiated sarcoma involving the nerves of the brachial plexus. A combination of pre-emptive and multimodal perioperative analgesic strategies was used; including intravenous (IV) infusions of fentanyl, morphine, lidocaine and ketamine.

Analgesia for the critically ill dog or cat: an update

Acute pain reliably accompanies severe illness and injury, and when sufficiently severe, it can complicate the recovery of critically ill patients. Because acute pain is closely tied to the neurologic process of nociception, pharmacologic therapy is often essential and effective. This update focuses on two methods of treatment of acute pain-local anesthetic infusion and continuous intravenous infusion of multimodal agents-that can be layered on top of standard care with other drugs.

Evaluation of a balloon constant rate infusion system for treatment of septic arthritis, septic tenosynovitis, and contaminated synovial wounds: 23 cases (2002–2005)

OBJECTIVE-To determine clinical findings and outcome in horses treated by means of a balloon constant rate infusion system. DESIGN-Retrospective case series. ANIMALS-23 horses. PROCEDURES-Medical records of horses examined at The Ohio State University veterinary teaching hospital from 2002 to 2005 that had septic arthritis, septic tenosynovitis, or penetration of a synovial structure and in which treatment involved a balloon constant rate infusion system were searched. Information pertaining to signalment, history, physical examination findings, clinicopathologic data, treatment, and duration of hospitalization was recorded. RESULTS-Mean+/- SD duration of hospitalization was 11.5+/-5.26 days. No correlation between duration of clinical signs and duration of hospitalization or duration of infusion pump use was detected, but correlations between WBC count and duration of hospitalization and WBC and duration of infusion-pump use were observed. All horses survived to discharge. Follow-up information was obtained on 17 horses, 16 of which were alive at the time of follow-up. Twelve of 13 horses for which followup information was available for at least 5 months were alive 5 months or longer after discharge. Thirteen of the 16 horses alive at follow-up were reported by owners as not lame, whereas the remaining 3 were mildly lame or intermittently moderately lame or had developed angular limb deformity in the contralateral limb. CONCLUSIONS AND CLINICAL RELEVANCE-Balloon constant rate infusion systems may be used effectively in treatment of septic arthritis, septic tenosynovitis, and contaminated synovial wounds. Clinical response and long-term outcome appeared to be comparable to results obtained with other techniques.