Local and regional anesthesia

Pain Mitigation Strategies for Disbudding in Goat Kids

Pain mitigation strategies for disbudding in goat kids have gained significant attention in recent years because of growing concerns for animal welfare. Disbudding, the removal of horn buds in young goats, is a common practice to enhance safety and manage herd dynamics. However, the procedure will cause pain and distress if not managed effectively. This review covers the array of pain mitigation techniques currently available for disbudding, including the efficacy of these strategies in reducing pain and stress during the disbudding process, with specific attention to the potential toxicity associated with local anesthetics. The current best practice for disbudding on the farm suggests sedation/analgesia with an alpha-2 agonist, the placement of a two-point cornual nerve block, and then an NSAID for postoperative pain. In conclusion, this review offers recommendations for future research directions aimed at enhancing the welfare of young goats subjected to the disbudding procedure. These suggestions hold the promise of fostering significant improvements in the overall well-being of these animals.

Image analysis comparison of nerve staining with food dye, methylene blue or tissue marker

OBJECTIVE

Novel locoregional techniques use dye studies to confirm successful nerve targeting. The goal was to objectively quantify and compare nerve staining characteristics of dye mixtures commonly reported in the literature using image analysis software.

STUDY DESIGN

Prospective, randomized cadaveric study.

METHODS

Thirty-six brachial plexus nerves from unpreserved pig cadavers were randomized into three groups of 12: FD (1:10 mixture of blue food dye and bupivacaine 0.5%), MB (methylene blue 1%) and TM (0.1:10 mixture of blue tissue marker and lidocaine 2%). Nerves were immersed in dye for 1, 15, 30 or 60 minutes (n = 3 each). Images of nerves before immersion (baseline) and at each time point with epineurium intact (superficial staining) and after longitudinal bisection (deep staining) were processed using image analysis software. Color saturation values were divided into quartiles (dark, medium-dark, medium-light or light). Percentage of stained nerve area in each quartile was calculated and compared using two-way anova.

RESULTS

Superficially, at minute 1, dark saturation covered 40% of nerve area in FD versus 19% in MB (p = 0.04) and 0% in TM (p < 0.0001). In bisected nerves, dark and medium-dark saturations occurred only in FD; medium-light saturation comprised anywhere from 4% to 22.5% over time in FD versus <1% at any time in MB (p = 1.000; p = 0.343; p = 0.383; p = 0.262). Deep staining was not found in TM at any point.

CONCLUSION AND CLINICAL RELEVANCE

Food dye rapidly stains superficial and deep nerve layers. Based on these characteristics, investigators can choose the appropriate dye for their study.

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.

Update on the anatomy of the brachial plexus in dogs: Body weight correlation and contralateral comparison in a cadaveric study

A thorough knowledge of the anatomy of the brachial plexus is pivotal for diagnostic, therapeutic and anaesthetic purposes in order to correctly locate the nerve and reduce the incidence of complications when performing surgery or a local anaesthetic block of the brachial plexus. In this study, the anatomy of the brachial plexus in dogs was reviewed; the depth and diameter of each nerve were evaluated, and the contralateral limbs were compared. Eighteen canine cadavers were included and were divided into: small (SB); medium (MB) and large (LB) breed dogs. After dissection, the spinal roots and the suprascapular, subscapular, axillary, radial, ulnar, median, and musculocutaneous nerves were identified. The following evaluations were recorded: the origin of the nerves from the spinal roots, the roots and the nerve diameters, and the distance of the nerves root from the skin at the level of the scapula-humeral joint and from the interscapular region. A total of thirty-six brachial plexuses were evaluated; all originated from the ventral rami of the C6 to T1 spinal nerves. In the LB dogs, the root and the nerve diameters were larger as compared with the other two groups. In this group, also the mean distance of T1 from the skin at the level of the scapula-humeral joint and the average distance of the nerve roots from the skin of the interscapular region were also greater as compared with the other groups. No significant differences were recorded between the contralateral limbs. In the dogs in the present study, the origin of the nerves of the brachial plexus were similar to those previously reported; however, the presence of minor individual variations was confirmed between the right and the left limbs within the same dog between the right and the left limb. This is the first time that the diameters and the depth of the nerves have been described and positively correlated with body weight.

Treatment of Pain in Rats, Mice, and Prairie Dogs

Recent myomorph and scuiromorph rodent analgesia studies are reviewed and evaluated for potential clinical application. Differences between laboratory animal studies and clinical use in diseased animals are discussed. Analgesia classes reviewed include local anesthetics, nonsteroidal anti-inflammatories, acetaminophen, opioids, and adjuvants such as anticonvulsants. Routes of administration including sustained-release mechanisms are discussed, as are reversal agents. Drug interactions are reviewed in the context of beneficial multimodal analgesia as well as potential adverse effects. Dosage recommendations for clinical patients are explored.

Comparison of intraperitoneal and incisional lidocaine or ropivacaine irrigation for postoperative analgesia in dogs undergoing major abdominal surgeries

This study compared the postoperative analgesic efficacy of intraperitoneal and incisional lidocaine versus ropivacaine in dogs undergoing major abdominal surgeries. Dogs randomly received intraperitoneal lidocaine irrigation (4 mg kg-1, diluted to 5 ml kg-1, L group), ropivacaine (4 mg kg-1, diluted to 5 ml kg-1, R group) or 0.9% saline (5 ml kg-1, C group). Prior to skin closure, dogs received incisional lidocaine 2 mg kg-1 (group L), incisional ropivacaine 2 mg kg-1 (group R) or incisional saline 0.2 ml kg-1 (group C). Pain was assessed at different time points up to 24 hours after extubation, using the Short Form-Glasgow Composite Measure Pain Scale and VAS Scale. In group C, postoperative pain scores were significantly higher than in groups L and R from T0.5 to T6 (p < 0.05). In R group, postoperative pain scores were significantly lower than in groups L and C from T12 to T24 (p < 0.05). Rescue analgesia was administered to 5/11 dogs in L group, 1/10 dogs in R group and 8/10 dogs in C group. Groups L and R experienced a significantly lower postoperative pain during the first 6 hours after extubation, compared with group C. Ropivacaine provided lower postoperative pain scores than lidocaine and saline up to 24 hours after extubation. According to the obtained results, ropivacaine seemed to provide better and longer lasting postoperative analgesia compared with lidocaine. Therefore, intraperitoneal and incisional administration of ropivacaine in dogs undergoing major abdominal surgeries is recommended.

Evaluation of the Two-Point Ultrasound-Guided Transversus Abdominis Plane Block for Laparoscopic Canine Ovariectomy

The transversus abdominis plane (TAP) block causes desensitization of the abdominal wall and peritoneum. Of all the approaches proposed to perform it, the two-injection-point TAP showed the best results in terms of the area reached by the anesthetic solution. However, to date, no clinical data exist. The aim of this study was to evaluate the intra- and postoperative analgesic efficacy of a two-injection-point TAP block in dogs undergoing laparoscopic ovariectomy. A total of 26 animals were assigned to receive general inhalation anesthesia (control group), and 26 dogs were assigned to general inhalation anesthesia combined with TAP block (TAP group). The ultrasound-guided TAP block was carried out with a subcostal and cranial-to-ilium injection per hemiabdomen. The end-tidal concentration of isoflurane (EtISO) was recorded at different moments during the surgery. Postoperative pain was assessed at different time points during the first 24 h after surgery. The control group required significantly higher EtISO concentration during the ovarian resection and showed higher postoperative pain scores than the TAP group. Fewer dogs in the TAP group required intra- or postoperative rescue analgesia. TAP block can be implemented to improve postoperative pain management after laparoscopy, reducing the dosage of the systemic drugs used and, hence, their possible side effects.

Pharmacokinetics of Bupivacaine Following Administration by an Ultrasound-Guided Transversus Abdominis Plane Block in Cats Undergoing Ovariohysterectomy

Bupivacaine is commonly used for peripheral nerve block in veterinary medicine. This study described the pharmacokinetics of two doses of bupivacaine following administration by an ultrasound-guided transversus abdominis plane (TAP) block in cats undergoing ovariohysterectomy. Twelve healthy female adult cats were included in a randomized, prospective, blinded clinical trial. Anaesthetic protocol included acepromazine–buprenorphine–propofol–isoflurane–meloxicam. Each cat received 1 mL/kg of bupivacaine 0.2% or 0.25% (BUPI-2 and BUPI-2.5, respectively) via bilateral two-point TAP block before surgery (n = 6/group). Plasma concentrations of bupivacaine were detected using liquid chromatography-mass spectrometry. A one-compartment model and non-compartmental analysis described the pharmacokinetic parameters. Bupivacaine was detected up to 480 min (335 ± 76 in BUPI-2 and 485 ± 198 ng/mL in BUPI-2.5). For BUPI-2 and BUPI-2.5, maximum plasma concentrations were 1166 ± 511 and 1810 ± 536 ng/mL at 33 ± 14 and 47 ± 22 min, clearance was 5.3 ± 1.8 and 4.9 ± 1.5 mL/min/kg, and elimination half-life were 253 ± 55 and 217 ± 52 min, respectively. The two doses of bupivacaine via TAP block produced concentrations below toxic levels in cats. A dose of 2.5 mg/kg bupivacaine was safe to be administered using this block in healthy cats.

Evaluation of intraperitoneal administration of morphine on post-operative pain management after ovariohysterectomy in dogs

The present prospective randomized experimental study was designed to assess pain control with intraperitoneal morphine following ovariohysterectomy in dogs. A group of 12 mixed breed female dogs, aged 1-2 years, weighing 19.95 ± 0.95 kg were included. Forty minutes after sedation with 0.05 mg/kg intramuscular acepromazine 1%, anaesthesia was induced with propofol (4 mg/kg). The dogs were connected to the inhalation anaesthesia circuit using isoflurane. Ovariohysterectomy was performed, and before the closure of linea alba, the animals received intraperitoneal morphine (0.5 mg/kg) (in group M) and saline (0.2 ml/kg) (in group S). No significant difference was detected in total protein and glucose levels between the groups, while the cortisol level in group M was significantly lower than group S 1, 3 and 6 h after surgery. Furthermore, the comparison of the rectal temperature, heart rates and respiratory rates showed no major differences. Additionally, no significant alterations were detected between the groups considering the changes in the pain scores with simple descriptive score, Glasgow, University of Melbourne pain scale, sedation status and Sammarco methods. Finally, three cases in group S and two cases in group M were given an intramuscular analgesic rescue dose of morphine. Although a significant decline was observed in cortisol levels following intraperitoneal morphine administration, there were no beneficial changes in the efficiency of post-operative analgesia in status and clinical signs compared to the control group. Further studies are required to investigate intraperitoneal morphine effectiveness in post-operative pain management.

The effect of splash block on the need for analgesia in dogs subjected to video-assisted ovariectomy

Objectives

The present study aimed to demonstrate the efficacy of splash block using lidocaine to provide additional analgesia during ovariectomy in bitches. To identify an acute intraoperative nociceptive response, three clinical parameters were used: increased blood pressure, heart rate and respiratory rate.

Material and Methods

Forty healthy bitches were randomly assigned to receive 2% lidocaine (L group) topical application (splash block) on both ovaries (2 mg/kg each), or an equal volume of NaCl 0.9% at the same sites (C group). A fentanyl bolus (2 µg/kg) was administered intraoperatively in response to an increase in blood pressure, heart rate or respiratory rate during surgery (> 30% compared with the pre‐incisional values).

Results

Local lidocaine administration significantly reduced the need for supplementary fentanyl. Dogs in the L group showed greater intraoperative hemodynamic stability and lower surgical pain than those in the C group. In addition to the routine anaesthetic protocol, the local anaesthesia used in the present study was safe and caused no cardiopulmonary suppression. In addition, it significantly reduced the need for mandatory systemic or rescue analgesia.

Clinical Significance

Ovariectomy is a common surgical procedure in bitches. Analgesia during this procedure is important because intraoperative pain can cause negative effects that prevent patient recovery. This study aimed to demonstrate the analgesic efficacy of lidocaine splash block in video‐assisted ovariectomy in dogs. The results showed that splash block improved surgical analgesia during canine laparoscopic ovariectomy. Considering its relative simplicity, low cost, and safety, splash block could be used in daily clinical practice.

Evaluation of Targeted Bupivacaine, Bupivacaine-lidocaine-epinephrine, Dexamethasone, and Meloxicam for Reducing Acute Postoperative Pain in Cats Undergoing Routine Ovariohysterectomy

This study compared bupivacaine (BUP), bupivacaine-lidocaine-epinephrine (BLE), dexamethasone (DEX), and meloxicam (MEL) targeted at specific, potentially painful sites for reducing acute postoperative pain in cats undergoing elective ovariohysterectomy. One hundred fifty-one cats were included in a prospective, randomized, double-blinded clinical trial. Anesthesia consisted of a standardized protocol including buprenorphine, ketamine, dexmedetomidine, and isoflurane. A ventral midline ovariohysterectomy was performed, and cats were administered targeted injections of 0.5% bupivacaine (2 mg/kg); a combined 0.25% bupivacaine (1 mg/kg), 1% lidocaine (2 mg/kg), and 1:100,000 epinephrine (0.005 mg/kg); dexamethasone (0.125 mg/kg); or meloxicam (0.2 mg/kg) intraoperatively at the ovarian suspensory ligaments, uterine body, and incisional subcutaneous tissues. A 0-10 Numeric Pain Rating Scale (NRS) was used to assess cats postoperatively, 1 hour and 3 hours after anesthesia recovery prior to a same day discharge. Pain scores among evaluators were in good agreement with an overall Intraclass Correlation Coefficient (ICC) of 0.7897 (95% Confidence Interval 0.795-0.8313).  In all groups, overall pain scores 1-hour post anesthesia recovery were significantly higher than scores 3 hours post anesthesia recovery (P < .0001). Averaged pain scores compared among treatment groups did not differ at 1 hour post recovery. At 3-hours post anesthesia recovery, MEL group cats had significantly lower pain scores than the BLE group (P = .018). Study results indicate that early postoperative pain scores were similar for cats receiving local infiltrations of BUP, BLE, DEX, and MEL as part of a multimodal pain therapy for routine ovariohysterectomies. MEL showed somewhat better results 3 hours post anesthesia recovery, gaining significance over the BLE group.

Age and Sex Variation in the Duration of Action and Corneal Touch Threshold (CTT) following Instillation of 0.5% Topical Ophthalmic Proparacaine and Tetracaine Hydrochlorides

PURPOSE

We investigated the effect of age and sex on corneal touch threshold (CTT) and duration of action following administration of 0.5% topical ophthalmic proparacaine and tetracaine hydrochlorides.

METHODS

A prospective, randomized, subject-masked, crossover study design was used. Two hundred and forty human volunteers were enrolled in the study. Corneal touch threshold (CTT) was determined using a Cochet-Bonnet esthesiometer. CTT was measured every 15 seconds for the first 1-minute and at 5-minute intervals subsequently for a period of 40 minutes after the application of each anesthetic. CTT and duration of action of the ophthalmic solutions were tested for statistical significance using repeated measures ANOVA.

RESULTS

The total duration of effect was 20 minutes for females and 25 minutes for males for both anesthetics. The total duration of the effect of both solutions decreased with increasing age; however, elderly participants had the longest duration (5 minutes) of the maximal effect (minimum CTT) of the two ophthalmic preparations. There was a significant influence of sex, F (2.39, 569.65) = 2.86, p=0.04; F (3.48, 828.19) = 4.41, p=0.003, and age, F (4.78, 566.18) = 8.97, p < 0.001; F (7.19, 852.56) = 20.55, p < 0.001 on CTT following application of proparacaine hydrochloride and tetracaine hydrochloride, respectively.

CONCLUSION

CTT and duration of anesthetic effect after instillation of 1 drop of 0.5% proparacaine hydrochloride and 0.5% tetracaine hydrochloride vary based on sex and age.

Analgesic efficacy of intrathecal morphine and bupivacaine during the early postoperative period in patients who underwent robotic-assisted laparoscopic prostatectomy: a prospective randomized controlled study

Background

The present study was performed to investigate the analgesic efficacy of intrathecal morphine and bupivacaine (ITMB) in terms of treating early postoperative pain in adult patients who underwent robotic-assisted laparoscopic prostatectomy (RALP).

Methods

Fifty patients were prospectively enrolled and randomly classified into the non-ITMB (n = 25) and ITMB (n = 25) groups. The ITMB therapeutic regimen consisted of 0.2 mg morphine and 7.5 mg bupivacaine (total 1.7 mL). All patients were routinely administered the intravenous patient-controlled analgesia and appropriately treated with rescue intravenous (IV) opioid drugs, based on the discretion of the attending physicians who were blinded to the group assignments. Cumulative IV opioid consumption and the numeric rating scale (NRS) score were assessed at 1, 6, and 24 h postoperatively, and opioid-related complications were measured during the day after surgery.

Results

Demographic findings were comparable between patients who did and did not receive ITMB. The intraoperative dose of remifentanil was lower in the ITMB group than in the non-ITMB group. Pain scores (i.e., NRS) at rest and during coughing as well as cumulative IV opioid consumption were significantly lower in patients who received ITMB than in those who did not in the post-anesthesia care unit (PACU; i.e., at 1 h after surgery) and the ward (i.e., at 6 and 24 h after surgery). ITMB was significantly associated with postoperative NRS scores of ≤ 3 at rest and during coughing in the PACU (i.e., at 1 h after surgery) before and after adjusting for cumulative IV opioid consumption. In the ward (i.e., at 6 and 24 h after surgery), ITMB was associated with postoperative NRS scores of ≤ 3 at rest and during coughing before adjusting for cumulative IV opioid consumption but not after. No significant differences in complications were observed, such as post-dural puncture headache, respiratory depression, nausea, vomiting, pruritus, or neurologic sequelae, during or after surgery.

Conclusion

A single spinal injection of morphine and bupivacaine provided proper early postoperative analgesia and decreased additional requirements for IV opioids in patients who underwent RALP.

Trial registration: Clinical Research Information Service, Republic of Korea; approval number: KCT0004350 on October 17, 2019. https://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=15637

Influence of peri-incisional epaxial muscle infiltration with bupivacaine pre- or post-surgery on opioid administration in dogs undergoing thoraco-lumbar hemilaminectomy

This study investigated the influence of bupivacaine infiltration before or after hemilaminectomy on peri-operative opioid requirement in dogs. Thirty dogs undergoing T3-L3 hemilaminectomy were randomly assigned to receive peri-incisional infiltration of bupivacaine 2 mg/kg into the epaxial muscles before surgery (Group A), at wound closure (Group B), or no infiltration (Group C). Anaesthesia comprised dexmedetomidine 4 mcg/kg and methadone 0.3 mg/kg IV (premedication), alfaxalone IV (induction), and isoflurane in oxygen (maintenance). All dogs received meloxicam SC/PO prior to induction of general anaesthesia. Response to surgery, defined as a change in autonomic physiological variables >20% above baseline, was treated with fentanyl 2.5 mcg/kg boluses, followed by a continuous rate infusion of fentanyl at 5 mcg/kg/h. The Glasgow Composite Pain Score-Short Form (GCPS-SF) was performed before premedication and at regular intervals until 24 h postoperatively. Methadone 0.2 mg/kg analgesia was given IV if GCPS-SF was ≥5/20. Number of intraoperative, postoperative and total analgesic interventions were recorded. Analgesic interventions were analysed using a chi-squared test using a Pocock approach and statistical significance was set at P < 0.029. The number of intra-operative analgesic interventions in Group A (median, 0; range, 0-2), was significantly lower than in Group B (median, 3; range, 0-5) and Group C (median, 3; range, 0-5; P = 0.019). Regarding postoperative interventions, there were significantly fewer in Group A (median, 0; range, 0-1) and Group B (median, 0; range, 0-1) than in Group C (median, 1; range, 0-2; P = 0.047). Group A (median, 0; range, 0-3), had significantly fewer total analgesic interventions than Group B (median, 3; range, 0-6) and Group C (median, 4; range, 1-7; P = 0.014). Bupivacaine reduced peri-operative opioid administration and pre-surgical peri-incisional infiltration yielded the greatest benefit.

The Immediate Effect of Trigger Point Injection With Local Anesthetic Affects the Subsequent Course of Pain in Myofascial Pain Syndrome in Patients With Incurable Cancer by Setting Expectations as a Mediator

A trigger point injection (TPI) with local anesthetic in myofascial pain syndrome (MPS) often has the immediate effect of a decrease in pain. It is unknown whether the immediate effect of a decrease in pain affects the subsequent course of pain. It is also unknown whether expectations of a decrease in pain mediate such effects. We aimed to clarify how the effect of a decrease in pain immediately after TPI with local anesthetic affected the subsequent course of pain, and whether it increased expectations of a decrease in pain. This was a prospective, single-center, observational clinical trial. Patients with incurable cancer who visited the palliative care department and received TPI with local anesthetic for MPS were prospectively examined. We evaluated whether the immediate effect of a TPI with local anesthetic affects the subsequent course of pain in MPS by setting expectations as a mediator, using path analysis. From 2018 to 2020, 205 patients with incurable cancer received TPI for MPS. Of these, 58.1% of patients reported an immediate effect of decreased pain. Compared with the non-immediate effect group, the immediate effect group had higher expectations of a decrease in pain, and the higher expectation was maintained at 7 days (p < 0.001). The percentage of patients with pain reduction at 7 days after TPI was 88.2% in the immediate effect group and 39.5% in the non-immediate effect group (p < 0.001). The immediate effect of decreased pain had the greatest influence on pain reduction at 7 days, both directly (β = 0.194) and indirectly through increased expectations (β = 0.293), as revealed by path analysis. The effect of a decrease in pain immediately after TPI with local anesthetic affected the subsequent course of MPS pain in patients with incurable cancer by setting expectations as a mediator. There were limitations to the discussion of these findings because this was an observational study.

Clinical techniques in veterinary dermatology: regional anaesthesia of the canine and feline distal limb

BACKGROUND

Local anaesthesia for procedures involving the distal limb are a useful component of balanced protocols to achieve effective procedural analgesia for patients. A ring block is an effective and straightforward technique.

HYPOTHESIS/OBJECTIVE

To review and describe the ring block technique for local anaesthesia of the canine and feline distal limb.

ANIMALS

Images of hospitalized patients were used. These photographs were obtained with owner permission.

RESULTS

The clinical technique for the ring block of the canine or feline distal limb is described.

CONCLUSIONS AND CLINICAL IMPORTANCE

The ring block can be implemented simply and successfully for a variety of procedures involving the distal limb to provide effective analgesia.

Comparison of liposomal bupivacaine and 0.5% bupivacaine hydrochloride for control of postoperative pain in dogs undergoing tibial plateau leveling osteotomy

OBJECTIVE

To compare liposome-encapsulated bupivacaine (LEB) and (nonliposomal) 0.5% bupivacaine hydrochloride (0.5BH) for control of postoperative pain in dogs undergoing tibial plateau leveling osteotomy (TPLO).

ANIMALS

33 client-owned dogs.

PROCEDURES

In a randomized clinical trial, dogs undergoing TPLO received LEB (5.3 mg/kg [2.4 mg/lb]) or 0.5BH (1.5 mg/kg [0.68 mg/lb]) by periarticular soft tissue injection. All dogs received carprofen (2.2 mg/kg [1 mg/lb], SC, q 12 h) beginning at extubation. Signs of pain were assessed at extubation and predetermined times up to 48 hours later with the Colorado State University-Canine Acute Pain Scale and Glasgow Composite Pain Scale-Short Form. A pressure nociceptive threshold device was used at the affected stifle joint before surgery and at 5 postoperative time points. Methadone (0.1 mg/kg [0.05 mg/lb], IV) was administered if the Colorado State University pain scale score was ≥ 2 (scale, 0 to 4). Surgical variables; pain scores; pressure nociceptive thresholds; times to first administration of rescue analgesic, first walk, and first meal consumption; and total opioid administration were compared between treatment groups.

RESULTS

28 dogs completed the study. Dogs administered LEB were less likely to require rescue analgesia and received lower amounts of opioids than dogs administered 0.5BH. There were no significant intergroup differences in other measured variables.

CONCLUSIONS AND CLINICAL RELEVANCE

The LEB appeared to provide adequate analgesia after TPLO with lower requirements for opioid treatments, which may allow dogs to be discharged from the hospital earlier than with traditional pain management strategies.

Efficacy of greater auricular and auriculotemporal nerve blocks performed in rabbits

OBJECTIVE

To evaluate the efficacy, duration and safety of greater auricular and auriculotemporal nerve blocks in rabbits.

STUDY DESIGN

Prospective, randomized, crossover, experimental study.

ANIMALS

A total of 11 healthy adult Dutch-belted rabbits.

METHODS

The rabbits underwent general anesthesia and injections of the greater auricular and auriculotemporal nerves using either bupivacaine (0.3 mL kg^-1, 0.5%) or the same volume of saline. After anesthesia, the efficacy and duration of nerve blocks were assessed using analgesiometry forceps on the pinna and cotton-tipped applicators within the vertical ear canal. Rabbits were monitored for abnormal carriage of the ear and auriculopalpebral nerve block of the ipsilateral eye. Body weight, food intake, fecal output and fecal pellet diameter were measured daily for 6 days after the nerve blocks were performed and compared with baseline to assess short-term effects.

RESULTS

The greater auricular nerve was successfully blocked in 12/16 (75%) ears for mean ± standard deviation duration of 88 ± 52 minutes. In successfully blocked ears, altered ear position was noted in five/16 (31%) cases. The auriculotemporal nerve was blocked in one/16 ears for 120 minutes. The auriculopalpebral nerve was inadvertently blocked in three/16 ears. Food intake and fecal output decreased significantly during the treatment day but returned to pretreatment values after 24 hours. There was no change in body weight or fecal pellet diameter for either treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

The results suggest that duration of the greater auricular nerve block with 0.5% bupivacaine was short-lived in the live rabbit. Auriculotemporal nerve block was only achieved in one ear; therefore, further studies are warranted to evaluate the contribution of these blocks in the pain management of rabbits undergoing auricular surgery.

Anatomy of the Brachycephalic Canine Hard Palate and Treatment of Acquired Palatitis Using CO2Laser

The goal of this article is to review the anatomy of the brachycephalic canine hard palate and provide a step-by-step guide on diagnosis and treatment of acquired palatitis using the CO2surgical laser. Brachycephalic breed-related defects are not only limited to the upper airways, some dogs may develop secondary systemic or localized problems. An abnormality that is over-represented in some breeds such as boxers and bulldogs is prominent palatal rugae. The greater depth of the palatal rugae allows for the entrapment of plaque, food debris and hair. Thus, acquired palatitis or granulomatous lesions may develop. This oral pathology and its consequences are commonly neglected by the owners and frequently missed by the veterinarians. Scientific evidence-based diagnosis and treatment for this breed-related oral pathology are absent in the veterinary literature. This article is the first in providing the elements needed for an adequate morphological characterization of the canine hard palate, allowing veterinarians to appropriately identify anomalous areas of the soft tissue component of the hard palate. This article illustrates the use of a noninvasive surgical technique to prevent and cure the sequelae associated with anomalous palatal rugae. The CO2surgical laser provides a suitable method by offering the fast resolution of the lesions and permanent results.

Clinical comparison of two techniques of brachial plexus block for forelimb surgery in dogs

The objective of this study was to compare two different local anaesthesia techniques for intraoperative analgesia in dogs undergoing surgical procedures distal to the mid humeral diaphysis. Thirty-two dogs were divided into two groups: the US group received an ultrasound-guided brachial plexus block at the level of the first rib and the N group received a neurostimulation-guided paravertebral brachial plexus block. Ropivacaine 0.75% at 1.5mg/kg was injected in each case. Dogs were monitored during the surgical procedure, and rescue analgesia was administered whenever the heart rate, respiratory rate or blood pressure increased more than 20% from the basal values. Success rate was defined as no need for rescue analgesia during surgery and complete blockade of the operated leg evaluated just after anaesthesia recovery. Complications were also recorded. Data was analysed using Fisher exact and Mann/Whitney tests. Success rate was observed in 14/16 (87%) dogs and in 12/16 (75%) dogs in the US and N groups, respectively (P=0.65). Complications recorded were hypotension in three cases (US group, n=1; N group, n=2) and Horner's syndrome in three cases (US group, n=1; N group, n=2; P=0.65). Both techniques were found to provide good level of analgesia that allowed performing the orthopaedic procedures from the mid humeral diaphysis and distal in the limb, without the need for further analgesia.

Evaluation of targeted bupivacaine for reducing acute postoperative pain in cats undergoing routine ovariohysterectomy

Objectives

This study sought to determine if bupivacaine targeted at specific, potentially painful sites could enhance postoperative analgesia in routine feline ovariohysterectomies. A secondary objective was to assess the utility of multiple acute pain scales for cats in a high-volume surgery setting.

Methods

Two hundred and twelve cats were included in a prospective, randomized, double-blinded, placebo-controlled clinical trial. Anesthesia included buprenorphine, ketamine, dexmedetomidine and isoflurane. A ventral midline ovariohysterectomy was performed and cats were administered bupivacaine (2 mg/kg), placebo control (0.9% saline) or sham control (observation only) intraoperatively at the ovarian suspensory ligaments and vessels, uterine body and incisional subcutaneous tissues. Two pain scales were used to assess cats postoperatively. Initially, a multidimensional composite pain scale (MCPS) and a 0–10 numeric pain rating scale (NRS) were used. Subsequently, the MCPS was replaced with a modified Colorado State University Feline Acute Pain Scale (mCSU). Pain scores for the test groups were compared using a one-way ANOVA and a Holm–Bonferroni post hoc analysis when a difference was found ( P <0.05).

Results

Pain for the bupivacaine group was lower than the control groups at 1 h post-recovery and discharge, attaining significance with higher body weights. The P values were 0.008 and 0.004 for 1 h post-recovery and discharge, respectively. Pain scores between evaluators for the MCPS and NRS correlated poorly with r values for 1 h post-recovery and discharge of −0.08 and 0.22, respectively. Additionally, the MCPS proved difficult to use and time consuming, especially for feral and fractious patients, and was replaced with the mCSU.

Conclusions and relevance

Targeted bupivacaine reduced early postoperative pain scores following routine feline ovariohysterectomies. The technique used was simple, requiring just over a minute to perform at minimal additional cost. The MCPS was not ideal for use in a high-volume spay setting.

Regional anesthetic techniques for the pelvic limb and abdominal wall in small animals: A review of the literature and technique description

Increasing interest in using peripheral nerve blocks in small animals is evident, given the numerous studies published recently on this topic in important veterinary journals. Initially, research was focused on intraoperative analgesia to the pelvic limb, and several descriptions of lumbosacral plexus, femoral and sciatic nerve blocks have been described in studies. There is recent interest in developing techniques for somatosensory blockade of the abdominal wall. This article is the second part of a two-part review of regional anesthesia (RA) in small animals, and its aim is to discuss the most relevant studies in the veterinary literature, where objective methods of nerve location have been used, and to illustrate in pictures the currently used techniques for providing RA to the abdominal wall and the pelvic limb in small animals.

Intramuscular infiltration of a local anesthetic, lidocaine, does not result in adverse behavioural side effects in rainbow trout

Fish are a useful animal model for research, but our improvement in some aspects of their welfare has not kept pace with their increased popularity for this use. For example, researchers rarely use analgesics. We evaluated the side effects of lidocaine, a local anesthetic widely used in human and veterinary medicine. We infiltrated lidocaine on each side of the dorsal fin (total 20 mg/kg) of young rainbow trout (15 fish per group) compared with infiltration with an equal volume of saline. We monitored behaviour of individual trout during the 4-hour trial. Food was presented 5 times during the trial (30 min, 1 h, 2 h, 3 h, 4 h after infiltration) and we analyzed behaviour for 1 minute before and after food presentation. Behaviour of Saline-Infiltrated trout compared with trout that received no infiltration showed that infiltration in and of itself had no statistically significant effects on trout behaviour. However, there were many statistically significant effects of Lidocaine-Infiltrated trout compared with Saline-Infiltrated trout; none of the side-effects were adverse.

Combination of Transversus abdominis plane block and Serratus plane block anesthesia in dogs submitted to masctetomy

ABSTRACT: This paper pretends to demonstrate the effect of the combination of transversus abdominis plane block (TAP block) and Serratus plane block (SP block) techniques in analgesia of 4 dogs undergoing total unilateral mastectomy. Dogs were premedicated with methadone (0.5mg.kg-1) intramuscularly. Anesthesia was induced with propofol (6mg.kg-1) and midazolam (0.3mg.kg-1) and maintained with isoflurane. SP and TAP block were performed unilaterally using ultrasound by the injection of bupivacaine 0.25% (0.3mL kg-1) diluted with NaCl solution 1:1. Heart rate (HR), respiratory rate (f), non-invasive arterial pressure, esophageal temperature (T), oxygen saturation (SpO2) and electrocardiogram were monitored continuously. Animals were monitored for two and four hours after extubation for pain by using the Canine Acute Pain Scale from Colorado State University. Two hours after extubation, tramadol (4mg.kg-1) and dipyrone (25mg.kg-1) was administered to all dogs. It was not observed any alteration on cardiac rhythm. HR, f, T and mean arterial pressure remained below the preincisional values for all dogs. No dog required intraoperative rescue analgesia. Recovery from anesthesia was without any complication. All animals scored 0 (0/5) at pain scale, two and four hours after extubation and none of them expressed concern over the surgical wound. Dogs were able to walk before two hours after extubation. The combination of both techniques is effective in anesthetic blocking the thoracic and abdominal walls and it is suggested both may be included in the multimodal analgesia protocols for this type of surgery.

Effect of intrafragmentary bupivacaine (haematoma block) on analgesic requirements in dogs undergoing fracture repair

OBJECTIVE

To test the efficacy of intraoperative intrafragmentary administration of bupivacaine (haematoma block) in controlling postoperative pain in dogs undergoing osteosynthesis of long-bone isolated diaphyseal fractures.

STUDY DESIGN

Randomized, 'blinded', placebo-controlled, prospective study.

ANIMALS

A total of 23 client-owned dogs with isolated long-bone fractures.

METHODS

Dogs were allocated randomly to two groups: bupivacaine group (B) or placebo group (P). Group B dogs (n = 11) were administered an intraoperative intrafragmentary injection of 0.5% bupivacaine (1.1 mg kg^-1) just before fracture fixation, whereas group P dogs (n = 12) were administered normal saline. Postoperative pain evaluations using the University of Melbourne Pain Scale (UMPS) and algometer were performed upon arrival to the recovery room and 1, 2, 4, 6, 8, 20 and 32 hours later. Algometer measurements were performed on: the incision site, a healthy region near the fracture line and the contralateral healthy limb. When the pain score exceeded 14 points in the UMPS, rescue analgesia was administered. The time-standardised area under the curve (AUCst) was used to compare UMPS scores and mechanical pain thresholds between the two groups.

RESULTS

None of the group B dogs required rescue analgesia, whereas eight of the 12 group P dogs did (p = 0.001). The pain threshold AUCst at the incision line was higher in group B [16.3 (2.9-41.6) N] than in group P [5.6 (2.5-17.4) N] (p = 0.029). The mean UMPS score AUCst was lower in group B (3.7 ± 1.8) than in group P (9.4 ± 4.6) (p = 0.016). In a small number of animals of both groups that were evaluated radiologically, adequate bone healing was noted.

CONCLUSIONS AND CLINICAL RELEVANCE

An intraoperative bupivacaine haematoma block is a simple, quick and effective method that can be used to aid in postoperative pain control in dogs submitted to long-bone osteosynthesis.

Evaluation of intraoperative analgesia provided by incisional lidocaine and bupivacaine in cats undergoing ovariohysterectomy

Objectives

The objective of this study was to assess the intraoperative analgesic effect of preoperative infiltration of the incision site with lidocaine or a mixture of lidocaine with bupivacaine in cats undergoing ovariohysterectomy (OHE).

Methods

This was a prospective, randomised clinical study. Healthy female intact cats (n = 75) undergoing OHE under medetomidine–ketamine–buprenorphine anaesthesia were assigned randomly into three treatment groups (n = 25 per group) to receive one of two local anaesthesia protocols or placebo preoperatively in the midline incision: lidocaine 1.5 mg/kg (group GL) or mixture of lidocaine 1 mg/kg and bupivacaine 1 mg/kg (group GLB) or sodium chloride 0.9% (control group). Blood pressure, heart and respiratory rate, temperature, muscle tonus and pupillary reflex were registered during surgery. During recovery, the cats were observed for side effects. Postoperative analgesia was provided with meloxicam (0.2 mg/kg). Most cats were rechecked 2 weeks postoperatively to remove skin sutures.

Results

There was no significant difference between groups regarding breed, age, body weight, surgical time and postoperative complication rate. The majority of the cats (60%) included in the control group received a supplemental bolus of propofol during surgery, when compared with 43% and 44% of the cats included in the GL and GLB groups, respectively. Heart rate was significantly higher ( P <0.05) in the control group at the time of excision of the second ovary and the uterine body. Mean arterial pressure (MAP) was stable in both treatment groups; in contrast, it tended to increase in the control group. Heart rate and MAP were similar between treatment groups.

Conclusions and relevance

Preoperative incisional block with only lidocaine or combined with bupivacaine seems to produce a similar intraoperative analgesia in cats undergoing OHE. Despite the similar intraoperative analgesic effect between treatment groups, the combination of lidocaine and bupivacaine reduced the required doses, and had a faster onset of action and prolonged effect.

Objective Measures for the Assessment of Post-Operative Pain in Bos indicus Bull Calves Following Castration

Simple Summary

Surgical castration of cattle is a common husbandry procedure, and although this procedure is known to cause pain in cattle and other species, in some countries it is often performed without anaesthesia or analgesia. Society is increasingly aware of this animal welfare issue and it is creating pressure to drive research into animal welfare science with the aim of identifying practical and economical approaches to pain management in livestock. To effectively manage pain, a pain assessment must be performed. Pain assessment methods are often subjective and therefore influenced by the observer. Ideally, objective assessments that generate consistent and repeatable results between observers should be identified. Bos indicus bull calves were divided into four groups: no castration (NC, n = 6); castration with pre-operative local anaesthetic (CL n = 12); castration with pre-operative anti-inflammatory medication (CM, n = 12); and, castration without pain relief (C, n = 12). A range of objective assessments was performed: bodyweight measurements, activity, and rest levels, and four different compounds in the blood. The results of this study suggest that animals rest for longer periods after the pre-operative administration of anti-inflammatory medication. The other objective assessments measured in this study were not able to consistently differentiate between treatment groups. These findings emphasise the need for alternative quantifiable and objective indicators of pain in Bos indicus bull calves.

Abstract

The aim of the study was to assess pain in Bos indicus bull calves following surgical castration. Forty-two animals were randomised to four groups: no castration (NC, n = 6); castration with pre-operative lidocaine (CL, n = 12); castration with pre-operative meloxicam (CM, n = 12); and, castration alone (C, n = 12). Bodyweight was measured regularly and pedometers provided data on activity and rest from day −7 (7 days prior to surgery) to 13. Blood was collected for the measurement of serum amyloid A (SAA), haptoglobin, fibrinogen, and iron on days 0, 3 and 6. Bodyweight and pedometry data were analysed with a mixed effect model. The blood results were analysed with repeated measure one-way analysis of variance (ANOVA). There was no treatment effect on bodyweight or activity. The duration of rest was greatest in the CM group and lowest in the C group. There was a significant increase in the concentrations of SAA, haptoglobin, and fibrinogen in all of the groups from day 0 to 3. Iron concentrations were not different at the time points it was measured. The results of this study suggest that animals rest for longer periods after the pre-operative administration of meloxicam. The other objective assessments measured in this study were not able to consistently differentiate between treatment groups.

Assessing cow-calf welfare. Part 1: Benchmarking beef cow health and behavior, handling; and management, facilities, and producer perspectives

Assessment programs are one way beef producers communicate information about animal welfare to retailers and the public. Programs that monitor cattle through the production cycle (e.g., the Global Animal Partnership) or at individual stages (e.g., slaughter; the North American Meat Institute) exist, but to date, there is no assessment program addressing welfare specifically in the cow-calf sector. The objectives of this study were to measure cow-calf health and handling welfare outcomes and gather management, facility, and producer perspective information to 1) describe current practices and 2) inform assessment design. A welfare assessment, designed using features of similar beef and dairy programs, was conducted on 30 California ranches that varied in size (mean 1,051 cows [SD 1,849], range 28 to 10,000 cows) and location within the state. Cattle health and behavior and stockperson handling were measured during a routine procedure (e.g., pregnancy checks) on breeding females ( = 3,065). Management and producer perspectives were evaluated through an interview, and facility features were recorded at the chute and water access points. Cattle health problems were rare and seen only on specific ranches (e.g., prevalence of lame cattle: mean 1.3% [SD 1.5], range 0 to 7.1%). Cattle behavior and stockperson handling varied between ranches (e.g., cattle balking: mean 22.0% [SD 21.9], range 1.6 to 78.3%; electric prod use: mean 23.5 [SD 21.5], range 0 to 73.0%). Although some management and facility characteristics were shared by most (e.g., all ranches castrated bull calves; 86% used alleyways with an anti-back gate), other aspects varied (e.g., weaning age: mean 8.2 mo [SD 1.4], range 6 to 11 mo; 43% used shade cover over chute). Most producers shared similar perspectives toward their herd health management plan, but their responses varied when asked to evaluate an animal's pain experience. In terms of assessment design, there were challenges with feasibility (e.g., scheduling a ranch visit on a day cattle were processed was difficult), validity (e.g., cattle may back up calmly to adjust posture or quickly in response to an aggressive handler; without this context, the welfare implications of this behavior are unclear), and comparability (e.g., an explicit animal observation period needed to be defined to make comparisons across ranches). Future assessment programs should consider these qualities when selecting measures to evaluate welfare.

Defining local nerve blocks for feline distal pelvic limb surgery: a cadaveric study

Objectives

Anatomical and methodological detail is lacking regarding local anesthetic peripheral nerve block techniques for distal pelvic limb surgery in cats. The aim of this study was to develop, describe and test nerve block methods based on cadaveric dissections and dye injections.

Methods

Ten pairs of feline pelvic limbs (n = 20) were dissected and the tibial nerve (T n.), common fibular (peroneal) nerve (CF n., and its two branches, the superficial fibular [peroneal] nerve [SpF n.] and the deep fibular [peroneal] nerve [DpF n.]) and the saphenous nerve (Sa n.) were identified. Based on these dissections, a ‘distal crus block’ (selective blockade of the CF n., T n. and Sa n.) and a ‘distal pes block’ (selective blockade of the SpF n., DpF n., T n. and Sa n.) were developed for surgical procedures in two different regions of the distal pelvic limb. Techniques were tested using new methylene blue (NMB) dye injections in feline pelvic limbs (n = 12). Using a 25 G × 5/8 inch needle and 1 ml syringe, 0.1 ml/kg of NMB dye solution was injected at the site of the CF n., and 0.05 ml/kg was injected at the sites of the SpF n., DpF n., Sa n. and T n. The length and circumference (fully or partially stained) of each stained nerve were measured.

Results

Positive staining of nerves was observed in 12/12 limbs. The lengths stained for the CF n., DpF n., SpF n., Sa n. and T n. were 27.19 ± 7.13, 20.39 ± 5.57, 22.82 ± 7.13, 30.89 ± 6.99 and 25.16 ± 8.09 mm, respectively. The nerves were fully stained in 12, 12, 10, 11 and 11 out of 12 limbs, respectively.

Conclusions and relevance

These two, three-point injection methods may be an effective perioperative analgesia technique for feline distal pelvic limb procedures.

[Comparison of ultrasound guided femoral and sciatic nerve block versus epidural anaesthesia for orthopaedic surgery in dogs]

OBJECTIVE

Comparison of ultrasound-guided femoral and sciatic nerve block versus epidural anaesthesia with bupivacaine and morphine for orthopaedic surgery of the pelvic limb in dogs with respect to analgesic effectiveness, clinical utility and side effects.

MATERIAL AND METHODS

The study included 22 dogs (American Society of Anesthesiologists, ASA grades I and II) undergoing orthopaedic surgery distal to the mid-femoral bone. The study was designed as a randomized, prospective, blinded clinical trial. All dogs were randomly assigned to receive 0.5 mg/kg bupivacaine (0.5%) and 0.1 mg/kg morphine sulphate (1%) either as epidural anaesthesia (group EPI) or by ultrasound-guided femoral and sciatic nerve block (group LA). During surgery, the heart rate, respiratory rate, mean arterial pressure (MAP), end-tidal isoflurane concentrations and dose of rescue analgesia (fentanyl boluses of 5 µg/kg i. v.) were measured. Pain severity was scored (short form of the Glasgow Composite Measure Pain Scale, GCMPS) before surgery and postoperatively at 2, 4, 6, 12 and 24 hours after extubation. Post-operative rescue analgesia consisted of methadone (0.2 mg/kg i. v.), and was applied when the GCMPS > 6. For statistical analysis, the Chi-square, Fisher, and Wilcoxon tests and one- and two-way ANOVA were applied. Differences were considered statistically significant at p < 0.05.

RESULTS

Only the MAP was significantly different between the two treatment groups. Intra- and postoperative MAP of group LA (111.2 ± 11.2 mmHg and 119.3 ± 18.2 mmHg, respectively) was higher than in group EPI (86.6 ± 8.7 mmHg and 95.2 ± 13.1 mmHg, respectively). None of the dogs developed urinary retention or ambulatory deficits when completely recovered from anaesthesia. No other side effects were noted.

CLINICAL RELEVANCE

In conclusion, femoral and sciatic nerve blocks and epidural anaesthesia ensure comparable analgesic effects in canine patients undergoing orthopaedic surgery of the pelvic limb. The lower mean arterial blood pressure of group EPI was not of clinical relevance.

Comparison of lidocaine and lidocaine-epinephrine for the paravertebral brachial plexus block in dogs

OBJECTIVE

To compare the motor and sensory block efficacy and duration of a modified paravertebral brachial plexus block (PBPB) after administration of lidocaine alone (LI) or combined with epinephrine (LE).

STUDY DESIGN

Prospective, randomized, blinded, crossover study.

ANIMALS

A total of eight healthy female Beagle dogs.

METHODS

Under general anesthesia, modified PBPB was performed on the left thoracic limb using neurostimulation and/or ultrasound guidance to administer lidocaine (2 mg kg^-1; 0.2 mL kg^-1) either alone (treatment LI, n = 10) or with epinephrine (1:100,000; treatment LE, n = 9). Sensory block was evaluated through reaction to a painful mechanical stimulus applied at five sites on the limb. Motor block effect was evaluated according to visual gait assessments and thoracic limb vertical force measurements under dynamic and static conditions. Data were analyzed using repeated-measures generalized estimating equations. All statistical tests were performed two-sided at the α = 0.05 significance threshold.

RESULTS

The duration of sensory block did not differ significantly between treatments. Visible gait impairment was more persistent in LE than in LI (118 ± 63 minutes for LI and 163 ± 23 minutes for LE; mean ± standard deviation) (p = 0.027). At nadir value, dynamic peak vertical force was lower in LE than in LI (p = 0.007). For both dynamic and static evaluations, the nadir and the return to baseline force were delayed in LE (return to normal at 180-200 minutes) when compared with LI (130-140 minutes) (p < 0.005).

CONCLUSIONS AND CLINICAL RELEVANCE

The addition of epinephrine to lidocaine prolonged the duration and increased the intensity of the regional block, as verified by visual gait assessment and kinetic analysis. No significant difference was noted between treatments regarding sensory blockade. Kinetic analysis could be useful to evaluate regional anesthetic effect in dogs.

Cardioprotective effects of curcumin-loaded magnetic hydrogel nanocomposite (nanocurcumin) against doxorubicin-induced cardiac toxicity in rat cardiomyocyte cell lines

Curcumin, is a yellow substance extracted from Curcuma longa rhizomes, it is a crystalline compound that has been traditionally applied in culinary practices and medicines in India. The aim of our study is to demonstrate the efficacy of curcumin-loaded magnetic hydrogel nanocomposite in the treatment of heart hypertrophy. 10 rats weighing 150-200 g each were induced with heart failure using 2.5 mg/kg doxorubicin for 2 weeks. The test groups were treated with curcumin-loaded magnetic hydrogel nanocomposite while the control was treated with curcumin alone. malondialdehyde (MDA) levels, superoxide dismutase (SOD), and glutathione peroxidase (GPX) enzymes activities were monitored after two weeks of last the dose. In addition, the expression of three heart failure markers; atrial natriuretic peptide (ANP), B type natriuretic peptide (BNP), and beta major histocompatibility complex (β-MHC) were observed, it was found that the expression of these markers decreases with an increase in the concentration of curcumin (P < 0.05). Curcumin elevated the decreased level of GPX and SOD, and reduced the elevated level of MDA in cardiac tissue. We suggest this combination to be a potent therapy for heart failure and hypertension in the nearest future.

Pilot, randomized, placebo-controlled clinical field study to evaluate the effectiveness of bupivacaine liposome injectable suspension for the provision of post-surgical analgesia in dogs undergoing stifle surgery

BACKGROUND

Local anesthetics are an important component of perioperative pain management, but the duration of action of available products is limited. We hypothesized that a single local infiltration of a novel bupivacaine liposome injectable suspension (AT-003) would provide clinically effective analgesia over a 72-h period. In a masked, randomized, placebo-controlled, multi-center pilot field study, dogs undergoing lateral retinacular suture placement for cranial cruciate insufficiency were randomly assigned to surgical site infiltration with AT-003 (5.3 mg/kg) or an equivalent volume of saline. Infiltration of the surgical site was done prior to closure. Primary outcome measure was the Glasgow Composite Measure Pain Scale (CMPS-SF) assessed prior to surgery and at 2, 4, 8, 12, 24, 30, 36, 48, 54, 60 and 72 h following surgery by trained individuals. Provision for rescue analgesia was employed. Repeated measures analysis of variance were utilized to test for possible differences between treatment groups and a success/failure analysis was also employed, based on the need for rescue analgesia.

RESULTS

Forty-six dogs were enrolled and evaluated. For CMPS-SF scores there was a significant overall treatment effect (p = 0.0027) in favor of AT-003. There were significantly more successes in the AT-003 group compared to placebo over each time period (p = 0.0001 for 0-24 h, p = 0.0349 for 0-48 h, and p = 0.0240 for 0-72 h). No significant adverse events were seen.

CONCLUSIONS

AT-003 (bupivacaine liposome injectable suspension) provided measurable local analgesia over a 72-h period following post-stifle surgery surgical site tissue infiltration. Further work is indicated to develop this product for clinical use.

Evaluation of an ultrasound-guided technique for axillary brachial plexus blockade in cats

Objectives

The aim of this study was to evaluate and refine an ultrasound (US)-guided technique to block the brachial plexus (BP) at the level of the axillary space in live cats.

Methods

Eight adult experimental cats were enrolled into the study. The animals were sedated and positioned in dorsal recumbency with the limb to be blocked abducted 90º. The US transducer was placed in the axillary region and a non-traumatic peripheral nerve block needle was inserted in-plane with respect to the transducer, medial to the BP up to the level of the axillary artery. Lidocaine 1% (0.4 ml/kg) was injected as the needle was being progressively withdrawn in a caudal-to-cranial direction. The efficacy of the block was confirmed by evaluation of the motor and sensory functions of the blocked forelimb. Motor blockade was assessed observing the position of the blocked leg on standing and walking patterns. Sensory blockade was evaluated by the stimulation of mechanical nociceptors in the dermatomes supplied by the four major sensory nerves of the distal thoracic limb.

Results

The BP was successfully located by US in all cases. The achieved BP block was complete in six cats (75%) and partial in the remaining two cats (25%). All animals recovered uneventfully from the sedation and the BP blocks.

Conclusions and relevance

The US-guided block at the axillary space evaluated in this study is a feasible, reproducible and safe technique to block the BP plexus in experimental live cats.

[Perioperative pain therapy in dogs and cats - an overview]

Undermanaged pain leads to negative systemic effects that may greatly disturb our patients' welfare. Therefore, a pain assessment tool should be routinely implemented into clinical practice. Validated pain assessment tools are available for dogs and cats. Advanced analgesic therapy follows the principle of a multimodal approach. This means that different analgesic drugs, which act on different targets within the nociceptive pathway, are combined to achieve the desired analgesic effects. In addition to opioids, nonsteroidal anti-inflammatory drugs and local anaesthetics, α2-receptor-agonists, ketamine and gabapentin as well as different nonpharmacologic analgesic techniques are used within the framework of a multimodal analgesic plan.

Unilateral retrobulbar hematoma following maxillary nerve block in a dog

OBJECTIVE

To describe the clinical findings and management of a case of retrobulbar hematoma formation secondary to performance of a maxillary nerve block in a dog.

CASE SUMMARY

An 11-year-old dog was presented for a routine dental procedure including dental extraction to be performed under general anesthesia. After premedication with intramuscular methadone, anesthesia was induced with intravenous alfaxalone until depth of anesthesia was sufficient to allow orotracheal intubation. Anesthesia was maintained with isoflurane delivered in 100% oxygen. A bilateral maxillary nerve block was performed. During administration of the left nerve block, blood was aspirated. Twenty minutes after placement of the left maxillary nerve block, exophthalmos, periorbital swelling, extensive scleral hemorrhage, and ecchymosis with a 2 × 2 cm region of moderate swelling on the palatal mucosa around the injection site were noted. These lesions were the result of retrobulbar hematoma formation following vessel puncture. Treatment included immediate creation of a drainage tract and administration of anti-inflammatories (carprofen 2 mg/kg PO q 12 h for 7 days), broad spectrum antimicrobial therapy (cefovicin 8 mg/kg SC once), and eye drops (viscotears, 2 drops OS q 12 h for 7 days). The periorbital swelling was significantly reduced within 1 hour of drainage and had almost completely resolved 1 week later.

NEW OR UNIQUE INFORMATION PROVIDED

This clinical report details the development and successful management of a unilateral retrobulbar hemorrhage following maxillary nerve block. Management of this condition requires prompt recognition and treatment to prevent permanent damage to the eye. The cornerstone of treatment is drainage, which rapidly decreases the increased intraorbital and intraocular pressure. To our knowledge, this is the first documentation of this complication in the English language literature.