Peripheral nerve block versus systemic analgesia in dogs undergoing tibial plateau levelling osteotomy: Analgesic efficacy and pharmacoeconomics comparison

A comparative analysis of opioid-free and opioid-sparing anaesthesia techniques for laparoscopic ovariectomy in healthy dogs

OBJECTIVE

To compare the perioperative analgesic effects of an opioid-free (OFA) and an opioid-sparing (OSA) anaesthetic protocol in dogs undergoing laparoscopic ovariectomy.

STUDY DESIGN

Prospective, randomized, blinded, clinical trial.

ANIMALS

A group of 28 client-owned dogs.

METHODS

Dogs were allocated to one of two groups. The OFA group was administered intramuscular (IM) dexmedetomidine 5 μg kg-1 and ketamine 1 mg kg-1, followed by two intraoperative constant rate infusions (CRIs) of dexmedetomidine (3 μg kg-1 hour-1) and lidocaine (1 mg kg-1 loading dose, 2 mg kg-1 hour-1). The OSA group was administered IM dexmedetomidine 5 μg kg-1, ketamine 1 mg kg-1 and methadone 0.2 mg kg-1, followed by two intraoperative saline CRIs. In both groups, anaesthesia was induced with intravenous (IV) propofol 2 mg kg-1 and diazepam 0.2 mg kg-1 and maintained with isoflurane. Rescue dexmedetomidine (0.5 μg kg-1) was administered IV if there was a 20% increase in cardiovascular variables compared with pre-stimulation values. Ketorolac (0.5 mg kg-1) was administered IV when the surgery ended. Postoperative analgesia was evaluated using the Short Form-Glasgow Composite Measure Pain Scale and methadone (0.2 mg kg-1) was administered IM if the pain score was ≥ 6/24. Statistical analysis included mixed analysis of variance, Chi-square test and Mann-Whitney U test.

RESULTS

There were no significant differences in the intraoperative monitored variables between groups. The OFA group showed a significantly lower intraoperative rescue analgesia requirement (p = 0.016) and lower postoperative pain scores at 3 (p =0.001) and 6 (p < 0.001) hours. No dogs were administered rescue methadone postoperatively.

CONCLUSIONS AND CLINICAL RELEVANCE

Although both groups achieved acceptable postoperative pain scores with no need for further intervention, the analgesic efficacy of the OFA protocol was significantly superior to that of the OSA protocol presented and was associated with a lower intraoperative rescue analgesia requirement and early postoperative pain scores.

A comparison of the motor effects and analgesic efficacy following lumbar plexus block combined with sciatic nerve block or epidural in dogs undergoing tibial plateau leveling osteotomy

OBJECTIVE

To compare motor effects and analgesic efficacy following an ultrasound-guided lateral approach to lumbar plexus blockade at L7 and sciatic nerve blockade (LPSNB) against epidural injection in dogs undergoing tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Prospective, randomized, blinded clinical trial.

ANIMALS

A total of 27 healthy adult dogs undergoing unilateral TPLO surgery.

METHODS

Dogs were allocated to either LPSNB (bupivacaine 2 mg kg-1, 0.75%) or epidural (morphine PF 0.1 mg kg-1 and bupivacaine 0.5 mg kg-1, 0.75%). Other aspects of clinical management were identical, including anesthetic drug protocol, area of presurgical clipping and bladder care. Time to perform the block, response to surgical stimuli, pain scores, rescue analgesia, time to stand and walk, motor score and time to first urination were recorded. One evaluator, unaware of treatment status, performed all evaluations. Student's t-test or Mann-Whitney U test was used to compare continuous variables between groups, and Fisher's exact test for categorical variables.

RESULTS

Median (range) times to stand and walk were shorter for LPSNB [60 (40-120) minutes and 90 (60-150) minutes, respectively, p = 0.003] than for epidural [150 (120-240) minutes and 180 (120-360) minutes, respectively, p = 0.006]. Four dogs required rescue intraoperatively (three in epidural group, one in LPSNB group, p = 0.438). Pain scores over the 24 hour evaluation period were similar, and not significantly different, for each group. Time to spontaneous urination [LPSNB, 330 (240-360) minutes; epidural, 300 (120-1440) minutes, p = 1.0] did not differ between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

An ultrasound-guided lateral paravertebral approach to the lumbar plexus within the psoas compartment at L7, combined with sciatic nerve blockade, allows faster return to normal motor function, with similar pain control and impact on urination when compared with epidural in dogs after TPLO surgery.

Evaluation of the addition of adrenaline in a bilateral maxillary nerve block to reduce hemorrhage in dogs undergoing sharp staphylectomy for brachycephalic obstructive airway syndrome. A prospective, randomized study

OBJECTIVE

To assess the use of adrenaline (0.00198%) in a bilateral maxillary nerve block to reduce intraoperative hemorrhage in dogs undergoing staphylectomy for the treatment of brachycephalic obstructive airway syndrome (BOAS).

STUDY DESIGN

Prospective, randomized, double-blinded controlled study.

SAMPLE POPULATION

A total of 32 client owned, clinically affected dogs undergoing a cut and sew sharp staphylectomy for treatment of BOAS. A total of 16 dogs randomly assigned to adrenaline (A) group and 16 to no-adrenaline (NA) group.

METHODS

A bilateral maxillary nerve block was performed in all dogs prior to staphylectomy using lidocaine alone (group NA) or a combination of lidocaine and adrenaline (group A). Total hemorrhage was measured by weighing cotton-tipped applicators and swabs used on precision scales. In addition, a semi-quantitative hemorrhage score (1-5) was determined. Dogs were monitored for intraoperative hemodynamic stability during the procedure.

RESULTS

Total hemorrhage was significantly (p = .013) lower in group A compared with group NA. The median semi-quantitative hemorrhage score was significantly lower for group A (p = .029) compared with group NA. No significant adverse effects were noted due to adrenaline usage.

CONCLUSION

This study demonstrated that the use of adrenaline in a bilateral maxillary nerve block results in significantly lower intraoperative hemorrhage during cut and sew sharp staphylectomy and appeared safe to use.

CLINICAL SIGNIFICANCE

Potential clinical advantages include improved visualization, prevention of unnecessary blood loss and reduction in risk of blood aspiration.

Saphenous and Sciatic Nerve Blockade with and without Obturator Nerve Block for Tibial Plateau Levelling Osteotomy Surgery in Dogs: A Randomized Controlled Trial

The objective of our study was to compare the efficacy of sciatic and saphenous ultrasound nerve blocks with and without US-guided obturator nerve block in dogs undergoing tibial-plateau-levelling-osteotomy (TPLO) surgery. This study was developed in two phases: identification of an ultrasound window in the inguinal region for obturator nerve block and utilization of it in dogs undergoing TPLO. Dogs were assigned randomly to one of two groups: one received the three blocks with 0.5% ropivacaine (ON group) and the second one (NoON group) with NaCl instead of ropivacaine for the obturator block. In phase 1, the obturator nerve was visible between the pectineus and the abductor muscles and was approached using an in-plane technique. It was possible to use the ultrasound window for phase two. The number of dogs that received at least one bolus of intraoperative rescue analgesia in the NoON group (12/15 dogs) was significantly higher (p = 0.003) in comparison with the ON group (4/15). An ultrasound window to block the obturator nerve in the inguinal compartment with an in-plane technique was found. The use of this approach could produce adequate analgesia with less motor function impairment in dogs for TPLO surgery.

Incidence of postoperative administration of opioids in dogs undergoing a tibial plateau leveling osteotomy after intra-operative liposomal bupivacaine administration with or without morphine epidural

OBJECTIVE

To determine the influence of two intraoperative pain management protocols on the need for additional opioids in patients receiving an epidural and periarticular liposomal bupivacaine (PLB) vs. PLB alone in the 12-24 h period after undergoing a TPLO.

STUDY DESIGN

Retrospective study.

ANIMALS

One hundred seventy-four dogs with cranial cruciate ligament tears presenting for TPLO.

METHODS

Medical records of dogs presenting for a unilateral or bilateral cranial cruciate ligament tear who had a TPLO performed were reviewed for signalment, weight, body condition score, and peri-operative pain management protocol. Dogs were divided into two groups: those who received an epidural and PLB, and those who received only PLB. Post-operative opioid administration was recorded for each group.

RESULTS

Patients who received an epidural and PLB received fewer postoperative opioids. There were 36% fewer opioid injections administered to dogs who received epidurals compared to dogs who did not receive epidurals (IRR) (95% CI) = 0.64 (0.45-0.92), P = 0.02). BCS was not a significant predictor of the post-operative opioid requirement (IRR (95% CI) = 1.3 (0.75-2.4), P = 0.38). When adjusting for BCS as a possible confounder, there were 39% fewer opioid injections in dogs who received epidurals than dogs without (IRR (95% CI) = 0.61 (0.42-0.88), P = 0.009).

CONCLUSIONS

The incidence of postoperative opioid administration was significantly diminished in patients receiving both an epidural and PLB.

CLINICAL SIGNIFICANCE

Administration of an epidural in addition to infiltration of PLB significantly decreased the incidence of postoperative opioid administration in dogs undergoing a TPLO.

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.

Efficacy of dexmedetomidine as adjuvant to bupivacaine in femoral-sciatic nerve blocks in dogs undergoing tibial plateau levelling osteotomy (TPLO)

The aim of this randomized, prospective clinical study was to evaluate the efficacy of dexmedetomidine combined with bupivacaine on sciatic and femoral nerve blocks in dogs. Thirty dogs were selected for elective unilateral tibial plateau levelling osteotomy, and each subject was assigned randomly to receive perineural bupivacaine 0.5% (0.1 mL/kg) and intramuscular dexmedetomidine (0.5 μg/kg) in the BDs group, perineural bupivacaine 0.5% (0.1 mL/kg) plus dexmedetomidine (0.5 μg/kg) in the BDloc group, and perineural bupivacaine 0.5% (0.1 mL/kg) plus intramuscular administration of saline solution the in Bupi group. Nerve blocks were guided by electrolocation. The main intraoperative parameters were registered 10 min before the start of surgery (BASE) and during the skin incision (SKIN), the osteotomy (BONE) and the suture (SUTURE). At 2, 4, 6, 8, 10, 15, 20 and 24 h after blocks, the Glasgow Composite Pain scale (GPCs) was used to identify the degree of pain during the postoperative period. Patients with scores ≥5/20 received rescue analgesia and were excluded. Furthermore, heart rate, mean arterial pressure, footstep capacity, reaction to wound touch and femoral and sciatic skin sensitivity were registered. Parametric data were compared at each time point of the study with the one-way ANOVA for repeated measures and Fisher's test for yes/no variables analysis (p < 0.05). No subject required intraoperative rescue analgesia. In BDloc group, the GCPs score was <5/20 for all dogs at all times of the study, and 70% of dogs did not need systemic analgesia. In the Bupi and BDs groups, 100% of subjects achieved a score ≥ 5/20 between 8 and 10 h after the blocks, and 100% of subjects showed femoral and sciatic skin sensitivity and required rescue analgesia within 10 h. Our results showed that the addition of dexmedetomidine as an adjuvant to bupivacaine in SF blocks may prolong the sensory block and ensure sufficient analgesia for up to 24 h in dogs undergoing TPLO surgery.

Development of Enhanced Recovery After Surgery (ERAS) protocols in veterinary medicine through a one-health approach: the role of anesthesia and locoregional techniques

Enhanced Recovery After Surgery (ERAS) is a new and emerging concept in human medicine that involves rethinking the preoperative, intraoperative, and postoperative periods. The ultimate, overarching aim is to improve patient outcome following surgery and, thus, return to a normal daily routine as soon as possible. The development and implementation of locoregional anesthetic techniques in humans is one of the key elements driving these protocols. In veterinary medicine, we are no exception: the rapidly growing interest, development, and refinement of these techniques in our veterinary species is changing the way we think of anesthesia and analgesia. The potential real benefits are yet to be determined, as this concept is implemented into our veterinary hospitals in general, and our surgical patients in particular, in a more systematic and routine way. In this article, we will introduce the reader to the concept of ERAS protocols and the role of regional anesthesia in some common surgical procedures.

Evaluation of the Iatrogenic Sciatic Nerve Injury following Double Pelvic Osteotomy Performed with Piezoelectric Cutting Tool in Dogs

(1) Background: The double pelvic osteotomy (DPO) is a prophylactic surgical procedure associated with 0.4% incidence of sciatic nerve injury. The piezoelectric cutting tool is a surgical device able to involve only mineralized tissue avoiding neurovascular tissue and other soft tissue. This study aimed to evaluate the sciatic nerve injury observed in dogs underwent iliac osteotomy performed using the piezoelectric cutting tool. (2) Methods: Dogs underwent DPO performed with piezoelectric cutting tool were included. Neurological assessment was performed 6 and 24 h after surgery and then repeated 12 days, 4 and 8 weeks after surgery. Temporary and or permanent sciatic nerve injury were recorded. (3) Results: 84 DPOs performed in fifty dogs were included. No temporary/permanent neurological disease associated with iatrogenic damage of the sciatic nerve were observed. (4) Conclusions: The iliac osteotomy performed with piezoelectric cutting tool was not associated to iatrogenic sciatic nerve injury.

A comparison of 0.375% ropivacaine psoas compartment block and 2% prilocaine spinal anaesthesia in dogs undergoing tibial plateau levelling osteotomy

BACKGROUND

In dogs undergoing routine elective orthopaedic surgeries carried out as same-day surgeries regional anaesthetic techniques (RATs) should aim to produce analgesia but minimising the postoperative motor dysfunction. Our objective was to compare the perioperative analgesic effects and the time to motor recovery between spinal anaesthesia (SA) with hyperbaric solution of prilocaine 2% (mg = 4 x [0.3 × BW (kg) + 0.05 × SCL (cm)]) and morphine (0.03 mg/kg) and combined ultrasound (US) and electro stimulator-guided psoas compartment and ischiatic nerve block (PB) with ropivacaine 0.375% (0.45 mL/kg). Dogs undergoing tibial plateau levelling osteotomy (TPLO) were randomly assigned to receive either SA or PB. Procedural failure, perioperative rescue analgesia, motor block recovery and complications were recorded.

RESULTS

Procedural failure rate (PFR) was 19% (7 out of 36) for SA and 9% (3 out of 32) for PB (p = 0.31). Intraoperative rescue analgesia was administered to 6/29 (21%) SA group dogs and in 15/29 (52%) PB group dogs, respectively (p = 0.03). At 3 h after RAT, percentage of dogs with complete block recovery was 25/29 (86%) and 25/29 (86%) in group SA and PB, respectively (p = 1). Two cases of pruritus and one case of urinary retention were recorded in the SA group. Residual ischiatic nerve block was noted at 12 h after RAT in 2/15 (13%) of dogs in group PB; it completely resolved 24 h after RAT.

CONCLUSIONS

SA with prilocaine 2% and PB with ropivacaine 0.37% were found suitable for dogs undergoing same-day TPLO surgery. Pruritus and urinary retention in SA and residual block in both groups might occasionally delay the time of discharge.

Clinical efficacy of dexmedetomidine combined with lidocaine for femoral and sciatic nerve blocks in dogs undergoing stifle surgery

OBJECTIVE

To evaluate the effects of dexmedetomidine administered perineurally or intramuscularly (IM) on sensory, motor function and postoperative analgesia produced by lidocaine for sciatic and femoral nerve blocks in dogs undergoing unilateral tibial tuberosity advancement surgery.

STUDY DESIGN

Prospective, blinded, clinical study.

ANIMALS

A group of 30 dogs.

METHODS

Dogs were anaesthetized with acepromazine, propofol and isoflurane in oxygen/air. Electrolocation-guided femoral and sciatic nerve blocks were performed: group L, 0.15 mL kg^-1 2% lidocaine (n = 10); group LD_loc, lidocaine and 0.15 μg kg^-1 dexmedetomidine perineurally (n = 10); group LD_sys, lidocaine and 0.3 μg kg^-1 dexmedetomidine IM (n = 10). After anaesthesia, sensory blockade was evaluated by response to forceps pinch on skin innervated by the saphenous/femoral, common fibular and tibial nerves. Motor blockade was evaluated by observing the ability to walk and proprioception. Analgesia was monitored with Short Form of Glasgow Composite Pain Scale for up to 4 hours after extubation. Methadone IM was administered as rescue analgesia. Data were analysed by linear mixed effect models and Kaplan-Meier test (p < 0.05).

RESULTS

Median duration of the sensory blockade for all nerves was longer (p < 0.001) for group LD_loc than for groups L and LD_sys and was longer (p = 0.0011) for group LD_sys than for group L. Proprioception returned later (p < 0.001) for group LD_loc [285 (221-328) minutes] compared with group L [160 (134-179) minutes] or LD_sys [195 (162-257) minutes]. Return of the ability to walk was similar among all groups. Dogs in group LD_loc required postoperative rescue analgesia later (p = 0.001) than dogs in groups LD_sys and L.

CONCLUSIONS AND CLINICAL RELEVANCE

Dexmedetomidine administered perineurally with lidocaine prolonged sensory blockade and analgesia during the immediate postoperative period. Systemic dexmedetomidine also prolonged the sensory blockade of perineural lidocaine.

Success Rate and Perioperative Complications of Lumbosacral Extradural Anaesthesia in Dogs Undergoing Total Hip Replacement: A Double-Centre Retrospective Study

OBJECTIVE

 The aim of this study was to retrospectively evaluate the success rate and perioperative complications of lumbosacral extradural anaesthesia in dogs undergoing total hip replacement.

STUDY DESIGN

 Records of dogs undergoing total hip replacement in which lumbosacral extradural anaesthesia with 0.5% levo- or bupivacaine combined with either morphine or buprenorphine were retrieved. Success rate was defined as intraoperative fentanyl consumption <1 μg/kg/h with no intravenous infusion of other analgesic drugs and no additional morphine/methadone within the first 3 hours from premedication. Prevalence of intraoperative anaesthetic and postoperative surgical complications was calculated.

RESULTS

 Overall, 206 dogs were included in the study. Success rate was 88.7%. Hypercapnia (75.2%), hypotension (46.1%), hypothermia (27.7%) and regurgitation (6.3%) were recorded during anaesthesia. Within 24 hours post-surgery, urinary retention (17.8%), vomiting/regurgitation/diarrhea (8.2%) and sciatic neurapraxia of the operated limb (5.8%) were recorded. Luxation of the operated hip occurred at 48 and 72 hours after surgery in two dogs and one dog respectively. One dog had cardiopulmonary arrest at 52 hours after surgery.

CONCLUSION

 While hypercapnia, hypotension and hypothermia might develop intraoperatively, the high success rate and the relatively low prevalence of postoperative surgical complications directly associated with lumbosacral extradural anaesthesia justify its use in dogs undergoing total hip replacement.

Clinical effects of preemptive intra-articular lidocaine, dexmedetomidine and lidocaine-dexmedetomidine administration in dogs undergoing arthroscopy

This study investigated the perioperative effects of preemptive intra-articular lidocaine (L group), dexmedetomidine (D group) and lidocaine-dexmedetomidine (LD group) in dogs. Physiological variables were intraoperatively recorded at 5 min intervals starting from baseline (5 min before intra-articular injection). If nociception occurred, IV fentanyl was administered. Postoperative pain was assessed using the Short Form-Glasgow Composite Measure Pain Scale. Twenty-four dogs (eight in each group) were included in this prospective, randomized, masked clinical study. In the LD group, systolic arterial pressure significantly increased at T10 (P = 0.027), T15 (P = 0.021) and T20 (P = 0.022), compared with baseline. In the D and LD groups, mean arterial pressure significantly increased at T10 (P = 0.022; 0.024), T15 (P = 0.024; 0.09) and T20 (P = 0.019; 0.021), compared with baseline and diastolic arterial pressure significantly increased at T10 (P = 0.026; 0.047), T15 (P = 0.021; 0.023), T20 (P = 0.011; 0.012) and T25 (P = 0.019; 0.027), compared with baseline. In the LD group, heart rate significantly decreased at T5 (P = 0.031), T10 (P = 0.026) and T15 (P = 0.034), compared with baseline. Atrioventricular blocks appeared more frequently in the LD group than in L and D groups (P = 0.002). Group L received more fentanyl than the D and LD groups (P = 0.03). No differences in postoperative pain score were detected (P = 0.121). These findings suggested systemic absorption of intra-articular dexmedetomidine. Intra-articular lidocaine-dexmedetomidine was associated with a greater incidence of atrioventricular blocks. Intra-articular dexmedetomidine, alone and combined with lidocaine, provided better intraoperative analgesia than lidocaine in dogs undergoing arthroscopy, although the 12 h postoperative analgesic effect of the three treatments was similar.

Effects of perioperative saphenous and sciatic nerve blocks, lumbosacral epidural or morphine-lidocaine-ketamine infusion on postoperative pain and sedation in dogs undergoing tibial plateau leveling osteotomy

OBJECTIVE

To compare the quality of postoperative analgesia and sedation after preoperative saphenous and sciatic nerve blockade, preoperative lumbosacral epidural injection and perioperative intravenous (IV) morphine, lidocaine and ketamine infusions in dogs undergoing stifle arthroscopy and tibial plateau leveling osteotomy (TPLO) under general anesthesia.

STUDY DESIGN

Prospective, blinded, randomized, clinical comparison study.

ANIMALS

A total of 45 dogs weighing 33.9 (15.9-56.7) kg and aged 5.2 (1.0-12.0) years, mean (range), undergoing elective unilateral TPLO for spontaneous cranial cruciate ligament rupture.

METHODS

Client-owned dogs were enrolled. Dogs were randomly assigned to one of three groups: group MLK, perioperative IV morphine, lidocaine and ketamine infusion; group EPID, lumbosacral epidural with ropivacaine and morphine; or group SSNB, saphenous and sciatic nerve blockade with ropivacaine. Routine stifle arthroscopy followed by TPLO surgery was performed. Sedation and pain scores were assessed at 0, 2, 4, 8 and 24 hours following extubation. Rescue analgesia was administered as prescribed by Glasgow composite pain score-short form score >5.

RESULTS

Sedation scores for MLK were higher than EPID and SSNB. Pain scores for SSNB were lower than those for EPID and MLK. No significant differences were found in anesthesia duration or surgery duration among groups. No dogs required rescue analgesia.

CONCLUSIONS AND CLINICAL RELEVANCE

Although analgesia was adequate in all groups, the best combination of analgesia without increased sedation was recorded for SSNB.