Intraoperative Rescue Analgesia Research Articles

Evaluating the Efficacy of a Peripheral Nerve Simulator-Guided Brachial Plexus Block in Rabbits Undergoing Orthopaedic Surgery Compared to Systemic Analgesia.

Locoregional anaesthetic techniques are invaluable for providing multimodal analgesia for painful surgical procedures. This prospective, randomised study describes a nerve stimulator-guided brachial plexus blockade (BPB) in rabbits undergoing orthopaedic surgery in comparison to systemic lidocaine. Premedication was provided with intramuscular (IM) medetomidine, fentanyl, and midazolam. Anaesthesia was induced (propofol IV) and maintained with isoflurane. Nine rabbits received a lidocaine BPB (2%; 0.3 mL kg-1), and eight received a lidocaine constant rate infusion (CRI) (2 mg kg-1 IV, followed by 100 µg kg-1 min-1). Rescue analgesia was provided with fentanyl IV. Carprofen was administered at the end of the surgery. Postoperative pain was determined using the Rabbit Grimace Scale (RGS) and a composite pain scale. Buprenorphine was administered according to the pain score for two hours after extubation. Rabbits were filmed during the first two hours to measure distance travelled and behaviours. Food intake and faeces output were compared. Every rabbit in CRI required intraoperative rescue analgesia compared to none in BPB. However, rabbits in both groups had similar pain scores, and there was no difference in the administration of postoperative analgesia. There were no significant differences in food intake or faeces production over 18 h, and no significant differences in distance travelled or behaviours examined during the first two hours. BPB seems superior for intraoperative analgesia. Postoperatively, both groups were comparable.

Comparison of analgesic efficacy of tramadol, morphine and methadone in cats undergoing ovariohysterectomy.

The aim of this study was to compare the analgesic efficacy and the effect on physiological variables and behavior of the use of tramadol, methadone and morphine as preoperative analgesia in healthy cats undergoing elective ovariohysterectomy. Cats undergoing ovariohysterectomy were randomly assigned to receive one of the following premedication treatments intramuscularly: methadone (0.2 mg/kg; n = 10); morphine (0.2 mg/kg; n = 10); or tramadol (3 mg/kg; n = 10). Induction of anesthesia was done with propofol, and maintenance of anesthesia was done with isoflurane. Intraoperative heart rate, arterial blood pressure, respiratory rate, end-tidal isoflurane concentration and frequency of rescue analgesia (fentanyl 2.5 µg/kg) were compared between groups. Postoperative analgesia was assessed using the UNESP-Botucatu Multidimensional Composite Pain Scale, and perioperative serum glucose, cortisol concentrations and postoperative rescue analgesia were evaluated. Intraoperative rescue analgesia was required in 76.5% of cats at some time during surgery, and 27% of cats required postoperative rescue analgesia up to 6 h after extubation. There were no significant differences between groups with respect to intraoperative and postoperative rescue analgesia, pain scale scores and end-tidal isoflurane concentrations. In the immediate postoperative period, after extubation, most of the patients presented with hypothermia; however, 1-6 h postoperatively, hyperthermia was observed in most of the patients, and was most common in the tramadol group. Under the conditions of this study, methadone, morphine and tramadol produced satisfactory postoperative analgesia in most of the cats undergoing ovariohysterectomy, and the effects lasted up to 6 h postoperatively. Intraoperative analgesia was not sufficient in most cases. Significant cardiovascular or respiratory effects contraindicating the use of these drugs were not found. Postanesthetic hyperthermia occurred with all opioids studied and was more frequent in the tramadol group.

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

ObjectiveTo compare the perioperative analgesic effects of an opioid-free (OFA) and an opioid-sparing (OSA) anaesthetic protocol in dogs undergoing laparoscopic ovariectomy. Study designProspective, randomized, blinded, clinical trial. AnimalsA group of 28 client-owned dogs. MethodsDogs 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. ResultsThere 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 relevanceAlthough 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.

Paracetamol add-on treatment for perioperative pain management in dogs undergoing single-site thoracolumbar hemilaminectomy: a prospective clinical study

In this prospective, double-blinded, randomized, clinical trial, it was evaluated whether paracetamol, as an adjunct to NSAID and opioid analgesia, might limit the requirements for intraoperative fentanyl and postoperative methadone administration in dogs undergoing a singlesite thoracolumbar hemilaminectomy for surgical treatment of an intervertebral disc extrusion. Twelve client-owned dogs were randomly assigned to two multimodal analgesia groups: NSAID + paracetamol group (group NP) and NSAID + placebo group (group N). Intraoperative analgesic assessment was based on the clinical evaluation of a nociceptive response, whereas postoperative analgesic assessment was determined by using the short form of the Glasgow Composite Pain Scale. No statistically significant difference was found in both groups for the intraoperative need for fentanyl (P = 0.18). The probability of having to administer rescue analgesia postoperatively was significantly higher in group N than in group NP (P = 0.01). For both groups, there were no serious side effects reported, nor was any significant difference found between both groups regarding the occurrence of side effects (P = 0.55). Despite multimodal perioperative pain management consisting of a full μ-agonist opioid, a NSAID and paracetamol, intraoperative rescue analgesia was still required, although the need for postoperative opioid based analgesia was significantly lower in group NP.

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.

Efficacy of lumbosacral and sacrococcygeal epidural ropivacaine in dogs undergoing surgery for perineal hernia.

Epidural anesthesia is commonly administered as part of balanced anesthesia for perioperative analgesia. The main goal of this randomized clinical trial was to compare the efficacy of two epidural approaches in dogs undergoing surgery for a perineal hernia. A secondary aim was to compare motor blockade. Intact ASA 1 and 2 male dogs, weighing ≤25 kg with no previous surgery for perineal hernia were enrolled. After premedication with IM acepromazine 0.02 mg/kg and butorphanol 0.3 mg/kg, general anesthesia was induced with propofol and maintained with sevoflurane in oxygen. Dogs were randomly allocated to receive either a lumbosacral (LS, n = 30) or a sacrococcygeal (SC, n = 26) epidural injection with ropivacaine 1% (0.2 mL/kg) under computed tomography guidance. Successful analgesia was defined as no need of intraoperative rescue analgesia (fentanyl 3 μg/kg IV). Clinical failure was defined as the need of more than two boluses of fentanyl/h each dog received meloxicam 0.2 mg/kg IV at the end of the surgery. The Glasgow Composite Pain Scale short form (GCPS-SF), tactile sensitivity, pressure pain thresholds and motor blockade were assessed at 4, 6, 8, and 24 h after the epidural injection. Methadone (0.2 mg/kg, IV) was administered if the GCPS-SF was ≥6/24 points. Differences between groups were analyzed with the Mann-Whitney U test, Student's t-test or Fisher's Exact test, as appropriate. Success rate was assessed for non-inferiority between groups. The non-inferiority margin was set at -10%. Epidural analgesia was successful in 24 dogs in group LS and 17 dogs in group SC (p = 0.243), resulting in success rates of 80 and 65% in LS and SC groups, respectively. The non-inferiority of group SC versus group LS was confirmed. Clinical failure was recorded in two dogs in group LS and one dog in group SC. No significant differences between groups were detected in the GCPS-SF score, tactile sensitivity, pressure pain thresholds, need of post-operative methadone, or motor blockade. Both epidural techniques are valuable analgesic options for perineal hernia repair in dogs.

Sacrococcygeal epidural administration of 0.5% bupivacaine in seven cats undergoing pelvic or hind limb orthopaedic procedures

BackgroundEpidural administration of local anaesthetic agents provides good intraoperative antinociception for orthopaedic procedures of the pelvis and the pelvic limb. However, in cats the spinal cord extends approximately to the level of the first sacrococcygeal vertebra, and therefore the sacrococcygeal epidural could be a safer alternative to the lumbosacral epidural in cats. This case series describes perioperative analgesia and the haemodynamic status of seven client-owned cats that received sacrococcygeal epidural injection of 0.5% bupivacaine and underwent orthopaedic hind leg or pelvic surgeries under general anaesthesia.Case presentationEach cat received either 0.2 or 0.3 mL/kg of 0.5% bupivacaine with or without 0.2 mg/kg of morphine in the sacrococcygeal epidural space. Intraoperative antinociceptive response to surgical stimulus and haemodynamic changes were monitored and reported.ConclusionIn these seven anaesthetised cats, 0.2 or 0.3 mL/kg of 0.5% bupivacaine, administered alone or in combination with morphine into the sacrococcygeal epidural space, enhanced antinociception so that intraoperative rescue analgesia was unnecessary in all but one cat. It also reduced the anticipated requirement for postoperative opioid use. However, a high incidence of hypotension was observed in the cats in this report, and hence intraoperative blood pressure monitoring should be considered mandatory in anaesthetised cats following epidural injection of local anaesthetic agents, regardless of injection site.

Lumbosacral plexus block using a combination of ultrasound-guided lateral pre-iliac and parasacral approaches in cats

ObjectiveTo describe an ultrasound-guided lateral pre-iliac (LPI) and parasacral (PS) approach in feline cadavers (phase I) and compare the perioperative analgesic use and complications in cats administered LPI and PS blocks (group PNB) or epidural anesthesia (group EPI) for pelvic limb surgery (phase II). Study designExperimental uncontrolled, anatomic and retrospective cohort study. AnimalsA group of eight feline cadavers and 52 medical records. MethodsBilateral LPI and PS approaches with 0.1 mL kg–1 of dye to stain the femoral and obturator nerves and the lumbosacral trunk, respectively, were performed on each cadaver. Nerve staining effect was evaluated upon dissections (phase I). Perioperative analgesics use, and complication rates were retrospectively compared between groups PNB and EPI (phase II). Continuous data were compared using the Mann–Whitney U test and the prevalence of events with Fisher’s exact test. Differences were considered significant when p < 0.05. ResultsDissections revealed that the LPI approach stained 94% and 75% of the femoral and obturator nerves, respectively. The PS approach stained 100% of the lumbosacral trunks. Cats enrolled in group PNB (n = 23) were administered lower doses of intraoperative opioids than those in group EPI (n = 25) (p = 0.006). Intraoperative rescue analgesia was required in 60% and 17.4% of cats enrolled in groups EPI and PNB, respectively (p = 0.003). Group PNB required more intraoperative anticholinergics than group EPI (p = 0.02). There were no differences in postoperative pain scores, analgesic use and complication rates. Conclusions and clinical relevanceThe ultrasound-guided LPI and PS approach stained the femoral/obturator nerves and the lumbosacral trunk, respectively, in feline cadavers. Furthermore, PNB was associated with lower intraoperative opioid use and similar postoperative pain and analgesic use compared with epidural anesthesia in a cohort of cats undergoing surgery of the pelvic limb.

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.

Thoracolumbar retrolaminar block in seven dogs undergoing spinal surgery

BackgroundThoracolumbar intervertebral disc extrusion is a common neurologic complaint in dogs and is associated with debilitating pain that requires careful analgesic management to avoid the transition to a chronic pain state. Recently, there has been an increased effort to incorporate regional anaesthetic techniques whenever possible, both for perioperative analgesia management and for prevention of chronic pain. A novel regional anaesthetic technique named retrolaminar block is a fascial plane block where the local anaesthetic is injected directly on top of the dorsal aspect of the vertebral lamina, in the fascial plane between the lamina and the epaxial muscles. The technique was recently described in humans and it is claimed to provide analgesia in patients undergoing thoracic and lumbar procedures. To the authors’ knowledge, the retrolaminar block has not been previously reported in live dogs.Case presentationSeven dogs presented to our hospital for suspected thoracolumbar intervertebral disc extrusion were anaesthetised using an anaesthetic premedication and induction protocol tailored for each individual animal. Once the suspected diagnosis was confirmed, all seven dogs were placed in sternal recumbency, and the target thoracolumbar vertebral spinous process was identified with palpation. A unilateral retrolaminar block was performed in all dogs with 2 mg/kg of 0.25% bupivacaine. Physiologic parameters, as well as responses to nociceptive stimuli, were monitored throughout the anaesthetic event.Intraoperatively, one dog required a bolus of fentanyl to control nociceptive stimulation while the epaxial muscles were retracted. No further intraoperative rescue analgesia was required in any of the cases. The postoperative pain was assessed using the Short Form of Glasgow Composite Measure Pain Scale for dogs every four hours for the duration of the dogs’ hospitalization. The retrolaminar block reduced the intraoperative requirement for systemic opioids and other adjunct analgesic agents and all dogs were comfortable throughout their hospitalization and up until the time of their discharge.ConclusionsThis case report presents the performance of the retrolaminar block technique as part of multimodal analgesia management in seven dogs undergoing thoracolumbar spinal surgery.

Thoracic epidural anaesthesia vs intrathecal morphine in dogs undergoing major thoracic and abdominal surgery: clinical study

BackgroundThere is scant clinical research on neuraxial analgesia in dogs undergoing major surgery. With this study we compared the perioperative analgesic effects of thoracic epidural anaesthesia (TEA) and intrathecal morphine (ITM) in dogs scheduled for thoracic or cranial abdominal surgery. The dogs received methadone and dexmedetomidine, were anaesthetized with propofol maintained with sevoflurane, and randomly assigned to receive either TEA (ropivacaine 0.5% at 0.2 mg/kg and morphine 0.1 mg/kg administered at T12-T13) or ITM (morphine 30 μg/kg administered at L6-L7). Intraoperative rescue analgesia (iRA) was fentanyl 1 μg/kg administered if heart rate or mean arterial pressure increased by 30% above the pre-stimulation level. Glasgow Pain Composite Scale score (GPCS) dictated the use of postoperative rescue analgesia (pRA) with methadone 0.2 mg/kg.ResultsThere was a statistically significant difference in iRA, median time to first fentanyl bolus, median fentanyl dose after surgical opening, and median GPCS score at 30 minutes (min), 1 ,2, 4, 6, and 8 hours (h) between the two groups (p<0.001; p<0.001; p<0.001; p<0.01; p<0.01; p<0.001; p<0.01; p=0.01; p=0.01, respectively). Fewer TEA than ITM group dogs required iRA during surgical opening and pRA: 5% (1/18) and 2/18 (11%), respectively, in the TEA and 83% (16/18) and 10/18 (55%), respectively, in the ITM group. Side effects were urinary retention in 3/18 (16%) TEA group dogs and 2/18 (11%) ITM group dogs and prolonged sedation in 2/18 (11%) in ITM group dogs.TEA and ITM were effective in managing perioperative pain in dogs undergoing thoracic or cranial abdominal surgery.

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

BackgroundIn 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.ResultsProcedural 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.ConclusionsSA 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.

Infraclavicular block in children: Is blocking lateral or posterior cord equally successful?

The most effective approach for infraclavicular brachial plexus block in adults is to target the posterior cord, usually situated posterior to axillary artery. However, we do not know if this can be extrapolated in children. Our primary objective was to compare the clinical success rate of ultrasound guided infraclavicular brachial plexus block in children with local anesthetic injection aimed at two targets. These were posterior to axillary artery (posterior cord) and lateral to axillary artery (lateral cord). The secondary objectives involved need for intraoperative rescue analgesia, evaluation of duration of analgesia, incidence of complications such as pneumothorax and arterial puncture, comparison of postoperative pain scores and fluoroscopic dye spread pattern was also observed. It was a randomized, prospective pilot study. Forty children undergoing forearm and hand surgeries were randomized to two groups, in accordance with the target site of the block. Target sites of Group P (20 patients) and Group L (20 patients) were posterior and lateral to the axillary artery, i.e., posterior and lateral cord respectively. Aforesaid objectives were assessed. SPSS (Version 15.0) statistical package was used. Comparison between Group L and P was by using student's unpaired t test for age and weight. Fisher's exact probability test was applied to compare percentages between groups. Blocks of both groups were equally successful. No patient required intraoperative rescue analgesia. Duration of analgesia was comparable. Both groups had no major complications and similar postoperative pain scores. The success rate of infraclavicular brachial plexus block by aiming at the lateral and posterior cord was similar.

Feasibility of Opioid-Free Anesthesia for Cervical Rib Excision: A Case Series and Review of Literature

AbstractBackground Perioperative pain management following cervical rib excision can be compounded in the background of chronic pain disorder caused by the neurovascular compression. The former mandates an enhanced analgesic requirement wherein the perioperative opioid use, in particular, can be associated with a peculiar adverse-effect profile and abuse potential. Appropriate to the context, an opioid-free anesthesia (OFA) protocol can be instrumental in minimizing the incidence of the aforementioned.Case Series While two patients necessitated OFA owing to opioid contraindication, the formulated protocol was evaluated in another six consecutive patients posted for elective cervical rib excision. A combined paravertebral block and superficial cervical plexus block was employed alongside general anesthesia. Intravenous dexmedetomidine and lignocaine assisted the conduct of OFA, and paracetamol dosing was continued into the postoperative period. Intraoperative rescue analgesia was ensured by a ketofol bolus (1:1 mixture of ketamine and propofol) whereas intravenous diclofenac was used for postoperative rescue analgesia.Results OFA could be successfully contemplated in all eight patients. A single bolus rescue dose of ketofol had to be administered in two patients intraoperatively and diclofenac had to be administered as postoperative rescue analgesic in two patients. There was no incidence of postoperative nausea/vomiting or any block-related complications. The postoperative stay was uneventful with an acceptable patient satisfaction.Conclusion The index experience reiterates the fact that a prudent combination of nonopioid multimodal analgesics with case-based locoregional techniques can feature as a successful OFA protocol, albeit mandating future prospective studies in this novel area of clinical interest.

Pre-emptive intravenous paracetamol vs. ketorolac for shoulder pain in cesarean section under spinal anesthesia: A randomized double-blind placebo-controlled trial

Introduction: Intraoperative shoulder pain (ISP) is a common side-effect of spinal anesthesia (SA) for cesarean sections (CS), but in most cases, it does not receive sufficient attention by the anesthesiologists. Following a randomized prospective double-blinded design, we aimed to compare the effect of ketorolac and paracetamol in prevention of the development and intensity of intraoperative ISP in patients undergoing CS under SA. Methodology: A total of 147 parturients, American Society of Anesthesiologists (ASA) Physical status II, who were planned for elective CS under SA were randomly allocated to three groups, to receive either intravenous ketorolac 30 mg (K group, n= 50), paracetamol 1 g (P group n= 50) or normal saline (Control group, n-52). Demographic data, surgery, negative outcomes, and average severity of ISP were collected by a blinded observer. Intraoperative ISP and intensity of intraoperative and postoperative ISP were defined as primary and secondary outcomes, respectively. Hypotension, bradycardia, and request for intraoperative rescue analgesia were other secondary outcomes. Results: The prevalence of ISP was significantly higher in the control group than in the other two groups (33.3% vs. 14% and 6.1 %, respectively, p = 0.002). The intensity of the pain was higher in the control group. (p = 0.748), and the parturients in the control group had a considerably higher demand for intraoperative analgesia (12.2 % vs. 0 % and 2 %, p < 0.001). We found no significant difference regarding incidences of bradycardia and hypotension between the groups (p = 0.99, p = 0.854). Conclusion: Single shot ketorolac 30 mg and paracetamol 1 g may decline both development and intensity of intraoperative shoulder pain in C-sections under spinal anesthesia without enhancing negative events. Key words: Ketorolac; Acetaminophen; Shoulder pain; Cesarean section Abbreviations: ISP – intraoperative shoulder pain; CSI – combined spinal epidural anesthesia; SA – spinal anesthesia; CS – cesarean sections; NSAID – nonsteroidal anti-inflammatory analgesic; NRS – Numerical Rating Scale Citation: Dehghanpisheh L, Azemati S, Feiz F, Karami MY. Pre-emptive intravenous paracetamol vs. ketorolac for shoulder pain in cesarean section under spinal anesthesia: A randomized double-blind placebo-controlled trial. Anaesth. pain intensive care 2021;25(3):359–366. DOI: doi.org/10.35975/apic.v25i3.1425 Received: January 15, 2021, Reviewed: January 17, 24, 2021, Accepted: February 19, 2021

Ultrasound-guided erector spinae interfascial plane block for spinal surgery in three cats.

Case series summaryThe erector spinae plane (ESP) block consists of an interfascial injection of local anaesthetic between the erector spinae muscle group and the transverse processes of the thoracic vertebrae. This block targets the dorsal rami of the thoracic spinal nerves to desensitise the cutaneous area near the dorsal midline, the paraspinal muscles, the dorsal vertebral laminae and the facet joints. The purpose of this case series is to describe the perioperative analgesic effect and complications of ultrasound-guided ESP block with bupivacaine in three cats undergoing spinal surgery. Only one cardiovascular response was recorded in this case series. Just one cat received intraoperative rescue analgesia. Cats 1 and 2 recorded just one high pain score in the first 24 h postoperatively, and cat 3 recorded three high pain scores. The total amount of methadone given in the 24 h postoperatively was 0.6 mg/kg in cat 1, 0.9 mg/kg in cat 2 and 0.8 mg/kg in cat 3. All three cats suffered mild and transient intraoperative complications, which were easily addressed. There were no postoperative complications.Relevance and novel informationThis case series documents a novel locoregional anaesthesia technique as an alternative to traditional systemic analgesia. The technique is part of a multimodal analgesia approach for spinal surgery in cats. Perioperative analgesic effect and complications presented in this case series are evaluated and discussed.

Retrospective assessment of the relationship between intraoperative nociception and postoperative analgesia requirements in dogs undergoing thoracic surgery.

The analgesia management of thoracic surgery can be challenging and debate exists regarding the efficacy of pre-emptive analgesia and its relationship with postoperative pain. The aim of this study was to assess the relationship between intraoperative nociception and postoperative pain in dogs undergoing thoracic surgery. If proven, effective prevention of intraoperative nociception could imply prospective lower postoperative analgesia requirements. The study was retrospective and observational. Clinical records from dogs undergoing thoracic surgery (2015-2019) were reviewed and cases were allocated to one of two groups: NOCI-FREE - dogs with no evidence of intraoperative nociception; NOCI - dogs that required intraoperative rescue analgesia to address a nociceptive response. Pre-anaesthetic medication, locoregional analgesia, intraoperative infusions and rescue analgesia were used. Additionally, postoperative pain scores and analgesia plans were registered and compared between groups. Our study failed to identify a difference in the postoperative pain scores and analgesia requirements between dogs having signs of intraoperative nociception and those without. Additionally, the use of postoperative analgesic preventive infusions and rescue analgesia was similar for both NOCI and NOCI-FREE. Being on an intraoperative infusion of opioids, dexmedetomidine or lidocaine was identified as a protective factor for nociception [OR=11; (4.15-29.7)]. In the population studied, it appears that dogs showing signs of nociception intraoperatively do not necessarily show higher pain scores nor do they need additionally pain relief in the postoperative period.

The Role of Dexmedetomidine as an Additive to Intravenous Regional Anesthesia: A Systematic Review and Meta-analysis.

Background: Intravenous Regional Anesthesia (IVRA) is a reliable and cost-effective anesthetic method for minor surgical procedures to the extremities. Limitations of this block include tourniquet discomfort, short duration of anesthesia, and absence of postoperative analgesia. Dexmedetomidine has been used as an adjuvant to minimize these negative characteristics with inconclusive results.Aim: To perform a systematic review of the existing evidence on the role of dexmedetomidine as an additive to intravenous regional anesthesia in upper limb surgery.Study Design: Systematic Review and Meta-analysis.Methods: The databases searched were MEDLINE, Embase, PubMed, CINAHL, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials databases, and clinicaltrials.gov (1990-2019). Seven randomized controlled trials (RCTs) were included. We analyzed the duration of analgesia, onset time of sensory and motor block, intraoperative tourniquet pain scores, the incidence of tourniquet pain, need for rescue analgesia, intraoperative rescue analgesia consumption, sedation scores, postoperative pain scores, and anesthesia quality.Results: Intraoperative analgesia duration (MD 11.08 min; 95% CI 5.42, 16.75; P < .0001) was longer and sensory block onset time (MD −2.10 min; 95% CI −3.345, −0.86; P = .00009) was shorter in the dexmedetomidine group. Anesthesia quality scores (MD 0.58; 95% CI 0.47, 0.70; P < .00001) and postoperative sedation scores (MD 1.03; 95% CI 0.88, 1.24; P < .00001) were significantly higher. There was a significant reduction in intraoperative rescue analgesia consumption (MD −19.70 mg; 95% CI −24.15, −15.26; P < .00001) in the dexmedetomidine group. The risk of tourniquet pain as well as postoperative pain scores were lower in favor of dexmedetomidine. The addition of dexmedetomidine to IVRA slightly increased the risk of sedation. A limitation of our study is that some of the interesting outcomes derive from a small number of RCTs.Conclusion: The addition of dexmedetomidine to IVRA ameliorates the block’s characteristics and carries a low risk of potential side effects.

Retrospective comparison of three locoregional techniques for pelvic limb surgery in dogs

ObjectiveTo retrospectively compare the efficacy and duration of effect of three commonly used locoregional blocks in dogs undergoing pelvic limb orthopaedic surgery. Study designRetrospective clinical study. AnimalsA total of 236 dogs that underwent pelvic limb surgery and were administered a locoregional technique. MethodsA total of 236 hospital records were reviewed and 230 included in statistical analysis. Dogs were grouped as following: electrostimulation-guided pre-iliac femoral and sciatic nerve block (group PFS, n = 70); ultrasound-guided saphenous and sciatic nerve block (group SS, n = 76); or lumbosacral epidural (group EPI, n = 84). In group EPI, bupivacaine 0.5% or ropivacaine 0.75% was used with morphine. Dogs were pain scored (short form of the Glasgow Composite Measure Pain Scale) hourly following recovery from anaesthesia. Analysed data included: time to first postoperative dose of methadone, pain score at that time, intraoperative rescue analgesia, intraoperative hypotension and ability to walk and urinate overnight. Separate analyses were performed including all pelvic limb surgeries and including only elective stifle surgeries. Kruskal–Wallis and Mann–Whitney tests were performed. A p value < 0.05 was considered significant. The median (range) is reported. ResultsFor all pelvic limb surgeries, the time to first postoperative methadone was 530 (110–1337), 440 (140–1030) and 466 (135–1094) minutes in groups EPI, PFS and SS, respectively, and was not significantly different. Postoperatively, 10/84, 15/70 and 12/76 dogs in groups EPI, PFS and SS, respectively, did not require methadone (nonsignificant). Significantly fewer dogs in group EPI (18%) required intraoperative rescue analgesia compared with group SS (38%), but not compared with PFS (30%). Significantly more dogs in group EPI had hypotension intraoperatively (30%) and urinary retention postoperatively (62%). Conclusions and clinical relevanceIntraoperative analgesia may be superior with EPI than SS for some surgeries of the pelvic limb, but not for stifle surgeries. All three techniques provided similar requirement for postoperative analgesia, but EPI caused higher incidence of intraoperative hypotension and postopertive urinary retention.

Caudal versus intravenous ketamine for supplementation of analgesia in children undergoing hypospadias repair: a randomized controlled trial

Background Different additives have been reported to prolong the duration of caudal anesthesia in pediatrics. Although these drugs successfully increased the duration of the block, ketamine has been found to effectively increase the duration of caudal block in pediatrics. Aim This study aimed to assess the clinical effectiveness of ketamine after caudal or intravenous administration in pediatric patients who underwent hypospadias repair to distinguish between local and systemic analgesia. Patients and methods After induction of general anesthesia, 48 patients, aged 1–6 years, assigned to undergo hypospadias repair, received a caudal injection of bupivacaine and were randomly blinded into two groups: K1 group received 1 mg/kg S-ketamine as the caudal group, and K2 group received 1 mg/kg S-ketamine as the intravenous group. Postsurgical measurements included the effectiveness of postsurgical analgesia, which was assessed by using observational pain scale, duration of analgesia, sedation score, and hemodynamic and complications. Results The caudal block was successful in all the patients included in the study. None of the patients in either groups required intraoperative rescue analgesia. All patients remained vitally stable during the procedure, and intraoperative hemodynamic parameters were comparable in the two groups. The time to the administration of first analgesia was statistically longer in K1 group (11.5±4.6 h) than in the K2 group (8.7±3.1 h). Time to spontaneous leg movement and time to first micturition were statistically nonsignificant between both groups. The number of patients requested for additional analgesic drugs (acetaminophen and ibuprofen) was statistically significant, being higher in the K2 group than the K1 group. Conclusion This study demonstrates that ketamine if added to caudal epidural in a dose of 1 mg/kg provided prolonged postoperative analgesia with improved quality, had longer duration of analgesia, decreased the supplemental acetaminophen analgesia during the first 24 h postoperatively, had stable hemodynamic changes, and had comparable adverse effects and complications in comparison with systemic ketamine in a dose of 1 mg/kg.