Dose safety and pharmacodynamics of subcutaneous bupivacaine in a novel extended-release microparticle formulation: A phase 1, dose-ascending study in male volunteers

A novel microparticle-based extended-release local anaesthetic containing a bupivacaine/poly-lactic-co-glycolic acid (PLGA; LIQ865A) or plain bupivacaine (LIQ865B) was examined in a first-in-human trial. The objectives were to examine the dose safety/tolerability and pharmacodynamics. Randomized subcutaneous injections of LIQ865A (n = 16) or LIQ865B (n = 12) and diluent, contralaterally, were administered in a dose-ascending manner (150- to 600-mg bupivacaine). Subjects were admitted 24 h post-injection and followed for 30 days post-injection. The risk ratios (RRs; 95% CI) of erythematous reactions for LIQ865A versus diluent was 9.00 (1.81-52.23; P = 0.006) and for LIQ865B versus diluent 2.50 (0.69-9.94; P = 0.37). The RR for the development of hematomas (LIQ865A versus diluent) were 3.25 (1.52-8.16; P = 0.004) and 4.00 (0.72-24.89; P = 0.32) (LIQ865B versus diluent). Subcutaneous indurations persisting for 4-13 weeks were seen in 6/16 subjects receiving LIQ865A. One subject receiving LIQ865A (600-mg bupivacaine) developed intermittent central nervous system (CNS) symptoms of local anaesthetic systemic toxicity (85 min to 51 h post-injection) coinciding with plasma peak bupivacaine concentrations (490-533 ng/ml). Both LIQ865 formulations demonstrated dose-dependent hypoesthesia and hypoalgesia. The duration of analgesia ranged between 37 and 86 h. The overall number of local adverse events, however, prohibits clinical application without further pharmacological modifications.

Super-refractory status epilepticus, rhabdomyolysis, central hyperthermia and cardiomyopathy attributable to spinal anesthesia: a case report and review of literature

BACKGROUND

There are only six past reports of super-refractory status epilepticus induced by spinal anesthesia. None of those patients have died. Only < 15 mg of bupivacaine was administered to all six of them and to our case. Pathophysiology ensuing such cases remains unclear.

CASE PRESENTATION

A 27 year old gravida 2, para 1, mother at 37 weeks of gestation came to the operating theater for an elective cesarean section. She had no significant medical history other than controlled hypothyroidism and one episode of food allergy. Her current pregnancy was uneventful. Her American Society of Anesthesiologists (ASA) grade was 2. She underwent spinal anesthesia and adequate anesthesia was achieved. After 5-7 min she developed a progressive myoclonus. After delivery of a healthy baby, she developed generalized tonic clonic seizures that continued despite the induction of general anesthesia. She had rhabdomyolysis, one brief cardiac arrest and resuscitation, followed by stress cardiomyopathy and central hyperthermia. She died on day four. There were no significant macroscopic or histopathological changes in her brain that explain her super refractory status epilepticus. Heavy bupivacaine samples of the same batch used for this patient were analyzed by two specialized laboratories. National Medicines Quality Assurance Laboratory of Sri Lanka reported that samples failed to confirm United States Pharmacopeia (USP) dextrose specifications and passed other tests. Subsequently, Therapeutic Goods Administration of Australia reported that the drug passed all standard USP quality tests applied to it. Nonetheless, they have detected an unidentified impurity in the medicine.

CONCLUSIONS

After reviewing relevant literature, we believe that direct neurotoxicity by bupivacaine is the most probable cause of super-refractory status epilepticus. Super-refractory status epilepticus would have led to her other complications and death. We discuss probable patient factors that would have made her susceptible to neurotoxicity. The impurity in the drug detected by one laboratory also would have contributed to her status epilepticus. We propose several possible mechanisms that would have led to status epilepticus and her death. We discuss the factors that shall guide investigators on future such cases. We suggest ways to minimize similar future incidents. This is an idiosyncratic reaction as well.

Transitioning from intrathecal bupivacaine to mepivacaine for same-day discharge total joint arthroplasty: a quality improvement study

INTRODUCTION

Same-day discharge total knee and hip arthroplasty is becoming more common. Anesthetic approaches that optimize readiness for discharge are important. Based on an institutional change from low-dose bupivacaine to mepivacaine, we aimed to assess the impact on postanesthesia care unit (PACU) recovery in a quaternary care, academic medical center.

METHODS

In this quality improvement retrospective study, a single surgeon performed 96 combined total knee and hip arthroplasties booked as same-day discharge from September 20, 2021 to December 20, 2021. Starting on November 15, 2021 the subarachnoid block was performed with isobaric mepivacaine 37.5-45 mg instead of hyperbaric bupivacaine 9-10.5 mg. We compare these cohorts for time to discharge from PACU, perioperative oral morphine milligram equivalent (OMME) administration, PACU pain scores, conversion to general anesthesia (GA), and overnight admission.

RESULTS

We found the use of isobaric mepivacaine as compared with hyperbaric bupivacaine for intrathecal block in same-day discharge total joint arthroplasty was associated with decreased length of PACU stay at our academic center (median 4.03 vs 5.33 hours; p=0.008), increased perioperative OMME (mean 22.5 vs 11.4 mg; p<0.001), increased PACU pain scores (mean 6.29 vs 3.41; p<0.01) and no difference in conversion to GA or overnight admission.

CONCLUSIONS

Intrathecal mepivacaine was associated with increased perioperative OMME consumption and PACU pain scores, but still realized a decreased PACU length of stay.

Lipid emulsion treatment for local anesthetic systemic toxicity in pediatric patients: A systematic review

BACKGROUND

Local anesthetic systemic toxicity (LAST) is rare, but fatal; the current widely used treatment is lipid emulsion (LE). The goal of this study was to analyze and review case reports on LE treatment for LAST in pediatric patients.

METHODS

We performed a systematic review using case reports on LE treatment for LAST in pediatric patients, searching PubMed and Scopus databases to March 2023 using the following keywords: ("local anesthetic toxicity" OR "local anesthetic systemic toxicity" OR LAST") AND ("newborn" OR "infant" OR "child" OR "children" OR "adolescent" OR "pediatric") AND ("lipid emulsion" OR "Intralipid").

RESULTS

Our search yielded 21 cases, revealing that nearly 43% patients with LAST were less than 1 year old, and most cases were caused by bupivacaine (approximately 67% cases). "Inadvertent intravascular injection" by anesthesiologists and "overdose of local anesthetics" mainly by surgeons were responsible for 52% and 24% cases of LAST, respectively. LAST occurred in the awake state (52%) and under general anesthesia (48%), mainly causing seizures and arrhythmia, respectively. Approximately 55% of patients received LE treatment in <10 minutes after LAST, mainly improving cardiovascular symptoms. A 20% LE (1.5 mL/kg) dose followed by 0.25 mL/kg/minutes dose was frequently used. LE and anticonvulsants were mainly used in the awake state, whereas LE with or without vasopressors was mainly used under general anesthesia. LE treatment led to full recovery from LAST in 20 cases; however, 1 patient died due to underlying disease.

CONCLUSION

Consequently, our findings reveal that LE is effective in treating pediatric LAST.

Local anesthetic dosing and toxicity of adult truncal catheters: a narrative review of published practice

BACKGROUND/IMPORTANCE

Anesthesiologists frequently use truncal catheters for postoperative pain control but with limited characterization of dosing and toxicity.

OBJECTIVE

We reviewed the published literature to characterize local anesthetic dosing and toxicity of paravertebral and transversus abdominis plane catheters in adults.

EVIDENCE REVIEW

We searched the literature for bupivacaine or ropivacaine infusions in the paravertebral or transversus abdominis space in humans dosed for 24 hours. We evaluated bolus dosing, infusion dosing and cumulative 24-hour dosing in adults. We also identified cases of local anesthetic systemic toxicity and toxic blood levels.

FINDINGS

Following screening, we extracted data from 121 and 108 papers for ropivacaine and bupivacaine respectively with a total of 6802 patients. For ropivacaine and bupivacaine, respectively, bolus dose was 1.4 mg/kg (95% CI 0.4 to 3.0, n=2978) and 1.0 mg/kg (95% CI 0.18 to 2.1, n=2724); infusion dose was 0.26 mg/kg/hour (95% CI 0.06 to 0.63, n=3579) and 0.2 mg/kg/hour (95% CI 0.06 to 0.5, n=3199); 24-hour dose was 7.75 mg/kg (95% CI 2.1 to 15.7, n=3579) and 6.0 mg/kg (95% CI 2.1 to 13.6, n=3223). Twenty-four hour doses exceeded the package insert recommended upper limit in 28% (range: 17%-40% based on maximum and minimum patient weights) of ropivacaine infusions and 51% (range: 45%-71%) of bupivacaine infusions. Toxicity occurred in 30 patients and was associated with high 24-hour dose, bilateral catheters, cardiac surgery, cytochrome P-450 inhibitors and hypoalbuminemia.

CONCLUSION

Practitioners frequently administer ropivacaine and bupivacaine above the package insert limits, at doses associated with toxicity. Patient safety would benefit from more specific recommendations to limit excessive dose and risk of toxicity.

Aseptic meningitis following spinal anaesthesia: An uncommon and challenging diagnosis

Drug-induced aseptic meningitis (DIAM) or chemical meningitis following spinal anaesthesia has rarely been reported. DIAM is caused by meningeal inflammation due to intrathecally administered drugs or secondary to systemic immunological hypersensitivity. We hereby present a case of a young adult with aseptic meningitis following neuraxial anaesthesia possibly provoked by bupivacaine. The initial cerebrospinal fluid (CSF) picture revealed neutrophilic pleocytosis and normal glycorrhachia. CSF culture was negative. The patient was put on invasive mechanical ventilation and started on intravenous antibiotics. There was a rapid improvement in clinical condition without any residual neurological deficit within the next few days. Aseptic meningitis following neuraxial anaesthesia can be prevented by strict aseptic protocols and careful inspection of visible impurities while administering the intrathecal drug. Detailed history taking, clinical examination, and focused investigations can distinguish between bacterial and chemical meningitis. Appropriate diagnosis of this entity may guide the treatment regimen, reducing hospital stay and cost.

Local anesthetic dosing and toxicity of pediatric truncal catheters: a narrative review of published practice

BACKGROUND/IMPORTANCE

Despite over 30 years of use by pediatric anesthesiologists, standardized dosing rates, dosing characteristics, and cases of toxicity of truncal nerve catheters are poorly described.

OBJECTIVE

We reviewed the literature to characterize dosing and toxicity of paravertebral and transversus abdominis plane catheters in children (less than 18 years).

EVIDENCE REVIEW

We searched for reports of ropivacaine or bupivacaine infusions in the paravertebral and transversus abdominis space intended for 24 hours or more of use in pediatric patients. We evaluated bolus dosing, infusion dosing, and cumulative 24-hour dosing in patients over and under 6 months. We also identified cases of local anesthetic systemic toxicity and toxic blood levels.

FINDINGS

Following screening, we extracted data from 46 papers with 945 patients.Bolus dosing was 2.5 mg/kg (median, range 0.6-5.0; n=466) and 1.25 mg/kg (median, range 0.5-2.5; n=294) for ropivacaine and bupivacaine, respectively. Infusion dosing was 0.5 mg/kg/hour (median, range 0.2-0.68; n=521) and 0.33 mg/kg/hour (median, range 0.1-1.0; n=423) for ropivacaine and bupivacaine, respectively, consistent with a dose equivalence of 1.5:1.0. A single case of toxicity was reported, and pharmacokinetic studies reported at least five cases with serum levels above the toxic threshold.

CONCLUSIONS

Bolus doses of bupivacaine and ropivacaine frequently comport with expert recommendations. Infusions in patients under 6 months used doses associated with toxicity and toxicity occurred at a rate consistent with single-shot blocks. Pediatric patients would benefit from specific recommendations about ropivacaine and bupivacaine dosing, including age-based dosing, breakthrough dosing, and intermittent bolus dosing.

Local anaesthetic systemic toxicity complicating intraoperative intercostal nerve blocks: What do clinicians need to know to prevent similar occurrence?

Local anaesthetic systemic toxicity is a life-threatening adverse event that may occur after administration of local anaesthetics through a variety of routes. Local anaesthetic systemic toxicity is always a potential complication and may occur with all local anaesthetics and in any route of administration. Local anaesthetic systemic toxicity primarily affects the central nervous system and the cardiovascular system and may be fatal. The following is a case of local anaesthetic systemic toxicity complicating surgeon-performed intraoperative intercostal nerve blocks at multiple levels, with a mixture of liposomal bupivacaine and bupivacaine hydrochloride in a patient who underwent video-assisted segmental lung resection for lung cancer under general anaesthesia. Local anaesthetic systemic toxicity presented with seizures and hypotension. The patient was successfully managed and fully recovered. This case illustrates the importance of awareness regarding the prevention, diagnosis and treatment of local anaesthetic systemic toxicity among medical professionals who administer local anaesthetics.

Electroacupuncture alleviates multifidus muscle injury by modulating mitochondrial function and Ca2+ uptake

Multifidus muscles maintain the stability of the lumbar spine and play a crucial role in the pathogenesis of nonspecific lower back pain. Previous studies have shown that electroacupuncture (EA) can relieve the symptoms of low back pain and reduce injury to the lumbar multifidus muscles. In this study, a rat model of lumbar multifidus muscle injury was established by 0.05% bupivacaine injection and subsequently treated with EA at bilateral "Weizhong" (BL40) acupoints. Disruption of the function and structure of multifidus muscles, increased cytosolic Ca2+ in multifidus myocytes, and reduced mitochondrial fission and ATP production were observed in the model group. Additionally, increased expression of the mitochondrial calcium uniporter (MCU) promoted mitochondrial reuptake of Ca2+ , reversing the excessive increase in cytoplasmic Ca2+ . However, the excessive increase in MCU not only aggravated the increased cytoplasmic Ca2+ but also decreased the expression of the mitochondrial division proteins dynamin-related protein 1 (Drp1) and mitochondrial fission factor (MFF). EA inhibited the overexpression of MCU, promoted mitochondrial reuptake of Ca2+ , and reversed cytosolic Ca2+ overload. Furthermore, EA regulated the expression of the mitochondrial fission proteins Drp1 and MFF and promoted the production of ATP, helping the recovery of mitochondrial function after multifidus injury. Therefore, EA can protect against bupivacaine-induced mitochondrial dysfunction, possibly by attenuating MCU overexpression in the inner mitochondrial membrane and reducing Ca2+ overloading in muscle cells, thereby protecting mitochondrial function and maintaining the normal energy demand of muscle cells.

Local Anesthetic Systemic Toxicity During Transversus Abdominis Plane Block With Liposomal Bupivacaine

Local anesthetic systemic toxicity (LAST) is a rare but potentially fatal outcome associated with local anesthetic administration. Liposomal bupivacaine (LB; EXPAREL®) is a widely used local anesthetic with extended-release and liposomal formulation that carries an improved cardiac and central nervous system safety profile. However, there is limited data regarding LAST associated with liposomal bupivacaine. Here is described a case of local anesthetic systemic toxicity in a 68-year-old male who presented with obstructing sigmoid adenocarcinoma and underwent open sigmoidectomy with end descending colostomy. The operation was complicated by LAST following transversus abdominis plane block injection with liposomal bupivacaine resulting in cardiac arrest. Return of spontaneous circulation was achieved following advanced cardiac life support and infusion of 20% I.V. fat emulsion. Given the widespread use of local anesthetics, providers must be aware of the pathophysiology, diagnosis, and immediate treatment of LAST.

TRANSCARUNCULAR DOUBLE INJECTION TECHNIQUE FOR PERIBULBAR ANESTHESIA IN VITREORETINAL SURGERY

PURPOSE

Local anesthesia is commonly adopted in vitreoretinal surgery to reach painless and akinesia surgical condition. Currently, peribulbar anesthesia (PBA) and subtenon injection (STN) are the most widely used methods. We propose a transcaruncular double injection peribulbar technique (TRS) and aim to compare it with both standard PBA and STN injections.

METHODS

A total of 105 patients underwent TRS, PBA, or STN. A numerical rating scale was used to assess preoperative, postoperative, and intraoperative pain. Best akinesia score and onset and duration of akinesia were evaluated by two independent graders. The need for supplementary injection was also registered.

RESULTS

TRS group was characterized by a lower intraoperative numerical rating scale variation and absolute numerical rating scale score both at the beginning of surgery ( P 0.046), after 30 minutes ( P 0.032), and at the end of surgery ( P 0.002) compared with the other groups. The TRS group also showed better akinesia score ( P 0.004), fastest onset ( P 0.002), and longer duration ( P 0.042) compared with both PBA and STN. No injection-related complications were reported in the three groups.

CONCLUSION

The newly proposed transcaruncular PBA provided superior pain control and akinesia level with no additional adverse events.

Comparison of fentanyl and nalbuphine as adjuvants to intrathecal 0.5% bupivacaine in lower limb surgeries: A randomised double-blind prospective study

INTRODUCTION

Local anaesthetics used in spinal anaesthesia have a limited duration of action. To prolong postoperative analgesia, adjuvants, mainly opioids, are used. As µ agonist drugs have side effects, other receptor agonists are considered. Nalbuphine is a safe and effective kappa agonist adjuvant.

AIM

To compare the analgesic efficacy between fentanyl and nalbuphine adjuvants added to 3 mL of 0.5% intrathecal hyperbaric bupivacaine.

MATERIALS AND METHODS

This prospective, double-blind, comparative study was conducted in 60 patients of either sex belonging to the American Society of Anesthesiologists classes I and II aged 18-65 years undergoing lower limb surgery with entropy monitoring, randomly allocated into two groups. Group F (n = 30) received 0.5% hyperbaric bupivacaine (3 mL) + 25 µg (0.5 mL) fentanyl. Group N (n = 30) received 0.5% hyperbaric bupivacaine (3 ml) + 0.8 mg (0.5 mL) nalbuphine intrathecally. Hemodynamics, entropy, motor and sensory block characteristics, and complications were noted.

RESULTS

The nalbuphine group had a significantly longer two-segment regression time of sensory blockade and extended analgesia duration than the fentanyl group. Haemodynamics, entropy, time for onset of sensory and motor blockade and adverse effects were comparable in both groups.

CONCLUSION

Nalbuphine prolongs sensory blockade and postoperative analgesia duration with minimal side effects and is a safe intrathecal adjuvant.

Postoperative injectable opioid use and incidence of surgical site complications after use of liposomal bupivacaine in canine gastrointestinal foreign body surgery

OBJECTIVE

To compare postoperative analgesic use and postoperative complications between dogs that received liposomal bupivacaine (LB) during surgical gastrointestinal foreign body (GIFB) removal and those that did not.

STUDY DESIGN

Retrospective study.

ANIMALS

Two hundred five dogs.

METHODS

Medical records for all dogs with GIFB removal at the Purdue University Veterinary Hospital between May 2017 and August 2021 were searched. Incomplete records and dogs with less than 2 weeks' veterinary follow up were excluded. Data collected included: patient information, time until surgery, intraoperative findings, surgical data (including perforation at time of surgery, linear vs. solid, enterotomy vs. enterectomy), use of LB (including time and manner of administration), time to extubation after surgery, in-hospital postoperative analgesic use and duration, and postoperative complications. Fentanyl was noted as used/not used, quantified as mean hourly rate over 12 h intervals. All analyses were performed using commercial statistical software with p < .05 as the significance level.

RESULTS

Dogs that received LB were heavier (n = 65, median 28.5 kg) than those that did not (n = 140, median 24.4 kg) (p = .005). Postoperative fentanyl use (p < .05 between 13 and 72 h) and hourly rates (p < .05 between 13 and 48 h) were less, and postoperative time in the intensive care unit (ICU) (p < .001) and hospital were shorter (p < .001) in dogs receiving LB. Postoperative wound complications were seen in 7/65 dogs (10.8%, 95% CI = 4.4-21.0%) with LB and 4/140 (2.9%, 95% CI = 0.8-7.2%) without LB (p = .039).

CONCLUSION

Use of LB was associated with reduced postoperative analgesic use, and shortened ICU and hospital stay but also with wound complications.

CLINICAL SIGNIFICANCE

Caution should be used when using LB in (clean) contaminated surgeries.

Protocol for a randomized controlled trial of endoscopic ultrasound guided celiac plexus neurolysis (EUS-CPN) with vs without bupivacaine

BACKGROUND

Pancreatic cancer is a devastating disease with less than 5% 5-year survival. Inoperable patients often present with pain. Randomized controlled trial have shown that endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) improves pain control. It is usually performed by injecting bupivacaine followed by absolute alcohol around the celiac axis.

STUDY DESIGN

Single center, randomized, double blind controlled trial of EUS-CPN with and without bupivacaine in patients with inoperable malignancy (pancreatic or other) involving the celiac plexus. The study was approved by research ethics board with approval number of 2022-9969, 21.151 and registered on ClinicalTrials.gov (NCT04951804).

DISCUSSION

We hypothesize that bupivacaine is superfluous and may actually reduce pain control by diluting the neurolytic effect of alcohol. Bupivacaine is also potentially dangerous in that it may produce serious adverse events such as arrythmias and cardiac arrest if inadvertently injected intravascularly.

CONCLUSION

This randomized trial is designed to assess whether bupivacaine is of any value during EUS-CPN.

Pericapsular nerve group block in hip arthroplasty: A prospective randomized trial

OBJECTIVES

This study aimed to evaluate the analgesic effect of the ultrasound-guided pericapsular nerve group (PENG) block in hip arthroplasty (HA) surgery.

DESIGN

A prospective double-blinded, randomized study.

SETTING

Tertiary institutional clinical care.

PARTICIPANTS

Fifty patients, more than 50 years old of both genders, were chosen according to the American Society of Anesthesiologists classification, with physical status I-III, and scheduled for unilateral HA surgeries.

INTERVENTIONS

Patients were randomized to receive either a sham PENG block with 20 mL of normal saline (control group) or a PENG block with 20 mL of bupivacaine 0.25 percent (PENG group).

MAIN OUTCOME MEASURES

From the onset of the first request for rescue opioid analgesia, preoperative pain scores before and after block (at rest and with a raised straight leg), the incidence of quadriceps weakness after the block, intraoperative fentanyl consumption, post-operative pain scores, and morphine consumption, besides the presence and frequency of adverse events, were recorded.

RESULTS

The patients undergoing PENG block with bupivacaine had prolonged durations before the first analgesic request, lower perioperative pain scores, less intraoperative rescue fentanyl, and less post-operative morphine consumption than the control group, with nonsignificant motor weakness after the block and similar adverse events.

CONCLUSIONS

The PENG block provided effective perioperative analgesia for HA with prolonged duration of analgesia, nonsignificant motor effects, reduced perioperative opioids consumption, and no major side effects.

Plasma concentrations of levobupivacaine in neonates during caudal epidural analgesia maintained over 48 hours

BACKGROUND

Differences in neonatal pharmacokinetics are known to cause systemic accumulation of levobupivacaine with adverse effects during epidural analgesia. Therefore, it is not recommended to surpass 48 hours of administration in neonates. Free and total levobupivacaine levels are considered as predictors of toxicity.

OBJECTIVE

The aim of the LEVON pilot study was to detect the accumulation of levobupivacaine during epidural analgesia exceeding 48 hours in neonates.

METHODS

Ten neonates received a loading dose of levobupivacaine (1.25 mg/kg) followed by a continuous infusion (0.2 mg/kg/hour) epidurally. Free and total levobupivacaine concentrations were measured 0.5, 1, 6, 12, 36, 72 and 144 hours after the start of infusion. Cumulative doses of levobupivacaine, pain scores and clinical signs of toxicity were used for assessing efficacy and safety.

RESULTS

The median concentrations of total levobupivacaine were 586.0, 563.0, 837.5, 957.0, 1930.0, 708.5 and 357.5 ng/ml. The median concentrations of free levobupivacaine were 4.0, 3.6, 5.5, 3.6, 5.5, 0.8 and 0.0 ng/ml. Three patients reached concerning concentrations of total levobupivacaine. Levels of free levobupivacaine remained low. No signs of toxicity were observed.

CONCLUSION

Caudal epidural analgesia with levobupivacaine lasting longer than 48 hours appears to be safe providing that free levobupivacaine levels are below the presumed threshold for toxicity (Tab. 1, Fig. 1, Ref. 29). Text in PDF www.elis.sk Keywords: free levobupivacaine, total levobupivacaine, neonate, caudal continuous epidural analgesia, postoperative pain.

Troubleshooting obstetric spinal anaesthesia at district hospital level

Obstetric spinal anaesthesia is routinely used in South African district hospitals for caesarean sections, providing better maternal and neonatal outcomes than general anaesthesia in appropriate patients. However, practitioners providing anaesthesia in this context are usually generalists who practise anaesthesia infrequently and may be unfamiliar with dealing with complications of spinal anaesthesia or with conversion from spinal to general anaesthesia. This is compounded by challenges with infrastructure, shortages of equipment and sundries and a lack of context-sensitive guidelines and support from specialised anaesthetic services for district hospitals. This continuous professional development (CPD) article aims to provide guidance with respect to several key areas related to obstetric spinal anaesthesia, and to address common concerns and queries. We stress that good clinical practice is essential to avoid predictable, common complications, and hence a thorough preoperative preparation is essential. We further discuss clinical indications for preoperative blood testing, spinal needle choice, the use of isobaric bupivacaine, spinal hypotension, failed or partial spinal block and pain during the caesarean section. Where possible, relevant local and international guidelines are referenced for further reading and guidance, and a link to a presentation of this topic is provided.

Mepivacaine Versus Bupivacaine for Spinal Anesthesia: A Systematic Review and Meta-analysis of Random Controlled Trials

INTRODUCTION

Bupivacaine is a more widely used anesthetic than mepivacaine. However, the long-acting effects of bupivacaine often lead to slow and unpredictable return. As an intermediate-acting local anesthetic, mepivacaine can enable earlier ambulation and thus has other benefits. We performed a systematic review and meta-analysis of available randomized controlled trials (RCTs) comparing the anesthetic effects of mepivacaine and bupivacaine.

METHODS

On August 12, 2021, a search was performed in PubMed, Embase, and the Cochrane Library. Effect estimates with 95% CI were combined using a random effects model. We performed sensitivity analyses to explore sources of heterogeneity and stability of results.

RESULTS

Of the 406 papers screened, 14 population-based randomized controlled trials were included, with a total of 1007 patients. Overall, compared to bupivacaine, mepivacaine was associated with higher numbers of motor block 3 (OR, 4.05; 95% CI 1.92-8.57), shorter length of stay (SMD, - 0.77; 95% CI - 1.52 to - 0.03), faster recovery from motor block (SMD, - 1.45; 95% CI - 2.39 to - 0.51), and shorter time to return to voiding (SMD, - 1.24; 95% CI - 1.83 to - 0.64). Mepivacaine was associated with a higher incidence of transient neurologic symptoms (TNS) and transient nerve root irritation (TRI) (OR, 9.18; 95% CI 2.42-34.88). There was no statistical difference between the two anesthetics in terms of pain index on the postoperative day (SMD, 0.20; 95% CI - 0.06 to 0.46) and incidence of urinary retention (OR, 0.98; 95% CI 0.47-2.03).

CONCLUSIONS

Mepivacaine may have advantages over bupivacaine in terms of achieving motor block 3, shorter length of stay, earlier recovery from motor block, and earlier time to return to voiding, but it may have a higher incidence of TNS or TRI than bupivacaine. Therefore, mepivacaine may be used before bupivacaine in spinal anesthesia.

SABER-Bupivacaine Reduces Postoperative Pain and Opioid Consumption After Arthroscopic Subacromial Decompression: A Randomized, Placebo-Controlled Trial

INTRODUCTION

Shoulder arthroscopy can result in substantial postoperative pain. Sucrose acetate isobutyrate extended-release bupivacaine (SABER-Bupivacaine; trade name Posimir) is a novel depot formulation of bupivacaine designed to provide analgesia at the surgical site for up to 72 hours. The objective of this study was to evaluate the effect of SABER-Bupivacaine on pain and opioid consumption after arthroscopic subacromial decompression and to assess short-term and long-term safety.

METHODS

In this double-blind, placebo-controlled trial, 78 subjects were randomized in a 2:1 ratio to SABER-Bupivacaine 5 mL or SABER-placebo 5 mL injected into the subacromial space just before skin closure. Twenty-nine additional subjects were randomized on an exploratory basis to bupivacaine hydrochloride 20 mL, also injected subacromially. Subjects rated pain intensity on a 0 to 10 scale over the first 3 postoperative days and received intravenous or oral morphine for breakthrough pain. The coprimary efficacy end points were pain intensity on 90° shoulder flexion and cumulative morphine intake from 0 to 72 hours after surgery. The time to first use of opioid rescue analgesia was a secondary end point.

RESULTS

The mean (SD) pain intensity was 5.16 (1.94) for SABER-Bupivacaine and 6.43 (1.77) for placebo (P = 0.012). The median consumption of intravenous morphine equivalents was 4.0 mg for SABER-Bupivacaine and 12.0 mg for placebo (P = 0.010). The median time to first use of morphine rescue was 12.4 hours for SABER-Bupivacaine and 1.2 hours for placebo (P = 0.014). The corresponding values for bupivacaine hydrochloride were 5.16 (2.38), 8.0 mg, and 1.4 hours. The incidence and severity of treatment-emergent adverse events were similar for all treatment groups, and no functional or radiographic differences were noted at the 6-month follow-up.

DISCUSSION

Compared with placebo, SABER-Bupivacaine reduced pain and opioid analgesic consumption over 72 hours after arthroscopic subacromial decompression and prolonged the time to first use of opioid rescue analgesia. No safety signals were noted during the immediate postoperative period or at 6-month follow-up.

Comparison of equipotent doses of intrathecal hyperbaric prilocaine 2% and hyperbaric bupivacaine 0.5% for elective caesarean section: A prospective, randomised, controlled, two-centre clinical trial

BACKGROUND

Elective caesarean section is performed mainly under spinal anaesthesia using hyperbaric bupivacaine combined with opioids. Despite rapid onset, good quality anaesthesia, bupivacaine provides a long duration of motor block and is related to maternal hypotension. Current policies appeal for implementation of enhanced recovery procedures after caesarean section. Hyperbaric prilocaine is an intermediate-acting local anaesthetic known for its efficacy in ambulatory surgery. Evidence on the clinical relevance of intrathecal prilocaine use for caesarean section is currently lacking.

OBJECTIVES

We aimed to investigate whether hyperbaric prilocaine would offer a shorter motor block and recovery than bupivacaine, when comparing equipotent doses. We also assessed the characteristics of sensory block, maternal haemodynamics and side effects for both mother and newborn.

DESIGN

Prospective, randomised, double-blind, controlled, two-centre, clinical trial.

SETTING

One university teaching hospital and one general teaching hospital in Brussels, Belgium.

PATIENTS

American Society of Anesthesiologists' physical status 2 parturients (n = 40) undergoing caesarean section under spinal anaesthesia.

INTERVENTIONS

Patients were randomly assigned to receive spinal anaesthesia using hyperbaric prilocaine 50 mg or hyperbaric bupivacaine 10 mg, both given with sufentanil 2.5 μg and morphine 100 μg. An epidural catheter was introduced as a backup in case of failure.

MAIN OUTCOMES

The primary outcome was the motor block regression (modified Bromage scale 1 to 6). Secondary outcomes included sensory block characteristics, first unassisted ambulation, maternal side effects, newborns' parameters and overall satisfaction.

RESULTS

Median [IQR] motor block was significantly shorter in the hyperbaric prilocaine group (110 [104 to 150] min versus 175 [135 to 189] min, P = 0.001). First unassisted ambulation was achieved earlier after prilocaine (204.5 [177 to 246.5] min versus 314 [209.25 to 400] min, P = 0.007), and the incidence of maternal hypotension was significantly higher with bupivacaine (P = 0.033). No supplementary epidural analgesia was needed.

CONCLUSION

Prilocaine provides shorter motor block, faster recovery and better haemodynamic stability than bupivacaine while offering equivalent surgical anaesthesia.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02973048, EudraCT: 2016-003010-26.

Impact of Transversus Abdominis Plane Block With Bupivacaine or Ropivacaine Versus Intrathecal Morphine on Opioid-related Side Effects After Cesarean Delivery: A Meta-analysis of Randomized Controlled Trials

OBJECTIVES

Intrathecal morphine (ITM) is frequently associated with side effects such as postoperative nausea and vomiting (PONV) and pruritus. The aim of this meta-analysis was to compare the impact of transversus abdominis plane (TAP) block versus ITM on side effects following cesarean delivery.

MATERIALS AND METHODS

PubMed, Embase, Web of Science, and CENTRAL were searched for randomized controlled trials that compared TAP with ITM for cesarean delivery. The primary outcomes were opioid-related side effects. The secondary outcomes included pain scores, opioid consumption, patient satisfaction, and time to the first analgesia request.

RESULTS

Seven studies involving 660 patients were included. TAP blocks were performed with bupivacaine or ropivacaine. There was less PONV with TAP versus ITM (risk ratio [RR]=0.45, 95% confidence interval [CI]: 0.33-0.63, P<0.001; I2=0%), but no significant difference in pruritus (RR=0.76, 95% CI: 0.49-1.18, P=0.22; I2=78%) and sedation (RR=0.44, 95% CI: 0.19-1.00, P=0.05; I2=0%). TAP had a greater morphine consumption in 24 hours (mean difference: 5.80 mg; 95% CI: 1.38-10.22 mg, P=0.01; I2=89%) and higher pain score at rest at 6 hours (mean difference: 0.70, 95% CI: 0.39-1.02, P<0.001; I2=56%), but similar pain at rest at 24 hours and on movement compared with ITM. No differences were found in time to first analgesia and patient satisfaction.

DISCUSSION

Compared with ITM, TAP block is associated with less PONV but inferior early analgesia after cesarean delivery. However, the heterogeneity among the studies highlights the need for more well-designed studies to obtain more robust conclusions.

Analysis of bupivacaine and ropivacaine-related cardiac arrests in regional anesthesia: A systematic review of case reports

Regional anesthesia as a component of multimodal analgesia protocols has become more and more a part of modern perioperative pain management. The widespread adoption of ultrasound guidance in regional anesthesia has surely played an important role in that growth and it has significantly improved patient safety, decreased the incidence of block failure, cardiac arrest, and reduced complication rates. The objective of this systematic review is to extract, analyze, and synthesize clinical information about bupivacaine and ropivacaine related cardiac arrest that we might have a clearer picture of the clinical presentation. The literature search identified 268 potentially relevant publications and 22 relevant case reports were included in the review. Patients' demographics, types of regional anesthesia, hypotension, heart rhythm disorders, seizures, cardiac arrest, fatal outcome, recommendations and limitations on prevention and treatment of bupivacaine and ropivacaine related cardiac arrest are analyzed and discussed in the systematic review. Both bupivacaine and ropivacaine-induced local anesthetic toxicity can result in cardiac arrest. Lipid emulsion, telemetry, local anesthetic toxicity resuscitation training appears to be promising in improvement of survival but more research is needed. Improvement and encouragement of reporting the local anesthetic toxicity are warranted to improve the quality of information that can be analyzed in order to make more precise conclusion.

Efficacy and Safety of a Surgeon-Performed Laparoscopic-Guided, 4-point Transversus Abdominis Plane Block: A retrospective review

We performed a retrospective chart review from October 2017 to March 2019 to demonstrate the safety and efficacy of a surgeon-performed, laparoscopically guided, transversus abdominis plane (TAP) blocks for robot-assisted gynecologic procedures. A total of 116 patients who underwent robot-assisted gynecologic surgery, at 1 academic hospital, with administration of a 4-point TAP block were included. A 4-point TAP block was performed under laparoscopic visualization, by the same surgeon, after induction of anesthesia and immediately after placement of the laparoscope. Liposomal bupivacaine (20 mL) and 0.5% bupivacaine (20 mL) mixed with saline were used as the injectant. All information from the surgical admission and the postoperative follow-up were reviewed. Data were presented in our descriptive study. A total of 116 patients were included with a mean age of 40.6 years (19-80 years) and a mean body mass index of 30.6 kg/m² (17.2-53.3 kg/m²). Of the patients, 70.7% were discharged to home on the day of surgery. Of the 29.3% of patients who were admitted, 20.6% were admitted because of pain control. Those who were admitted for pain control comprised 6.0% of the total of all study participants. There were no adverse events in our cohort and no readmissions because of pain control. A surgeon-performed TAP block, under laparoscopic visualization, is a safe and efficacious intervention to reduce postoperative pain and may add to a multimodal approach for enhanced recovery protocols.

Retrospective analysis of complications associated with retrobulbar bupivacaine in dogs undergoing enucleation surgery

OBJECTIVE

To investigate complications associated with, and without, bupivacaine retrobulbar local anesthesia in dogs undergoing unilateral enucleation surgery.

STUDY DESIGN

Retrospective, observational study.

ANIMALS

A total of 167 dogs underwent unilateral enucleation surgery via a transpalpebral approach.

METHODS

Records from 167 dogs that underwent unilateral enucleation surgery that did (RB) or did not (NB) include retrobulbar bupivacaine anesthesia were reviewed, including anesthetic record, daily physical examination records, surgery report, patient discharge report and patient notes within 14 days of the surgery. Specific complications and severity were compared between RB and NB using the Wilcoxon rank-sum test. A 'complication burden' (0-5) comprising five prespecified complications was assigned and tested using rank-sum procedures. Statistical significance was set to 0.05.

RESULTS

Group RB included 97 dogs and group NB 70 dogs. Dogs in NB had a 17.0 percentage points (points) greater risk for a postoperative recovery complication (38.6% versus 21.6%; 95% confidence interval: 3.0-30.6 points; p = 0.017). There was inconclusive evidence that dogs in group RB had a lower risk of requiring perioperative anticholinergic administration (12.4% versus 22.9%; 10.5 points; p = 0.073). Other complications were similar between groups RB and NB with risks that differed by <10 points. The risk of hemorrhage was similar between groups RB (22.7%) and NB (20.0%) with no significant difference in the level of severity (p = 0.664).

CONCLUSIONS AND CLINICAL RELEVANCE

In this retrospective study, the use of retrobulbar bupivacaine for enucleation surgery in dogs was not associated with an increased risk of major or minor complications.

The effects of isobaric and hyperbaric bupivacaine on maternal hemodynamic changes post spinal anesthesia for elective cesarean delivery: A prospective cohort study

BACKGROUND

Spinal anesthesia is a form of regional anesthesia frequently used in various lower abdominal, orthopedic, obstetric operations such as a cesarean delivery. The most common local anesthetic used for spinal anesthesia in obstetric and non-obstetric surgery is bupivacaine which can be utilized as an isobaric or hyperbaric solution, producing differences in maternal hemodynamic changes. Against this backdrop, the study aims to compare the effects of isobaric and hyperbaric bupivacaine on maternal hemodynamic alterations after administering spinal anesthesia for elective cesarean delivery at Gandhi Memorial Hospital, Addis Ababa, Ethiopia.

METHODS

A hospital-based prospective cohort study design was employed for the period December 1, 2017 to January 30, 2018. A total of 100 parturient were involved, with one group exposed to isobaric bupivacaine and the other to hyperbaric bupivacaine to observe their effects on maternal hemodynamic changes post spinal anesthesia. The participants were selected through systematic random sampling. Data analysis was performed using SPSS (version 20) through descriptive statistic, independent sample t-test, Mann-Whitney U-test, Fisher's exact test, and Chi-square test were used. P values of <0.05 was assumed as statistically significant for all tests.

RESULTS

The incidence of hypotension was found to be greater in isobaric than hyperbaric groups (82% vs. 60% respectively; p = 0.015). No statistical significant differences were found in mean arterial pressure value at baseline, but, statistically significant changes were observed among the groups (p <0.05) at all study timing after spinal anesthesia, except at 30thmin. No statistically significant differences were seen in the mean heart rate variability after spinal anesthesia at all periods, except the 15th minute (p = 0.033). A greater rate of vasopressor was used in the isobaric group as compared to the hyperbaric group (36% vs. 14% respectively; p = 0.011).

CONCLUSION

Baricity is a significant factor in maternal hemodynamic changes in the parturient for elective cesarean section. Isobaric bupivacaine produces greater change in blood pressure and incidence of hypotension and entails a greater vasopressor requirement than hyperbaric bupivacaine after spinal anesthesia for elective cesarean section.

Height-based dosing algorithm of bupivacaine in spinal anaesthesia for decreasing maternal hypotension in caesarean section without prophylactic fluid preloading and vasopressors: study protocol for a randomised controlled non-inferiority trial

INTRODUCTION

Effectively preventing or treating spinal-induced maternal hypotension is considered to be the Holy Grail of obstetric anaesthesia. Prophylactic fluid preloading and vasopressors decrease hypotension but may aggravate heart load, induce fetal acidosis or maternal bradycardia. Using low-dose local anaesthetic decreases hypotension but may cause insufficient anaesthesia. Whether there is a height-based dosing algorithm of local anaesthetic in spinal anaesthesia for caesarean section that can provide sufficient anaesthesia with less hypotension without prophylactic fluid preloading and vasopressors is unclear. This study was designed to investigate a height-based dosing algorithm of bupivacaine in spinal anaesthesia for caesarean section.

METHODS AND ANALYSIS

This single-centre, double-blinded, prospective, non-inferiority, randomised controlled trial will include 264 parturients (between 18 and 45 years of age) who are scheduled for caesarean section. All participants will not receive prophylactic fluid preloading. The participants will be randomly divided into two groups: the test group or conventional group. For parturients in the test group, 0.5% isobaric bupivacaine (1.15-1.70 mL) will be injected into the subarachnoid space without prophylactic vasopressors. The bupivacaine dose depends on the height of subjects. For parturients in the conventional group, 0.5% bupivacaine (1.8 mL) will be injected into the subarachnoid space along with prophylactic vasopressors. The primary outcome is the incidence of maternal hypotension. The secondary outcomes include the failure rate of spinal anaesthesia, level of sensory block, degree of motor block, other complications in parturients, time of operation, neonatal outcome and quality of anaesthesia.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Shenzhen People's Hospital of Jinan University (Permit No. SZY-00251, chairperson Xiaofang Yu) on 8 February 2018The study results will be disseminated through peer-reviewed journals, professional societies and meetings.

TRIAL REGISTRATION NUMBER

NCT03497364; Pre-results.

High Glucose Enhances Bupivacaine-Induced Neurotoxicity via MCU-Mediated Oxidative Stress in SH-SY5Y Cells

Bupivacaine, a typical local anesthetic, induces neurotoxicity via reactive oxygen species regulation of apoptosis. High glucose could enhance bupivacaine-induced neurotoxicity through regulating oxidative stress, but the mechanism of it is not clear. Mitochondrial calcium uniporter (MCU), a key channel for regulating the mitochondrial Ca2+ (mCa2+) influx, is closely related to oxidative stress via disruption of mCa2+ homeostasis. Whether MCU is involved in high glucose-sensitized bupivacaine-induced neurotoxicity remains unknown. In this study, human neuroblastoma (SH-SY5Y) cells were cultured with high glucose and/or bupivacaine, and the data showed that high glucose enhanced bupivacaine-induced MCU expression elevation, mCa2+ accumulation, and oxidative damage. Next, Ru360, an inhibitor of MCU, was employed to pretreated SH-SY5Y cells, and the results showed that it could decrease high glucose and bupivacaine-induced mCa2+ accumulation, oxidative stress, and apoptosis. Further, with the knockdown of MCU with a specific small interfering RNA (siRNA) in SH-SY5Y cells, we found that it also could inhibit high glucose and bupivacaine-induced mCa2+ accumulation, oxidative stress, and apoptosis. We propose that downregulation expression or activity inhibition of the MCU channel might be useful for restoring the mitochondrial function and combating high glucose and bupivacaine-induced neurotoxicity. In conclusion, our study demonstrated the crucial role of MCU in high glucose-mediated enhancement of bupivacaine-induced neurotoxicity, suggesting the possible use of this channel as a target for curing bupivacaine-induced neurotoxicity in diabetic patients.

Onset Time of Local Anesthesia After Single Injection in Toe Nerve Blocks: A Randomized Double-Blind Trial

PURPOSE

The study was conducted to investigate the onset time and safety profile of four different local anesthetic solutions.

DESIGN

Randomized controlled clinical trial study.

METHODS

One hundred twelve healthy volunteers were assigned to receive digital block on their second toe. Individuals were randomly assigned to one of the following groups: lidocaine 2%, lidocaine 2% with epinephrine, bupivacaine 0.5%, or bupivacaine 0.5% with epinephrine. Onset time was measured until detecting the absence of pinprick sensation. Oxygen saturation was measured in the infiltrated toe up to 60 minutes.

FINDINGS

The subjects in the groups of anesthetics with epinephrine had a significantly lower mean onset time. There were no significant differences regarding oxygen saturation between the groups and no adverse effects were recorded.

CONCLUSIONS

The use of anesthetics with epinephrine can be an effective form of local anesthetic for digital blocks when a rapid onset of action, prolonged duration of anesthesia, and vasoconstrictive action are required.

Analgesic Effect of Caudal Bupivacaine with or without Clonidine in Pediatric Patient

BACKGROUND

Caudal analgesia has long been the cornerstone to successful pain management in children undergoing abdominal and lower limb surgeries. Its analgesic duration with single shot injection is however limited. So adjuvants are used with local anesthetics in an attempt to increase the duration of caudal analgesia. This study aims to investigate the duration of analgesia provided by Clonidine when added to caudal Bupivacaine.

METHODS

A randomized, double blinded, comparative study was conducted on 64 patients, aged two to seven years, scheduled for unilateral inguinal hernia repair. Patients were randomly allocated into two groups of 32 each, with group A receiving bupivacaine two milligram/kilogram and group B receiving bupivacaine two milligram/kilogram with one microgram/kilogramclonidine, (total volume of injectate was one milliliter/kilogram). Duration of analgesia, hemodynamic response and adverse effects, if any were noted.

RESULTS

Mean duration of analgesia in group A was 264.12 ± 68.77 minutes and in group B was 520 ± 57.37 minutes, p-value <0.001.Incidence of vomiting was 9% in group A compared to 6% in group B.

CONCLUSIONS

Clonidineas an adjuvant to caudal bupivacaine prolongs the duration of analgesia without increasing the adverse effects.

Clonidine as an Analgesic Adjuvant to Continuous Paravertebral Bupivacaine for Post-thoracotomy Pain

We prospectively evaluated the effect of Clonidine as an adjuvant to bupivacaine for continuous paravertebral intercostal nerve block, measuring pain and sedation scores and pulmonary function tests. Thirty patients scheduled to undergo thoracotomy were randomized to receive either a bolus of 0.125% bupivacaine 2 mg/kg (group BUP) or 0.125% bupivacaine 2 mg/kg with Clonidine 2 μg/kg (group BUP+CLO), followed by an infusion of 0.125% bupivacaine at 0.5 mg/kg/h, or 0.125% bupivacaine at 0.5 mg/kg/h with Clonidine at 2 μg/kg/h, in respective groups, through a paravertebral intercostal catheter. Haemodynamic parameters, pain and sedation scores and pulmonary function tests were recorded at 6, 12, 24 and 48 hours after arrival in postoperative care unit.

There were significantly lower pain scores at rest and on coughing in group BUP+CLO compared with group BUP (P<0.01). Multiple comparisons revealed a significant reduction in pain score at each time point (P<0.01), except at 12h to 24h, in group BUP+CLO. Sedation scores were significantly higher in group BUP+CLO compared with group BUP at each time point (all P<0.01). There was a linear effect of time on sedation score in group BUP whereas in group BUP+CLO, the effect was quadratic. Patients in the Clonidine group had a higher incidence of hypotension (P<0.01). There was no significant difference in pulmonary function between the groups.

We conclude that using Clonidine as an adjunct to bupivacaine for continuous paravertebral intercostal nerve block improves pain relief after thoracotomy, but hypotension and sedation are adverse effects interfering with its clinical application.

Spinal-induced Hypotension in Elderly Patients with Hip Fracture. A Comparison of Glucose-free Bupivacaine with Glucose-free Bupivacaine and Fentanyl

Intraoperative hypotension is a common and potentially deleterious event in elderly patients undergoing spinal anaesthesia for repair of hip fractures. The synergism between intrathecal opioids and local anaesthetics may allow a reduction in the dose of local anaesthetic and cause less sympathetic block and hypotension, while still maintaining adequate anaesthesia. We studied 40 elderly patients having either an insertion of a dynamic hip screw or a hemi-arthroplasty and compared 9.0 mg glucose-free bupivacaine with added fentanyl 20 μg (group BF) with 11.0 m glucose-free bupivacaine alone (group B). Hypotension was defined as a fall in systolic blood pressure to less than 75% baseline or less than 90 mmHg. The incidence and frequency of hypotension in group BF were less than in group B. Similarly, falls in systolic, diastolic and mean blood pressures were all less in group BF than in group B. However, there were four failed blocks in group BF and one in group B.

[Mix-up of medication in spinal anaesthetics]

BACKGROUND

Administration of the wrong medication can cause severe injury and harm to the patient; it can also have a big impact on the healthcare professionals involved.

CASE DESCRIPTION

We describe two patient cases in which the antifibrinolytic agent tranexamic acid was accidentally administered instead of the planned anaesthetic drug bupivacaine. The medication mix-up resulted in serious adverse outcomes for both patients. Both incidents were the result of a sequence of the following human errors and system failures: (1) the packaging for bupivacaine and the label for tranexamic acid were altered; (2) the spinal trolley was restocked incorrectly; and (3) the medication was not double-checked before administration.

CONCLUSION

These cases illustrate how important it is to carefully adhere to safety procedures, such as double-checking of medication. Care providers must see to it that these procedures are also complied with if circumstances change. If necessary, the safety procedures must be adapted.

Ultrasound guided erector spinae plane block as a cause of unintended motor block

Erector spinae plane block (ESPB) as postoperative analgesia method has been successfully carried out in several surgical interventions. Postoperative pain treatment for cesarean section is considered one of the important challenges for anesthesiologists due to the risk of chronic pain development and even pospartum depression. Regional anesthesia techniques were effectively used to prevent the pain together with multimodal analgesia regimes in cesarean section. Formerly, successful erector spinae plane block was documented as postoperative analgesia treatment for cesarean section; however, no motor weakness was recorded as a side effect. In this case report, we present an unexpected motor weakness as a side effect of the erector spinae plane block after cesarean delivery operation in a 29 year old patient. To our knowledge, this is the first report of motor weakness related to the ESPB.

Beta-adrenergic activation induces cardiac collapse by aggravating cardiomyocyte contractile dysfunction in bupivacaine intoxication

In order to determine the role of the adrenergic system in bupivacaine-induced cardiotoxicity, a series of experiments were performed. In an animal experiment, male Sprague-Dawley (SD) rats under chloral hydrate anesthesia received intravenous bupivacaine, followed by an intravenous injection of adrenalin or isoprenalin, and the electrocardiogram (ECG), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of rise of left ventricular pressure (+dP/dtmax) and the maximum rate of pressure decrease (-dP/dtmax) were continually monitored. In a cellular experiment, freshly isolated adult SD rat ventricular myocytes were perfused with bupivacaine at different concentrations in the presence or absence of isoprenalin, with or without esmolol. The percentage of the sarcomere shortening (bl% peak h), departure velocity (dep v) of sarcomere shortening and time to 50% of the peak speed of myocyte contraction (Tp50) was assessed by a video-based edge-detection system. In an additional experiment, Swiss mice pretreated with saline, isoprenalin, esmolol or dexmedetomidine received bupivacaine to determine the 50% lethal dose (LD50) of bupivacaine. Electron microscopy of myocardial mitochondria was performed to assess damage of these structures. To test mitochondrial reactive oxygen species (ROS) production, freshly isolated SD rat ventricular myocytes were incubated with bupivacaine in the presence of isoprenalin, with or without esmolol. First, our results showed that bupivacaine significantly reduced the LVSP and +dP/dtmax, as well as enhanced the LVEDP and -dP/dtmax (P < 0.05, vs. control, and vs. baseline). Adrenalin and isoprenalin induced a further reduction of LVSP and +dP/dtmax (P < 0.05, vs. before adrenalin or isoprenalin delivery, and vs. control). Second, bupivacaine induced a dose-dependent cardiomyocyte contractile depression. While 5.9 μmol/L or 8.9 μmol/L of bupivacaine resulted in no change, 30.0 μmol/L of bupivacaine prolonged the Tp50 and reduced the bl% peak h and dep v (P < 0.05, vs. control and vs. baseline). Isoprenalin aggravated the bupivacaine-induced cardiomyocyte contractile depression, significantly prolonging the Tp50 (P < 0.05, vs. bupivacaine alone) and reducing the dep v (P < 0.05, vs. bupivacaine alone). Third, esmolol and dexmedetomidine significantly enhanced, while isoprenalin significantly reduced, the LD50 of bupivacaine in mice. Fourth, bupivacaine led to significant mitochondrial swelling, and the extent of myocardial mitochondrial swelling in isoprenalin-pretreated mice was significantly higher than that compared with mice pretreated with saline, as reflected by the higher mitochondrial damage score (P < 0.01). Meanwhile, esmolol pretreatment significantly reduced the mitochondrial damage score (P < 0.01). Fifth, bupivacaine significantly increased the ROS in freshly isolated cardiomyocytes, and added isoprenalin induced a further enhancement of ROS production (P < 0.05, vs. bupivacaine alone). Added esmolol significantly decreased ROS production (P < 0.05, vs. bupivacaine + isoprenalin). Our results suggest that bupivacaine depressed cardiac automaticity, conductivity and contractility, but the predominant effect was contractile dysfunction which resulted from the disruption of mitochondrial energy metabolism. β-adrenergic activation aggravated the cellular metabolism disorder and therefore contractile dysfunction.

A liver transplant recipient with possible bupivacaine-induced liver injury caused by intra-articular injection after total knee arthroplasty: A case report

RATIONALE

Although the survival period of patients who undergo liver transplantation is improving due to advances in surgical techniques and medical treatment, there is a lack of detailed, sufficient data that compare the choice of anesthetic agent in post-liver transplant surgery to avoid liver injury.

PATIENT CONCERNS

The authors describe acute liver injury observed in a 61-year-old man who underwent liver transplantation surgery 13 years previously and who was on immunosuppressive therapy. The patient underwent bilateral total knee arthroplasty under general anesthesia, for which a total of 200 mg bupivacaine was injected into each knee after wound closure. Liver enzyme levels increased to more than 10 times the upper limit of normal after the conclusion of surgery and remained extremely high on postoperative day 1.

DIAGNOSES

Clinical and laboratory findings were consistent with bupivacaine-induced liver injury. Intra-articular administration of bupivacaine after total knee arthroplasty is a widely used intraoperative analgesic method and complications are rare; nevertheless, the risk for inadvertent delivery into the systemic circulation remains.

INTERVENTIONS

Clinical presentations and hepatobiliary ultrasound examination allowed a conservative management.

OUTCOMES

Serum liver enzyme levels normalized 12 days after surgery, and the patient was discharged 22 days after surgery.

LESSONS

Acute liver injury can lead to graft failure from late death after liver transplantation. Transplant recipients with long-term survival have the highest risk for anesthesia because of post-transplant complications, including diabetes, hypertension, and renal insufficiency. Clinicians should be aware that analgesic techniques and anesthetics may affect graft function.

Fixed dose vs height and weight adjusted dose of bupivacaine for caesarean section: A randomised controlled trial

OBJECTIVE

To determine frequency of maternal hypotension during spinal anaesthesia for elective caesarean section by comparing fixed dose with height and weight-adjusted dose of hyperbaric 0.5% bupivacaine.

METHODS

This randomised controlled trial was carried out at Pakistan Naval Ship Shifa Hospital, Karachi, and comprised patients with singleton pregnancy who were randomly divided into two groups. After preloading with 10ml/kg of Ringers lactate, Group A received fixed dose of 10mg of 0.5% hyperbaric bupivacaine, while Group B received dose according to height and weight using Harten's dose chart. Patients were made supine with wedge placed below the right hip. Variation in blood pressure was recorded and hypotension was treated with phenylephrine. Data was analysed with SPSS 16..

RESULTS

There were 80 subjects divided into groups of 40(50%) each. Hypotension occurred in 20(50%) subjects in group A and in 15(37.5%) patients in group B(p>0.05). Median dose of 0.5% bupivacaine in group B was 9(IQR=0.5)mg and minimum dose was 8mg. Additional analgesia with ketamine was given to 2(5%) patients in group A and 3(7.5%) patients in group B.

CONCLUSIONS

Fixed dose of 10mg of hyperbaric 0.5% bupivacaine had similar results to height and weight-adjusted dose of bupivacaine in spinal anaesthesia for caesarean section.

Linoleic Acid Attenuates the Toxic Dose of Bupivacaine-Mediated Reduction of Vasodilation Evoked by the Activation of Adenosine Triphosphate-Sensitive Potassium Channels

The goal of this study was to investigate the effect of lipid emulsion on a toxic dose of local anesthetic-mediated reduction of vasodilation evoked by the ATP-sensitive potassium (K_ATP) channel agonist levcromakalim. The effect of lipid emulsion (LE) and linoleic acid on the local anesthetic-mediated reduction of vasodilation and membrane hyperpolarization evoked by levcromakalim was assessed in isolated endothelium-denuded vessels (rat aorta and mesenteric artery) and aortic vascular smooth muscle cells. The effect of LE and linoleic acid on K_ATP channel activity in transfected HEK-293 cells was investigated, as was the effect of LE on bupivacaine concentration. The efficacy of LE in attenuating the local anesthetic-mediated reduction of vasodilation evoked by levcromakalim was correlated with the lipid solubility of the local anesthetic. Linoleic acid attenuated the bupivacaine-mediated reduction of vasodilation evoked by levcromakalim. LE decreased the bupivacaine-mediated reduction of membrane hyperpolarization evoked by levcromakalim but did not significantly alter the mepivacaine-mediated reduction. LE and linoleic acid both reversed the bupivacaine-mediated decrease of K_ATP activity and enhanced K_ATP activity. LE decreased the bupivacaine concentration. Linoleic acid may be the major contributor to LE-induced attenuation of bupivacaine-mediated reduction of vasodilation evoked by levcromakalim via the direct activation of K_ATP channels and indirect effects.

Mepivacaine Spinal Anesthesia Facilitates Rapid Recovery in Total Knee Arthroplasty Compared to Bupivacaine

BACKGROUND

Mepivacaine as a spinal anesthetic for rapid recovery in total knee arthroplasty (TKA) has not been assessed. The purpose of this study is to compare spinal mepivacaine vs bupivacaine for postoperative measures in patients undergoing primary TKA.

METHODS

Retrospective review of a prospectively collected single-institution database was performed on 156 consecutive patients who underwent primary TKA. Fifty-three patients were administered mepivacaine and 103 patients were administered bupivacaine. Primary outcomes were urinary retention, length of stay, pain control, opioid consumption, and distance associated with physical therapy. Statistical analysis with univariate logistic regression was performed to evaluate the effect of anesthetic with primary outcomes.

RESULTS

Patients undergoing TKA with mepivacaine had a shorter length of stay (28.1 ± 11.2 vs 33.6 ± 14.4 hours, P = .002) and fewer episodes of straight catheterization (3.8% vs 16.5%, P = .021) compared to bupivacaine. Patients administered mepivacaine exhibited slightly higher VAS pain scores and morphine consumption in the postanesthesia care unit (1.3 ± 1.9 vs 0.5 ± 1.3, P = .002; 2.2 ± 3.3 vs 0.8 ± 2.1 equivalents/h, P = .002), but otherwise exhibited no difference in VAS scores or morphine consumption afterwards. There was no need to convert to general anesthesia or transient neurologic symptom complication in either group.

CONCLUSION

Mepivacaine for spinal anesthesia with TKA had adequate duration to complete the surgery and facilitated a more rapid recovery with less urinary complications and a shorter length of stay. Patients administered mepivacaine did not display worse pain control or transient neurologic symptoms afterwards.

Cauda equina syndrome following an uneventful spinal anesthesia in a patient undergoing drainage of the Bartholin abscess: A case report

RATIONALE

Neuraxial anesthesia is a commonly used type of regional anesthesia. Cauda equina syndrome is an unusual and severe complication of neuraxial anesthesia, and is caused by damage to the sacral roots of the neural canal. We present a case of cauda equina syndrome following spinal anesthesia in a patient who underwent Bartholin abscess drainage.

PATIENT CONCERNS

A 23-year old female scheduled to undergo surgical drainage of Bartholin abscess. Spinal anesthesia was performed with bupivacaine and fentanyl. There were no perioperative adverse events reported. On postoperative day 1, the patient went to the emergency department describing bilateral weakness and pain of the lower extremities (LE).

DIAGNOSES

Lumbar magnetic resonance imaging showed increased gadolinium accumulation in the neural sheath at the level of the cauda equina tracts, consistent with the diagnosis of arachnoiditis and the diagnosis of cauda equina was established.

INTERVENTIONS

The patient received the following emergent treatment: 75 mg pregabalin (oral) every 12 hours, 20 mg (8 drops) tramadol (oral) every 8 hours, and 4 mg dexamethasone (intravenous) every 6 hours. On postoperative day 4, the patient still experienced bilateral flaccid paraparesis (accentuated in the left side), neuropathic pain in low extremities, and left brachial monoparesis. Hence, dexamethasone was instantly replaced with 1 g methylprednisolone (intravenous) for 5 days.

OUTCOMES

After completing 5 days of methylprednisolone, on postoperative day 9, the patient experienced less pain in left extremities, osteotendinous reflexes were slightly diminished, and she was able to walk with difficulty for 3 to 5 minutes. Greater mobility was evidenced, with right proximal and distal low extremities Medical Research Council Scale grades of 2 and 3 and left proximal and distal low extremities Medical Research Council Scale grades 1 and 2, respectively. Oral prednisone was restarted. Consequently, she was discharged home in stable conditions on postoperative day 25 with a prescription for sertraline, clonazepam, pregabalin, paracetamol, and prednisone.

LESSON

The early detection and treatment of complications after neuraxial anesthesia is essential to minimize the risk of permanent damage.

A Comparative Study of the Duration and Efficacy of Tetracaine 1% and Bupivacaine 0.75% in Controlling Pain following Photorefractive Keratectomy (PRK)

Objective

To evaluate if topical bupivacaine 0.75% provides better pain control after excimer laser over topical tetracaine 1% without affecting corneal wound healing, refractive outcome of visual function.

Design

A prospective, double-masked trial was conducted in which 38 patients were randomized to receive either tetracaine or bupivacaine every 30 minutes for 24 hours post-operatively. Pain was recorded over a four day period using a Visual Analogue Pain Scale. The rate of epithelial healing was assessed during digitized retro-illumination photography. Visual performance was recorded using best corrected Snellen acuity, objective measurements of haze, halo and glare over a six month period.

Results

Tetracaine afforded better pain control (p=0.05). Full epithelial closure occurred in all patients within 72 hours and no statistically significant difference was recorded in any of the parameters measured.

Conclusions

Contrary to our expectation, the longer acting anaesthetic, bupivacaine, was inferior to tetracaine. Limited and supervised use of topical anaesthetics is recommended in controlling pain following photorefractive keratectomy.

The Efficacy of 0.75% Bupivacaine with ph Adjustment and Hyaluronidase for Peribulbar Blockade: The Incidence of Prolonged Ptosis

A prospective, double masked, randomised study was performed to compare the speed of onset of peribulbar anaesthesia using pH adjusted 0.75% bupivacaine, with and without the addition of hyaluronidase. No significant difference in speed of onset occurred due to the addition of hyaluronidase. There were 7 cases of post operative ptosis in the study group, including 1 case of orbital apex syndrome and 2 cases of transient 3rd nerve palsy. This incidence of post operative ptosis using pH adjusted 0.75% bupivacaine was statistically significantly greater than in a matched control group who received a 50:50 mixture of 1% lignocaine and 0.5% bupivacaine with hyaluronidase (p < 0.05). The possible causes of this increased incidence of post operative ptosis are discussed.

Total spinal block after local anesthetic administration through the wrong access port of a spinal infusion pump

We present a case reported on the SENSAR database. A patient with a spinal infusion pump was admitted for reservoir refill. On administration of 22ml of 0.75% bupivacaine the patient suffered a total spinal block with widespread loss strength and respiratory arrest. The patient required emergency orotracheal intubation, mechanical ventilation and admission to ICU, where extubation was achieved within two hours without incidences. At a later stage it was stated that the local anaesthetic had been administered via the access port for bolus or contrast administration instead of via the access to the reservoir. Analysis of the incident showed up latent factors related to absence lack of personnel training and internal protocols. The following measures were taken: pain unit meeting, alert sent to SENSAR bulletin and training request for members of the service.

Can Multimodal Pain Management in TKA Eliminate Patient-controlled Analgesia and Femoral Nerve Blocks?

BACKGROUND

TKA pain management protocols vary widely with no current consensus on a standardized pain management regimen. Multimodal TKA pain management protocols aim to address pain control, facilitate functional recovery, and maintain patient satisfaction.

QUESTIONS/PURPOSES

(1) Did changes to our pain management protocol, specifically adding liposomal bupivacaine, eliminating patient-controlled analgesia (PCA), and discontinuing femoral nerve blocks (FNBs), affect narcotic consumption after TKA? (2) Did these changes to our pain management protocols affect patient-reported pain scores? (3) Does the use of an immediate postoperative PCA affect rapid rehabilitation and functional recovery? (4) How did changes to our pain management regimen affect discharge disposition and pain-related Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores?

METHODS

We retrospectively analyzed an institutional arthroplasty database between September 2013 and September 2015 containing 1808 patients who underwent primary TKA. Departmental pain management protocols were compared in 6-month periods as the protocol changed. All patients received a multimodal pain management protocol including preoperative oral medications, spinal or general anesthesia, a short-acting intraoperative pericapsular injection, and continued postoperative oral narcotics for breakthrough pain. From September 2013 to April 2014, all patients received an intraoperative FNB and a PCA for the first 24 hours postoperatively (Cohort 1). From May 2014 to October 2014, a periarticular injection of liposomal bupivacaine was added to the protocol and FNBs were discontinued (Cohort 2). After April 2015, PCA was eliminated (Cohort 3). No other major changes were made to the TKA pain management pathways. Narcotic use, pain scores on 8-hour intervals, physical therapy milestones, and discharge disposition were compared.

RESULTS

Total narcotic use was the least in Cohort 3 (Cohort 3: 66 ± 54 morphine milligram equivalents versus Cohort 2: 82 ± 72 versus Cohort 1: 96 ± 62; p < 0.001). There was an increase in pain score immediately after surgery in Cohort 3 (4.0 ± 3.5 versus 1.2 ± 2.2 versus 1.2 ± 2.5, post hoc analysis of Cohort 2 versus 3: mean difference 2.6, 95% confidence interval [CI] 2.2-3.0; p < 0.001); however, it was not different for the remainder of the hospital stay. Patients who did not receive PCA reached functional milestones for both gait and stairs faster by postoperative day 1 (47% [328 of 698] versus 30% [158 of 527] versus 16% [93 of 583], p < 0.001; Cohort 3 versus 2: odds ratio 2.1, 95% CI 1.6-2.6; p < 0.001). Discharge to home occurred more frequently (84% [583 of 698] versus 78% [410 of 527] versus 72% [421 of 583], p = 0.010) in Cohort 3. There were no differences in pain-related HCAHPS scores across all cohorts.

CONCLUSIONS

Discontinuing PCAs and FNBs from our multimodal TKA pain management protocols and adding liposomal bupivacaine resulted in fewer narcotics consumed with no difference in pain control and faster functional recovery while maintaining high HCAHPS scores relating to pain.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The Effect of Rectus Sheath Block as a Supplement of General Anesthesia on Postoperative Analgesia in Adult Patient Undergoing Umbilical Hernia Repair

BACKGROUND

Ultrasound guided rectus sheath block can block the ventral rami of the 7th to 12th thoracolumbar nerves by injection of local anesthetic into the space between the rectus muscle and posterior rectus sheath. The aim of this randomized double-blind study was to evaluate the analgesic effect of the bilateral ultrasound guided rectus sheath block as supplement of general anesthesia on patents undergoing elective umbilical hernia repair.

METHODS

After the hospital ethics committee approval, 60 (ASA I-II) adult patients scheduled for umbilical hernia repair were included in this study. The group I (n=30) patents received only general anesthesia. In the group II (n = 30) patents after induction of general anesthesia received a bilateral ultrasound guided rectus sheath block with 40 ml of 0.25% bupivacaine. In this study we assessed demographic and clinical characteristics, pain score - VAS at rest at 2, 4, 6, 12 and 24 hours after operation and total analgesic consumption of morphine dose over 24-hours.

RESULTS

There were statistically significant differences in VAS scores between the groups I and II at all postoperative time points - 2hr, 4 hr, 6 hr, 12 hr and 24 hr. (P < 0.00001). The cumulative 24 hours morphine consumption after the operation was significantly lower in the group II (mean = 3.73 ± 1. 41) than the group I (mean = 8.76 ± 2.41). This difference was statistically significant (p = 0.00076).

CONCLUSION

The ultrasound guided rectus sheath block used for umbilical hernia repair could reduce postoperative pain scores and the amount of morphine consumption in 24 hours postoperative period.