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.

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.

A hybrid nanoparticle-protein hydrogel system for prolonged local anesthesia.

Local anesthetics are effective in relieving pain, but their duration of action is short. Therefore, the development of injectable sustained release systems to prolong the effect of local anesthetics has been of interest. In such systems delivering conventional local anesthetics, it has been challenging to achieve long durations of effect, particularly without incurring tissue toxicity. To overcome these challenges, we created a platform comprising a protein hydrogel incorporating hydrophobic local anesthetic (bupivacaine) nanoparticles. The nanoparticles were prepared by anti-solvent precipitation stabilized with bovine serum albumin (BSA), followed by crosslinking with glutaraldehyde (GA). The resulting BSA hydrogels prolonged release of bupivacaine in vitro. When bupivacaine nanoparticles within crosslinked BSA were injected at the sciatic nerve in rats, a duration of nerve block of 39.9 h was obtained, compared to 5.5 h for the commercial bupivacaine liposome suspension EXPAREL®. Tissue reaction was benign. We further demonstrated that this system could control the release of the amphiphilic drug diphenhydramine and the hydrophobic paclitaxel.

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.

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.

Effects of subconjunctival ropivacaine, liposomal bupivacaine, and mepivacaine on corneal sensitivity in healthy horses.

OBJECTIVE: To evaluate corneal sensitivity and adverse events following subconjunctival administration of three local anesthetics in horses. STUDY DESIGN: Randomized, masked, crossover study. ANIMALS: Twelve healthy adult mares. METHODS: The subconjunctival space of the treated eye was injected with 0.2 mL of liposomal bupivacaine (1.3%), ropivacaine (0.5%), or mepivacaine (2%). All horses received each medication once and the contralateral eye received saline (control). Corneal touch threshold (CTT) was measured using a Cochet-Bonnet esthesiometer before sedation, after sedation, and at specified intervals until it returned to baseline. Ocular examinations were performed at 24-, 72, and 168 h post-injection to monitor for adverse effects. RESULTS: The mean total time of anesthesia (TTA) was 168.3 min for ropivacaine, 169.2 min for liposomal bupivacaine, 103.3 min for mepivacaine and 30.7 min for the control. TTA for liposomal bupivacaine (p < .001) and ropivacaine (p = .001) was longer than the control. TTA for mepivacaine was not different from the control (p = .138), liposomal bupivacaine (p = .075) or ropivacaine (p = .150). Injection site hemorrhage reduced TTA regardless of treatments (p = .047). No adverse effects attributed to injections were noted. CONCLUSION: All three medications were well tolerated. Subconjunctival administration of ropivacaine and liposomal bupivacaine resulted in longer TTAs compared to the control; however, their TTAs were not different from that of mepivacaine. CLINICAL SIGNIFICANCE: Subconjunctivally administered liposomal bupivacaine and ropivacaine are viable options to provide prolonged corneal analgesia in horses. Future studies are needed to assess the efficacy in diseased eyes.

Buffered Versus Nonbuffered Local Anesthetics and Local Pain Scores in Upper Eyelid Blepharoplasty: Randomized Controlled Trial.

PURPOSE: This split-face study aimed to see whether different types of local anesthetics or their buffered/nonbuffered combinations produce lower pain scores in upper eyelid blepharoplasty. METHODS: The study involved 288 patients, randomly divided into 9 groups: 1) 2% lidocaine with epinephrine-Lid + Epi; 2) 2% lidocaine with epinephrine and 0.5% bupivacaine (1:1)-Lid + Epi + Bupi; 3) 2% lidocaine with 0.5% bupivacaine (1:1)-Lid + Bupi; 4) 0.5% bupivacaine-Bupi; 5) 2% lidocaine-Lid; 6) 4% articaine hydrochloride with epinephrine-Art + Epi; 7) buffered 2% lidocaine/epinephrine with sodium bicarbonate (SB) in a 3:1 ratio-Lid + Epi + SB; 8) buffered 2% lidocaine with SB in a 3:1 ratio-Lid + SB; 9) buffered 4% articaine hydrochloride/epinephrine with SB in a 3:1 ratio-Art + Epi + SB. Following the injection of the first eyelid and a 5-minute period of soft pressure on the injection site, patients were asked to rate their pain level on the Wong-Baker Face Pain Rating Visual Analogue Scale. Rating of the pain level was repeated 15 and 30 minutes following anesthetic administration. RESULTS: The lowest pain scores at the first time point were observed in Lid + SB when compared with all of the other groups ( p < 0.05). At the final time point, significantly lower scores were also observed in Lid + SB, Lid + Epi + SB, and Art + Epi + SB when compared with the Lid + Epi group ( p < 0.05). CONCLUSION: These findings could help surgeons select an appropriate combination of local anesthetics, particularly in patients with lower pain threshold and tolerance because buffered combinations of local anesthetics produce significantly lower pain scores compared with nonbuffered solutions.

Chronological changes in plasma levobupivacaine concentrations after bilateral modified thoracoabdominal nerve block through perichondrial approach.

The local anesthetic (LA) systemic toxicity of trunk blocks is a major concern. Recently, modified thoracoabdominal nerve block through perichondrial approach (M-TAPA) has attracted attention; however, plasma LA level is unknown. We tested whether the peak plasma LA concentration following M-TAPA, using 25 mL of 0.25% levobupivacaine mixed with epinephrine on each side, would be below the toxic level (2.6 µg/mL). We recruited 10 patients undergoing abdominal surgery with planned M-TAPA between November 2021 and February 2022. In all patients, 25 mL of 0.25% levobupivacaine mixed with 1:200,000 epinephrine was administered on each side. Blood samples were obtained at 10, 20, 30, 45, 60, and 120 min after the block. The highest individual peak and the mean peak plasma LA concentrations were 1.03 and 0.73 µg/mL, respectively. We could not capture the peak in five patients; however, the highest concentrations in all patients were significantly lower than the toxic level. A negative correlation between the peak level and body weight was observed. Our results indicated that the plasma LA concentration following M-TAPA using total of 50 mL of 0.25% levobupivacaine with epinephrine remains below the toxic level. Further research is required due to the small sample size of this study.Trial registry number: UMIN000045406.

Sustained release of levobupivacaine from temperature-sensitive injectable hydrogel for long-term local anesthesia in postoperative pain management.

Postoperative pain is a major concern for most of the surgical patients, and an inadequate postoperative pain control may cause a series of complications. With an effective pain control and lesser side effects, local anesthetics are preferred for use in postoperative pain management. However, the action duration of current local anesthetics is too short to meet the requirements of postoperative analgesia. In this study, an injectable levobupivacaine (LB)-loaded thermo-sensitive hydrogel system based on biodegradable poly(D,L-lactide)-poly(ethylene glycol)-poly(D,L-lactide) (PLEL) was developed for long-acting local anesthetic, in which the soluble charged cation form of LB (LB HCl) was partly alkalified to the poorly soluble base form (LB base). This hybrid LB loaded PLEL system (hLB/PLEL) is a free flowable liquid at room temperature and changes into a semi-solid hydrogel once injection in response to the physiological temperature. Then, the dissolved LB HCl could release firstly from the hydrogel contributing to a quick work, and the insoluble LB base dissolved and released gradually as the decrease of the pH during the biodegradation of PLEL hydrogel, resulting in a long-term LB release in local. The drug release behavior, pharmacokinetic, and biocompatibility of the thermo-sensitive hLB/PLEL were studied in vitro and in vivo. The anesthetic effects of hLB/PLEL system were evaluated in the rat models of sciatic nerve block, subcutaneous infiltration anesthesia and postoperative pain as well. This hLB/PLEL system generated a significantly prolonged analgesic effect in rat models, which produced approximately 7 times longer duration than 0.75% LB HCl and effectively relieved the spontaneous pain for 3 days. In general, the presented hLB/PLEL system can not only achieve a fast-acting but also sustainably release LB to block the nerve and significantly extend the effect of local analgesia, which means a promising candidate for long-acting postoperative pain management.

Comparison of the efficacy of 0.5% isobaric bupivacaine, 0.5% levobupivacaine, and 0.5% hyperbaric bupivacaine for spinal anesthesia in lower limb surgeries.

Various advantages of isobaric bupivacaine, levobupivacaine, and hyperbaric bupivacaine are described. There are no studies reliably determining the benefits of these forms of bupivacaine. The purpose of the study was to compare the efficacy of spinal anesthesia (SA) performed with 0.5% isobaric bupivacaine, 0.5% levobupivacaine, and 0.5% hyperbaric bupivacaine. The clinical study was approved by the ethics committee. The sample size was calculated for a confidence level of 99%. 111 patients were randomly allocated into 3 equal groups for spinal anesthesia in lower limb surgeries. In group 1 (1B) spinal anesthesia was performed with 3 ml of 0.5% isobaric bupivacaine (n = 37); in group 2 (2L)-3 ml of 0.5% levobupivacaine (n = 37), in group 3 (3H)-3 ml of 0.5% hyperbaric bupivacaine (n = 37). The criterion for assessing the effectiveness of anesthesia was the need to switch to another type of anesthesia (criterion-no anesthesia), or the need for additional use of narcotic analgesics or local anesthesia during surgery (criterion-reporting of painful feelings during the operation). In 1B anesthesia efficiency by the criterion of additional intraoperative analgesia was 100% (37 patients; 95% CI [0.88-1.0]); 2L-86.4%; (31 patients; 95% CI [0.68-0.92]); 3H-72.9% (27 patients; 95% CI [0.56-0.84]). There were significant differences between groups 1B and 2L: p < 0.05 (p = 0.0104). There were no significant differences between groups 2L and 3H (p = 0.2587). All patients in group 1B developed complete sensory block (++) within 4 (3; 5) min. In group 2L complete sensory block developed in 34 patients (89.4%) within 9 (5; 14) min, in group 3H sensory block developed in all patients within 3 (2.5; 4). The duration of analgesia period between 1B and 2L did not statistically differ (p = 0.73). In 3H the duration of analgesia was 170 (150; 200) min. The study found 83.7% efficacy of levobupivacaine and 72.9% efficacy of hyperbaric bupivacaine in comparison with isobaric bupivacaine (100%) when administered intrathecally in equal volumes and amounts (by the criterion of additional intraoperative analgesia).Trial registration: NCT05184465 (Initial Release: 12/01/2021; date of first publication-11/01/2022).

Injectable and topical local anesthetics for acute dental pain: 2 systematic reviews.

BACKGROUND: Local anesthesia is essential for pain control in dentistry. The authors assessed the comparative effect of local anesthetics on acute dental pain after tooth extraction and in patients with symptomatic irreversible pulpitis. TYPES OF STUDIES REVIEWED: The authors searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and the US Clinical Trials registry through November 21, 2020. The authors included randomized controlled trials (RCTs) comparing long- vs short-acting injectable anesthetics to reduce pain after tooth extraction (systematic review 1) and evaluated the effect of topical anesthetics in patients with symptomatic pulpitis (systematic review 2). Pairs of reviewers screened articles, abstracted data, and assessed risk of bias using a modified version of the Cochrane risk of bias 2.0 tool. The authors assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS: Fourteen RCTs comparing long- vs short-acting local anesthetics suggest that bupivacaine may decrease the use of rescue analgesia and may not result in additional adverse effects (low certainty evidence). Bupivacaine probably reduces the amount of analgesic consumption compared with lidocaine with epinephrine (mean difference, -1.91 doses; 95% CI, -3.35 to -0.46; moderate certainty) and mepivacaine (mean difference, -1.58 doses; 95% CI, -2.21 to -0.95; moderate certainty). Five RCTs suggest that both benzocaine 10% and 20% may increase the number of people experiencing pain reduction compared with placebo when managing acute irreversible pulpitis (low certainty). PRACTICAL IMPLICATIONS: Bupivacaine may be superior to lidocaine with epinephrine and mepivacaine with regard to time to and amount of analgesic consumption. Benzocaine may be superior to placebo in reducing pain for 20 through 30 minutes after application.

Intraoperative local instillation anesthesia using injection technique from J-VACTM drain for postoperative pain relief in male-type chest wall contouring surgery.

For postoperative acute pain during mastectomy, a few studies have reported the usefulness of an intraoperative local anesthesia instillation technique in which analgesics are injected through a drain placed under the skin, intraoperatively. This study presented a novel administration method, and the efficacy of local instillation anesthesia in male-type chest wall contouring surgery was assessed. Fifty-four patients underwent chest wall contouring surgery under general anesthesia. The 27 patients in each of the study and control groups, with our instillation technique and without the technique were compared, in terms of the maximum numerical rating scale (NRS) score within 24 h after surgery, the postoperative analgesic use frequency, and dosage until 6 d. The analgesic used was a mixture of 5 ml 1% lidocaine hydrochloride, epinephrine (0.05 mg), 10 ml 0.75% bupivacaine, and 10 ml saline. Thereon, 25 ml analgesia was administered from the left and right drain (15-Fr J-VACTM) and infiltrated for 15 min. Both NRS scores of postanesthesia care unit (PACU) discharge and the maximum NRS score within 24 h after PACU discharge were significantly lower in the study group than in the control group (p < 0.001, p = 0.048). The frequency of analgesics administered within 24 h after surgery was significantly lower in the study group than in the control group (p = 0.025). Our anesthesia instillation method for chest wall contouring surgery was effective in relieving acute pain occurring within 24 h after surgery and can be a useful analgesic administration method.

Wide Awake Local Anesthesia No Tourniquet Technique in Hand Surgery: The Patient Experience.

BACKGROUND: We attempted to evaluate patient satisfaction and overall experience during wide awake, local anesthesia, with no tourniquet (WALANT) hand surgery and quantify surgery-related outcomes. METHODS: We conducted a retrospective analysis of patient demographics, comorbidities, and patient reported outcomes via Single Assessment Numeric Evaluation (SANE) scores collected pre- and postoperatively of patients undergoing WALANT surgery by the 2 participating senior authors. A solution of 1% lidocaine with 1:100,000 epinephrine was used by 1 surgeon, while the other used a 1:1 ratio of 1% lidocaine with 1:100,000 epinephrine and 0.5% bupivacaine for local anesthetic injection. Patients were administered a postoperative survey to assess patient experience, including anxiety and pain levels, and overall satisfaction in the perioperative period. RESULTS: Overall, 97.7% of patients indicated that they would undergo a WALANT-style surgery if indicated in the future, 70.5% ate the day of surgery, and a total of 39.1% of patients reported driving to and from surgery. Postoperative SANE scores increased as compared with preoperative scores across all patients. The use of combination 1% lidocaine with 1:100,000 epinephrine and 0.5% bupivacaine was associated with lower intraoperative and postoperative visual analog scale pain scores. CONCLUSIONS: WALANT hand surgery was generally well tolerated with excellent surgical outcomes. Patients reported ease of preparation for surgery, faster recovery, and lack of anesthetic side effects as the main benefits of wide-awake surgery. Combination use of lidocaine and bupivacaine may be better than lidocaine alone with respect to pain control in the initial recovery period.

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.

Narcotic Utilization After Cleft Lip Repair: Does Local Anesthetic Choice Matter?

To analyze whether the choice of intraoperative local anesthetic for cleft lip repair is associated with the amount of perioperative narcotic utilization.Retrospective cohort study.Hospitals participating in the Pediatric Health Information System.Primary cleft lip repairs performed in the United States from 2010 to 2020.Local anesthesia injected-treatment with lidocaine alone, bupivacaine alone, or treatment with both agents.Perioperative narcotic administration.During the study interval, 8954 patients underwent primary cleft lip repair. Narcotic utilization for unilateral (P < .001) and bilateral (P = .004) cleft lip repair has decreased over the last 5 years. Overall, 21.8% (n = 1950) of infants were administered perioperative narcotics for cleft lip repair, such that 14.3% (n = 1282) required narcotics on POD 0, and 7.2% (n = 647) required narcotics on POD 1.In this study, 36.5% (n = 3269) patients received lidocaine, 22.0% (n = 1966) patients received bupivacaine, and 19.7% (n = 1762) patients received both local anesthetics. Administration of any perioperative narcotic was significantly lower in patients receiving both lidocaine and bupivacaine than those receiving only lidocaine (P = .001, 17.5% vs 21.7%) or only bupivacaine (P < .001, 17.5% vs 22.9%). Narcotic utilization on the day of surgery was significantly lower in patients receiving both lidocaine and bupivacaine than those receiving only lidocaine (P < .001, 11.5% vs 15.1%) or only bupivacaine (P = .004, 11.5% vs 14.6%). Narcotic utilization on the first postoperative day was significantly lower in patients receiving both lidocaine and bupivacaine than those receiving only bupivacaine (P = .009, 5.9% vs 8.1%). CONCLUSIONS: In children undergoing cleft lip repair, local anesthetic combination of lidocaine and bupivacaine is associated with decreased perioperative narcotic use compared to lidocaine or bupivacaine alone.

The Benefits of Local Anesthesia Used in Mastectomy Without Reconstruction.

BACKGROUND: The opioid epidemic has driven renewed interest in local anesthesia to reduce postoperative opioid use. Our objective was to determine if local anesthesia decreased hospital pain scores, oral morphine equivalents (OME), length of stay (LOS), and nausea/vomiting. METHODS: Single institution retrospective study of females who underwent mastectomy without reconstruction. RESULTS: Overall, 712 patients were included; 63 (8.8%) received bupivacaine (B), 512 (72%) liposomal bupivacaine (LB), and 137 (19%) no local. 95% were discharged on POD1. Liposomal bupivacaine use increased from 2014 to 2019. Additional factors associated with use of local regimen were surgeon and extent of axillary surgery. Fewer patients used postop opioids during their hospital stay if any local was used compared to none (76 vs 88%; 0.003). Compared to none, local had shorter mean PACU LOS (95 vs 87 min; P = .02), lower mean intraoperative-OME (96 vs 106; P < .001), and lower mean postoperative OME/hr (1.4 vs 1.8 P = .001). Multivariable analysis (MVA) showed lower OME/hr with LB compared to B and none (P = .002); this translates to 22 mg and 30 mg of oxycodone in a 24-hr period, respectively. MVA showed lower POD1 pain scores with LB relative to none (P = .049). Local did not impact nausea/emesis. CONCLUSION: Local anesthesia was superior to no local in several measures. However, a consistent benefit of a specific local anesthetic agent was not demonstrated (LB vs B). A prospective study is warranted to determine the optimal local regimen for this cohort and further inform clinical relevance.

Incidence of conversion to general anaesthesia and need for intravenous supplementation in parturients undergoing caesarean section under spinal anaesthesia: A retrospective observational study.

BACKGROUND: Conversion from spinal anaesthesia to general anaesthesia (GA) was shown to be associated with more complications. It has been postulated that spinal injection of a low dose of local anaesthetic is a risk factor. We aimed to discover the rate of conversion from spinal anaesthesia to GA in women who received at least 10 mg heavy bupivacaine and opioids and assess its risk factors. METHODS: All women that underwent spinal anaesthesia for caesarean section from 1 January 2017 to 31 December 2020 were included in this analysis. Spinal anaesthesia was performed according to department protocol using heavy bupivacaine 0.5% 10-13 mg, fentanyl 20 µg, and morphine 0.1 mg. We examined rate of conversion from spinal anaesthesia to GA and rate of need for analgesia/sedation. RESULTS: There were 1.7% of women that required conversion to GA. Bupivacaine dose (OR 0.54 [95% CI 0.38 to 0.75], p < 0.001), surgery time (OR 1.03 [95% CI 1.02 to 1.04], p < 0.001), emergency caesarean section (OR 1.06 [95% CI 1.16 to 3.76], p = 0.015), and postpartum haemorrhage (OR 5.96 [95% CI 1.09 to 25.18], p = 0.025) were independent predictors of need for conversion to GA. Of the women who had CS under spinal anaesthesia, 4.1% of parturients required intraoperative analgesics/sedatives and 9.1% required anxiolysis. CONCLUSIONS: A small proportion of women required conversion to GA. This conversion occurred especially with emergency caesarean section and when low spinal bupivacaine doses were used.

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.