Pharmacokinetics of bupivacaine after bilateral ultrasound-guided transversus abdominis plane block following cesarean delivery under spinal anesthesia

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.

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.

Analgesic benefits of pre-operative versus postoperative transversus abdominis plane block for laparoscopic cholecystectomy: a frequentist network meta-analysis of randomized controlled trials

BACKGROUND

Transversus abdominis plane (TAP) block has been utilized to alleviate pain following laparoscopic cholecystectomy (LC). However, the optimal timing of administration remains uncertain. This study aimed to compare the efficacy of pre-operative and postoperative TAP blocks as analgesic options after LC.

METHODS

A frequentist network meta-analysis of randomized controlled trials (RCTs) was conducted. We systematically searched PubMed (via the National Library of Medicine), EMBASE, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science up to March 2023. The study included RCTs that enrolled adult patients (≥ 18 years) who underwent LC and received either pre-operative or postoperative TAP blocks. The primary outcome assessed was 24-hour postoperative morphine consumption (mg). Additionally, pain rest scores within 3 hours, 12 hours, and 24 hours, as well as postoperative nausea and vomiting (PONV), were considered as pre-specified secondary outcomes.

RESULTS

A total of 34 trials with 2317 patients were included in the analysis. Postoperative TAP block demonstrated superiority over the pre-operative TAP block in reducing opioid consumption (MD 2.02, 95% CI 0.87 to 3.18, I2 98.6%, p < 0.001). However, with regards to postoperative pain, neither pre-operative nor postoperative TAP blocks exhibited superiority over each other at any of the assessed time points. The postoperative TAP block consistently ranked as the best intervention using SUCRA analysis. Moreover, the postoperative TAP block led to the most significant reduction in PONV.

CONCLUSIONS

The findings suggest that the postoperative TAP block may be slightly more effective in reducing 24-hour postoperative opioid consumption and PONV when compared to the pre-operative TAP block.

TRIAL REGISTRATION

PROSPERO, CRD42023396880 .

Plasma bupivacaine levels (total and free/unbound) during epidural infusion in liver resection patients: a prospective, observational study

INTRODUCTION

Liver resection patients may be at an increased risk of local anesthetic (LA) toxicity because the liver is essential for metabolizing LA and producing proteins (mainly α1-acid glycoprotein (AAG)) that bind to it and reduce the free (and pharmacologically active/toxic) levels in circulation. The liver resection itself, manipulation during surgery, and pre-existing liver disease may all interfere with normal hepatic protein synthesis and result in an attenuation of the increased AAG (a positive acute-phase protein) that normally occurs postoperatively. The purpose of this study was to determine whether the AAG response is attenuated postoperatively following liver resection and whether patients approach toxicity thresholds with continuous postoperative epidural infusion of bupivacaine.

METHODS

Prospective, observational study with blood drawn preoperatively, in the postanesthetic care unit, on postoperative day (POD) 2, and prior to discontinuation of epidural analgesia on POD3/POD4. Plasma was analyzed for total and unbound bupivacaine via liquid chromatography-mass spectrometry and AAG via ELISA. Signs/symptoms of local anesthetic systemic toxicity (LAST), pain, and sedation scores were also recorded.

RESULTS

For the 19 patients completed, total plasma bupivacaine was correlated with total administered, but unbound levels were not associated with the total administered. Unlike non-hepatectomy surgery where unbound LA plasma levels remain stable (or decrease) with continuous postoperative epidural administration, we observed an overall increase. Several patients approached toxicity thresholds and 47% reported at least one symptom of LAST, but no epidurals were discontinued because of LAST. In contrast to the AAG response reported following major non-liver surgery where AAG levels increase twofold, we observed a reduction until POD2 and the magnitude was proportional to resection weight.

DISCUSSION

Our results are supported by the literature in suggesting that major liver resection patients may be at an increased vulnerability for LAST. Factors such as the extent of liver disease, resection and intraoperative blood loss should be considered when using continuous postoperative epidural infusion of bupivacaine and vigilance should be used in monitoring, for signs/symptoms of LAST, even for those subtle and non-specific. Future research will be required to verify these findings.

TRIAL REGISTRATION NUMBER

NCT03145805.

Multimodal opioid-sparing pain management for emergent cesarean delivery under general anesthesia: a quality improvement project

BACKGROUND

Opioid-sparing multimodal analgesic approach has been shown to provide effective postoperative pain relief and reduce postoperative opioid consumption and opioid-associated adverse effects. While many studies have evaluated analgesic strategies for elective cesarean delivery, few studies have investigated analgesic approaches in emergent cesarean deliveries under general anesthesia. The primary aim of this quality improvement project is to evaluate opioid consumption with the use of a multimodal opioid-sparing pain management pathway in patients undergoing emergent cesarean delivery under general anesthesia.

METHODS

Seventy-two women (age > 16 years) undergoing emergent cesarean delivery under general anesthesia before (n = 36) and after (n = 36) implementation of a multimodal opioid-sparing pain management pathway were included. All patients received a standardized general anesthetic. Prior to implementation of the pathway, postoperative pain management was primarily limited to intravenous patient-controlled opioid administration. The new multimodal pathway included scheduled acetaminophen and non-steroidal anti-inflammatory medications and ultrasound-guided classic lateral transversus abdominis plane blocks with postoperative opioids reserved only for rescue analgesia. Data obtained from electronic records included demographics, intraoperative opioid use, and pain scores and opioid consumption upon arrival to the recovery room, at 2, 6, 12, 24, 48, and 72 h postoperatively.

RESULTS

Patients receiving multimodal opioid sparing analgesia (AFTER group) had lower opioid use for 72 h, postoperatively. Only 2 of the 36 patients (5.6%) in the AFTER group required intravenous opioids through patient-controlled analgesia while 30 out of 36 patients (83.3%) in the BEFORE group required intravenous opioids.

CONCLUSIONS

Multimodal opioid-sparing analgesia is associated with reduced postoperative opioid consumption after emergent cesarean delivery.

Is Opioid-free Anesthesia Possible by Using Erector Spinae Plane Block in Spinal Surgery?

Objective: Erector spinae plane (ESP) block can be a method to be used for postoperative pain control in lumbar herniated disc operations. The aim of this study is to investigate the effect of erector spinae block in lumbar herniated disc operation on intraoperative and postoperative opioid consumption.

Methods: Sixty patients scheduled for lumbar herniated disc surgery were included in the study. Patients were randomized into two groups: ESP block and control. Ultrasound-guided ESP block with 20 ml 0.25% bupivacaine at the bilateral L3 vertebral level was applied preoperatively to all patients in the ESP group. Patients in both groups were provided with intravenous patient-controlled analgesia (PCA) device containing fentanyl for postoperative analgesia. Fentanyl consumption and visual analogue scale (VAS) score were recorded at 15 min, 1, 6, 12, and 24 hours postoperatively.

Results: Fentanyl consumption (group C: 59.3 ± 20.66, group E: 41.3 ± 21.61, p: 0,02) and VAS score (group C: VASm 4 (2-4), group E: 2 (2-4), p: 0.009) decreased with ESP block application at postoperative one hour. No difference was detected between the two groups in terms of fentanyl consumption and VAS score at 6, 12, and 24 hours postoperatively (p>0.05). The intraoperative heart rate of patients in the ESP group was lower than the control group (p<0.05).

Conclusion: ESP block decreases opioid consumption and VAS score at postoperative one hour in patients, and also patients who receive ESP block do not require intraoperative opioid administration.

Safety of treatment options available for postoperative pain

IntroductionPostoperative pain is one of the most common adverse events after surgery and has been shown to increase the risk of other complications. On the other hand, liberal opioid use in the perioperative period is also associated with risk of adverse events. The current consensus is therefore to provide multimodal, opioid minimizing analgesia after surgery.Areas CoveredIn this review, we will discuss the benefits and risks associated with non-opioid analgesics, including non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, α-2 agonists, and corticosteroids. In addition, we will discuss the general and block-specific risks associated with regional anesthestic techniques.Expert OpinionAdverse events associated with non-opioid analgesics are rare outside their specific contraindicated patient groups, especially when dosed appropriately. α-2 agonists can cause transient hypotension and bradycardia, and gabapentinoids may cause sedation in higher risk patient populations. Regional anesthesia techniques are generally safe when done by an experienced practitioner. We therefore encourage the development of standardized multimodal analgesic protocols, which may facilitate opioid minimization and lead to better patient outcomes.

Regional anesthesiological support for the implementation of surgical interventions in the abdomen of dogs

Widespread use of surgical interventions in the abdomen of dogs determines the relevance of the study. The research tested the influence of therapeutic epidural blockade with 0.2% bupivacaine after surgical interventions on the background of potentiated local anaesthesia on the body of clinically healthy dogs undergoing ovariohysterectomy. In the control group postoperative analgesia was performed with the nonsteroidal anti-inflammatory drug rimadyl on the background of potentiated thiopental anaesthesia. Wound healing rates were determined in 10 animals of both control and experimental groups; blood counts and the level of inflammatory response were indicated in 5 animals of each group. The dynamics of reparative processes and complete wound healing in dogs of the experimental group occurred earlier than in animals of the control group, which confirmed the fact that the use of bupivacaine had a beneficial effect on tissue regeneration. The results of morphological and biochemical parameters of blood in animals of the experimental group manifested only an increase of leukocytes by 1.58 times, fibrinogen by 2.02 times, while in dogs of the control group the level of erythrocytes, haemoglobin and hematocrit decreased, leukocytes increased by 1.74 times, platelets decreased by 2.87 times and fibrinogen increased by 1.72 times. Among the stress response markers in the control group there was a 1.94 times increase in glucose level after surgery. In the experimental group there was a decrease in the intensity of the inflammatory reaction in dogs, accompanied by an increase of anti-inflammatory interleukin 4 (IL-4) only on the seventh day – 1.86 times, while in the control group the level of anti-inflammatory interleukin 1 receptor antagonist (IL-1RA) after three days increased by 2.30 times, after seven days – by 2.48 times, and the level of proinflammatory interleukin 6 (IL-6) after surgery increased by 2.57 times. It will be promising to conduct further research on the influence of therapeutic blockades with bupivacaine in animals in cases of various surgical interventions and pathological conditions, which will lead to faster recovery of animals and alleviate pathological processes.

Transversus Abdominis Plane Block Appears to Be Effective and Safe as a Part of Multimodal Analgesia in Bariatric Surgery: a Meta-analysis and Systematic Review of Randomized Controlled Trials

Purpose

Pain after bariatric surgery can prolong recovery. This patient group is highly susceptible to opioid-related side effects. Enhanced Recovery After Surgery guidelines strongly recommend the administration of multimodal medications to reduce narcotic consumption. However, the role of ultrasound-guided transversus abdominis plane (USG-TAP) block in multimodal analgesia of weight loss surgeries remains controversial.

Materials and Methods

A systematic search was performed in four databases for studies published up to September 2019. We considered randomized controlled trials that assessed the efficacy of perioperative USG-TAP block as a part of multimodal analgesia in patients with laparoscopic bariatric surgery.

Results

Eight studies (525 patients) were included in the meta-analysis. Pooled analysis showed lower pain scores with USG-TAP block at every evaluated time point and lower opioid requirement in the USG-TAP block group (weighted mean difference (WMD) = − 7.59 mg; 95% CI − 9.86, − 5.39; p < 0.001). Time to ambulate was shorter with USG-TAP block (WMD = − 2.22 h; 95% CI − 3.89, − 0.56; p = 0.009). This intervention also seemed to be safe: only three non-severe complications with USG-TAP block were reported in the included studies.

Conclusion

Our results may support the incorporation of USG-TAP block into multimodal analgesia regimens of ERAS protocols for bariatric surgery.

Electronic supplementary material

The online version of this article (10.1007/s11695-020-04973-8) contains supplementary material, which is available to authorized users.

Cytotoxicity of amide-linked local anesthetics on melanoma cells via inhibition of Ras and RhoA signaling independent of sodium channel blockade

BACKGROUND

Substantial clinical and preclinical evidence have indicated the association between amide-linked local anesthesia and the long-term outcomes of cancer patients. However, the potential effects of local anesthesia on cancer recurrence are inconclusive and the underlying mechanisms remain poorly understood.

METHODS

We systematically examined the effects of three commonly used local anesthetics in melanoma cells and analyzed the underlying mechanisms focusing on small GTPases.

RESULTS

Ropivacaine and lidocaine but not bupivacaine inhibited migration and proliferation, and induced apoptosis in melanoma cells. In addition, ropivacaine and lidocaine but not bupivacaine significantly augmented the in vitro efficacy of vemurafenib (a B-Raf inhibitor for melanoma with BRAF V600E mutation) and dacarbazine (a chemotherapeutic drug). Mechanistically, ropivacaine but not bupivacaine decreased the activities of Ras superfamily members with the dominant inhibitory effects on RhoA and Ras, independent of sodium channel blockade. Rescue studies using constitutively active Ras and Rho activator calpeptin demonstrated that ropivacaine inhibited migration mainly through RhoA whereas growth and survival were mainly inhibited through Ras in melanoma cells. We further detected a global reduction of downstream signaling of Ras and RhoA in ropivacaine-treated melanoma cells.

CONCLUSION

Our study is the first to demonstrate the anti-melanoma activity of ropivacaine and lidocaine but not bupivacaine, via targeting small GTPases. Our findings provide preclinical evidence on how amide-linked local anesthetics could affect melanoma patients.

Comparison of nalbuphine, ondansetron and placebo for the prevention of shivering after spinal anaesthesia for urgent caesarean delivery: a randomised double-blind controlled clinical trial

BACKGROUND

Shivering is a common complication of caesarean delivery with neuraxial anaesthesia. The effective prevention and treatment of shivering, especially before delivery, is important and difficult. We tested the hypothesis that prophylactic nalbuphine and ondansetron can prevent post-spinal anaesthesia shivering in parturients undergoing urgent caesarean delivery.

METHODS

Sixty parturients scheduled for urgent caesarean delivery before spinal anaesthesia were selected and divided randomly into three groups. After peripheral venous catheterisation, parturients were given intravenous nalbuphine 0.08 mg/kg (group N), ondansetron 8 mg (group O), or normal saline (group C).

RESULTS

The incidence of shivering and of severe (grade ≥3) shivering was significantly lower in group N (15% and 15%, respectively) than in group C (80% and 65%) before delivery (P <0.001 and P=0.003); and significantly less shivering was observed in group N than in group C in the first 30 min after anaesthesia (P=0.001). Up to 60 min after anaesthesia, the incidence of grade ≥3 shivering remained lowest in group N (P=0.003). According to the data during the period from anaesthesia until delivery, the number needed-to-treat for nalbuphine was 1.54 (95%CI 1.13 to 2.41). No significant differences were found between groups O and N or groups O and C at any time. The incidence of dizziness in group N was significantly higher than that of groups O or C (P=0.009).

CONCLUSION

Nalbuphine 0.08 mg/kg can prevent post-spinal anaesthesia shivering in parturients undergoing urgent caesarean delivery but causes transient dizziness, while ondansetron 8 mg had no significant effect.

Transversus Abdominis Plane Block

In this narrative review article, the authors discuss the anatomy, nomenclature, history, approaches (posterior vs. lateral vs. subcostal), techniques, pharmacology, indications, and complications of transversus abdominis plane blocks, as well as possible alternative truncal blocks.

Despite the scarcity of evidence and contradictory findings, certain clinical suggestions can nonetheless be made. Overall transversus abdominis plane blocks appear most beneficial in the setting of open appendectomy (posterior or lateral approach). Lateral transversus abdominis plane blocks are not suggested for laparoscopic hysterectomy, laparoscopic appendectomy, or open prostatectomy. However, transversus abdominis plane blocks could serve as an analgesic option for Cesarean delivery (posterior or lateral approach) and open colorectal section (subcostal or lateral approach) if there exist contraindications to intrathecal morphine and thoracic epidural analgesia, respectively.

Future investigation is required to compare posterior and subcostal transversus abdominis plane blocks in clinical settings. Furthermore, posterior transversus abdominis plane blocks should be investigated for surgical interventions in which their lateral counterparts have proven not to be beneficial (e.g., laparoscopic hysterectomy/appendectomy, open prostatectomy). More importantly, because posterior transversus abdominis plane blocks can purportedly provide sympathetic blockade and visceral analgesia, they should be compared with thoracic epidural analgesia for open colorectal surgery. Finally, transversus abdominis plane blocks should be compared with newer truncal blocks (e.g., erector spinae plane and quadratus lumborum blocks) with well-designed and adequately powered trials.

A review of peripheral nerve blocks for cesarean delivery analgesia

Peripheral nerve blocks have a unique role in postcesarean delivery multimodal analgesia regimens. In this review article, options for peripheral nerve blocks for cesarean delivery analgesia will be reviewed, specifically paravertebral, transversus abdominis plane, quadratus lumborum, iliohypogastric and ilioinguinal, erector spinae, and continuous wound infiltration blocks. Anatomy, existing literature evidence, and specific areas in need of future research will be assessed. Considerations for local anesthetic toxicity, and for informed consent for these modalities in the context of emergency cesarean deliveries, will be presented.

Exploring the transversus abdominis plane block in cesarean sections and the subsequent toxicity risk to neonates via breast milk

The transversus abdominis plane (TAP) block with its wide application has shown to be an analgesic effective for use in abdominal surgeries, including for cesarean section. However, the bupivacaine delivered in the TAP block comes with the risk of toxicity, both central nerve system (CNS) and cardiovascular system, and has been shown in some instances to reach maximum serum concentrations in excess of the 2 μg/mL associated with the lower end of CNS toxicity. There is a specific concern with cesarean section TAP blocks of the anesthetic passage to the neonate via maternal breast milk and whether this poses a toxicity risk. Bupivacaine has been shown to pass into maternal milk at concentrations 0.34 times the maternal serum concentration. Preliminary statistical analyses suggest that the bupivacaine delivered in breast milk is not in concentrations high enough to cause neonatal toxicity, but further studies would be useful in identifying what the toxicity risk is, if any, to the neonates' breastfeeding after the delivery and TAP block.

Both Bupivacaine and Levobupivacaine inhibit colon cancer cell growth but not melanoma cells in vitro

BACKGROUND

Retrospective studies indicate that the use of regional anaesthesia causes a reduction in cancer recurrence after oncological surgery, which could be due to anaesthetic's negating effect on immunosuppression related to the surgical stress response. Local anaesthetics may also exert direct suppressive effects on malignant cells, an area where further investigation is urgently needed.

METHODS

Human colon cancer cells and human melanoma cells were cultured and then treated with 1 mM bupivacaine or levobupivacaine for up to 24 or 48 h. Their migratory ability was measured by scratch assay, proliferation determined with Ki67 immunofluorescence staining, and apoptosis accessed with annexin V and PI staining on flow cytometry. The effects of bupivacaine and levobupivacaine on cellular signaling and molecular response, specifically, on endoplasmic reticulum stress (ERS), were studied with immunostaining and western blot.

RESULTS

In colon cancer cells, treatment with bupivacaine and levobupivacaine significantly inhibited cell migration (**p < 0.01, ***p < 0.001; n = 4) and proliferation (**p < 0.01; n = 4), while increasing the expression of CHOP (***p < 0.001; n = 4) and decreased the expression of Grp78 (*p < 0.05; n = 4). These effects were not mirrored by melanoma cells, such that no significant increase in apoptosis was seen in either melanoma cell lines following treatment.

CONCLUSION

These in vitro data suggested that both bupivacaine and levobupivacaine suppress colorectal adenocarcinoma cell proliferation and migration, which are concurrent with increased endoplasmic reticulum stress. Conversely, melanoma cells are more resilient to these two commonly used local anaesthetics. Further in vivo studies or clinical trials are needed.

Local anesthetic systemic toxicity: current perspectives

Local anesthetic systemic toxicity (LAST) is a life-threatening adverse event that may occur after the administration of local anesthetic drugs through a variety of routes. Increasing use of local anesthetic techniques in various healthcare settings makes contemporary understanding of LAST highly relevant. Recent data have demonstrated that the underlying mechanisms of LAST are multifactorial, with diverse cellular effects in the central nervous system and cardiovascular system. Although neurological presentation is most common, LAST often presents atypically, and one-fifth of the reported cases present with isolated cardiovascular disturbance. There are several risk factors that are associated with the drug used and the administration technique. LAST can be mitigated by targeting the modifiable risk factors, including the use of ultrasound for regional anesthetic techniques and restricting drug dosage. There have been significant developments in our understanding of LAST treatment. Key advances include early administration of lipid emulsion therapy, prompt seizure management, and careful selection of cardiovascular supportive pharmacotherapy. Cognizance of the mechanisms, risk factors, prevention, and therapy of LAST is vital to any practitioner using local anesthetic drugs in their clinical practice.