Regional Anesthesia: An Overview

Nanotherapeutics for Alleviating Anesthesia-Associated Complications

Current management of anesthesia-associated complications falls short in terms of both efficacy and safety. Nanomaterials with versatile properties and unique nano-bio interactions hold substantial promise as therapeutics for addressing these complications. This review conducts a thorough examination of the existing nanotherapeutics and highlights the strategies for developing prospective nanomedicines to mitigate anesthetics-related toxicity. Initially, general, regional, and local anesthesia along with the commonly used anesthetics and related prevalent side effects are introduced. Furthermore, employing nanotechnology to prevent and alleviate the complications of anesthetics is systematically demonstrated from three aspects, that is, developing 1) safe nano-formulization for anesthetics; 2) nano-antidotes to sequester overdosed anesthetics and alter their pharmacokinetics; 3) nanomedicines with pharmacodynamic activities to treat anesthetics toxicity. Finally, the prospects and challenges facing the clinical translation of nanotherapeutics for anesthesia-related complications are discussed. This work provides a comprehensive roadmap for developing effective nanotherapeutics to prevent and mitigate anesthesia-associated toxicity, which can potentially revolutionize the management of anesthesia complications.

Human dissection for anesthesiology resident training augments anatomical knowledge and clinical skills

Anatomy is an essential component of clinical anesthesiology. The use of simulated patients and alternative materials, including embalmed human bodies, have become increasingly common during resident physician training due to the deemphasis on anatomical education during undergraduate medical training. In this report, the need for a more extensive review of relevant anatomy for the practice of anesthesiology was addressed by the design, evaluation, and dissemination of a human dissection course for procedural training of anesthesiology residents. The course utilized "freedom art" embalmed human bodies that allowed trainees to perform ultrasound-based regional and neuraxial techniques followed by detailed dissections of critical anatomy. One hundred and four residents participated in workshops and small group discussions and were evaluated using pre- and post-course assessments. A variety of clinical techniques were performed on the bodies, including regional blocks and neuraxial catheter placement. Insertion of peripheral/neuraxial catheters was successful, with dissections demonstrating the expected placement. Assessment scores improved following the course (pre-course mean 52.7%, standard deviation (σ) 13.1%; post-course mean 72.2%, σ 11.6%; t-test p < 0.0001) and feedback highlighted the usefulness and clinical relevance of course content. The ability to correlate ultrasound imaging with subsequent dissections of the "blocked" area and visualization of dye staining was extremely relevant for spatial understanding of the anatomy relevant for the clinical practice of these techniques. This manuscript demonstrates successful implementation of a comprehensive course for anesthesiology resident physicians to address gaps in undergraduate anatomical education and suggests that broader adoption of dissection courses may be beneficial for training anesthesiologists.

Double-Edge, Single-Edge, and Intermediate-Edge Ultrasound Sign and Correlation With Fascial Plane Block Efficacy: An Experimental Study

Introduction Ultrasound-guided fascial plane blocks are nowadays the gold standard technique for regional anesthesia and postoperative analgesia. Despite their high success rate, cases of partial or total failure of this method have been reported. This experimental study aims to address the corresponding ultrasound signs and their association with fascial plane block efficacy. Methods After capturing the appropriate sonographic image that included muscle layers and their fasciae, an 18-gauge epidural needle penetrated the cadaveric porcine tissue and was forwarded until the tip of the needle reached the target fascial plane. The infusion of methylthioninium chloride or methylene blue dye was performed, causing tissue hydro dissection. The documentation of the generated ultrasound images was followed by surgical exposure of the tip of the needle. Results The distribution of the dye into the plane of interest (double-edge sign) was equivalent to block success, whereas the single-edge sign (accumulation of the dye between fascia and epimysium) indicated total block failure. The intermediate-edge sign, a combination of the previous ultrasound signs, is related to partial failure of block performance. Conclusion The identification of the three novel sonographic signs is an accurate predictive factor of peripheral nerve block efficacy. The respective data are expected to aid the rapid improvement of interfascial plane block accuracy and techniques, leading to their more effective execution and simultaneously eliminating the failure rates. Thereby, the amelioration of intra and postoperative analgesia will be accomplished, expediting the patient's hospital discharge and reducing or even avoiding opioid consumption.

Comparative analysis of lumbar quadratus lumborum block and epidural block for analgesia in uterine surgery at Dr. Soetomo Hospital, Surabaya

Over 80% of surgical patients experience postoperative pain, which, if inadequately managed, can lead to complications, prolonged rehabilitation, chronic pain, and decreased quality of life. Epidural block and quadratus lumborum block are techniques commonly used for postoperative pain management. This comparative analytic study aimed to analyze the differences in the analgesic effects of quadratus lumborum block and epidural block in uterine surgery at Dr. Soetomo General Hospital. The outcomes assessed were the numerical rating score (NRS) as a pain score and the administration of opioids as an adjuvant analgesic. Statistical analysis employed the Mann-Whitney test and Chi-square test. The study included 32 patients who underwent uterine surgery at Dr. Soetomo General Hospital and met the inclusion and exclusion criteria. Among the patients, 90.6% experienced mild pain, and 9.4% experienced moderate pain. Epidural blocks were performed in 50% of the patients, while quadratus lumborum blocks were performed in the other 50%. Additionally, 9.4% of the patients received opioids as adjuvant analgesics. The Mann-Whitney test revealed no significant difference in NRS between the epidural block and quadratus lumborum block groups (p-value>0.05). However, the Chi-square test indicated a significant difference in NRS between patients who received additional opioids as adjuvant analgesics and those who did not (p-value<0.00). There was no significant difference in NRS between patients who underwent epidural block and quadratus lumborum block as analgesic techniques.

Perfusion index for early identification of regional anesthesia effectiveness: a narrative review

Regional anesthesia (RA) is a common and irreplaceable technique in clinical, which can be used in different surgery sites and control of acute and chronic pain, especially for outpatients, pediatrics and the elderly. RA demands are increasing during COVID-19 pandemic because many surgeries could be performed under RA to reduce the risk of cross-infection between patients and health care workers. Early and accurate identification of the effects of RA can help physicians make timely decisions about whether to supplement analgesics or switch to general anesthesia, which will save time and improve patient satisfaction in a busy operating room. Perfusion index (PI) is a parameter derived from photoplethysmography (PPG) and represents the ratio of pulsatile and non-pulsatile blood flow at monitoring sites. It reflects local perfusion and is mainly affected by stroke volume and vascular tone. With characteristics of non-invasive, rapid, simple, and objective, PI is widely used in clinical practice, such as fluid responsiveness prediction, nociceptive assessment, etc. Recently, many studies have assessed the accuracy of PI in early prediction of RA success, including brachial plexus block, sciatic nerve block, neuraxial anesthesia, paravertebral block, caudal block and stellate ganglion block. Successful RA often parallels increased PI. In this narrative review, we describe the principles and influencing factors of PI, and introduce the effects of PI on early identification of RA effectiveness.

The potential value of exosomes as adjuvants for novel biologic local anesthetics

The side effects of anesthetic drugs are a key preoperative concern for anesthesiologists. Anesthetic drugs used for general anesthesia and regional blocks are associated with a potential risk of systemic toxicity. This prompted the use of anesthetic adjuvants to ameliorate these side effects and improve clinical outcomes. However, the adverse effects of anesthetic adjuvants, such as neurotoxicity and gastrointestinal reactions, have raised concerns about their clinical use. Therefore, the development of relatively safe anesthetic adjuvants with fewer side effects is an important area for future anesthetic drug research. Exosomes, which contain multiple vesicles with genetic information, can be released by living cells with regenerative and specific effects. Exosomes released by specific cell types have been found to have similar effects as many local anesthetic adjuvants. Due to their biological activity, carrier efficacy, and ability to repair damaged tissues, exosomes may have a better efficacy and safety profile than the currently used anesthetic adjuvants. In this article, we summarize the contemporary literature about local anesthetic adjuvants and highlight their potential side effects, while discussing the potential of exosomes as novel local anesthetic adjuvant drugs.

Regional Anesthesia (2012-2021): A Comprehensive Examination Based on Bibliometric Analyses of Hotpots, Knowledge Structure and Intellectual Dynamics

In the last decade, there has been a significant advancement in the area of regional anesthesia (RA). Continuous evaluation of research in any developing field using modern technologies and available software is critical to identify future trends, hot spots, and intellectual dynamics. The current study was designed to bibliometrically evaluate the global research in RA using VOSviewer, MS Excel, and CVS-Scopus bibliographic data (2012–2021). Knowledge structure and intellectual dynamics were analyzed using clustering of keyword co-occurrence. Literature screening in the last decade found 6092 original articles (96.1%) and conference papers (3.9%). The top four countries producing articles were the United States (n = 30.57%), India (7.51), the United Kingdom (7.22%), and Canada (6.06%). A significant positive correlation was found in global publication productivity (R² = 0.9161). The most productive organizations were Harvard University, the University of Toronto, and the Hospital for Special Surgery – New York. A tremendous collaboration was spotted nationally and internationally, especially in pediatric RA. This comprehensive study, which summarizes and evaluates 6902 original research materials on regional anesthesia, may serve as a resource for anesthesiologists, physicians, researchers, and students.

Use of Ultrasound-Guided Interfascial Plane Blocks in Anterior and Lateral Thoracic Wall Region as Safe Method for Patient Anesthesia and Analgesia: Review of Techniques and Approaches during COVID-19 Pandemic

Ultrasound-guided interfascial plane blocks performed on the anterior and lateral thoracic wall have become an important adjuvant method to general anesthesia and an independent method of local anesthesia and pain management. These procedures diminish the harmful effects of anesthesia on respiratory function and reduce the risk of phrenic nerve paralysis or iatrogenic pneumothorax. In postoperative pain management, interfascial plane blocks decrease the dosage of intravenous drugs, including opioids. They can also eliminate the complications associated with general anesthesia when used as the sole method of anesthesia for surgical procedures. The following procedures are classified as interfascial plane blocks of the anterior and lateral thoracic wall: pectoral nerve plane block (PECS), serratus anterior plane block (SAP), transversus thoracic muscle plane block (TTP), pectoral interfascial plane block (PIF), and intercostal nerve block (ICNB). These blocks are widely used in emergency medicine, oncologic surgery, general surgery, thoracic surgery, cardiac surgery, orthopedics, cardiology, nephrology, oncology, palliative medicine, and pain medicine. Regional blocks are effective for analgesic treatment, both as an anesthesia procedure for surgery on the anterior and lateral thoracic wall and as an analgesic therapy after trauma or other conditions that induce pain in this area. In the era of the COVID-19 pandemic, ultrasound-guided interfascial plane blocks are safe alternatives for anesthesia in patients with symptoms of respiratory distress related to SARS-CoV-2 and appear to reduce the risk of COVID-19 infection among medical personnel.

Effect of Fentanyl as an Adjuvant to Brachial Plexus Block for Upper Extremity Surgeries: A Systematic Review and Meta-Analysis of RCTs

Objective. To assess if the addition of fentanyl to brachial plexus block has an impact on anesthetic outcomes and complication rates in patients undergoing upper extremity surgeries. Methods. We explore the PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases for all randomized controlled trials (RCTs) comparing adjuvant fentanyl with placebo/no drug for patients undergoing upper extremity surgery under brachial plexus block. Outcomes assessed were onset, duration of sensory and motor anesthesia, complications, and postoperative analgesia scores. Meta-analysis was conducted utilizing a random-effects model. The risk of bias was assessed using the Cochrane Collaboration’s risk of bias assessment tool 2. Certainty of evidence was assessed using GRADE. Subgroup analysis was conducted depending upon the approach of brachial plexus block and type of local anesthetic. Results. Twelve RCTs with 660 patients were included. Addition of fentanyl had no effect on onset of sensory anesthesia (11 studies; MD: 0.48; 95% CI: −1.81, 0.85; I2 = 96%; $p=0.48$ ) but significantly shortened onset of motor anesthesia (8 studies; MD: −2.36; 95% CI: −3.99, −0.74; I2 = 96%; $p=0.48$ ). Duration of sensory anesthesia (9 studies; MD: 82.81; 95% CI: 41.81, 123.81; I2 = 99%; $p<0.0001$ ) and motor anesthesia (7 studies; MD: 93.41; 95% CI: 42.35, 144.46; I2 = 99%; $p=0.0003$ ) was significantly increased with addition of fentanyl. The certainty of evidence-based on GRADE was deemed to be moderate for both onset and duration of anesthesia. The incidence of overall complications (nausea/vomiting and pruritis) was significantly higher in the fentanyl group (7 studies; OR: 2.14; 95% CI: 1.04, 4.40; I2 = 8%; $p=0.04$ ) but with low certainty of evidence. Conclusions. Adjuvant fentanyl with brachial plexus block improves the onset of motor anesthesia but not sensory anesthesia. The duration of both sensory and motor anesthesia is significantly prolonged with fentanyl by around 83–93 minutes. However, clinicians should be aware that complications such as nausea/vomiting and pruritis are increased twofold with the addition of the drug. Current evidence is limited risk of bias in the RCTs and high heterogeneity in the meta-analyses.

Review of clinical evidence of caudal block for postoperative analgesia in children with ketamine added local anesthetics

Background

Adding ketamine to local anesthetics used for caudal block in children is an emerging clinical practice. This review aims to resolve controversies related to this adjuvant for a caudal block in children who underwent sub-umbilical surgeries.

Methods

Between January 2010 and November 2021, PubMed, Cochrane Review, and Google Scholar were searched for a caudal block with ketamine added local anesthetics for children. After screening for eligibility and removing duplicates, 38,187 articles were found, 13 reviewed.

Discussion

Despite adding ketamine to local anesthetics used for a caudal block, it is a recent technique practiced worldwide. Ketamine showed equi-efficacious as other adjuvants used for the caudal block to control postoperative pain in children.

Conclusion

Ketamine with a 0.5 mg/kg dose is safe and effective to manage postoperative children's pain when used as an adjuvant to local anesthetics used for caudal block.

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Caudal additives prolong the length of analgesia than local anesthetics alone

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Ketamine is an alternative to be added for local anesthetics in a caudal block for children

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Ketamine in caudal block prolongs analgesia and reduces opioid intake.

Regional Anaesthetic Techniques and Their Implications During the COVID Pandemic

The current pandemic has highlighted the need to protect both patients and medical staff. The increased use of regional anaesthesia as a primary anaesthetic modality for operations and other invasive procedures has limited the number of aerosol-generating procedures performed during general anaesthesia. Its use is further characterized by decreases in postoperative pain and length of hospitalization. This article provides an overview of regional anaesthetic techniques (peripheral nerve locks, epidural and spinal anaesthesia) and their uses during the COVID pandemic.