Single-Center In-Hospital and Outpatient Opioid Use for Lower Extremity Arterial Disease.

INTRODUCTION: The pain associated with lower extremity arterial disease is difficult to treat, even with lower extremity revascularization. We sought to evaluate in-hospital and post-operative opioid usage in patients with different disease severities and treatments for lower extremity vascular disease. METHODS: A retrospective review was performed for all hospital encounters for patients with an International Classification of Diseases (ICD) code consistent with lower extremity arterial disease admitted to a single center between January 2018 and March 2023. Cases included patients admitted to the hospital with a primary diagnosis of lower extremity arterial disease. These patients were subdivided based on disease severity, treatment type, and comorbid diagnosis of diabetes mellitus. The analysis focused on in-hospital opioid use frequency and dosage among these patients. The control group (CON) included encounters for patients admitted with a secondary diagnosis of lower extremity atherosclerotic disease. A total of 438 patients represented by all the analyzed encounters were then reviewed for the number and type of vascular procedures performed as well as opioid use in the outpatient setting for one year. RESULTS: Critical limb ischemia (CLI) encounters were more likely to use opioids as compared to the CON and peripheral arterial disease (PAD) without rest pain, ulcer or gangrene groups (CLI 67.9% (95% CI: 63.6%-71.6%) versus CON 52.1% (95% CI: 48.5%-55.7%), p < 0.001 and CLI 67.9% (95% CI: 63.6%-71.6%) versus PAD 50.2% (95% CI: 42.6%-57.4%), p < 0.001). Opioid use was also more common in encounters for gangrene and groups treated with revascularization (REVASC) and amputation (AMP) as compared to CON (gangrene 74.5% (95% CI: 68.5%-82.1%) versus CON 52.1% (95% CI: 48.5%-55.7%), p < 0.01; REVASC 58.3% (95% CI: 57.3%-66.4%) versus CON 52.1% (95% CI: 48.5%-55.7%), p =0.01; and AMP 72.3% (95% CI: 62.1%-74.0%) versus CON 52.1% (95% CI: 48.5%-55.7%), p < 0.01). Significantly increased oral opioid doses per day (MME/day) were not noted for any of the investigated groups as compared to the CON. In the outpatient setting, 186 (42.5% (95% CI: 37.2%-46.4%)) patients were using opioids one month after the most recent vascular intervention. By one year, 31 (7.1% (95% CI: 1.30%-7.70%)) patients were still using opioids. No differences in opioid usage were noted for patients undergoing single versus multiple vascular interventions at one year. Patients undergoing certain vascular surgery procedures were more likely to be using opioids at one year. CONCLUSION: Patients with CLI and gangrene as well as those undergoing vascular treatment have a greater frequency of opioid use during hospital encounters as compared to those patients with less severe disease and undergoing conservative management, respectively. However, these findings do not equate to higher doses of opioids used during hospitalization. Patients undergoing multiple vascular procedures are not more likely to be using opioids long-term (at one year) as compared to those patients treated with single vascular procedures.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of upper and lower limb nerve blocks.

BACKGROUND: Inconsistent nomenclature and anatomical descriptions of regional anesthetic techniques hinder scientific communication and engender confusion; this in turn has implications for research, education and clinical implementation of regional anesthesia. Having produced standardized nomenclature for abdominal wall, paraspinal and chest wall regional anesthetic techniques, we aimed to similarly do so for upper and lower limb peripheral nerve blocks. METHODS: We performed a three-round Delphi international consensus study to generate standardized names and anatomical descriptions of upper and lower limb regional anesthetic techniques. A long list of names and anatomical description of blocks of upper and lower extremities was produced by the members of the steering committee. Subsequently, two rounds of anonymized voting and commenting were followed by a third virtual round table to secure consensus for items that remained outstanding after the first and second rounds. As with previous methodology, strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement. RESULTS: A total of 94, 91 and 65 collaborators participated in the first, second and third rounds, respectively. We achieved strong consensus for 38 names and 33 anatomical descriptions, and weak consensus for five anatomical descriptions. We agreed on a template for naming peripheral nerve blocks based on the name of the nerve and the anatomical location of the blockade and identified several areas for future research. CONCLUSIONS: We achieved consensus on nomenclature and anatomical descriptions of regional anesthetic techniques for upper and lower limb nerve blocks, and recommend using this framework in clinical and academic practice. This should improve research, teaching and learning of regional anesthesia to eventually improve patient care.

The Role of Regional Anaesthesia and Acute Pain Services in Value-Based Healthcare.

Value-based healthcare prioritizes patient outcomes and quality relative to costs, shifting focus from service volume to delivered value. This review explores the significant role of regional anaesthesia (RA) and acute pain services (APS) within the evolving value-based healthcare (VBHC) framework. At the heart of VBHC is the goal to enhance patient outcomes while simultaneously optimizing operational efficiency and reducing costs. The review underscores the need for VBHC and illustrates how integrating RA/APS with Enhanced Recovery Protocols can lead to improved outcomes, aligning directly with the goals of the Triple Aim. Several clinical studies show that RA improves patient outcomes, enhances operating room efficiency, and reduces costs. This is complemented by a discussion on the integration of RA and APS into the VBHC model, highlighting emerging value-based payment structures and strategies for their successful implementation. By merging specialized RA/APS protocols with standardized clinical practices, significant improvements in operating room efficiency and associated economic benefits are observed. Across the healthcare spectrum, from providers to payers, this synergy results in enhanced operational efficiency and communication, raising the standard of patient care. Additionally, the potential of RA and APS to address the opioid crisis, through alternative pain management methods, is emphasized. Globally, the shift towards VBHC requires international collaboration, sharing of best practices, and efficient resource allocation, with RA and APS playing a crucial role. In conclusion, as healthcare moves toward a value-driven model, RA and APS become increasingly essential, signaling a future of refined, patient-centered care.

Vasovagal Pre-Syncope Induced by Epidural Electrical Stimulation Test: A Rare Case Report in a 61-Year-Old Woman Undergoing Ventral Hernia Repair.

BACKGROUND Thoracic epidural analgesia is a commonly applied technique for perioperative pain management in major thoraco-abdominal surgery, but is complicated by high failure rates. The epidural electrical stimulation test (EEST) or "Tsui test" is a safe and effective method whereby low electrical current is used to confirm correct epidural catheter position and decrease the variability in analgesic effectiveness of the neuraxial technique. CASE REPORT We present the case of a 61-year-old woman with no prior cardiac or pulmonary comorbidities who was scheduled to undergo a ventral and parastomal hernia repair with component separation. The patient was offered a low thoracic epidural for perioperative analgesia. Technical aspects of the siting of the epidural catheter were uneventful and a confirmatory Tsui test was planned. At the initiation of electrical stimulation via the epidural catheter to confirm optimal catheter positioning, the patient experienced symptomatic bradycardia and hemodynamic instability that persisted despite terminating the electrical stimulation, and required pharmacologic intervention. CONCLUSIONS This report describes a rare case of vasovagal pre-syncope associated with the EEST or Tsui test. Although vasovagal reactions can be commonly associated with neuraxial procedures due to augmented venous return or severe emotional stress, we raise the possibility that through direct electrical stimulation in the epidural space, the EEST may have the potential to trigger such a physiologic response.

Indian Biosimilars and Vaccines at Crossroads-Replicating the Success of Pharmagenerics.

BACKGROUND: The global pharma sector is fast shifting from generics to biologics and biosimilars with the first approval in Europe in 2006 followed by US approval in 2015. In the form of Hepatitis B vaccine, India saw its first recombinant biologics approval in 2000. Around 20% of generic medications and 62% of vaccines are now supplied by the Indian pharmaceutical industry. It is this good position in biologics and biosimilars production that could potentially improve healthcare via decreased treatment cost. India has witnessed large investments in biosimilars over the years. Numerous India-bred new players, e.g., Enzene Biosciences Ltd., are keen on biosimilars and have joined the race alongside the emerging giants, e.g., Biocon and Dr. Reddy's. A very positive sign was the remarkable disposition during the COVID-19 pandemic by Bharat Biotech and the Serum Institute of India. India's biopharmaceutical industry has been instrumental in producing and supplying preventives and therapeutics to fight COVID-19. Despite a weak supply chain and workforce pressure, the production was augmented to provide reasonably priced high-quality medications to more than 133 nations. Biosimilars could cost-effectively treat chronic diseases involving expensive conventional therapies, including diabetes, respiratory ailments, cancer, and connective tissue diseases. Biologics and biosimilars have been and are being tested to treat and manage COVID-19 symptoms characterized by inflammation and respiratory distress. PURPOSE OF REVIEW: Although India boasts many universities, research centers, and a relatively skilled workforce, its global University-Industry collaboration ranking is 24, IPR ranking remains 47 and innovation ranking 39. This reveals a wide industry-academia gap to bridge. There are gaps in effective translational research in India that must be promptly and appropriately addressed. Innovation demands strong and effective collaborations among universities, techno-incubators, and industries. METHODOLOGY: Many successful research findings in academia do not get translation opportunities supposedly due to low industrial collaboration, low IP knowledge, and publication pressure with stringent timelines. In light of this, a detailed review of literature, including policy papers, government initiatives, and corporate reviews, was carried out, and the compilation and synthesis of the secondary data were meticulously summarized for the easy comprehension of the facts and roadmap ahead. For easy comprehension, charts, figures, and compiled tables are presented. RESULTS: This review assesses India's situation in the biosimilar space, the gaps and areas to improve for Indian investment strategies, development, and innovation, addressing need for a more skilled workforce, industrial collaboration, and business models. CONCLUSIONS: This review also proposes forward an approach to empowering technopreneurs to develop MSMEs for large-scale operations to support India in taking innovative thoughts to the global level to ultimately realize a self-reliant India. The limitations of the compilation are also highlighted towards the end.

Evaluating the Impact of Assessment Metrics for Simulated Central Venous Catheterization Training.

INTRODUCTION: Performance assessment and feedback are critical factors in successful medical simulation-based training. The Dynamic Haptic Robotic Trainer (DHRT) allows residents to practice ultrasound-guided needle insertions during simulated central venous catheterization (CVC) procedures while providing detailed feedback and assessment. A study was performed to examine the effectiveness of the DHRT in training the important skills of needle tip tracking and aspiration and how these skills impact procedural complications in simulated CVC. METHODS: The DHRT data were collected for 163 residents at 2 hospitals for 6 simulated needle insertions. Users were given automated feedback on 5 performance metrics, which measure aspiration rate, arterial punctures, punctures through and through the vein, loss of access to the vein, and successful access to the vein. Aspiration rates and tip tracking rates were analyzed to determine their significance in preventing CVC complications and improving performance. RESULTS: Tip tracking rates higher than 40% were 2.3 times more likely to result in successful venous access than rates less than 10%. Similarly, aspiration rates higher than 80% were 2.6 times more likely to result in successful venous access than rates less than 10%. Proper tip tracking and aspiration both reduced mechanical complications. Resident performance improved for all metrics except tip tracking. CONCLUSIONS: Proper tip tracking and aspiration both reduced complications and increased the likelihood of success. However, the skill of tip tracking was not effectively learned through practice without feedback. Therefore, ultrasound-guided needle-based procedures, including CVC, can be improved by providing specific feedback to users on their ultrasound usage to track needle insertions.

In Vivo Transfection of Rat Salivary Glands With Fluorescently Tagged Aquaporin-5 Channel DNA.

Background  The acinar cells of salivary glands are responsible for most saliva production and are, unfortunately, h--ighly radiosensitive. As such, dry mouth or xerostomia is an adverse effect experienced by half of head and neck cancer patients treated with radiation. We evaluate a novel method of gene transfection of aquaporin channels to rat salivary glands. Materials and methods A green fluorescent protein (GFP)-tagged human Aquaporin-5 (AQP5) cDNA sequence cloned into a pCMV6-AC-GFP vector was complexed with lipofectamine 2000. One submandibular gland of the anesthetized rats was injected with the complexed cDNA and lipid solution under ultrasound guidance, while the opposite gland was injected with the vehicle control. The animals were sacrificed between 24 to 48 hours post-injection. The salivary glands were removed and evaluated via fluorescence imaging. Western blot assays were also performed to determine AQP5 cDNA expression. Results  In the experiments, the submandibular glands were identified and injected under ultrasound guidance. Four control glands and eight experimental glands were evaluated. The cDNA was expressed successfully and variably within the experimental glands, noting greater intensity along the cell surface consistent with appropriate trafficking of the AQP5 channel. Western blot analysis demonstrated variable expression in the experimental sample with no expression in the control sample. Several glands across the groups showed mild to moderate interstitial edema or inflammation. Conclusion  In this study, we demonstrate an alternative in vivo transfection method via lipofection and demonstrate the successful expression of the AQP5 channel in rat salivary gland tissue.

Eye-Tracking Technology to Determine Procedural Proficiency in Ultrasound-Guided Regional Anesthesia.

Background: Eye-tracking measures attention patterns, which may offer insight into evaluating procedural expertise. The purpose of this study was to determine the feasibility of using eye tracking to assess visual fixation patterns when performing an ultrasound-guided regional anesthesia procedure and to assess for differences between experienced, intermediate, and novice practitioners. Methods: Participants performed an ultrasound-guided sciatic nerve block 3 times on a fresh cadaver model while wearing eye-tracking glasses. Gaze fixation and dwell time on each location were compared between participants. Eye-gaze paths were used to derive a measure of entropy, or how often participants switched gaze fixations between locations. Results: Five attending anesthesiologists, 5 third-year anesthesiology residents with prior ultrasound-guided regional anesthesia experience, and 5 medical students completed the study. Individuals with more experience were more likely to successfully perform the sciatic nerve block (5/5 attendings, 5/5 residents, 0/5 students; P = .002) and performed the procedure faster (average: attendings 62.6 seconds, residents 106.4 seconds, students 134.4 seconds; P = .089). Participants were progressively faster with practice (Trial 1: 41.8 seconds, Trial 2: 29.2 seconds, Trial 3: 28.9 seconds; P = .012), and the average number of eye shifts per trial decreased from 10.8 to 6.5 to 6 (P = .010). Attending physicians spent significantly less time fixating on the ultrasound monitor compared to trainees (P = .035). Average visual entropy progressively decreased from Trial 1 to Trial 3 (P = .03) and with greater experience (P = .15). There was a strong correlation between entropy and time on task (r(16) = 0.826, P = .001). Conclusions: Experienced providers make fewer back-and-forth visual fixations, spend less time in the procedure, and demonstrate less entropy during ultrasound-guided regional anesthesia procedures. Mobile eye-tracking has the potential to provide additional objective measures of performance that may help not only determine procedural competence but also distinguish between levels of proficiency.

Recommendations for effective documentation in regional anesthesia: an expert panel Delphi consensus project.

BACKGROUND AND OBJECTIVES: Documentation is important for quality improvement, education, and research. There is currently a lack of recommendations regarding key aspects of documentation in regional anesthesia. The aim of this study was to establish recommendations for documentation in regional anesthesia. METHODS: Following the formation of the executive committee and a directed literature review, a long list of potential documentation components was created. A modified Delphi process was then employed to achieve consensus amongst a group of international experts in regional anesthesia. This consisted of 2 rounds of anonymous electronic voting and a final virtual round table discussion with live polling on items not yet excluded or accepted from previous rounds. Progression or exclusion of potential components through the rounds was based on the achievement of strong consensus. Strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement. RESULTS: Seventy-seven collaborators participated in both rounds 1 and 2, while 50 collaborators took part in round 3. In total, experts voted on 83 items and achieved a strong consensus on 51 items, weak consensus on 3 and rejected 29. CONCLUSION: By means of a modified Delphi process, we have established expert consensus on documentation in regional anesthesia.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of abdominal wall, paraspinal, and chest wall blocks.

BACKGROUND: There is heterogeneity in the names and anatomical descriptions of regional anesthetic techniques. This may have adverse consequences on education, research, and implementation into clinical practice. We aimed to produce standardized nomenclature for abdominal wall, paraspinal, and chest wall regional anesthetic techniques. METHODS: We conducted an international consensus study involving experts using a three-round Delphi method to produce a list of names and corresponding descriptions of anatomical targets. After long-list formulation by a Steering Committee, the first and second rounds involved anonymous electronic voting and commenting, with the third round involving a virtual round table discussion aiming to achieve consensus on items that had yet to achieve it. Novel names were presented where required for anatomical clarity and harmonization. Strong consensus was defined as ≥75% agreement and weak consensus as 50% to 74% agreement. RESULTS: Sixty expert Collaborators participated in this study. After three rounds and clarification, harmonization, and introduction of novel nomenclature, strong consensus was achieved for the names of 16 block names and weak consensus for four names. For anatomical descriptions, strong consensus was achieved for 19 blocks and weak consensus was achieved for one approach. Several areas requiring further research were identified. CONCLUSIONS: Harmonization and standardization of nomenclature may improve education, research, and ultimately patient care. We present the first international consensus on nomenclature and anatomical descriptions of blocks of the abdominal wall, chest wall, and paraspinal blocks. We recommend using the consensus results in academic and clinical practice.

The Application of Fascia Iliaca Compartment Block for Acute Pain Control of Hip Fracture and Surgery.

PURPOSE OF REVIEW: Over 300,000 patients are hospitalized annually following hip fractures in the USA. Many patients experienced inadequate analgesia. We will review the perioperative effects of the fascia iliaca compartment block (FICB) in hip fracture patients. RECENT FINDINGS: FICB by injecting local anesthetics beneath the fascia iliaca results in significant pain relief in hip fractures. Neuropathies and vascular injuries are almost unlikely. Single-shot FICB is faster to place, yet providing about 8 h of analgesia when bupivacaine is used. Continuous FICB provides prolonged titratable analgesia, improved patient satisfaction, and leads to faster hospital discharge. FICB reduces opioid consumption, decreases morbidity and mortality, reduces hospital stay, reduces delirium, and improves satisfaction. FICB should form part of a multimodal analgesic regime, in the context of a multidisciplinary approach to the management of hip fracture patients. More clinical investigations are needed to validate the long-term outcome benefits of FICB in hip fracture patients.

Analgesic efficacy of ketamine and magnesium after laparoscopic sleeve gastrectomy: A randomized, double-blind, placebo-controlled trial.

Background Ketamine and magnesium are antagonists of the N-methyl-d-aspartate receptor, and are valuable adjuvants for multimodal analgesia and opioid sparing. Data are limited regarding the opioid sparing efficacy of the combined intraoperative application of these agents in laparoscopic bariatric surgery. The objective of this study was to compare the postoperative opioid sparing properties of a single intraoperative dose of ketamine versus a combination of single doses of ketamine and magnesium after laparoscopic gastric sleeve resection in bariatric patients. Methods One hundred and twenty- six patients were randomly assigned to receive single boluses of ketamine alone 0.5 mg kg-1 IV (ketamine group); combined ketamine bolus of 0.5 mg kg-1 IV and magnesium 2 g IV (ketamine and magnesium group); or placebo. Opioid consumption at 24 h (in morphine equivalents); pain at rest; postoperative nausea and vomiting impact score; sedation scores; and trends of transcutaneous carbon-di-oxide values were analysed. Results The median (inter-quartile range [range]) morphine consumption at 24 h were 32 (24-47 [4.8-91]) mg in the ketamine group, 37 (18-53 [1-144]) mg in the ketamine and magnesium group, and 26 (21-36 [5-89]) mg in the control group and were not significantly different between the groups. There were no differences for all other outcomes examined. Conclusion Combined single intraoperative bolus doses of ketamine and magnesium did not result in postoperative opioid sparing after laparoscopic gastric sleeve resection.

Current understanding of the fascial plane blocks for analgesia of the chest wall: techniques and indications update for 2020.

PURPOSE OF REVIEW: Thoracic myofascial plane blocks have gained popularity because of their ease of performance and relative safety. This review highlights current research demonstrating the efficacy of these blocks for specific surgical procedures and provides a brief description of how these techniques are performed. RECENT FINDINGS: Fascial plane blocks of the thorax and chest wall have been shown to be beneficial in providing perioperative analgesia for a variety of surgical procedures. Studies discussed in this review compare thoracic fascial plane blocks to systemic analgesia alone, contrast these novel methods of pain control to more traditional techniques, such as paravertebral nerve blocks and epidural anesthesia, and attempt to determine, which fascial plane blocks provide optimal postsurgical analgesia. SUMMARY: Thoracic fascial plane blocks provide the anesthesiologist a number of techniques to address postsurgical pain. The relative ease of performance and safety profile of these blocks make them an appealing option for pain control for many patients undergoing thoracic or chest wall surgery. Further research is needed to not only define additional indications for each of these blocks, but also explore optimal dosing including the use of continuous catheter techniques.

Airway Management in the Operating Room and Interventional Suites in Known or Suspected COVID-19 Adult Patients: A Practical Review.

Current evidence suggests that coronavirus disease 2019 (COVID-19) spread occurs via respiratory droplets (particles >5 µm) and possibly through aerosol. The rate of transmission remains high during airway management. This was evident during the 2003 severe acute respiratory syndrome epidemic where those who were involved in tracheal intubation had a higher risk of infection than those who were not involved (odds ratio 6.6). We describe specific airway management principles for patients with known or suspected COVID-19 disease for an array of critical care and procedural settings. We conducted a thorough search of the available literature of airway management of COVID-19 across a variety of international settings. In addition, we have analyzed various medical professional body recommendations for common procedural practices such as interventional cardiology, gastroenterology, and pulmonology. A systematic process that aims to protect the operators involved via appropriate personal protective equipment, avoidance of unnecessary patient contact and minimalization of periprocedural aerosol generation are key components to successful airway management. For operating room cases requiring general anesthesia or complex interventional procedures, tracheal intubation should be the preferred option. For interventional procedures, when tracheal intubation is not indicated, cautious conscious sedation appears to be a reasonable approach. Awake intubation should be avoided unless it is absolutely necessary. Extubation is a high-risk procedure for aerosol and droplet spread and needs thorough planning and preparation. As updates and modifications in the management of COVID-19 are still evolving, local guidelines, appraised at regular intervals, are vital in optimizing clinical management.

Resistance to local anesthesia in people with the Ehlers-Danlos Syndromes presenting for dental surgery.

BACKGROUND: People with the Ehlers-Danlos Syndromes (EDS), a group of heritable disorders of connective tissue, often report experiencing dental procedure pain despite local anesthetic (LA) use. Clinicians have been uncertain how to interpret this apparent LA resistance, as comparison of EDS and non-EDS patient experience is limited to anecdotal evidence and small case series. The primary goal of this hypothesis-generating study was to investigate the recalled adequacy of pain prevention with LA administered during dental procedures in a large cohort of people with and without EDS. A secondary exploratory aim asked people with EDS to recall comparative LA experiences. METHODS: We administered an online survey through various social media platforms to people with EDS and their friends without EDS, asking about past dental procedures, LA exposures, and the adequacy of procedure pain prevention. Among EDS respondents who both received LA and recalled the specific LA used, we compared agent-specific pain prevention for lidocaine, procaine, bupivacaine, mepivacaine, and articaine. RESULTS: Among the 980 EDS respondents who had undergone a dental procedure LA, 88% (n = 860) recalled inadequate pain prevention. Among 249 non EDS respondents only 33% (n = 83) recalled inadequate pain prevention (P < 0.001 compared to EDS respondents). The agent with the highest EDS-respondent reported success rate was articaine (30%), followed by bupivacaine (25%), and mepivacaine (22%). CONCLUSIONS: EDS survey respondents reported nearly three times the rate of LA non-response compared to non-EDS respondents, suggesting that LAs were less effective in preventing their pain associated with routine office dental procedures.

Impact of the NaV1.8 variant, A1073V, on post-sigmoidectomy pain and electrophysiological function in rat sympathetic neurons.

NaV1.8 channels play a crucial role in regulating the action potential in nociceptive neurons. A single nucleotide polymorphism in the human NaV1.8 gene SCN10A, A1073V (rs6795970, G>A), has been linked to the diminution of mechanical pain sensation as well as cardiac conduction abnormalities. Furthermore, studies have suggested that this polymorphism may result in a "loss-of-function" phenotype. In the present study, we performed genomic analysis of A1073V polymorphism presence in a cohort of patients undergoing sigmoid colectomy who provided information regarding perioperative pain and analgesic use. Homozygous carriers reported significantly reduced severity in postoperative abdominal pain compared with heterozygous and wild-type carriers. Homozygotes also trended toward using less analgesic/opiates during the postoperative period. We also heterologously expressed the wild-type and A1073V variant in rat superior cervical ganglion neurons. Electrophysiological testing demonstrated that the mutant NaV1.8 channels activated at more depolarized potentials compared with wild-type channels. Our study revealed that postoperative abdominal pain is diminished in homozygous carriers of A1073V and that this is likely due to reduced transmission of action potentials in nociceptive neurons. Our findings reinforce the importance of NaV1.8 and the A1073V polymorphism to pain perception. This information could be used to develop new predictive tools to optimize patient pain experience and analgesic use in the perioperative setting.NEW & NOTEWORTHY We present evidence that in a cohort of patients undergoing sigmoid colectomy, those homozygous for the NaV1.8 polymorphism (rs6795970) reported significantly lower abdominal pain scores than individuals with the homozygous wild-type or heterozygous genotype. In vitro electrophysiological recordings also suggest that the mutant NaV1.8 channel activates at more depolarizing potentials than the wild-type Na+ channel, characteristic of hypoactivity. This is the first report linking the rs6795970 mutation with postoperative abdominal pain in humans.

Sporadic Erythromelalgia Associated with a Homozygous Carrier of Common Missense Polymorphism in SCN9A Gene Coding for NaV1.7 Voltage-gated Sodium Channel.

A 68-year-old female with a history of sporadic type and presumably secondary erythromelalgia with chronic intractable pain presented for foot surgery. The procedure was performed with combined general anesthesia and regional anesthesia consisting of the placement of a popliteal pain catheter for postoperative pain management. Subsequent whole-genome sequencing revealed that the patient was a homozygous carrier of the common missense mutation in the SCN9A gene coding for voltage-gated sodium channel (NaV1.7) - dbSNP rs6746030 (R1150W). The occurrence of this single nucleotide polymorphism (SNP) was previously suggested not to be associated with erythromelalgia but rather thought to be part of quantitative changes in the pain threshold in different cohorts of patients. The placement of the pain catheter, although controversial in patients with erythromelalgia, provided effective postoperative pain relief without any side effects.