Effects Of Anesthesia Research Articles

Age-dependent cerebral vasodilation induced by volatile anesthetics is mediated by NG2+ vascular mural cells.

Anesthesia can influence cerebral blood flow by altering vessel diameter. Using in vivo two-photon imaging, we examined the effects of volatile anesthetics, sevoflurane and isoflurane, on vessel diameter in young and adult mice. Our results show that these anesthetics induce robust dilation of cortical arterioles and arteriole-proximate capillaries in adult mice, with milder effects in juveniles and no dilation in infants. This anesthesia-induced vasodilation correlates with decreased cytosolic Ca2+ levels in NG2+ vascular mural cells. Optogenetic manipulation of these cells bidirectionally regulates vessel diameter, and their ablation abolishes the vasodilatory response to anesthetics. In immature brains, NG2+ mural cells are fewer in number and express lower levels of Kir6.1, a subunit of ATP-sensitive potassium channels. This likely contributes to the age-dependent differences in vasodilation, as Kir6.1 activation promotes, while its inhibition reduces, anesthesia-induced vasodilation. These findings highlight the essential role of NG2+ mural cells in mediating anesthesia-induced cerebral vasodilation.

Comparative Effects of Spinal Anesthesia and Combined Spinal with Peripheral Nerve Blocks on Postoperative Outcomes in Anterior Cruciate Ligament Repair

Objectives: This study aimed to compare the effectiveness of spinal anesthesia (SA) alone versus combined spinal anesthesia with adductor canal block (ACB) and sciatic nerve block (SNB) (SA + ACB + SNB) in patients undergoing arthroscopic anterior cruciate ligament (ACL) reconstruction. We hypothesized that SA + ACB + SNB would provide better analgesia, greater patient satisfaction, and shorter postanesthesia recovery times than SA alone. Methods: A prospective randomized controlled trial was conducted with 60 patients aged 15–49 years scheduled for elective arthroscopic ACL reconstruction. Participants were randomly assigned to receive either SA or SA + ACB + SNB. Postoperative pain was assessed using the Visual Analog Scale (VAS) at 4, 12, and 24 h post-operation. General health was evaluated using the 12-item Short Form Survey (SF-12) at 1 month postoperatively. Range of motion and analgesic consumption were also recorded. Results: The median VAS score at 4 h post-operation was significantly lower in the SA + ACB + SNB group compared to the SA group (0 [IQR: 0–1] vs. 2 [IQR: 1–3], p = 0.0137). No significant differences in VAS scores were found at 12 h (p = 0.9282) and 24 h (p = 0.5809). PCS-12 and MCS-12 scores did not differ significantly between groups. The SA group had a lower postoperative range of motion (ROM) compared to the SA + ACB + SNB group, with a mean active ROM of 40.67 degrees (±23.52) versus 72.17 degrees (±24.69), respectively (p < 0.0001). Analgesic consumption was similar, with 53.33% of participants in each group using postoperative analgesics (p = 1.0). The mean surgery duration was 74.6 min. The gender distribution was 83% male and 17% female, with an average age of 27.7 years. Conclusions: Adding ACB and SNB to spinal anesthesia improved immediate postoperative pain relief and preserved range of motion in patients undergoing ACL reconstruction, suggesting potential clinical benefits in pain management and functional recovery.

A comparison of the effects of ENTONOX inhalation and spinal anesthesia on labor pain reduction and apgar score in vaginal delivery: a clinical trial study

A comparison of the effects of ENTONOX inhalation and spinal anesthesia on labor pain reduction and apgar score in vaginal delivery: a clinical trial study

Anesthetic effects on electrophysiological responses across the visual pathway.

Anesthetics are widely used in electrophysiological tests to assess retinal and visual system functions to avoid experimental errors caused by movement and stress in experimental animals. To determine the most suitable anesthetic for visual electrophysiological tests, excluding ketamine and chloral hydrate due to regulatory and side effect concerns, this study investigated the effects of ethyl carbamate (EC), avertin (AR), and pentobarbital sodium (PS) on visual signal conduction in the retina and primary visual cortex. Assessments included flash electroretinogram (FERG), pattern electroretinogram (PERG), pattern visual evoked potentials (PVEP), and flash visual evoked potentials (FVEP), FERG and FVEP were used to evaluate the responses of the retina and visual cortex to flash stimuli, respectively, while PERG and PVEP assessed responses to pattern stimuli. The research showed that AR demonstrates the least disruption to the visual signal pathway, as evidenced by consistently high characteristic peaks in the AR group across various tests. In contrast, mice given EC exhibited the lowest peak values in both FERG and FVEP, while subjects anesthetized with PS showed suppressed oscillatory potentials and PERG responses. Notably, substantial PVEP characteristic peaks were observed only in mice anesthetized with AR. Consequently, among the three anesthetics tested, AR is the most suitable for visual electrophysiological studies.

Scientometric analysis of articles of respiratory gas mixtures and their application in emergency medicine

Relevance. In humans, specific respiratory gas mixtures (RGMs) significantly maximize the effect of anesthesia and treatment of certain diseases, as well as enhance body functional reserves and exercise performance. The objective is to identify major research prospects on the RGM capacity to optimize the functional status of humans, as represented in publications by Russian investigators.Methods. In response to the RGMs query, the Scientific Electronic Library search engine generated a dataset of 513 publications by Russian investigators, published from 2006 to 2023. For further analysis of the publications, the VOSviewer 1.6.20 software was implemented for clustering of keywords with a frequency of ≥ 4 presented in ≥ 8 publications either by individual authors or co-authorship networks.Results and discussion. The average annual number of articles was (23 ± 3). The dynamics of increasing publications were revealed. The scientometric analysis of the selected publications revealed that the content was highly demanded among readers. For instance, the average citation number per paper was 3.29, with a substantial self-citation rate of 30.2 %. Journals with the largest number of publications by top scientific networks were identified. The VOSviewer analysis produced 7 keyword clusters: Cluster 1 for xenon anesthesia – 258 papers (35 %) with the total link strength of 29 %; Cluster 2 for hypoxic training – 171 papers (23.2%) with the total link strength of 22.5 %; Cluster 3 for gas composition in confined spaces – 76 papers (10.3 %) and 22 % total link strength; Cluster 4 for oxygen-helium gas mixture – 132 papers (17.9 %) with 16.4 % total link strength; Cluster 5 for the neuroprotective effects of gas mixtures – 32 papers (4.3 %) with 3.6 % total link strength; Cluster 6 for the anti-stress effect of xenon-rich inhalation therapy – 40 papers (5.4 %) with 3.6 % total link strength; Cluster 7 for low-flow anesthesia – 28 papers (3.8 %) with 3.6 % total link strength.Conclusion. Scientometric studies can enhance the data support for scientific research of advanced strategies to optimize human functional status and increasing performance at work for professionals operating in extreme occupational environments.

The Effects of Intra-Operative Lidocaine Infusion on Post Operative Pain and Morphine Consumption Following Major Gynaecological Surgeries Under General Anaesthesia

<i>Introduction</i>: Major gynaecological surgeries are associated with considerable postoperative pain, which remains a challenge for many practitioners. Multimodal forms of analgesia significantly reduce the requirement of opioids for pain management. Despite its local anaesthetic effects, lidocaine infusion improves postoperative pain and morphine consumption following gynaecological surgeries. <i>Materials and methods</i>: Sixty patients were assigned randomly into 2 groups (A and B) with 30 patients per group. Group A received intravenous lidocaine 1.5 mg/kg at induction via a bolus injection and 1.5 mg/kg/hr in normal saline infusion from onset of surgery to the end of surgery, while the control group (Group B) received equal volume of normal saline at the same timelines. Pain scores were assessed postoperatively using the numerical rating scale and the cumulative morphine consumed postoperatively were also measured. <i>Results</i>: The mean pain scores were significantly higher in the Saline Group than in the Lidocaine group. The cumulative morphine consumption after 48 hours was significantly reduced in the study group 4.87 ± 1.80 mg vs 14.13 ± 4.10 mg (P<0.0001). Conclusion: The administration of a bolus dose (1.5 mg/kg) of intravenous lidocaine at induction and a continuous intravenous infusion of 1.5 mg/kg/hr from onset of surgery till skin closure reduced the postoperative pain intensity and morphine consumption in patients undergoing major gynaecological surgeries under general anaesthesia.

Behavioral studies of the abuse potential and anesthetic and sedative effects of etomidate in male rodents.

Etomidate is a short-acting general anesthetic for clinical use and has been used as alternative to propofol or added to the powdered drug and e-cigarette cartridges recently, leading to an increase in abuse. But there have been no studies conducted on the abuse potential of etomidate. This study aimed to evaluate the abuse potential of etomidate via conditioned place preference (CPP) and self-administration tests, reflecting its rewarding and reinforcing effects. In addition, righting reflex and open-field tests were conducted to evaluate the anesthetic and sedative effects of etomidate. In male mice, the ED50 after intraperitoneal (i.p.) injection of anesthetic effect for etomidate was 9.156mg/kg and the ED50 of the sedative effect 5min after intraperitoneal injection was 2.389mg/kg. Etomidate induced CPP in male mice at the minimum dose of 3mg/kg i.p. and supported stable self-administration in male rats at the dose of 0.075mg/kg/intravenous infusion. The dose-response curve of etomidate was an inverted U-shape, which showed significant self-administrations compared with the vehicle group at doses of 0.05-0.1mg/kg/infusion etomidate and the highest intake of 21.1 ± 0.64 infusions per 4h-session. These results clearly demonstrate that etomidate has rewarding and reinforcing effects in male rodents, as well as effects on anesthesia and motor inhibition. These findings indicate the possibility of abuse potential in humans using etomidate.

Comparative Efficacy of Postoperative Pain Management Techniques Following Costal Cartilage Harvest: A Systematic Review and Network Meta-analysis.

Efficient pain control is essential in reconstructive surgeries, particularly in procedures involving the harvest of costal cartilage. This study examines and compares different pain relief treatments using a network meta-analysis (NMA) to determine the most effective techniques for managing pain. We performed a systematic review and network meta-analysis (NMA) by scanning several databases such as PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), China National Knowledge Infrastructure (CNKI), Wanfang, and Weipu till March 18, 2024. The review analyzed randomized controlled trials and observational studies that evaluated the effectiveness of local anesthetics and multimodal analgesia techniques in treating postoperative pain following costal cartilage harvest. Primary outcomes were pain scores at 6-, 12-, 24-, and 48-h post-surgery, while secondary outcomes included the need for rescue analgesia and opioid-related adverse effects. Fourteen studies involving 935 participants were included. The analysis revealed that multimodal strategies, particularly 'Methylene Blue and Ropivacaine Intercostal Nerve Block (MB & Ropivacaine ICNB) combined with Patient-Controlled Analgesia (PCA),' were the most effective techniques to reduce pain scores across 6, 24, and 48-h time points. "Pre-operation SAPB & PSB + PCA" was most effective in reducing pain score at 12h and significantly decreased the need for rescue analgesia and opioid-related adverse effects. In contrast, traditional ICNB with single drug consistently showed the least efficacy. The results of our study strongly support the use of multimodal analgesic techniques instead of typical single medication ICNB for managing postoperative pain after costal cartilage harvest. These strategies not only provide superior pain control but also contribute to reducing the dependency on opioids, aligning with current clinical priorities to enhance recovery and minimize opioid-related risks. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effects of combined anesthesia on pulmonary oxygenation function, hemodynamics, and respiratory compliance in elderly patients undergoing pulmonary lobectomy for lung cancer.

Traditional general anesthesia in elderly lung cancer patients undergoing pulmonary lobectomy may lead to hemodynamic fluctuations and postoperative complications. To optimize anesthesia efficacy, this study explores the application of combined anesthesia (general anesthesia combined with thoracic paravertebral block) in such surgeries. We evaluated the improvement of pulmonary oxygenation function, hemodynamic stability, and respiratory compliance in elderly lung cancer patients undergoing pulmonary lobectomy with combined anesthesia. This retrospective study analyzed 100 elderly lung cancer patients who underwent pulmonary lobectomy at our hospital from February 2020 to December 2023. Patients were divided into 2 groups: the control group received general anesthesia, while the treatment group received combined anesthesia (general anesthesia plus thoracic paravertebral block). By comparing intraoperative hemodynamic parameters, postoperative pulmonary oxygenation function, respiratory compliance, cognitive function, sleep quality, and postoperative complication rates between the 2 groups, we assessed the application efficacy of combined anesthesia. Compared to the control group, the treatment group exhibited better hemodynamic stability intraoperatively, significantly improved postoperative pulmonary oxygenation function and respiratory compliance. Additionally, patients in the treatment group showed faster recovery of cognitive function, better sleep quality, and a relatively lower incidence of postoperative complications. Combined anesthesia demonstrates unique advantages in pulmonary lobectomy for elderly lung cancer patients, optimizing intraoperative hemodynamic stability, promoting postoperative pulmonary function recovery, accelerating cognitive function recovery, improving sleep quality, and potentially reducing the risk of postoperative complications. This finding provides a new effective strategy for anesthesia management in elderly lung cancer patients.

Comparative Study to Evaluate the Efficacy of Dexmedetomidine and Magnesium Sulfate as Adjuvants to 0.5% of Hyperbaric Bupivacaine in Patient Undergoing Abdominal Hysterectomy by Spinal Anesthesia: A Randomized, Double-blind Study

Abstract Objective: Abdominal hysterectomy is a common gynecological procedure. While spinal anesthesia offers pain relief, its short analgesic effect is limiting. In this context, there are not many research that examined magnesium sulfate, dexmedetomidine, and 0.5% hyperbaric bupivacaine. Our research addresses this gap as “Comparing Dexmedetomidine and Magnesium Sulfate as Adjuvants to Hyperbaric Bupivacaine for Abdominal Hysterectomy”. Methods: Ninety patients with the American Society of Anesthesiologists Classification I and II, aged 30–60, planned for abdominal hysterectomy were randomized to either dexmedetomidine or magnesium sulfate or control group as adjuvants to hyperbaric bupivacaine. The primary objective was to find the effectiveness of the anesthesia in terms of both sensory and motor blocks (onset, duration, and severity), with the secondary objective was to find out any other associated complications. Results: In comparison to the magnesium sulfate group, the dexmedetomidine group’s anesthetic effect began significantly more immediately and persisted much longer (P < 0.001). The groups did not vary statistically significant in terms of side effects or hemodynamic instability. Conclusion: Adjuvants such as dexmedetomidine or magnesium sulfate along with hyperbaric bupivacaine, for abdominal hysterectomy under spinal anesthesia, provide effective anesthesia. Dexmedetomidine (10 μg) and magnesium sulfate (100 mg) both showed safe intrathecal adjuvant usage. Remarkably, dexmedetomidine surpasses magnesium sulfate by swiftly inducing sensory and motor blocks, extending their duration, and enhancing analgesia. Notably, both adjuncts yield no adverse effects. Overall, these findings underscore the potential of dexmedetomidine as a more effective adjuvant in spinal anesthesia protocols for abdominal hysterectomy procedures.

Effective correction of manifestations of vaginal microflora disorders

Pathological vaginal discharge is one of the main reasons for visiting gynecologists. Despite the abundance of drugs, not all are compliant and quickly effective for pronounced itching and swelling in the introitus area. One of the most common causes of pathological leukemia is vaginal infections, which are represented by three main clinical forms: bacterial vaginosis (BV) – up to 50% of all cases; vulvovaginal candidiasis (CVV) – 20–25% and trichomonas vaginitis (TV) – 15–20% of cases, respectively. In this regard, retrospective analysis shows that patients with BV, KV, TV most often actively turn to a gynecologist or venereologist However, the fact that the cause of pathological whites in more than 30% of cases can be a mixed infection creates problems in treatment with the use of monodrugs (many relapses up to 40% or more). Therefore, for their treatment, it is considered rational to use the concept of the etiotropic approach, based on the local effect of combined vaginal drugs. The role of a combined topical drug, including those with a rapid anesthetic effect, was evaluated. Neo-Penotran Forte L is a logical combination of antibacterial agents and a local anesthetic used to treat manifest forms of vaginal infections and provide rapid relief of intolerable symptoms.

Determining the appropriate concentration of an anesthetic mixture in three different fish species with the PROMETHEE decision model

Anesthesia is applied to protect fish welfare for reducing employee workload in aquaculture. The efficacy of the anesthetic agent varies depending on the fish species. In this study, the effect of a commercial anesthetic (VetiVital AquaSED) manufactured mainly with herbal extracts (includes eugenol, linalool, linalyl acetat etc.) on three different fish species (rainbow trout, common carp, and Danube sturgeon) was investigated. In addition, the best available concentration of the anesthetic mixture for each species was determined using the PROMETHEE decision model. Danube sturgeon showed more resistance to anesthetics than the other two species. It was determined that the increase in concentration caused histological deterioration in fish. On the other hand, hematological parameters were affected by the anesthetic mixture, and this effect returned to normal levels after 8 h. According to the multi-criteria decision model, the best available concentrations determined by considering 10 different criteria are 400, 480, and 675 mg L−1 for rainbow trout, common carp and Danube sturgeon, respectively. Future studies should focus on developing the most appropriate anesthesia mixture in terms of physiological and anesthesia effectiveness for the target fish species.

Cannabinoids and General Anesthetics: Revisiting Molecular Mechanisms of Their Pharmacological Interactions.

Cannabis has been used for recreation and medical purposes for more than a millennium across the world; however, its use's consequences remain poorly understood. Although a growing number of surgical patients are regular cannabis consumers, little is known regarding the pharmacological interactions between cannabis and general anesthetics; consequently, there is not a solid consensus among anesthesiologists on the perioperative management of these patients. The existing evidence about the molecular mechanisms underlying pharmacological interactions between cannabinoids and anesthetic agents, both in animal models and in humans, shows divergent results. While some animal studies have demonstrated that phytocannabinoids (tetrahydrocannabinol [THC], cannabidiol [CBD], and cannabinol [CBN]) potentiate the anesthetic effects of inhalation and intravenous anesthetics, while others have found effects comparable with what has been described in humans so far. Clinical studies and case reports have consistently shown increased requirements of GABAergic anesthetic drugs (isoflurane, sevoflurane, propofol, midazolam) to achieve adequate levels of clinical anesthesia. Several potential molecular mechanisms have been proposed to explain the effects of these interactions. However, it is interesting to mention that in humans, it has been observed that the ingestion of THC enhances the hypnotic effect of ketamine. Animal studies have reported that cannabinoids enhance the analgesic effect of opioids due to a synergistic interaction of the endogenous cannabinoid system (ECS) with the endogenous opioid system (EOS) at the spinal cord level and in the central nervous system. However, human data reveals that cannabis users show higher scores of postoperative pain intensity as well as increased requirements of opioid medication for analgesia. This review aims to improve understanding of the molecular mechanisms and pharmacological interactions between cannabis and anesthetic drugs and the clinical outcomes that occur when these substances are used together.

Effectiveness of phentolamine mesylate, vibration and photobiomodulation in reducing pain and the reversal of local anesthesia: A systematic review.

Dental anesthesia administration often triggers unpleasant sensations, particularly needle injection-related pain, which can evoke fear among patients, especially in the pediatric population. Vibration and low-level laser therapy (LLLT) have been extensively studied as potential methods for alleviating pain. Additionally, phentolamine mesylate (PM) has shown promise in reducing the duration of anesthesia. From a clinical perspective, inadequate control over the persistence of the anesthetic effect may lead to complications associated with its prolonged duration, such as self-injuries or functional impairments. This review aimed to systematically summarize and compare methods of alleviating pain during local anesthesia and reducing its duration. In November 2023, an electronic search was systematically conducted across PubMed, Web of Science, and Scopus databases using keywords (pain) AND (anesthesia) AND ((phentolamine) or (vibration) or (LLLT) OR (PBM)). The initial pool consisted of 495 records, from which 241 duplicates were eliminated. After careful examination of the remaining articles, 40 were included. The study adhered to the PRISMA guidelines. Most studies reported beneficial effects of LLLT and vibration; however, some did not corroborate these findings. Four studies had inconclusive results. Regarding anesthesia duration involving PM and LLLT, the majority of studies exhibited notable reductions, although no significant differences were revealed in 1 study. Vibration and LLLT appear to be advantageous methods in alleviating pain associated with local anesthesia administration. Phentolamine mesylate and LLLT are efficient in reversing local anesthesia.

Conditioned Pain Modulation Differences in Central and Peripheral Burning Mouth Syndrome (BMS) Patients.

To evaluate conditioned pain modulation (CPM) in burning mouth syndrome (BMS) patients with different pain mechanisms. Twenty BMS patients (52.0 ± 6.8 years, 17 women and 3 men) and age- and gender-matched 22 healthy controls were enrolled in this randomised controlled trial. The patients received an active lingual nerve block (lidocaine) and a placebo injection (saline) randomly with an interval of 1 week in a double-blinded manner. Patients evaluated their pain intensity on a 0- to 10-cm visual analogue scale (VAS) before and after each injection, with or without CPM. Based on the anaesthesia effect, BMS patients were divided into two groups with presumed different pain mechanisms; a 'central subgroup (n = 11)' with pain relief less than 1 cm and 'peripheral subgroup (n = 9)' with pain relief more than 1 cm on the VAS. Mechanical pain threshold (MPT) and wind-up ratio (WUR) were investigated at two oral mucosa regions: the region with most intense symptoms and a control region for the patient group; tongue and buccal region for the control group. CPM was induced by immersing the left hand into cold water. A moderate level of pain (around five on the VAS) was obtained by adjusting the water temperature. MPT and WUR were measured twice for all the participants with and without CPM, which was analysed and presented as relative change in MPT and WUR. Differences between groups were analysed using two-way ANOVA. Differences within group between tests were assessed by paired t-test. At baseline, there were no significant group differences for MPT or WUR between BMS patients and healthy controls (p ≥ 0.156). The mean bath temperature to evoke moderate pain for the BMS group was significantly lower than that for the healthy control group (8.9°C vs. 11.9°C, p = 0.003). The CPM evoked an inhibitory modulation in 18.2%-44.4% of BMS patients, while for the healthy group, the ratio was 68.2%-81.8%. Central BMS patients had smaller CPM effects than healthy participants at the painful site and control site, which indicated a decreased CPM function (p ≤ 0.034). Peripheral BMS patients had lower CPM effects than healthy participants only at the painful site (p = 0.037). The present findings documented impairment of central nociceptive inhibition processing in BMS patients which was more extensive in central BMS than peripheral BMS. These findings add to the suggestion that BMS may a heterogeneous pain condition with at least two different phenotypes.

The Role of Pain Medications in Modulating Peripheral Nerve Injury Recovery.

Peripheral nerve injuries (PNIs) are common, costly, and cause significant pain. Effective management of PNIs involves tailoring medications to the injury type as well as understanding the pharmacokinetics/pharmacodynamics to support nerve regeneration and reduce pain. Opioids act on opioid receptors to significantly reduce pain for many patients, but there are significant addiction risks and side effects. In addition, opioids may exacerbate pain sensitivity and affect nerve regeneration. Non-steroidal anti-inflammatory drugs or acetaminophen act on cyclooxygenase enzymes and are commonly used for nerve pain, with 34.7% of people using them for neuropathic pain. While effective for mild pain, they are often combined with opioids, gamma-aminobutyric acid (GABA) analogs, lidocaine, or corticosteroids for more severe pain. Corticosteroids, mimicking adrenal hormones like cortisol, treat PNI-related inflammation and pain. Their pharmacokinetics are complex, often requiring local injections in order to minimize systemic risks while effectively treating PNIs. Lidocaine, a common local anesthetic, blocks ion channels in the central nervous system (CNS) and peripheral nerves, providing strong analgesic and anti-inflammatory effects. If used improperly, lidocaine can cause neuronal toxicity instead of anesthetic effect. GABA acts as an inhibitory neurotransmitter in the CNS and its drug analogs like pregabalin and gabapentin can alleviate neuropathic pain by binding to voltage-gated Ca2+ channels, inhibiting neurotransmitter release. These pain medications are commonly prescribed for PNIs despite a limited guidance on their effects on nerve regeneration. This review will discuss these drug's mechanisms of action, pharmacokinetics/pharmacodynamics, and their clinical application to highlight their effect on the PNI recovery.

L’intoxication au protoxyde d’azote : un nouveau défi pour la biologie médicale

AbstractNitrous oxide (N2O) is a gas used in medicine for its anesthetic and analgesic properties, and in industry as an oxidizing gas or propellant. This gas is also available on self-service for food use. In recent years, its use has been increasingly diverted to recreational purposes. Between 2020 and 2021, the number of serious cases of intoxication increased by 320% in France, demonstrating a major public health concern. It is also a problem for road safety, with an increase in the number of road accidents linked to the consumption of this gas. Nitrous oxide causes both short-term effects (euphoria, disorientation, etc.) and long-term effects (sensory and motor neurological disorders and thrombosis). This gas acts on the central nervous system, inducing anxiolytic, anesthetic, antidepressant and analgesic effects. Nitrous oxide is difficult to quantify because of its rapid elimination. Biological investigation is thus based on secondary anomalies linked to vitamin B12 inactivation: increased methylmalonic acid and homocysteine levels. However, these two biological markers are not specific to nitrous oxide intoxication. To improve patient support, we need to find new biological markers that are more specific to nitrous oxide intoxication.

Effect of erector spinae plane block and thoracic epidural anesthesia on hospital length of stay and postoperative opioid use after mastectomy

BackgroundAdequate postoperative pain control is essential after mastectomy. This study compares the influence of 2 regional analgesia techniques on length of stay and opioid use to systemic analgesia alone. MethodsPatients treated with mastectomy from 2014 to 2020 were stratified according to perioperative analgesic modality (systemic analgesia versus thoracic epidural anesthesia or erector spinae plane block). Demographic, tumor, and treatment characteristics were compared. Outcome variables included postoperative anesthesia unit and hospital length of stay, postoperative day 1 and 2 discharge rates, and inpatient opioid use (in oral milligram morphine equivalents). ResultsOf 316 patients, 171 received systemic analgesia, 72 thoracic epidural anesthesia, and 73 erector spinae plane block. On univariate analysis, there were significant differences in age, neoadjuvant chemotherapy, bilateral surgery, immediate reconstruction, and Her2 positivity rates. Thoracic epidural anesthesia had the longest hospital length of stay, and erector spinae plane block the shortest, compared with systemic analgesia (52.1 vs 28 vs 30.6 hours, P < .0001). Postoperative day 1 discharge was more likely with erector spinae plane block than systemic analgesia and less likely with thoracic epidural anesthesia (89% vs 68.4% vs 30.6%, P < .0001). Erector spinae plane block required significantly less milligram morphine equivalents than thoracic epidural anesthesia or systemic analgesia on postoperative day 1 (10 vs 18.75 vs 20 milligram morphine equivalents, P < .0009), but no differences on postoperative day 2 (23.5 vs 20 vs 25 milligram morphine equivalents, P = .84). Total hospital opioid use was significantly lower for erector spinae plane block than thoracic epidural anesthesia or systemic analgesia (24 vs 32.3 vs 32 milligram morphine equivalents, P = .024). On multivariate analysis, thoracic epidural anesthesia was associated with significantly longer length of stay, whereas neither thoracic epidural anesthesia nor erector spinae plane block was associated with decreased opioid use. ConclusionRegional analgesia is not significantly associated with decreased opioid use or hospital length of stay.

The Utility of Electroencephalograhy in Guiding General Anesthesia in Children.

Traditional pediatric anesthetic dosing using pharmacokinetic estimates based on age and weight is often imprecise, frequently leading to oversedation. Intraoperative electroencephalography (EEG) allows visualization of the brain's response to anesthetic agents in real time, facilitating precise titration of anesthetic drug doses optimized for the individual child. The goal of EEG-guided anesthesia management is to maintain an optimal state of hypnosis during various stages of the procedure while minimizing hemodynamic instability and other adverse effects of anesthesia. This is especially important in children with less predictable anesthetic requirements, such as children with atypical neurodevelopment, altered levels of consciousness before anesthesia, or those receiving total intravenous anesthesia, neuromuscular blockers, or a combination of anesthetic agents with different mechanisms of actions. Children with limited cardiorespiratory reserves and those undergoing high-risk procedures such as cardiopulmonary bypass also benefit from EEG guidance as they have a narrower therapeutic window for optimal anesthetic dosing. Various processed EEG (pEEG) monitors are available for intraoperative monitoring in children. These monitors display a pEEG index based on the manufacturer's algorithm, purportedly indicating the patient's hypnotic state. Due to differences in developmental neurophysiology and EEG dynamics in children, pEEG indices may not always reliably indicate the hypnotic state, especially in neonates and infants. Learning to interpret nonproprietary EEG parameters including the raw EEG, spectral-edge frequency 95% (SEF95), and density spectral array can prevent overreliance on pEEG indices. This review provides an overview of the advantages of EEG guidance during clinical anesthesia, including potential reduction in anesthetic dosage, prevention of EEG suppression, and reduction in peri-operative adverse events. We describe the use of nonproprietary EEG parameters in guiding anesthesia in children for various clinical end points including laryngoscopy, surgical incision, and maintenance of anesthesia, as well as sedation. We illustrate these principles with various case examples commonly encountered during pediatric anesthesia. Lastly, we discuss strategies to expand intraoperative EEG monitoring in children through education and training programs, as well as advocate for further research to assess clinical outcomes associated with EEG guidance to support its routine use in clinical care.

Effects of hypotensive anesthesia compared to normotensive anesthesia in orthognathic surgery.

Orthognathic surgery is widely accepted for correcting dentofacial deformities. Due to the rich blood supply in the head and neck region, considerable bleeding can occur from the incised soft tissues and bone during orthognathic surgery. Hypotensive anesthesia is a method used in surgical practice by which blood pressure is decreased predictably and deliberately to reduce blood loss and improve surgical field. However, there is still uncertainty regarding its effectiveness and safety in orthognathic surgery. We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis, and generated a summary of findings table using the GRADE approach. We identified three systematic reviews, including 11 studies overall, which are randomized trials. We concluded that hypotensive anesthesia may reduce intraoperative blood loss and may improve the quality of surgical field, however, the certainty of the evidence has been assessed as low. On the other hand, orthognathic surgery with HA may make little or no difference in surgical time (low certainty evidence). Finally, no studies were found that reported adverse effects or mortality.