Volatile Anesthetics Research Articles

Mechanism of isoflurane‑mediated breast cancer growth in vivo.

Use of volatile anesthetics is associated with worse outcome following tumor resection surgery compared with the use of intravenous anesthetics. However, the underlying mechanism has not been clearly delineated yet in vivo. The EO771 cell-based congenic breast cancer model was used in the present study. Isoflurane directly binds to and inhibits two adhesion molecules, leukocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (Mac-1). Similarly, exposure to sevoflurane, another volatile anesthetic and LFA-1 inhibitor, is associated with an increase in breast cancer size compared with non-exposure. Thus, the present study first examined the role of LFA-1 and Mac-1 in the EO771 breast cancer model. Both LFA-1 deficiency and inhibition enhanced tumor growth, which was supported by cytokine and eicosanoid data profiles. By contrast, Mac-1 deficiency did not affect tumor growth. The exposure to isoflurane and sevoflurane was associated with an increase in breast cancer size compared with non-exposure. These data suggested that isoflurane enhanced tumor growth by interacting with LFA-1. Isoflurane exposure did not affect tumor growth in LFA-1-deficient mice. In summary, the present data showed that LFA-1 deficiency facilitated breast cancer growth, and isoflurane, an LFA-1 inhibitor, also increased breast cancer growth.

Effect of propofol and isoflurane on NK Cells: A pilot study on perioperative breast cancer patients from Eastern India

Introduction: In onco-anesthesiology, the selection between intravenous and volatile anesthetics for maintaining NK cell response during cancer surgery has been an ambiguous area. In the absence of any such comparative Indian report, this pilot study aimed to investigate the effect of intravenous anesthetic, Propofol, and volatile anesthetic, Isoflurane on the NK cell-mediated immune-inflammatory response of perioperative breast cancer patients. Materials and Methods: Treatment naive breast cancer patients (N, 50) selected for surgery were randomly subjected to either Isoflurane (N, 25) or Propofol (N, 25) anesthetic group. The peripheral blood samples were collected 1 day before surgery (Pre), 1 h after incision (Intra) and 48 h after surgery (Post). The blood samples were subjected to immunophenotyping, activation, degranulation, and cytokine analysis. Results: The frequency of NK cell populations did not differ between the Isoflurane and Propofol groups irrespective of cancer stage II/III. NK cell degranulation marker CD107a and activation marker CD335 expression were significantly reduced in the postoperative period compared to the preoperative group in the Isoflurane group but Propofol did not inflict such alterations. Both Isoflurane/Propofol elicited similar trends in the cytokine profiles of interleukin (IL)-6, IL-15, interferon (IFN)-g and transforming growth factor (TGF)-β levels. Isoflurane significantly increased IL-8 during the intraoperative period and matrix metalloproteinase (MMP)-9 during the postoperative period whereas no such changes were observed with Propofol. Conclusion: This pilot study indicated that Propofol partially proved better over Isoflurane in maintaining the activation (CD335) and degranulation of NK cells (CD107a) and alleviating inflammation (IL-8 and MMP-9) during the perioperative period in the breast cancer patients.

Spontaneous recovery from neuromuscular block after a single dose of a muscle relaxant in pediatric patients: A systematic review using a network meta-analytic and meta-regression approach.

Age-related differences in the pharmacokinetics and pharmacodynamics of neuromuscular blocking agents (NMBAs) and the short duration of many surgical procedures put pediatric patients at risk of postoperative residual curarization (PORC). To date, the duration of neuromuscular blocking agent effect in children has not been analyzed in a quantitative review. The current meta-analysis aimed to compare spontaneous recovery following administration of various types and doses of neuromuscular blocking agents and to quantify the effect of prognostic variables associated with the recovery time in pediatric patients. We searched for randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that compared the time to 25% T1 (t25), from 25% to 75% T1 (RI25-75), and to ≥90% train-of-four (tTOF90) neuromuscular recovery between common neuromuscular blocking agent treatments administered as a single bolus to healthy pediatric participants. We compared spontaneous t25, RI25-75, and tTOF90 between (1) neuromuscular blocking agent treatments and (2) age groups receiving a given neuromuscular blocking agent intervention and anesthesia technique. Bayesian random-effects network and pairwise meta-analyses along with meta-regression were used to evaluate the results. We used data from 71 randomized controlled trials/controlled clinical trials including 4319 participants. Network meta-analysis allowed for the juxtaposition and ranking of spontaneous t25, RI25-75, and tTOF90 following common neuromuscular blocking agent interventions. For all neuromuscular blocking agents a log-linear relationship between dose and duration of action was found. With the neuromuscular blocking agent treatments studied, the average tTOF90 (mean[CrI95]) in children (>2-11 y) was 41.96 [14.35, 69.50] and 17.06 [5.99, 28.30] min shorter than in neonates (<28 d) and infants (28 d-12 M), respectively. We found a negative log-linear correlation between age and duration of neuromuscular blocking agent effect. The difference in the tTOF90 (mean[CrI95]) between children and other age groups increased by 21.66 [8.82, 34.53] min with the use of aminosteroid neuromuscular blocking agents and by 24.73 [7.92, 41.43] min with the addition of sevoflurane/isoflurane for anesthesia maintenance. The times to neuromuscular recovery are highly variable. These can decrease significantly with age and are prolonged when volatile anesthetics are administered. This variability, combined with the short duration of many pediatric surgical procedures, makes quantitative neuromuscular monitoring mandatory even after a single dose of neuromuscular blocking agent.

Remimazolam-based total intravenous anesthesia in a patient with a confirmed diagnosis of malignant hyperthermia: a case report

BackgroundMalignant hyperthermia (MH) is a rare, life-threatening disorder of calcium homeostasis in skeletal muscle cells that is triggered by volatile anesthetics and succinylcholine, leading to a hypermetabolic reaction. The pathogenic ryanodine receptor 1 (RYR1) gene variant is critical. Patients susceptible to MH should avoid triggering agents, and total intravenous anesthesia (TIVA) is preferred. Remimazolam is safe in patients with suspected MH.Case presentationWe present the first case of remimazolam treatment in a genetically confirmed patient with MH without MH development. A 72-year-old man with a family history of MH underwent remimazolam-based TIVA. After informed consent was obtained, a muscle biopsy and genetic testing were performed. Intraoperatively and postoperatively, the patient exhibited no signs of MH. An enhanced function of the RYR1 channel into releasing calcium was indicated, and the genetic testing revealed a pathogenic variant of RYR1.ConclusionsRemimazolam-based TIVA is safe in patients confirming the diagnosis of MH.

The Effects of Volatile Anesthetics on Renal Sympathetic and Phrenic Nerve Activity during Acute Intermittent Hypoxia in Rats.

Coordinated activation of sympathetic and respiratory nervous systems is crucial in responses to noxious stimuli such as intermittent hypoxia. Acute intermittent hypoxia (AIH) is a valuable model for studying obstructive sleep apnea (OSA) pathophysiology, and stimulation of breathing during AIH is known to elicit long-term changes in respiratory and sympathetic functions. The aim of this study was to record the renal sympathetic nerve activity (RSNA) and phrenic nerve activity (PNA) during the AIH protocol in rats exposed to monoanesthesia with sevoflurane or isoflurane. Adult male Sprague-Dawley rats (n = 24; weight: 280-360 g) were selected and randomly divided into three groups: two experimental groups (sevoflurane group, n = 6; isoflurane group, n = 6) and a control group (urethane group, n = 12). The AIH protocol was identical in all studied groups and consisted in delivering five 3 min-long hypoxic episodes (fraction of inspired oxygen, FiO2 = 0.09), separated by 3 min recovery intervals at FiO2 = 0.5. Volatile anesthetics, isoflurane and sevoflurane, blunted the RSNA response to AIH in comparison to urethane anesthesia. Additionally, the PNA response to acute intermittent hypoxia was preserved, indicating that the respiratory system might be more robust than the sympathetic system response during exposure to acute intermittent hypoxia.

Comparison Between the Protective Effect of Isoflurane and Propofol on Myocardium During Coronary Artery Bypass Grafting: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Intravenous non-volatile anaesthetics like propofol are commonly used in cardiac surgeries across several countries. Volatile anaesthetics like isoflurane may help in protecting the myocardium and minimize ischaemia-reperfusion injury. Hence, we did this review to compare the cardioprotective effect of isoflurane and propofol among patients undergoing coronary artery bypass grafting (CABG). We conducted a search in the databases Medical Literature Analysis and Retrieval System Online (or MEDLINE), Embase, PubMed Central®, ScienceDirect, Google Scholar, and Cochrane Library from inception until April 2021. We carried out a meta-analysis with random-effects model and reported pooled risk ratio (RR) or standardized mean difference (SMD) with 95% confidence interval (CI) depending on the type of outcome. We analysed 13 studies including 808 participants. Almost all were low-quality studies. For cardiac index, the pooled SMD was 0.14 (95% CI: -0.22 to 0.50); for cardiac troponin I, pooled SMD was 0.10 (95% CI: -0.28 to 0.48). For mortality, the RR was 3.00 (95% CI: 0.32 to 28.43); for MI, pooled RR was 1.58 (95% CI: 0.59 to 4.20); and for inotropic drug use, pooled RR was 1.04 (95% CI: 0.90 to 1.21). For length of intensive care unit stay, the pooled SMD was 0.13 (95% CI: -0.29 to 0.55), while pooled SMD for mechanical ventilation time was -0.02 (95% CI: -0.54 to 0.51). Isoflurane did not have significant cardioprotective effect compared to propofol following CABG. Hence, the anaesthetists need to check some viable alternatives to manage these patients and reduce the rate of postoperative complications.

Outcomes in patients who received ECMO and/or volatile anesthetics as rescue therapies for status asthmaticus

Background: In the state of Kentucky many status asthmaticus (SA) patients require care in the Pediatric Intensive Care Unit (PICU) and a fraction of these patients may receive “rescue therapies” with inhaled volatile anesthetics (IVA) and/or Extracorporeal Membrane Oxygenation (ECMO). Our objective was to compare the clinical parameters of individual patients who received either or both therapies. Methods: Children between 2-18 years of age admitted to our PICU from January 2014- July 2020 with SA were reviewed categorized as 1) patients who received IVA alone 2) patients who received IVA and then subsequently ECMO and 3) patients on ECMO alone. Results: 1772 children with SA episodes were identified with a mortality of 13 patients. 7 children with SA were identified who received either IVA, ECMO or both. One patient received only IVA, 5 received both IVA and ECMO and one received only ECMO. All received standard asthma therapies of steroids, albuterol, magnesium sulphate and aminophylline prior to escalation. Six out of seven refractory SA received IVA, and five (83%) of those were subsequently escalated to ECMO. pCO2 levels had no improvement after IVA administration but decreased by an average of 20 points after ECMO. Patients peak inspiratory pressures decreased within the 1 st 24 hours of ECMO cannulation from a mean of 30 to 18. There were no other complications related to ECMO placement. Conclusion: While we cannot decisively draw any conclusions from our study due to small sample, it was noted that there was no clear advantage of using IVA prior to ECMO in our patients. Most patients who received IVA were escalated to ECMO indicating that early ECMO cannulation may be beneficial. Given the high cost and potential complications of both, there is a need for the development of well-defined guidelines for severe SA management in the PICU.

Mechanosensing and anesthesia of single internodal cells of Chara

ABSTRACT The giant (2–3 × 10−2 m long) internodal cells of the aquatic plant, Chara, exhibit a rapid (>100 × 10−6 m s−1) cyclic cytoplasmic streaming which stops in response to mechanical stimuli. Since the streaming – and the stopping of streaming upon stimulation – is easily visible with a stereomicroscope, these single cells are ideal tools to investigate mechanosensing in plant cells, as well as the potential for these cells to be anesthetized. We found that dropping a steel ball (0.88 × 10−3 kg, 6 × 10−3 m in diameter) through a 4.6 cm long tube (delivering ca. 4 × 10−4 J) reliably induced mechanically-stimulated cessation of cytoplasmic streaming. To determine whether mechanically-induced cessation of cytoplasmic streaming in Chara was sensitive to anesthesia, we treated Chara internodal cells to volatilized chloroform in a 9.8 × 10−3 m3 chamber for 2 minutes. We found that low doses (15,000–25,000 ppm) of chloroform did not always anesthetize cells, whereas large doses (46,000 and higher) proved lethal. However, 31,000 ppm chloroform completely, and reversibly, anesthetized these cells in that they did not stop cytoplasmic streaming upon mechanostimulation, but after 24 hours the cells recovered their sensitivity to mechanostimulation. We believe this single-cell model will prove useful for elucidating the still obscure mode of action of volatile anesthetics.

Prevention of accidental awareness under general anaesthesia: A regional service evaluation.

The United Kingdom's Fifth National Audit Project investigated the incidence and causes of accidental awareness during general anaesthesia. Subsequently, guidelines produced by the Association of Anaesthetists of Great Britain and Ireland provide key recommendations to minimise awareness. These include using processed electroencephalogram for patients receiving total intravenous anaesthesia while paralysed and using audible low end-tidal anaesthetic concentration alarms. The Southcoast Perioperative Audit and Research Collaboration undertook a five-day regional service evaluation, assessing the measures in place to minimise awareness and conducting a practitioner survey. Eight hospitals participated with 382 theatre attendances were analysed. Processed electroencephalograph monitoring for patients receiving total intravenous anaesthesia with neuromuscular blockade has been widely adopted into regional practice, from 23% of cases in the Fifth National Audit Project, to 85% in this snapshot. During volatile anaesthesia, age-adjusted low end-tidal anaesthetic concentration alarms were used in 34% cases. The range was 0-97% at different hospitals, suggesting heterogeneity in practice. Seventy-six per cent of anaesthetists rarely alter the default anaesthetic machine alarm settings. Therefore, instigating default low end-tidal anaesthetic concentration alarms could improve compliance with guidelines and reduce the risk of awareness for patients.

Innovations in anesthesia: Advances and ethical considerations

Understanding how these innovations are shaping the practice of anesthesiology and how emerging ethical issues are being addressed is critical to ensuring that patients receive the highest standards of care and that healthcare professionals are prepared to deal with the contemporary challenges they face. This research aims to contribute to the development of guidelines and policies that promote ethical and safe practices in anesthesiology, while driving innovation and progress in the field. A systematic review of the literature was carried out, through a survey of data in scientific databases: LILACS, PUBMED, SCIELO, VHL and Web of Science. The introduction of new techniques, such as ultrasonic guided regional anesthesia, has demonstrated significant benefits in reducing postoperative pain and improving patients' functional recovery. Additionally, advances in anesthetic medications, such as short-acting volatile anesthetic agents and alternative opioids, are providing safer and more effective therapeutic options. These innovations are redefining standards of anesthesia care, enabling more individualized and less invasive approaches. However, it is crucial to examine the ethical implications of these innovations in clinical practice. A central ethical consideration is the need to ensure patients' informed consent to new techniques and therapeutic options available.

Damage-associated molecular patterns as a mechanism of sevoflurane-induced neuroinflammation in neonatal rodents.

General anesthesia is inevitable for pediatric patients undergoing surgery, though volatile anesthetic agents may cause neuroinflammation and neurodevelopmental impairment; however, the underlying pathophysiology remains unclear. We aimed to investigate the neuroinflammation mechanism in developing rat brains associated with sevoflurane exposure time, by identifying the specific damage-associated molecular patterns (DAMPs) pathway and evaluating the effects of non-steroidal anti-inflammatory drugs (NSAIDs) in alleviating neuroinflammation. A three-step experiment was conducted to investigate neuroinflammation induced by sevoflurane. First, the exposure time required for sevoflurane to cause neuroinflammation was determined. Next, the specific pathways of DAMPs involved in neuroinflammation by sevoflurane were identified. Finally, the effects of NSAIDs on sevoflurane-induced neuroinflammation were investigated. The expression of various molecules in the rat brain were assessed using immunohistochemistry, immunofluorescence, quantitative real-time polymerase chain reaction, western blot analysis, and enzyme-linked immunosorbent assay. In total, 112 rats (aged 7 days) were used, of which six rats expired during the experiment (mortality rate, 5.3%). Expression of CD68, HMGB-1, galectin-3, TLR4, TLR9, and phosphorylated NF-κB was significantly increased upon 6 h of sevoflurane exposure. Conversely, transcriptional levels of TNF-α and IL-6 significantly increased and IFN-γ significantly decreased after 6 h of sevoflurane exposure. Co-administration of NSAIDs with sevoflurane anesthesia significantly attenuated TNF-α and IL-6 levels and restored IFN-γ levels. In conclusion, 6 h of sevoflurane exposure induces neuroinflammation through the DAMPs pathway, HMGB-1, and galectin-3. Co-administration of ibuprofen reduced sevoflurane-induced neuroinflammation.

How an Audit-and-Feedback-Based Educational Program Contributed to a Reduction in Environmentally Harmful Waste Anesthetic Gases Among Anesthesiology Residents.

Background Waste anesthetic gases (WAGs) contribute to greenhouse gas emissions. US anesthesiology resident education on how to reduce WAG-associated emissions is lacking, so we developed an electronic audit-and-feedback-based program to teach residents to reduce fresh gas flow (FGF) and WAG-associated emissions. Objective To assess the program's effectiveness, we measured individual and combined mean FGF of residents during their first, second, and last weeks of the 4-week rotation; then, we calculated the extrapolated annual emissions based on the combined resident mean FGFs. Resident attitudes toward the program were surveyed. Methods During 4-week rotations at a teaching hospital, anesthesia records were scanned to extract resident-assigned cases, FGF, and volatile anesthetic choice during the 2020-2021 academic year. Forty residents across 3 training years received weekly FGF data and extrapolated WAG-associated emissions data via email. Their own FGF data was compared to the low-flow standard FGF of ≤1 liter per minute (LPM) and to the FGF data of their peer residents on rotation with them. An online survey was sent to residents at the end of the project period. Results Between their first and last weeks on rotation, residents decreased their mean FGF by 22% (1.83 vs 1.42 LPM; STD 0.58 vs 0.44; 95% CI 1.67-2.02 vs 1.29-1.56; P<.0001). Ten of 18 (56%) residents who responded to the survey reported their individual case-based results were most motivating toward practice change. Conclusions An audit-and-feedback-based model for anesthesiology resident education, designed to promote climate-conscious practices with administration of volatile anesthetics, was effective.

Effect of Dexmedetomidine Premedication on Sevoflurane Requirement using BIS during General Anaesthesia in Laparoscopic Cholecystectomy

Background: Dexmedetomidine is a highly selective α2-adrenoreceptor agonist with sedative, anxiolytic and analgesic properties without any respiratory depression. It decreases the requirement of volatile anaesthetics with better hemodynamic stability in surgical patients. We avoided the risk of awareness under anaesthesia by using Bispectral index. Aims: To evaluate the efficacy of Dexmedetomidine pre-medication on Sevoflurane requirement and to assess the haemodynamic stability during elective laparoscopic cholecystectomy surgeries. Methods: Randomized double-blind control study. Design: Forty eight patients were randomly allocated into two groups. Group A received saline infusion and Group 2 received Dexmedetomidine infusion in a dose of 1µg/kg over 15 min before induction. Vital parameters and bispectral index were noted throughout the surgery. Patients were induced and intubated as per the standard protocol and maintained with Oxygen &amp; Nitrous oxide (1 litre Oxygen + 2 litre Nitrous oxide) with Sevoflurane concentration adjusted to achieve BIS values of 45–55. Demographic profile, hemodynamic parameters total Sevoflurane consumption were noted. Statistical Analysis: Statistical analysis was performed using SPSS software version 22.0. Percentage analysis was done for qualitative data. Parametric data were compared using an unpaired t-test. Nonparametric data were compared with Fisher’s exact test or Chi-square test. Results: Mean Sevoflurane consumption in Group A and Group B were 0.379 ± 0.10, 0.169 ± 0.05 ml/min respectively with P&lt;0.001 which was statistically significant. A 55.4% reduction in Sevoflurane consumption was found in patients receiving Dexmedetomidine premedication. Conclusions: Dexmedetomidine premedication is useful to reducing Sevoflurane consumption during general anesthesia and it provides better haemodynamic stability.

Are there beneficial effects to hybrid anesthesia*?

As the COVID-19 pandemic increased the use of propofol in the intensive care unit for the management of respiratory sequelae and supply had become a major issue. Indeed, most hospitals in Japan were forced to use propofol only for induction of anesthesia with inhalational maintenance. Large amounts of propofol remain in the syringe which exacerbates the problems by increased waste. I propose that use of low dose propofol in combination with a low concentration inhaled anesthetic as an alternative and call this hybrid anesthesia. Several advantages of hybrid anesthesia are evident in the literature. Volatile anesthesia has several disadvantages such as cancer progression, emergence agitation, marked reduction in motor evoked potentials (MEP), laryngospasm with desflurane and postoperative nausea and vomiting (PONV). Volatile anesthesia exerts some beneficial actions such as myocardial protection and fast emergence with desflurane. In contrast, total intravenous anesthesia (TIVA) provides better survival in patients undergoing radical cancer surgery, reduction in emergence agitation, laryngospasm, PONV and better MEP trace Intraoperative awareness occurs more often during TIVA. When intravenous and volatile anesthesia are combined (hybrid anesthesia), the disadvantages of both methods may be offset by clear advantages. Thus, hybrid anesthesia may, therefore, be a viable anesthetic choice.

An Association between OXPHOS-Related Gene Expression and Malignant Hyperthermia Susceptibility in Human Skeletal Muscle Biopsies.

Malignant hyperthermia (MH) is a pharmacogenetic condition of skeletal muscle that manifests in hypermetabolic responses upon exposure to volatile anaesthetics. This condition is caused primarily by pathogenic variants in the calcium-release channel RYR1, which disrupts calcium signalling in skeletal muscle. However, our understanding of MH genetics is incomplete, with no variant identified in a significant number of cases and considerable phenotype diversity. In this study, we applied a transcriptomic approach to investigate the genome-wide gene expression in MH-susceptible cases using muscle biopsies taken for diagnostic testing. Baseline comparisons between muscle from MH-susceptible individuals (MHS, n = 8) and non-susceptible controls (MHN, n = 4) identified 822 differentially expressed genes (203 upregulated and 619 downregulated) with significant enrichment in genes associated with oxidative phosphorylation (OXPHOS) and fatty acid metabolism. Investigations of 10 OXPHOS target genes in a larger cohort (MHN: n = 36; MHS: n = 36) validated the reduced expression of ATP5MD and COQ6 in MHS samples, but the remaining 8 selected were not statistically significant. Further analysis also identified evidence of a sex-linked effect in SDHB and UQCC3 expression, and a difference in ATP5MD expression across individuals with MH sub-phenotypes (trigger from in vitro halothane exposure only, MHSh (n = 4); trigger to both in vitro halothane and caffeine exposure, MHShc (n = 4)). Our data support a link between MH-susceptibility and dysregulated gene expression associated with mitochondrial bioenergetics, which we speculate plays a role in the phenotypic variability observed within MH.

COMPARATIVE EVALUATION OF SEVOFLURANE AND ISOFLURANE IN FAST TRACK ANAESTHESIA FOR VALVULAR CARDIAC SURGERY: A RANDOMIZED STUDY

Objective: Contemporary valvular cardiac surgery has evolved with the adoption of expedited postoperative recovery, known as fast-tracking. This paradigm shift results from advancements in anaesthetic agents, surgical techniques, and myocardial protection strategies. Fast-track anaesthesia aims to reduce intensive care unit (ICU) stays and overall hospital length of stay (LOS), optimizing resource utilization. Cardioprotective properties of volatile anaesthetic agents, especially in mitigating ischemic myocardial damage, have garnered attention.&#x0D; Methods: A hospital-based, randomized, comparative study was conducted at the Department of Anaesthesiology, S. M. S Medical College, Jaipur. 70 undergoing valvular heart surgery under general anaesthesia, were randomly assigned to two groups: Group A (Sevoflurane) and Group B (Isoflurane). Inclusion criteria encompassed ASA grade II to IV patients aged 20 to 50 y, with a body weight of 30-65 kg, and willingness to provide written consent. Anaesthesia induction and maintenance involved the administration of Sevoflurane or Isoflurane based on group allocation. Hemodynamic parameters were recorded at various surgical stages.&#x0D; Results: Heart rate, systolic blood pressure, and cardiac output were statistically insignificant between groups at different surgical stages (p&gt;0.05). Intraoperative variables demonstrated no significant differences, except for a transient decrease in systolic blood pressure post-induction in both groups.&#x0D; Conclusion: The study underscores the comparable efficacy of Sevoflurane and Isoflurane in valvular cardiac surgery, supported by similar hemodynamic profiles. Understanding the nuances of volatile anaesthetic agents is crucial for their optimal clinical application, considering challenges like beta-blocker usage and perioperative hyperglycemia.

Association of malignant hyperthermia and exertional heat illness in young athletes: An analysis of awareness among clinical and athletic first responders.

Malignant hyperthermia (MH), a rare inherited condition seen almost exclusively in the perioperative setting, is triggered by volatile anesthetics or an intravenous paralytic drug, succinylcholine. It can, however, occur without any exposure to anesthetic drugs, being associated with heat illness and rhabdomyolysis, thus presenting a little-known risk to young athletes exercising in hot environments. This study aimed to determine the first responder awareness of MH and its association with heat illness in young athletes within athletic and clinical environments. Awareness within the clinical milieu was assessed by an institutional chart review of 3296 charts. The identified heat illness cases were examined for treatment consistent with the management of a suspected episode of MH. Awareness among first responders in an athletic setting was examined by a survey administered to a total of 1,500 coaches and athletic trainers at the high school level along with emergency medical services providers across the United States. No treatment consistent with the suspicion of MH was noted among clinical first responders, suggesting a lack of awareness. Survey administration also revealed a limited amount of knowledge of MH and its potential role in heat illness. The results point to lack of awareness among pre-hospital and hospital-based first responders of the relationship between MH and heat illness in young athletes. An effort to educate these members of the healthcare community can contribute to an expeditious and life-saving intervention. First responders who may interact with a young athlete have low knowledge of MH and its relationship to heat illness. Similar lack of awareness exists among hospital personnel who care for young individuals with heat illness. Educating the first responders about this condition can speed up the time to intervene and save lives.

Long-term Survival after Volatile or Propofol General Anesthesia for Bladder Cancer Surgery: A Retrospective National Registry Cohort Study.

Prospective interventional trials and retrospective observational analyses provide conflicting evidence regarding the relationship between propofol versus inhaled volatile general anesthesia and long-term survival after cancer surgery. Specifically, bladder cancer surgery lacks prospective clinical trial evidence. Data on bladder cancer surgery performed under general anesthesia between 2014 and 2021 from the National Quality Registry for Urinary Tract and Bladder Cancer and the Swedish Perioperative Registry were record-linked. Overall survival was compared between patients receiving propofol or inhaled volatile for anesthesia maintenance. The minimum clinically important difference was defined as a 5-percentage point difference in 5-yr survival. Of 7,571 subjects, 4,519 (59.7%) received an inhaled volatile anesthetic, and 3,052 (40.3%) received propofol for general anesthesia maintenance. The two groups were quite similar in most respects but differed in American Society of Anesthesiologists Physical Status and tumor stage. Propensity score matching was used to address treatment bias. Survival did not differ during follow-up (median, 45 months [interquartile range, 33 to 62 months]) in the full unmatched cohort nor after 1:1 propensity score matching (3,052 matched pairs). The Kaplan-Meier adjusted 5-yr survival rates in the matched cohort were 898 of 3,052, 67.5% (65.6 to 69.3%) for propofol and 852 of 3,052, 68.5% (66.7 to 70.4%) for inhaled volatile general anesthesia, respectively (hazard ratio, 1.05 [95% CI, 0.96 to 1.15]; P = 0.332). A sensitivity analysis restricted to 1,766 propensity score-matched pairs of patients who received only one general anesthetic during the study period did not demonstrate a difference in survival; Kaplan-Meier adjusted 5-yr survival rates were 521 of 1,766, 67.1% (64.7 to 69.7%) and 482 of 1,766, 68.9% (66.5 to 71.4%) for propofol and inhaled volatile general anesthesia, respectively (hazard ratio, 1.09 [95% CI, 0.97 to 1.23]; P = 0.139). Among patients undergoing bladder cancer surgery under general anesthesia, there was no statistically significant difference in long-term overall survival associated with the choice of propofol or an inhaled volatile maintenance.

Intraoperative Anesthetic Strategies to Mitigate Early Allograft Dysfunction After Orthotopic Liver Transplantation: A Narrative Review.

Orthotopic liver transplantation (OLT) is the most effective treatment for patients with end-stage liver disease (ESLD). Hepatic insufficiency within a week of OLT, termed early allograft dysfunction (EAD), occurs in 20% to 25% of deceased donor OLT recipients and is associated with morbidity and mortality. Primary nonfunction (PNF), the most severe form of EAD, leads to death or retransplantation within 7 days. The etiology of EAD is multifactorial, including donor, recipient, and surgery-related factors, and largely driven by ischemia-reperfusion injury (IRI). IRI is an immunologic phenomenon characterized by dysregulation of cellular oxygen homeostasis and innate immune defenses in the allograft after temporary cessation (ischemia) and later restoration (reperfusion) of oxygen-rich blood flow. The rising global demand for OLT may lead to the use of marginal allografts, which are more susceptible to IRI, and thus lead to an increased incidence of EAD. It is thus imperative the anesthesiologist is knowledgeable about EAD, namely its pathophysiology and intraoperative strategies to mitigate its impact. Intraoperative strategies can be classified by 3 phases, specifically donor allograft procurement, storage, and recipient reperfusion. During procurement, the anesthesiologist can use pharmacologic preconditioning with volatile anesthetics, consider preharvest hyperoxemia, and attenuate the use of norepinephrine as able. The anesthesiologist can advocate for normothermic regional perfusion (NRP) and machine perfusion during allograft storage at their institution. During recipient reperfusion, the anesthesiologist can optimize oxygen exposure, consider adjunct anesthetics with antioxidant-like properties, and administer supplemental magnesium. Unfortunately, there is either mixed, little, or no data to support the routine use of many free radical scavengers. Given the sparse, limited, or at times conflicting evidence supporting some of these strategies, there are ample opportunities for more research to find intraoperative anesthetic strategies to mitigate the impact of EAD and improve postoperative outcomes in OLT recipients.

A Review of Muscular Dystrophies.

Muscular dystrophy encompasses a group of genetic conditions with progressive muscle damage and weakness. Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive disorders that affect the production of the protein dystrophin. Emery-Dreifuss muscular dystrophy (EDMD) is typically an X-linked-recessive disorder involving the gene that codes for emerin. Facioscapulohumeral muscular dystrophy and oculopharyngeal muscular dystrophy (OPMD) are both autosomal dominant disorders. Although commonly mistaken as a condition in which patients are susceptible to malignant hyperthermia with volatile inhalational anesthetics, muscular dystrophy is more closely associated with rhabdomyolysis. Providers developing an anesthetic plan for dental patients with muscular dystrophy must take into consideration the patient's baseline cardiac and pulmonary function as well as the potential for abnormalities. Nondepolarizing neuromuscular blocker use is safe but likely to result in prolonged skeletal muscle relaxation. Succinylcholine and volatile anesthetics are generally contraindicated due to the risks of rhabdomyolysis and hyperkalemia with subsequent ventricular fibrillation, cardiac arrest, and death if left untreated. In-depth understanding of the more commonly encountered forms of muscular dystrophy is vital to providing safe and effective ambulatory anesthesia care for patients undergoing dental treatment outside the traditional hospital operating room setting.