Anesthesia Research

Background/Objectives: Safe anesthesia and effective pain management in conflict-affected regions are limited by violence, damaged infrastructure, disrupted supply chains, medication and equipment shortages, and loss of trained personnel. This narrative review examines major barriers to perioperative care and practical strategies that may improve access and safety. Methods: A structured literature search evaluated peer-reviewed studies, global health reports, and humanitarian publications, primarily from January 2015 through September 2025, with older foundational clinical sources included when directly relevant to specific anesthesia techniques. Results: Major barriers included shortages of essential anesthetic medications and trained providers, damaged healthcare infrastructure, limited monitoring and oxygen availability, and disrupted supply chains. Reported strategies included ketamine-based anesthesia, regional anesthesia, portable oxygen and anesthesia technologies, telemedicine, and task-sharing models supported by training and local health-system capacity. Obstetric, neonatal, and pediatric patients may face additional risks when appropriately sized equipment, blood products, monitoring, and specialist support are limited. Conclusions: Improving anesthesia and pain management in conflict settings requires adaptable clinical strategies, workforce training, reliable access to essential medications and equipment, and partnerships that strengthen local capacity. Evidence remains heterogeneous, and more conflict-specific outcome data are needed. Full article

Background/Objectives: Fibromyalgia (FM) is a nociplastic pain syndrome characterized by chronic widespread pain, fatigue, sleep disturbance, cognitive dysfunction, and heightened sensitivity to somatic and environmental stimuli. Depressive symptoms and major depressive disorder (MDD) frequently co-occur with FM and are associated with greater disability, pain catastrophizing, sleep disruption, and poorer treatment response. Although pharmacological treatments can reduce symptoms in some patients, many individuals experience persistent functional and affective burden, highlighting the need for mechanism-based adjunctive strategies. Mindfulness-based interventions (MBIs), particularly mindfulness-based stress reduction (MBSR), have shown promise for improving functional impact, pain catastrophizing, perceived stress, depressive symptoms, sleep-related burden, and quality of life in FM. However, the effects of MBIs on pain intensity and biomarkers are less consistent. Methods: This narrative mechanistic review develops a hypothesis-generating multisystem neurobehavioral framework to explain how MBIs may influence pain–mood coupling in FM with depressive symptom burden. We define pain–mood recalibration as a reduction in the extent to which pain intensity, bodily vigilance, and interoceptive threat appraisal automatically drive depressive symptoms, rumination, avoidance, and functional disengagement. Results: Fibromyalgia-specific evidence most strongly supports cognitive–emotional mechanisms, including reduced catastrophizing, psychological inflexibility, rumination, perceived stress, and avoidance. Interoceptive, neural-network, autonomic, immune-inflammatory, and sleep-fatigue-behavioral pathways remain exploratory and require prospective mediation and moderation testing. Conclusions: Future trials should prioritize active controls, ecological momentary assessment, longitudinal biomarkers, neuroimaging, interoceptive tasks, and formal mediation/moderation models to determine which patients benefit, through which mechanisms, and under what biological and psychological conditions. Full article

Background/Objectives: Neuropathic and chronic centralized pain disorders remain difficult to treat because they involve central sensitization, maladaptive neuroplasticity, neuroimmune activation, affective amplification, and large-scale network dysfunction. Psilocybin, a serotonergic psychedelic acting primarily through 5-HT2A receptor agonism, has emerged as a candidate modulator of chronic pain states; however, clinical evidence remains preliminary. This review synthesizes preclinical, clinical, and mechanistic literature on psilocybin in chronic neuropathic and centralized pain, emphasizing biological plausibility, translational gaps, and future trial design. Methods: PubMed/MEDLINE, Google Scholar, bioRxiv, medRxiv, and targeted journal searches were reviewed through February 2026 and supplemented by reference screening. Thirty-seven peer-reviewed evidence sources were retained for mechanistic synthesis, and ClinicalTrials.gov records were reviewed separately to contextualize the registered clinical-trial landscape. Evidence was synthesized narratively because heterogeneity in study design, pain models, interventions, outcomes, and follow-up precluded meta-analysis. Results: Several preclinical studies reported psilocybin-associated reductions in allodynia, hypersensitivity, formalin-induced nociception, or pain-related affective behaviors in selected rodent models, with some effects linked to 5-HT2A signaling. However, findings were not uniform, and one rigorous null study found no immediate or persistent analgesic effect across multiple models. Human evidence remains limited and is primarily derived from one small open-label fibromyalgia pilot trial, case reports or case series, and survey studies, and has been summarized in recent systematic and narrative reviews. Collectively, these data remain insufficient to establish clinical efficacy. Four putative mechanistic domains were identified: descending serotonergic modulation, 5-HT2A- and TrkB/BDNF-related neuroplasticity, neuroimmune/microglial modulation, and affective-salience/default mode network reorganization. Conclusions: Psilocybin should not currently be regarded as an established analgesic. Available evidence supports a biologically plausible but clinically unproven model requiring phenotype-specific randomized trials with active controls, biomarkers, and long-term follow-up. Full article

Objective: We aimed to evaluate whether deep neuromuscular blockade (DNMB) improves surgical conditions and facilitates low-pressure pneumoperitoneum compared with moderate neuromuscular blockade (MNMB) during minimally invasive surgery. Data Sources: PubMed/MEDLINE, EMBASE, Cochrane CENTRAL, Scopus, Web of Science, and LILACS were searched from inception through May 2026. Study Selection: Randomized controlled trials comparing DNMB versus MNMB in adults undergoing laparoscopic or robot-assisted surgery were included. Data Extraction: Two reviewers independently screened studies, extracted data, and assessed risk of bias using the revised Cochrane Risk of Bias tool (RoB 2). Certainty of evidence was evaluated using the GRADE approach. Primary Outcomes: Primary outcomes were surgical workspace quality and intra-abdominal pressure requirements. Secondary Outcomes: Secondary outcomes included postoperative abdominal pain at 24 h and referred shoulder pain. Data Synthesis: Seventeen randomized controlled trials involving 1512 patients were included. DNMB consistently improved surgical workspace conditions and facilitated lower pneumoperitoneum pressures compared with MNMB. Pooled analyses additionally suggested reductions in postoperative abdominal pain and referred shoulder pain in selected studies, although postoperative outcomes demonstrated greater heterogeneity across procedures and perioperative protocols. Conclusions: Current evidence suggests that the principal clinical value of DNMB during minimally invasive surgery is optimization of surgical exposure and facilitation of low-pressure pneumoperitoneum strategies. Benefits related to postoperative abdominal pain may occur in selected settings but appear less consistent across procedures. Full article

Background: Recent clinical reports have described perioperative neurologic complications including delayed emergence, encephalopathy, seizures, basal ganglia injury, and death following general anesthesia in otherwise healthy pediatric and adult patients with maternal Venezuelan ancestry. Emerging genetic data suggest a possible association with the mitochondrial DNA variant MT-ND4 m.11232T>C affecting Complex I of the electron transport chain. Most reported cases have involved exposure to volatile anesthetics, particularly sevoflurane. However, the underlying mechanisms remain uncertain, and no structured perioperative framework currently exists to guide anesthetic management when mitochondrial vulnerability is suspected. Methods: This narrative review synthesizes published case reports, professional society safety communications, mitochondrial disease literature, anesthetic pharmacology, and perioperative physiology to develop a physiology-guided conceptual framework for suspected MT-ND4 m.11232T>C-associated mitochondrial vulnerability. Because the available evidence consists primarily of case reports, institutional observations, and professional society communications rather than prospective clinical studies, the proposed framework is intended to generate hypotheses and inform future investigation rather than establish evidence-based clinical guidelines. Results: The available literature suggests that MT-ND4–associated mitochondrial vulnerability may represent a state of reduced bioenergetic reserve in which cumulative perioperative physiologic stress exceeds ATP production capacity in susceptible individuals. We introduce the Mitochondrial Stress Gradient Model (MSGM), a conceptual framework describing the interaction among anesthetic exposure, physiologic perturbations, inflammatory signaling, and metabolic demand. Building on this model, we propose illustrative anesthetic frameworks emphasizing physiologic optimization, multimodal anesthesia, EEG-guided anesthetic titration, metabolic optimization, regional anesthesia considerations, and structured postoperative neurologic assessment as priorities for future investigation. Conclusions: This framework is intended to support individualized perioperative decision-making and should be interpreted as a physiology-guided conceptual model requiring prospective clinical validation rather than an evidence-based clinical guideline. Although current evidence remains preliminary, the proposed framework emphasizes proportionate physiologic optimization, identifies priorities for future clinical and genetic investigation, and provides a structured foundation for prospective research in this emerging area of perioperative medicine. Full article

Background/Objectives: Gabapentin is a first-line treatment for neuropathic pain, classically understood to reduce neuronal excitability through binding to the alpha-2-delta-1 (α2δ-1) subunit of voltage-gated calcium channels. However, this neuron-centric model does not fully explain its variable clinical efficacy across pain syndromes. In parallel, chronic pain is increasingly conceptualized as involving neuron–glia–immune interactions, in which microglial activation, astrocytic signaling, and inflammatory mediators may contribute to central sensitization. Methods: A structured narrative review was conducted using PubMed, Web of Science, and Google Scholar for articles available through December 2025. The search focused on gabapentin/gabapentinoids, chronic and neuropathic pain, α2δ-1 mechanisms, neuron–glia interactions, neuroinflammation, central and peripheral sensitization, nociplastic pain, cytokine/chemokine signaling, and neuroimmune modulation. Basic science studies, animal models, translational studies, clinical trials, reviews, meta-analyses, and guidelines were narratively synthesized. Results: Preclinical evidence indicates that gabapentin reduces neuronal hyperexcitability and may secondarily attenuate neuron-to-glia signaling, glial activation, and cytokine- and chemokine-related pathways. However, these neuroimmune effects remain predominantly preclinical, model-dependent, and incompletely validated in humans. Clinical evidence supports gabapentin for selected neuropathic pain conditions, but human studies rarely evaluate glial activation, cytokine signaling, or neuroimmune biomarkers. Conclusions: Gabapentin remains best understood as a neuronal α2δ-1 modulator. Although preclinical and translational evidence suggests biologically plausible secondary effects on neuroimmune signaling, these mechanisms have not been validated as biomarkers or prescribing targets in humans. The conceptual framework presented in this review supports mechanism-informed clinical reasoning and individualized pain management but should not be interpreted as a biomarker-guided prescribing algorithm. Clinically, gabapentin should be prescribed selectively for patients with neuropathic or sensitized pain features, using predefined functional goals, appropriate renal dose adjustment, careful safety monitoring, and discontinuation when meaningful benefit is not achieved. Full article

Background: Pharmacokinetic/pharmacodynamic (PK/PD)-guided intravenous anesthesia and target-controlled infusion (TCI) have progressively transformed modern anesthetic practice from empirical drug administration toward individualized, model-informed precision anesthesia. Recent advances in neuromonitoring, closed-loop systems, and artificial intelligence (AI) are further expanding this paradigm. Methods: This Perspective article provides a conceptual and educational synthesis of the historical foundations, mathematical principles, clinical applications, and AI-based perspectives of PK/PD-guided intravenous anesthesia and TCI. Results: The concentration–effect relationship derived from Hill’s equation represents the conceptual basis of modern anesthetic pharmacology. Contemporary TCI systems integrate PK/PD models, effect-site targeting, synergistic drug interactions, and multimodal monitoring to improve anesthetic precision and safety. Recent evidence supports the advantages of total intravenous anesthesia (TIVA) in postoperative recovery outcomes, including reduced postoperative nausea and vomiting, emergence delirium, and improved quality of recovery. Emerging developments include increasingly generalizable PK “supermodels,” adaptive closed-loop control systems, multimodal AI integration, and patient-specific digital twins that may eventually support simulation of physiological responses and optimization of drug administration. However, biological variability, monitoring limitations, signal artifacts, model uncertainty, and the need for prospective validation, regulatory oversight, and continuous clinician supervision remain major challenges to the routine implementation of AI-assisted individualized anesthesia. Conclusions: PK/PD-guided anesthesia and TCI increasingly represent a clinically relevant framework for precision anesthesia, integrating pharmacology, monitoring, adaptive control, and AI-assisted systems. Future developments may progressively reduce the discrepancy between predicted and observed clinical effects, moving anesthetic practice toward continuously adaptive, feedback-driven, and individualized anesthesia care. Full article

The carotid body (CB) is an interoceptive organ that transmits afferent information to the brain via the carotid sinus nerve (CSN) to maintain homeostasis, i.e., the regulation of internal equilibrium despite external changes. It functions as a complex polymodal receptor capable of sensing multiple stimuli, including blood flow, osmolarity, pO₂, pH, pCO₂, CO₂/H⁺, and temperature. In addition, the CB responds to a wide range of circulating molecules such as angiotensin II, endothelin-1, aldosterone, insulin, histamine, and leptin, and expresses receptors for interleukins (ILs) and tumor necrosis factor-α (TNF-α) (1). CB dysfunction has been associated with conditions such as obstructive sleep apnea (OSA), in which intermittent hypoxemia induces an inflammatory response mediated, among other mechanisms, by reactive oxygen species (ROS). This process contributes to alterations in respiratory drive and enhanced sympathetic nervous system activity. Following streptococcal toxic shock syndrome due to Streptococcus Pyogenes, severe abdominal septic shock, and multiple infectious complications, our patient developed an altered respiratory pattern and a hypercatabolic state that precluded weaning from mechanical ventilation (MV) despite respiratory physiotherapy. Given treatment failure, we hypothesized underlying carotid body (CB) hyperexcitability, likely pre-existing due to obstructive sleep apnea (OSA) and exacerbated by cytokine storm and severe systemic inflammation related to Strept. Pyogenes toxins and subsequent abdominal sepsis from colonic perforation. This may have contributed to sustained sympathetic overactivation and immune dysregulation. Clinically, the patient exhibited increased respiratory drive (30–35 breaths/min), excessive inspiratory effort, and marked patient–ventilator asynchrony in the absence of hypoxemia. Non-targeted physiotherapy may have acted as a second inflammatory hit, perpetuating the inflammatory cycle. Full article

In this Perspective, we present a non-systematic narrative synthesis and propose a hypothesis-generating framework that links regional anesthesia, local anesthetic strategies, surgery-induced NETosis, and perioperative metastatic biology. Surgical tumor resection coincides with a biologically vulnerable perioperative period characterized by inflammatory activation, innate immune remodeling, and potential metastatic susceptibility. Preclinical evidence suggests that this interval may represent a transient metastatic window in which circulating tumor cells and host inflammatory responses overlap, potentially favoring metastatic implantation. Among the mechanisms implicated in this process, neutrophil extracellular traps (NETs) have been implicated in tumor-cell capture, endothelial interaction, immune evasion, and metastatic outgrowth. Experimental studies further suggest that surgery-induced NETosis may contribute to prometastatic signaling and tumor-cell metabolic adaptation during the postoperative period. Human evidence remains more limited and heterogeneous. Observational studies indicate that NET-related biology is active during oncologic surgery, with the presence of tissue NETs and circulating NET-associated biomarkers correlating with tumor stage, inflammatory context, or tumor burden in selected malignancies. Perioperative clinical studies also suggest that regional anesthesia and local anesthetic-based strategies, including intravenous lidocaine, may influence neutrophil activation and postoperative NET-associated biomarkers. However, robust evidence of clinical oncologic outcomes remains limited, and a clear distinction between surrogate perioperative endpoints and long-term clinical outcomes is still lacking. Within this context, we propose that regional anesthesia may influence pathways associated with perioperative tumor–host interactions not primarily through opioid sparing but through modulation of mechanisms related to surgery-induced NETosis during a short-lived biological window. The neutral results of large survival-based trials do not necessarily invalidate this hypothesis; rather, they underscore the limitations of conventional oncologic endpoints in capturing transient perioperative biological effects. This Perspective outlines a translational research agenda centered on biomarker-driven perioperative studies integrating NET-specific markers, circulating tumor cell dynamics, and temporally precise postoperative sampling. Full article

For perioperative analgesia in thoracic surgery, epidural anesthesia has long been considered the gold standard. However, as surgical techniques have become less invasive, interest in less invasive analgesic strategies has increased. According to the procedure-specific postoperative pain management (PROSPECT) guidelines published by the European Society of Regional Anesthesia in 2021, epidural anesthesia is no longer recommended as the method of choice for regional anesthesia in video-assisted thoracic surgery (VATS), and thoracic paravertebral block (TPVB) and erector spinae plane block (ESPB) are now recommended. Understanding the effectiveness and limitations of each regional technique is essential to facilitating appropriate anesthetic planning for individual cases. This narrative review summarizes current evidence regarding thoracic epidural anesthesia, TPVB, ESPB, serratus anterior plane block, and emerging intertransverse process block techniques for thoracic surgery. Full article

Background: Exercise prehabilitation may improve physiological resilience before colorectal cancer (CRC) surgery. However, patient acceptance, reflected by recruitment, retention and adherence, is variably reported. Understanding how acceptance is captured and described is essential for designing effective, equitable interventions. Objectives: Map how CRC prehabilitation programmes report recruitment, retention and adherence, and identify characteristics associated with high acceptance. Methods: A scoping review was conducted following published guidance. MEDLINE, Embase, CINAHL, PsycINFO and Cochrane databases were searched. Studies of unimodal or multimodal prehabilitation interventions including an exercise component were included. Data relating to recruitment processes, retention, adherence and engagement-enhancing strategies were extracted and summarised using descriptive and content analysis. Reporting quality and variation were mapped. Results: Thirty-four studies were included: 15 randomised controlled trials, 12 prospective cohorts, four retrospective comparative cohorts, two non-randomised trials, and one quality-improvement project. Recruitment rates varied widely (3.8% to >90%), with four studies not reporting the proportion of eligible patients who declined and no study providing demographic characterisation of patients not recruited. Retention was reported in 31 of 34 studies and was generally high, including seven studies reporting 100% retention, although no consistent definition was used. Adherence was not reported in nine studies; among those reporting it, supervised programmes achieved attendance rates of 68–100% and unsupervised programmes 78–98%. Only four studies quantified adherence to prescribed exercise intensity or volume. No consistent association emerged between programme format (location, supervision, and digital support) and patient acceptance. Conclusions: Substantial variability exists in how CRC prehabilitation studies report recruitment, retention and adherence, constraining understanding of acceptance. Future research should prioritise standardised, detailed acceptance reporting and consider behaviour change theory informed, patient-centred intervention design to ensure effective and equitable CRC prehabilitation. Full article

Introduction: Uvular necrosis is a rare post-general anesthesia complication of airway instrumentation with an estimated 0.03% incidence characterized by delayed onset, disproportionate oropharyngeal pain, and uvular discoloration. Case Description: A 24-year-old male developed uvular necrosis following elective septoplasty–turbinoplasty under general anesthesia. Pain escalated 24–72 h post-operatively (8/10) and was refractory to oral analgesics (acetaminophen and tramadol). Topical 1% viscous lidocaine provided significant relief but required frequent application (q1–2 h). Pain decreased after day 6, with complete resolution by day 10. Conclusions: Uvular necrosis is an uncommon post-intubation complication. The take-home points of this study are as follows: (1) Uvular necrosis is characterized by delayed, disproportionate oropharyngeal pain and discoloration of the uvula. (2) Recommended treatments (oral analgesics, oral steroids, and topical lidocaine among others) are based on limited case reports. (3) Topical viscous lidocaine (1%) was an effective option in this case. Application with a cotton swab reduced dose and toxicity risk (20 to 2 mls) with no loss in analgesic efficacy. (4) Potential causes in this case include oral secretion suctioning, midline placement of endotracheal tube, and oropharyngeal manipulation. (5) Uvular necrosis is under-recognized and under-reported in anesthesia. Full article

Background/Objectives: Postoperative pulmonary complications (PPCs) significantly contribute to surgical morbidity, mortality, and healthcare costs, yet their definition remains heterogeneous in clinical literature. We aimed to develop and apply a standardized system for defining and measuring PPCs and their severity among a general, low-risk surgical population. Methods: A retrospective, observational design evaluated data from 95,808 adult patients undergoing elective surgery with general anesthesia between 2015 and 2023 at a large tertiary medical center. PPCs were identified using a curated list of ICD-10 codes based on the StEP-COMPAC consensus and were categorized into mild, moderate, or severe based on the intensity of postoperative oxygen delivery. Multivariable logistic and ordinal regression models were utilized to identify risk factors for the occurrence and clinical severity of PPCs. Results: The overall incidence of PPCs was 7.52% (n = 7206), with mild cases accounting for the majority (5.65%), followed by moderate (1.47%), and severe (0.40%) cases. Key risk factors for PPCs included ASA class 3 or 4, OSA, COPD, increased case duration, and the use of home oxygen devices. Higher mean pre-operative oxygen saturation was identified as a protective factor against PPCs. Conclusions: A feasible and promising framework for standardizing PPC measurement using EHR data and interprofessional collaboration is presented for use in ongoing initiatives aimed at reducing rates of PPCs. Identified risk factors may serve as critical triggers for implementing perioperative strategies to mitigate complications in the general surgical population. Full article

Background: Inguinal hernia repair is a high-volume procedure frequently performed in Day Surgery settings. While local anesthesia is often considered the gold standard, its feasibility is limited in complex cases or due to patient refusal, necessitating alternatives like general (GA) or spinal anesthesia (SA). This study evaluates the impact of these techniques on acute pain, complications, and chronic postoperative inguinal pain (CPIP). Methods: A retrospective observational study was conducted on 73 adult patients undergoing unilateral Lichtenstein hernioplasty (GA = 24; SA = 49). Pain was assessed using the Numeric Rating Scale (NRS) at discharge (T0), 24 h (T1), 7 days (T2), and 180 days (T3). Postoperative complications, rescue analgesic consumption, and perceived time to recovery were recorded. A multivariable linear regression analysis was performed to adjust pain outcomes for age, sex, and ASA status. Results: GA patients reported significantly lower median NRS scores at T0, T1, and T2 in univariate analysis (p < 0.05). However, the multivariable model did not show statistical significance for anesthetic technique as an independent predictor. Constipation was the most frequent complication (35.6%), while nausea occurred only in the SA group (10.2%). Descriptive data showed a trend toward lower rescue analgesic needs and a faster perceived time to recovery in the GA group compared to SA. CPIP incidence was remarkably low (2.7%). Conclusions: GA is a valid alternative to SA in Day Surgery, showing a clinical trend toward better early pain control, lower analgesic consumption, and improved recovery perception, although multivariable analysis did not reach statistical significance. Full article

Background/Objectives: Low back and neck pain are common musculoskeletal complaints among healthcare workers, including anesthesia providers. This study aims to quantify the prevalence of back and neck pain amongst anesthesiology providers to identify risk factors, mechanisms of injury, and recovery practices to guide preventative measures. Methods: A cross-sectional survey of anesthesiology clinicians in a multi-site academic healthcare system in New York City was administered using REDCap version 12.5.9. The recorded survey results were aggregated to determine percentages for each question. Descriptive statistics were used to determine the nature of low back and neck pain and detail causes. Oswestry Disability Index (ODI) and Neck Disability Index (NDI) scores were calculated. Results: The survey instrument was distributed to 380 anesthesiology clinicians at four separate institutions and yielded 191 responses for a response rate of 50.3%. Fifty-three-point-nine percent of survey respondents reported having current back or neck pain, with the majority reporting that it was chronic (87.4%). A substantial proportion of respondents reported not having back or neck pain prior to training (58.3%), and the majority reported that their back or neck pain was work-related (54.1%). Only 14.1% of respondents reported having had training in back or neck pain prevention. The most common location of pain was lumbar (81.6%). The most common inciting event for work-related pain was patient transfer/transport (68.6%). For ODI scoring, 98% of clinicians within the health system were classified as minimal disability and 2% of clinicians as moderate disability. For NDI scoring, 95.8% of clinicians were classified as minimally disabled, with 2.6% classified as moderate disabled. Conclusions: Back and neck pain are common pathologies amongst anesthesia providers. For most clinicians, the pain began to occur during training. Common inciting events include patient transfer/transport, procedure performance, and room setup. This provides a framework with which preventative practices can take place to reduce the prevalence of back and neck pain in anesthesiology and other related health care disciplines. Full article

Background/Objectives: Opioids are widely used for perioperative analgesia in small animal practice; however, their administration is associated with dose-dependent adverse effects, regulatory restrictions, and increasing stewardship concerns. Evidence supporting opioid-free anesthesia protocols in cats remains limited. The aim of this study was to evaluate the analgesic efficacy of a dexmedetomidine constant rate infusion as part of an opioid-free anesthetic protocol in cats undergoing ovariectomy, as well as to determine its effect on intraoperative opioid requirements. Methods: This prospective, randomized clinical trial included forty healthy female cats (mean age 1.9 ± 0.7 years; mean body weight 3.5 ± 0.6 kg; body condition score 5 [range 4–5]/9) undergoing elective ovariectomy. Cats were randomly assigned to receive either a dexmedetomidine constant rate infusion (CRI) at 1 mcg kg⁻¹ h⁻¹ (GR-E) or a control protocol without dexmedetomidine CRI (GR-C). Anesthesia was induced and maintained using standardized protocols in both groups. Intraoperative fentanyl (5 mcg kg⁻¹ IV) was administered as rescue analgesia when two of three physiological parameters (heart rate, respiratory rate, mean arterial pressure) increased by ≥20% compared to the previous recorded value. Cardiovascular and respiratory variables, rescue opioid requirements, and recovery quality were recorded. Results: The requirement for rescue analgesia was significantly lower in GR-E (4/20; 20%) compared to GR-C (13/20; 65%) (p = 0.0097). Cats receiving dexmedetomidine showed greater intraoperative cardiovascular stability during ovarian pedicle manipulation. No clinically relevant adverse effects were observed. Recovery was smooth in all cats, and all resumed feeding within eight hours postoperatively. Conclusions: A low-dose dexmedetomidine CRI effectively reduced intraoperative opioid requirements during feline ovariectomy while maintaining physiological stability and satisfactory recovery. This opioid-free anesthetic protocol represents a safe and clinically applicable alternative in settings where opioid use is restricted or limited. Full article

Introduction: Propofol is one of the most commonly used intravenous anesthetics worldwide and is considered safe for all age groups. However, there have been reports that propofol can induce severe atrioventricular block in humans, and several studies have shown that propofol hinders or prevents the inducibility of arrhythmias during electrophysiological studies (EPS) and radiofrequency (RF) ablation. Objectives: To compare arrhythmia inducibility during electrophysiological study and radiofrequency ablation in pediatric patients with Wolff–Parkinson–White syndrome undergoing propofol-based sedation versus sevoflurane-based general anesthesia. Methods: We conducted a retrospective observational cohort study including 45 pediatric patients aged 0–18 years. Patients were identified through a review and analysis of a database of individuals with Wolff–Parkinson–White syndrome who were referred for electrophysiological study and/or radiofrequency ablation at the Electrophysiology Laboratory of the Institute of Cardiology (IC/FUC) in Porto Alegre over the past five years (2019–2024). Patients with prior ablation, structural heart disease, or ongoing antiarrhythmic therapy were excluded. The patients were divided into two groups and designated as group S (who received sedation) or group G (who received general anesthesia). Sedation (group S) was performed with midazolam (0.08–0.2 mg/kg), fentanyl (0.1–0.2 μcg/kg), and propofol 50–60 µg/kg/min in continuous infusion. General anesthesia (group G), in turn, was performed with sevoflurane at an average dose of 2% (1 MAC according to age). Results: From 4874 invasive electrophysiology procedures performed during the study period, 45 involved pediatric patients with WPW. The sedation group (n = 29) had significantly older patients (14.6 ± 2.5 vs. 10.3 ± 2.8 years, p < 0.001) with higher weight (65.9 ± 16.3 vs. 41.2 ± 7.8 kg, p < 0.001) compared to the general anesthesia group (n = 16). Arrhythmia was successfully induced in 15/29 (51.7%) patients in the sedation group compared to 13/16 (81.2%) in the general anesthesia group (p = 0.062, Fisher’s exact test). Although this difference did not reach statistical significance, it represents a clinically relevant 29.5% lower induction rate in the sedation group. Post hoc power analysis revealed the study was underpowered (49.8%), suggesting a possible Type II error. Analysis of the “procedure room time” revealed a longer duration in the general anesthesia group (97.8 ± 36.7 vs. 67.8 ± 24.4 min), and this difference was statistically significant (p = 0.002). Conclusions: This study compared propofol-based sedation with sevoflurane-based general anesthesia in pediatric WPW patients. While sedation with propofol did not show a statistically significant reduction in arrhythmia inducibility, there was a concerning trend toward lower induction rates (29.5% difference) that may be clinically relevant. The study’s limited statistical power (49.8%) suggests these findings should be interpreted cautiously, and larger prospective studies are needed to definitively establish whether propofol affects arrhythmia inducibility in this population. Propofol remains a viable option for these procedures, but clinicians should be aware of the potential for reduced inducibility, particularly in cases where arrhythmia induction is critical for diagnosis and treatment. Full article

Background: While providing enough sedatives to avoid pain and trauma during surgery is important, studies show a link between the received sedatives and the development of postoperative delirium (POD). Therefore, predicting POD from clinical or physiological data before or during surgery is highly advantageous. This capability enables healthcare providers to proactively implement necessary measures, thereby mitigating or preventing potential complications. Methods: In this study, we focus on patients with Parkinson’s disease undergoing deep brain stimulation surgery who are particularly susceptible to POD. We investigate what aspects of EEG’s power, functional connectivity and complexity during the course of the surgery are influenced by the amount of sedative. Furthermore, we aim to determine whether and to what extent the recorded brain activity during surgery can serve as a reliable means for the prediction of POD in this group of patients. Results and Conclusions: Our results show significant correlations between various power, connectivity and complexity features of EEG and the amount of sedatives. Even though single EEG features are not significantly different between the two groups who either developed or did not develop POD, we show that a classifier based on support vector machines using the selected EEG features could predict POD. Furthermore, our results provide evidence that a classifier trained only on the amount of sedatives is unable to predict POD. Accompanying this paper, our code is published as an open-source toolbox for the analysis of the EEG signal recorded with the four-channel SEDLine Root system, which is among the widely used EEG systems in operation rooms and its recorded data come with challenges that are addressed in our toolbox. Full article