Anesth. Res., Volume 2, Issue 4 (December 2025) – 7 articles

The assessment of a conduction block following regional anaesthesia involves the clinical examination of motor and sensory neural pathways. Motor assessment includes the subjective evaluation of power, while sensory function is assessed using subjective perceptions of touch, cold and pain. There are considerable subjectivities and variabilities in the assessment of regional anaesthesia. Regional anaesthesia results in a blockade of not only somatosensory and motor nerve fibres but also sympathetic fibres. This results in vasodilation and an increase in blood flow, which leads to an increase in skin temperature. Multiple studies have demonstrated a high correlation between conduction block success and skin temperature changes at 10 min, detected using infrared thermography with a higher sensitivity and specificity and positive and negative predictive values up to 100%. Infrared thermography (IRT) is a non-invasive imaging tool which measures surface temperature. The role of IRT in assessing conduction blocks has been evaluated. We reviewed the literature to characterise the role of IRT in determining the onset of a conduction block following regional anaesthesia. This narrative review article synthesises the current evidence on the application of IRT in the evaluation of conduction block onset. In conclusion, IRT is a reliable tool to assess early block success as compared to routine assessment methods (touch, cold and pain perception). However, the limited studies and effects of environmental factors highlight the need for standardised protocols and multicentre studies to integrate into routine clinical practice. With further validation and integration into clinical practice, it has the potential to improve both patient safety and the reliability of block assessment. Full article

Background/Objectives: Chemogenetic excitation of a distinct subset of “effector-neurons” in the brainstem mesopontine tegmental anesthesia area (MPTA) is pro-anesthetic. GABAergic general anesthetics are believed to engage these neurons by disinhibition, thereby inducing loss-of-consciousness (LOC) and enabling pain-free surgery. The transition from wakefulness to LOC, however, does not occur intrinsically within the MPTA. Rather, evidence indicates that LOC is brought about (effected) by ascending and descending axonal projections of MPTA effector-neurons that terminate in a variety of downstream brain targets which, together, generate the various components of anesthesia. Previously we used anterograde and retrograde tracing to delineate the overall axonal trajectories of MPTA projection-neurons, to which targets they project. Effector-neurons, however, represent only a fraction of this neuronal pool. Which of these targets are also innervated by MPTA projecting effector-neurons? Methods: Here we marked MPTA effector-neurons with the adeno-associated virus (AAV) used in the discovery of this neuronal type, with retrograde labelling from the previously identified MPTA target structures, to establish which downstream brain structures receive direct input from effector-neurons. Results: Effector-neurons proved to contribute to all six of the major MPTA projection-targets: the prefrontal cortex, basal forebrain, intralaminar thalamus, zona incerta, rostro-ventromedial medulla and spinal cord. Conclusions: We conclude that a discrete population of projecting effector-neurons, probably representing only about 6% of all MPTA neurons, drive the multiple functional endpoints of surgical anesthesia: analgesia, atonia, amnesia and LOC. Further, we propose that these same neurons, via their associated axonal pathways, may also contribute to endogenous instances of LOC such as natural sleep, fainting, concussion, coma and hibernation. Full article

Background: Hip fracture surgery in elderly patients carries significant risks of both bleeding and thrombotic complications. Anaesthetists frequently face a dilemma between neuraxial anaesthesia, which may reduce thrombotic risk but is often limited by contraindications, and general anaesthesia, which is widely applicable but may exacerbate bleeding. Previous reviews have not specifically addressed bleeding and thrombotic outcomes, leaving a critical gap that this meta-analysis seeks to answer. Study objective: To evaluate the effect of neuraxial anaesthesia compared to general anaesthesia on the incidence of bleeding and thrombotic complications in acute neck of femur fracture surgery. Methods: Relevant studies comparing neuraxial and general anaesthetic for hip fracture surgery were searched for through Medline, Embase, Scopus, CINAHL and PubMed. Inclusion criteria were randomised control trials of hip fracture surgery patients aged >16 years with relevant outcome data. In total, 24 randomised control trials were included, with 5479 patients. A meta-analysis was performed using RevMan 5.4 software. The study was registered with PROSPERO ID: CRD42022348039. Outcome measurement: Primary outcomes were intra-operative blood loss, intra- or post-operative blood transfusion and post-operative deep vein thrombosis. Secondary outcomes were post-operative pulmonary embolism, post-operative myocardial infarction and post-operative stroke. Results: Neuraxial anaesthesia reduced deep vein thrombosis incidence by 45% and reduced blood loss by 58 mL, both of which reached statistical significance (p < 0.05). Albeit not reaching statistical significance, neuraxial anaesthesia also had a 35% relative risk reduction in myocardial infarction, and a 35% relative decrease in stroke in current studies published after 2010. Despite practise evolution over the decades, protective neuraxial trends have remained. Conclusions: Patients undergoing acute hip fracture surgery under general anaesthesia have higher volumes of blood loss, without requiring increased blood transfusion. General anaesthesia is also associated with higher thrombotic complications, with a 45% increased relative risk of deep vein thrombosis, compared to neuraxial anaesthesia. Multi-modal thromboprophylaxis is important, as up to a third of DVT cases occur in the non-operative leg. In frail patients with a low cardiopulmonary reserve for bleeding or in high-thrombotic-risk patients, extra consideration and optimisation for neuraxial technique is advised. Future studies on comorbidities and operation type may reveal a subgroup of patients which would benefit from a specific anaesthetic type. Full article

Sepsis is a life-threatening syndrome marked by a dysregulated host response to infection, resulting in systemic inflammation, organ dysfunction, and high mortality globally. Despite advancements in supportive care, effective immunomodulatory therapies remain elusive, necessitating exploration of novel biological pathways and subsequent therapeutic development. The endocannabinoid system (ECS), which regulates immune function and homeostasis, has emerged as a key modulator of immunological and metabolic pathways central to sepsis pathophysiology. The ECS mediates its effects through endogenous ligands, G-protein-coupled cannabinoid receptors (CB1 and CB1), and regulatory enzymes that control its synthesis and degradation. Following PRISMA-ScR guidelines, this scoping review synthesizes current evidence on the mechanistic roles of ECS components in experimental and clinical models of sepsis, identifies knowledge gaps, and delineates future areas of work. A comprehensive literature search across multiple databases without restrictions on date or publication type was executed to ensure broad coverage of original studies investigating ECS mechanisms and their intersection with sepsis and septic shock. Across 53 studies, CB2 receptor activation was consistently associated with anti-inflammatory process, organ-protective outcomes, and increased survival rates against septic challenges in preclinical rodent models. CB1 receptor activation trends, however, showed context dependent outcomes. Central antagonism improved hemodynamics and survival rate, but peripheral effects varied with cell type and timing. Non-canonical ECS components (TRPV1, GPR55, PPAR-α, FAAH, MAGL) also contributed to neuroimmune and metabolic regulation. Limited clinical data linked ECS lipid profiles and gene expression with sepsis severity and outcomes. Collectively, ECS modulation, particularly CB2 agonism, TRPV1 activation, and FAAH/MAGL inhibition, shows promise in mitigating sepsis-induced inflammation and organ dysfunction. However, complex, context-dependent effects, especially involving CB1, highlight the need for precision-targeted therapeutic approaches. Further preclinical research is needed to expand generalizable trends to allow translational research to refine ECS-based interventions for sepsis management. Full article

Background: Sepsis is a life-threatening syndrome caused by a dysregulated host response to infection leading to organ dysfunction. Distinguishing sepsis from localized infection is crucial, as it guides clinical decision-making and biomarker interpretation. Biomarkers may support diagnosis, prognosis, and therapeutic choices, but their integration into practice remains debated. Methods: This narrative review was conducted in accordance with the SANRA (Scale for the Assessment of Narrative Review Articles) guidelines. A comprehensive literature search was performed in PubMed, Embase, and Cochrane CENTRAL (January 2000–September 2025). Studies evaluating sepsis-related biomarkers for diagnosis, prognostication, shock assessment, antimicrobial stewardship, and post-acute follow-up were considered. Findings: Established biomarkers such as procalcitonin (PCT), C-reactive protein (CRP), and lactate remain widely used for diagnosis, monitoring of inflammatory response, and assessment of severity. Emerging candidates include pancreatic stone protein (PSP), neutrophil gelatinase-associated lipocalin (NGAL), and monocyte HLA-DR (mHLA-DR), which may provide insights into infection dynamics, renal injury, and immune suppression, respectively. However, limitations in standardization and heterogeneous evidence hinder routine implementation. Interleukin-6 (IL-6), despite extensive study, shows limited specificity and inconsistent clinical applicability. Renin has been proposed as a marker of shock severity rather than infection. Comparative evidence highlights the need for stage-specific biomarker use across prehospital, emergency, ICU, and recovery phases. Conclusions: No single biomarker is universally applicable in sepsis. Their utility depends on timing, clinical setting, and patient phenotype. Combining classical and emerging biomarkers with point-of-care technologies and dynamic monitoring may enhance personalized management. Limitations include heterogeneity of evidence and lack of standardized thresholds. Future research should validate biomarker panels, integrate them into stewardship strategies, and explore their cost-effectiveness in clinical practice. Full article

The teaching of medical history, once central to medical education, has been progressively displaced by science- and competency-focused curricula. In anesthesiology, despite the presence of historical scholarship and institutional resources, the history of this specialty is rarely used as a formal educational tool. This narrative review explores how historical narratives can support the development of professionalism and professional identity in anesthesia training. An exploratory search of the literature revealed no prior studies explicitly linking anesthesia history to professional identity formation, underscoring a gap in current scholarship. Drawing on the foundational literature in medical education and selected historical examples, including figures such as Crawford Long, Henry Beecher, and Virginia Apgar, this review illustrates how reflective engagement with historical episodes can deepen ethical awareness, foster identity formation, and contextualize the evolving role of the anesthesiologist. It proposes a theoretical framework and strategies for integrating historical content into anesthesia curricula and argues that historical reflection can complement existing methods for teaching professionalism. The history of anesthesia, when purposefully employed, offers a powerful means to humanize training, support critical reflection, and better prepare trainees for the ethical and professional challenges of contemporary practice. Full article

Opioid use disorder remains a leading national cause of mortality. Physician opioid prescribing contributes to this crisis. In urogynecology, most of these prescriptions are aimed at addressing postoperative pain. This expert review examines the factors that contribute to postoperative pain and opioid use in urogynecologic patients. We discuss patient characteristics, physician interventions and alternative therapies that may influence postoperative pain and opioid use. By identifying patients at higher risk for postoperative pain and opioid use and utilizing evidence-based strategies to mitigate postoperative pain, physicians caring for urogynecology patients can both reduce postoperative opioid use while still providing adequate patient pain control. Full article