Research Insights & Reviews: Anaesthesiology

Racial disparities in pulse oximetry: measurement bias and clinical implications—a systematic review

Oluwayemisi Esther Ekor — 2026-08-31

This review synthesised existing evidence on racial disparities in pulse oximeter accuracy, quantified the degree of bias, evaluated clinical effects, highlighted implications for practice, and identified research priorities needed to achieve equitable device performance. While prior systematic reviews have examined pulse oximeter accuracy across varying skin pigmentation levels, most have focused primarily on aggregate accuracy metrics without integrating downstream clinical consequences or anaesthesiology-specific implications. In contrast, this review synthesises paired SpO₂–SaO₂ comparisons stratified by race or skin tone and explicitly links measurement bias to occult hypoxaemia, treatment escalation thresholds, and perioperative decision-making. By integrating device-level performance characteristics with clinical risk pathways, this review aims to provide actionable insights for anaesthesiologists and critical care clinicians.

Perioperative anesthetic management for neurosurgical operations in a lounging, sitting or semi-sitting position

Peter Michels — 2026-08-06

In neurosurgery, positioning the patient in a lounging or (semi-)sitting position is used for surgical treatment of processes in the area of the posterior cranial fossa, as this can offer a number of advantages compared to other forms of positioning, e.g., good drainage of blood and cerebrospinal fluid as well as potentially better preservation of cranial nerve function. At the same time, this positioning requires vigilant perioperative anesthesiological monitoring. In addition to ensuring adequate cerebral blood flow, it is crucially important to recognize and treat a venous air embolism (VAE). The underlying mechanism of VAE is due to the elevated surgical area in relation to the heart and the resulting hydrostatic pressure difference between an open vein and the heart. If the incoming air enters the pulmonary arterial vascular bed, the effects are primarily equivalent to a pulmonary artery embolism and can lead to right heart failure and the need for resuscitation. It should be emphasized that the effects of a VAE are not primarily depending on the total volume of air entering the vasculature, but rather on the volume entering per time. Especially patients presenting with a persistent foramen ovale (PFO) are at high risk during operations in a (semi-)sitting position. In the case of VAE, this can lead to a direct passage of air bubbles from the right heart to the left heart, leading to cerebral and coronary vascular embolism with subsequent stroke or myocardial infarction. Therefore, there is a need for anesthesiologists to recognize and assess both a PFO before the start of positioning and an intraoperative VAE, as well as to treat this in a targeted manner in communication with the surgeon. Using transesophageal echocardiography (TEE), VAE can be directly visualized and objectively graded according e.g., to the “Tuebingen Venous Air Embolism Grading Scale”. Depending on the severity of the VAE, various measures must be taken: information of the surgeon, avoidance of further air entry, treatment of the hemodynamic depression, evaluation of the grade of VAE and, if necessary, aspiration of the entered air or the so-called “air lock”. Here, the authors discuss advantages and disadvantages, implementation, as well as special risks of this neurosurgical positioning, physiological changes caused by the sitting position itself, hemodynamic monitoring of the patient and intraoperative ventilation. A special focus is on pathophysiology, incidence, and TEE diagnosis of VAE in lounging or (semi-)sitting position, including discussion of the question of a PFO.

Convergent mitochondrial toxicity of fluorinated agents in oncological anaesthesia: sevoflurane, 5-fluorouracil, and the ACOD1/itaconate immune axis

Ivan N. Dushin — 2026-08-31

Aconitate decarboxylase 1 (ACOD1, formerly IRG1) and its product itaconate have emerged as central regulators of tumour immune surveillance: ACOD1-derived itaconate in tumour-associated macrophages (TAMs) suppresses inflammatory gene expression and limits CD8⁺ T-cell infiltration, while systemic itaconate modulates NLRP3 inflammasome activity and natural killer (NK) cell function. We propose that two agents routinely co-administered in fluoropyrimidine-treated oncological patients—sevoflurane and 5-fluorouracil (5-FU)—may converge on aconitase 2 inhibition, depleting the cis-aconitate substrate for ACOD1 and thereby disrupting itaconate-dependent immune regulation at a critical perioperative window. The fluoroacetate pathway of 5-FU is experimentally established; sevoflurane undergoes CYP2E1-mediated metabolism to fluorinated intermediates whose further biotransformation may generate aconitase-inhibitory species, as suggested by the work of Karpinski et al. (2006) and supported by prospective metabolomic evidence (Wei et al., 2021) demonstrating plasma metabolomic patterns consistent with aconitase perturbation in sevoflurane-anaesthetised patients. The immunological consequences of perioperative ACOD1/itaconate depletion—paradoxically encompassing both pro-tumorigenic immune evasion at the tumour microenvironment level and heightened systemic inflammatory susceptibility—represent a potentially unrecognised dimension of anaesthetic pharmacology in oncological surgery. Pre-operative dual genotyping for dihydropyrimidine dehydrogenase (DPYD) and ACOD1 variants is proposed as a pharmacogenomic framework for anaesthetic technique selection.

Anaesthetic profile and perioperative mobi-mortality according to renal function in patients undergoing urgent and elective surgery at Monkole Hospital, Kinshasa: a cross-sectional study

Arthur Isamba — 2026-08-31

Background: Chronic kidney disease (CKD) increases perioperative risk through metabolic, cardiovascular, and hematologic disturbances that complicate anaesthetic management. Evidence from sub-Saharan Africa on surgical outcomes across CKD stages is limited.

Objective: To describe anaesthetic practices and assess perioperative morbidity and mortality in CKD patients undergoing surgery at Monkole Hospital, Kinshasa.

Methods: This retrospective cross-sectional study included adult CKD patients who underwent urgent or elective surgery between February 2018 and December 2024. Renal function was classified using the CKD-EPI 2021 equation into GFR categories G1–G5. Outcomes included intraoperative incidents, perioperative complications, transfusion requirements, opioid use, and in-hospital mortality. Multivariate logistic regression identified predictors of adverse outcomes, comparing patients with GFR < 60 and ≥60 mL/min/1.73 m2.

Results: Among 418 patients, 48.1% were G3, 24.6% G2, and 15.3% G1. Complications and mortality rose with declining renal function. Patients with GFR < 60 mL/min/1.73 m² had higher mortality than those with GFR ≥ 60 (11.2% vs. 5.4%). After adjustment, GFR < 60 remained independently associated with mortality (OR 2.61, 95% CI 1.01–6.71).

Conclusion: Reduced renal function independently predicted increased perioperative mortality, highlighting the need for improved risk stratification in CKD patients.

The anesthesiologist’s role in preventing chronic post-surgical pain and opioid use through neurobiological programming: a mini review

Trisha Nair — 2026-05-13

Background: Chronic Post-Surgical Pain (CPSP) and Postoperative Chronic Opioid Use (COU) pose significant public health challenges. Anesthesiologists play a vital role in modulating acute pain during surgery and influencing its chronic trajectory. CPSP is defined as pain persisting for ≥3 months, localized to the surgical field or relevant nerve territory, and with other causes excluded. COU, a surrogate marker for prolonged utilization, is defined as prolonged utilization (≥10 prescriptions or ≥120 days’ supply) in the postsurgical year, excluding the initial 90 postoperative days. This mini-review synthesizes evidence on perioperative risk factors, mechanistic pathways, and anesthetic/analgesic interventions to influence the development of CPSP and COU.

Methods: We performed a narrative literature review (February 2000–December 2025) across PubMed and Google Scholar, focusing on risk factors and mitigation strategies for CPSP and COU. Key search terms included “CPSP,” “COU,” “multimodal analgesia,” “neuroinflammation,” “epigenetic changes,” “TIVA,” and “precision medicine.” The search prioritized randomized controlled trials, systematic reviews, and key preclinical studies.

Results: Chronicity is highly predictable based on preoperative psychosocial factors (e.g., anxiety, catastrophizing) and phenotypic hyperalgesia. Key mechanisms include central sensitization, neuroinflammation, epigenetic molecular programming, and gut-brain axis disruption. Evidence supports regional anesthesia (e.g., neuroaxial/paravertebral blocks) for CPSP prevention in high-risk procedures and targeted systemic non-opioids to mitigate opioid consumption and chronicity.

Conclusions: CPSP and COU require a precision medicine approach that accounts for individual variability. This necessitates thorough preoperative risk stratification and the implementation of targeted, mechanism-based perioperative analgesia to intercept the neurobiological programming underlying chronic pain and opioid dependence.