Daily Anesthesiology Research Analysis
Three impactful anesthesiology-related studies stood out today: a mechanistic mouse study links repeated sevoflurane exposure to microglia-driven hypomyelination and cognitive deficits; a prospective perioperative study validates a dielectric blood coagulometry point-of-care test to gauge factor Xa inhibitor effect; and a multicenter registry shows widespread adoption of rocuronium-sugammadex for neuromuscular reversal in renal impairment despite labeling cautions, with large inter-institutional
Summary
Three impactful anesthesiology-related studies stood out today: a mechanistic mouse study links repeated sevoflurane exposure to microglia-driven hypomyelination and cognitive deficits; a prospective perioperative study validates a dielectric blood coagulometry point-of-care test to gauge factor Xa inhibitor effect; and a multicenter registry shows widespread adoption of rocuronium-sugammadex for neuromuscular reversal in renal impairment despite labeling cautions, with large inter-institutional variation.
Research Themes
- Anesthetic neurotoxicity and microglial modulation in developing brain
- Perioperative anticoagulation monitoring and point-of-care diagnostics for DOACs
- Neuromuscular blockade reversal strategies in renal impairment and practice variation
Selected Articles
1. Myelination Trajectory and Microglial Dynamics Following Repeated Sevoflurane Exposure in Developing Brain.
In neonatal mice, repeated sevoflurane exposure impaired fine motor and cognitive functions and disrupted myelination in hippocampus and corpus callosum via microglial activation and lipid droplet accumulation. Conditioned media from sevoflurane-treated microglia suppressed OPC proliferation/differentiation, while minocycline or CSF1R inhibitor PLX5622 mitigated neuroinflammation and hypomyelination.
Impact: This mechanistic study advances understanding of anesthetic neurotoxicity by identifying microglial hyperactivation as a key driver of hypomyelination after sevoflurane, and demonstrates pharmacologic rescue. It provides targets and pathways for preventive strategies in vulnerable developing brains.
Clinical Implications: While not immediately practice-changing, the data caution against repeated or prolonged sevoflurane exposure in neonates/infants and suggest microglia-focused interventions as potential neuroprotective strategies to be tested clinically.
Key Findings
- Repeated sevoflurane exposure impaired fine motor and cognitive functions in neonatal mice.
- Myelination markers (MBP, PDGFR-α) were dysregulated in hippocampus and corpus callosum, with microglial lipid droplet accumulation.
- Conditioned media from sevoflurane-treated microglia inhibited OPC proliferation/differentiation.
- Microglial inhibition/depletion (minocycline, PLX5622) alleviated neuroinflammation and hypomyelination.
Methodological Strengths
- Multimodal approach combining in vivo behavioral, histologic, and molecular assays with in vitro co-culture.
- Pharmacologic manipulation (minocycline, CSF1R inhibitor PLX5622) to test causality of microglial involvement.
Limitations
- Animal model limits direct clinical translatability of dose/timing to human infants.
- Long-term functional outcomes and sex-specific effects were not detailed.
Future Directions: Define exposure thresholds and windows of vulnerability, test microglia-targeted neuroprotection in large animal models, and evaluate neurodevelopmental outcomes in prospective pediatric cohorts.
The myelination is a critical process during brain development. This study aimed to explore the impact of volatile anesthetic sevoflurane on developing myelination and the role of microglial activation in this process. Neonatal C57BL/6J mice were exposed to sevoflurane at their postnatal 6-8 days. Neurobehavioral tests were used to assess fine motor and cognitive functions. Myelination of hippocampus (HC) and corpus callosum (CC), as well as microglial activation, were determined by western blotting and immunostaining. Lipid droplets were assessed by Oil-Red-O and Bodipy staining. Further, primary microglia were co-cultured with oligodendrocyte precursor cell (OPC) to determine the role of microglia in the proliferation and differentiation of OPC. And microglial inhibitor minocycline and CSF1R inhibitor PLX5622 were administered to assess the effects of microglial activation on developing myelination. The results showed that repeated sevoflurane exposure impaired both fine motor and cognitive
2. Dielectric blood coagulometry to evaluate coagulation activity in patients prescribed factor Xa inhibitors undergoing elective surgery: A prospective observational study.
In a perioperative cohort, DBCM coagulation time correlated strongly with apixaban and rivaroxaban plasma concentrations (Rs=0.87 and 0.91) and inversely with peak thrombin generation, achieving AUC 0.98–0.99 to identify samples <30 ng/mL. Findings support DBCM as a promising point-of-care tool to assess residual DOAC effect before anesthesia/surgery.
Impact: Introduces and clinically validates a rapid point-of-care assay for DOAC activity with excellent diagnostic performance, addressing a pressing perioperative need to guide timing of surgery, neuraxial anesthesia, and reversal decisions.
Clinical Implications: DBCM could enable bedside assessment of residual factor Xa inhibitor effect to streamline OR scheduling, reduce unnecessary delays or bridging, and enhance safety for neuraxial procedures; multicenter validation and outcome studies are the logical next steps.
Key Findings
- DBCM coagulation time strongly correlated with apixaban (Rs=0.87, n=57) and rivaroxaban (Rs=0.91, n=49) plasma concentrations.
- DBCM coagulation time inversely correlated with peak thrombin generation (apixaban Rs=-0.80; rivaroxaban Rs=-0.84).
- AUC for identifying samples with <30 ng/mL DOAC: 0.98 (apixaban) and 0.99 (rivaroxaban).
Methodological Strengths
- Prospective perioperative sampling with direct comparison to plasma DOAC concentrations and calibrated thrombin generation.
- Diagnostic performance quantified with ROC analysis and high discriminative accuracy for clinically relevant thresholds.
Limitations
- Single-setting study with modest sample sizes limited to apixaban and rivaroxaban; generalizability to other DOACs (e.g., edoxaban) unknown.
- Clinical management outcomes (e.g., bleeding/thrombotic events) based on DBCM-guided decisions were not assessed.
Future Directions: Multicenter validation including additional DOACs, establishment of perioperative decision algorithms incorporating DBCM, and randomized studies testing DBCM-guided management on clinical outcomes.
BACKGROUND: Dielectric blood coagulometry (DBCM) is a coagulation test based on dielectric permittivity. We recently developed a new cartridge to evaluate the anticoagulation effect of factor Xa inhibitors and investigated the usefulness of this system in the clinical setting. Here, we evaluate the relationship among the coagulation time measured by DBCM, plasma concentrations of factor Xa inhibitors, and peak thrombin generation using blood samples from patients prescribed factor Xa inhibitors undergoing elective surgery. METHODS: Whole-blood samp
3. Neuromuscular Blockade and Antagonism in Patients with Renal Impairment: A Multicenter Retrospective Cross-sectional Study.
Across 243,944 anesthetics in patients with eGFR<60 mL/min, rocuronium–sugammadex use rose from 4.4% to 95.2% (0.5% to 86.9% for eGFR<15), while neostigmine strategies declined. Strategy choice varied substantially by institution and anesthesiologist, highlighting widespread off-label use of sugammadex in severe renal impairment and practice heterogeneity.
Impact: This large multicenter analysis quantifies contemporary neuromuscular reversal practices in renal impairment, informing risk–benefit discussions and highlighting the need for guidance where evidence is limited and label cautions exist.
Clinical Implications: Clinicians should recognize the prevalent use of sugammadex in severe renal impairment and consider institutional protocols, shared decision-making, and monitoring for residual blockade, while awaiting outcome-focused studies to refine dosing and safety recommendations.
Key Findings
- Rocuronium–sugammadex use increased from 4.4% to 95.2% (2016–2022) in eGFR<60 mL/min cases; in eGFR<15 mL/min, from 0.5% to 86.9%.
- Rocuronium–neostigmine and cisatracurium–neostigmine strategies declined to 4.3% and 0.5%, respectively.
- Variation in strategy choice was significantly attributable to institution (30.1%) and attending anesthesiologist (22.7%).
Methodological Strengths
- Very large multicenter registry (243,944 cases) with mixed-effects modeling.
- Stratified analyses by renal function including eGFR<15 mL/min.
Limitations
- Retrospective design cannot establish safety/efficacy outcomes of strategy choice.
- Unmeasured confounders and coding variability across institutions may affect estimates.
Future Directions: Prospective comparative studies to assess clinical outcomes and pharmacokinetics of sugammadex in severe renal impairment, and development of consensus guidance to reduce unwarranted practice variation.
BACKGROUND: Current practice guidelines do not address the use of neuromuscular blocking and antagonism agents in patients with renal impairment. The U.S. Food and Drug Administration (Silver Spring, Maryland) label for sugammadex advises against use in patients with severe renal impairment (estimated glomerular filtration rate [eGFR] less than 30 ml/min). Using a multicenter electronic health record registry, the authors sought to understand the modern use of neuromuscular blockade and antagonism agents in patients with significant renal impairment (eGFR less than 60 ml/min). METHODS: Data were obtained from the Multicenter Perioperative Outcomes Group (MPOG) registry for adult patients (older than 18 yr) with an eGFR less than 60 ml/min, based on most recent serum creatinine, receiving general anesthesia for a nonrenal transplant procedure with an endotracheal tube between January 1, 2016, and July 31, 2022. Patients were classified into three mutually exclusive blockade and reversal strategies: rocuronium-sugammadex, cisatracurium-neostigmine, and rocuronium-neostigmine. Adjusted incidence of each blockade reversal strategy was established by a multinomial mixed effects model. The contribution of institution, anesthesiologist, and patient or case factors to variation in strategy choice was assessed by multilevel mixed effects models. RESULTS: In 243,944 cases across 5,133 anesthesiologists and 48 institutions, adjusted use of rocuronium-sugammadex increased from 4.4 to 95.2%, rocuronium-neostigmine decreased from 84.7 to 4.3%, and cisatracurium-neostigmine decreased from 10.9 to 0.5%. In patients with an eGFR less than 15 ml/min, rocuronium-sugammadex use increased from 0.5 to 86.9%. Of the variation in choice of rocuronium-sugammadex versus cisatracurium-neostigmine, 30.1% was attributed to the institution, 22.7% to the attending anesthesiologist, and 47.2% to patient/case factors or was unexplained. The adjusted median odds ratio for this choice was 2.5 for clinicians and 3.1 for institutions. CONCLUSION: Rocuronium-sugammadex is the primary neuromuscular blockade-antagonism strategy for patients with moderate and severe renal impairment. Variation in choice is significantly impacted by the institution and attending anesthesiologist providing care.