Daily Anesthesiology Research Analysis
Analyzed 40 papers and selected 3 impactful papers.
Summary
Analyzed 40 papers and selected 3 impactful articles.
Selected Articles
1. Sevoflurane-induced disruption of critical period Arc signaling drives aberrant microglial synaptic pruning and cognitive deficits.
In rodent models, early-life sevoflurane activated GSK3β, suppressed critical-period Arc upregulation, and derailed microglial synaptic pruning, leading to later synaptic loss and cognitive deficits. Transient Arc knockdown phenocopied these effects, while critical-period restoration of Arc via a Dox-inducible system normalized pruning trajectories and prevented long-term cognitive impairment.
Impact: This study uncovers a precise, time-locked Arc-dependent mechanism linking pediatric anesthesia exposure to lasting cognitive harm and demonstrates successful rescue, defining a targetable window for intervention.
Clinical Implications: While preclinical, the work highlights Arc stabilization and modulation of GSK3β as candidate neuroprotective strategies and emphasizes timing as critical in mitigating anesthetic developmental neurotoxicity.
Key Findings
- The first three postnatal weeks constitute a critical vulnerability window to sevoflurane.
- Sevoflurane activated GSK3β and reduced Arc during the critical period, disrupting microglial synaptic pruning.
- Arc antisense knockdown recapitulated sevoflurane-induced pruning defects and later cognitive deficits.
- Critical-period Arc restoration via a Dox-inducible system prevented aberrant pruning and long-term cognitive impairment.
Methodological Strengths
- Rigorous mechanistic design with loss- and gain-of-function and temporal mapping across development.
- Convergent evidence linking molecular signaling (GSK3β–Arc), microglial function, synaptic outcomes, and behavior.
Limitations
- Preclinical rodent models may not fully recapitulate human anesthetic exposures and developmental timelines.
- Specific exposure paradigms and potential sex/species differences require further validation for clinical translation.
Future Directions: Test Arc-stabilizing or GSK3β-modulating agents in translational models, define human-equivalent critical windows, and develop perioperative neuroprotection protocols for pediatric anesthesia.
Early-life sevoflurane exposure is associated with long-term cognitive deficits. Given that hippocampal development relies on precise critical windows, disruption of developmental processes during these periods is likely the origin of these impairments. However, the molecular mechanisms underlying sevoflurane-induced perturbations during critical development periods and their progression to lasting cognitive dysfunction remain elusive. Here, we determined that the first three postnatal weeks are a critical window of vulnerability to early-life sevoflurane exposure. Mechanistically, sevoflurane exposure suppressed the physiological upregulation of activity-regulated cytoskeleton-associated protein (Arc; also known as Arg3.1) during the critical period of hippocampal development, a process driven by glycogen synthase kinase-3 beta (GSK3β)-mediated protein degradation. We demonstrated that transient suppression of Arc via hippocampal injection of Arc antisense oligonucleotide (ASO) during the third postnatal week was sufficient to recapitulate the sevoflurane-induced phenotype, impairing microglial synaptic pruning and causing initial synaptic redundancy. This early pathology subsequently evolved into aberrant microglial phagocytic activation in adolescence and adulthood, resulting in excessive synaptic loss and cognitive deficits. Crucially, restoration of Arc expression specifically during this critical period using a doxycycline (Dox)-inducible Tet-On system successfully reversed this pathological pruning trajectory and prevented long-term cognitive impairment. Our findings highlight that Arc upregulation during this critical period is essential for microglial function and synaptic homeostasis, establishing Arc as a time-sensitive therapeutic target for preventing the developmental neurotoxicity associated with pediatric anesthesia. This diagram illustrates the role of the Arc protein in microglial synaptic pruning and cognitive development under physiological conditions (upper panel, blue; Arc is highly expressed during the critical period) and sevoflurane exposure (lower panel, red; Arc expression during the critical period is downregulated). Under normal conditions, Arc is expressed during the critical period and is localized to synapses, where it facilitates the tagging of redundant synapses for elimination. Synaptic pruning peaks during the critical period, followed by further refinement during adolescence, leading to mature cognitive function in adulthood. Neonatal sevoflurane exposure leads to aberrant activation of GSK3β during the critical period. This promotes Arc degradation, thereby disrupting its synaptic localization. This leads to microglial dysfunction in terms of synaptic engulfment. In adolescence, this disruption leads to excessive microglial phagocytosis and significant synaptic loss, ultimately resulting in cognitive deficits. Graphical elements: GSK3β, green circles; Arc, orange circles; phosphorylation site, pale yellow circle containing the letter "P"; C1q, yellow umbrella shapes.
2. Patient versus surrogate decision making for life sustaining treatment and terminal care intensity.
In a nationwide ICU cohort, patient-determined POLSTs were associated with markedly lower odds of invasive terminal care, whereas surrogate-determined orders increased care intensity and daily costs. Even with prior advance directives, surrogate signing was linked to higher terminal care intensity, suggesting erosion of patient preferences.
Impact: Provides large-scale, policy-relevant evidence that the identity of the POLST signatory fundamentally alters terminal care trajectories and costs in ICU settings.
Clinical Implications: Promote early, patient-led POLST completion and workflows that minimize surrogate override, integrate real-time preference verification, and audit terminal care intensity for goal-concordance.
Key Findings
- Surrogate-determined POLSTs were >3× more prevalent than patient-determined POLSTs.
- Patient-determined POLSTs were associated with reduced invasive terminal care (OR 0.43; 95% CI 0.43–0.54).
- Surrogate-determined POLSTs increased invasive terminal care (OR 2.16; 95% CI 1.98–2.35).
- Even with prior ADs, surrogate signing increased care intensity (OR 1.69; 95% CI 1.51–1.89), and was linked to higher daily costs (cost ratio 1.04; 95% CI 1.02–1.06).
Methodological Strengths
- Nationwide cohort with 1,189,042 ICU admissions and high-dimensional fixed-effects modeling across 417 hospitals.
- Robust subgrouping of 90-day decedents and cost analyses to assess terminal care intensity.
Limitations
- Observational design limits causal inference and is susceptible to residual confounding.
- Administrative coding may not capture nuanced clinical context or patient–family discussions.
Future Directions: Prospective studies embedding POLST workflows that prioritize patient signing, real-time preference validation, and metrics for goal-concordant care; evaluate impacts on family outcomes and clinician burden.
RATIONALE: Physician Orders for Life-Sustaining Treatment (POLST) and Advance Directives (AD) aim to honor patient autonomy. However, the impact of the signatory's identity-whether the patient or a surrogate-on clinical trajectories in the intensive care unit (ICU) remains poorly characterized. OBJECTIVES: To evaluate the association between signatory identity and terminal care intensity and hospitalization costs among adult patients in the ICU. METHODS: This nationwide population-based cohort study utilized the South Korean National Health Insurance Service database, including 1,189,042 adult ICU admissions between 2020 and 2023. Statistical analyses employed high-dimensional fixed-effects models to account for institutional variability across 417 hospitals. RESULTS: Among 1,189,042 patients, surrogate-determined POLST (SD-POLST) was more than three times as prevalent as patient-determined POLST (PD-POLST). Among 90-day decedents, PD-POLST was associated with significantly reduced odds of invasive terminal care (OR, 0.43; 95% CI, 0.43-0.54). Conversely, SD-POLST more than doubled the odds (OR, 2.16; 95% CI, 1.98-2.35). Notably, even patients with proactive ADs experienced increased care intensity once a surrogate signed the final order (OR, 1.69; 95% CI, 1.51-1.89), indicating a phenomenon of "AD erosion." SD-POLST was also associated with significantly higher daily hospitalization costs (cost ratio, 1.04; 95% CI, 1.02-1.06) compared with no documentation. CONCLUSION: The clinical efficacy of POLST in limiting non-beneficial care depends fundamentally on the signatory. Surrogate-led decisions were associated with paradoxically higher care intensity and costs, potentially overriding prior patient wishes. These findings highlight the critical importance of early, patient-led discussions to ensure goal-concordant end-of-life care in the ICU.
3. A Prospective Study of Marsh PK-PD Model and Schnider PK-PD Model During Anesthesia Induction for Obese Patients Undergoing Elective Heart Surgery.
In 118 obese cardiac surgery patients randomized to Marsh (TBW) vs Schnider (LBW) TCI models, Marsh yielded lower post-TCI performance error, higher BIS, better preserved LVEF and SV, shorter QT intervals, reduced propofol dosing, and faster recovery. During TCI itself, ΔC did not differ, underscoring differences after infusion cessation.
Impact: Findings suggest that PK model selection and weight scalar materially affect propofol control and peri-induction physiology in obese cardiac patients, informing precision anesthesia strategies.
Clinical Implications: For obese cardiac surgery induction, consider Marsh (TBW-configured) TCI to improve control and recovery; standardize weight scalars and validate across centers before broad adoption.
Key Findings
- No significant ΔC differences during TCI, but Marsh showed significantly lower ΔC at all time points after TCI cessation (p<0.05).
- Marsh group had higher BIS and better preserved LVEF and SV vs Schnider (all p<0.05).
- Marsh was associated with shorter QTc/QTcd, reduced propofol requirements, and shorter recovery times (all p<0.05).
Methodological Strengths
- Randomized allocation with predefined primary PK accuracy endpoint and multiple physiologic secondary outcomes.
- Direct comparison of widely used TCI models in a clinically high-risk obese cardiac surgery population.
Limitations
- Single-center study; external validity may be limited.
- Configuration differed (TBW for Marsh vs LBW for Schnider), potentially confounding model vs weight-scalar effects; blinding not described.
Future Directions: Multicenter, blinded trials harmonizing weight scalars and exploring effect modification by obesity class and cardiac function; integration with closed-loop and EEG-guided systems.
This prospective study compared the Marsh and Schnider pharmacokinetic models for propofol target-controlled infusion (TCI) during anesthetic induction in obese patients undergoing elective cardiac surgery. A total of 118 patients were randomly assigned to either the Marsh or Schnider group (n = 59 each). The primary outcome was the performance error (ΔC = measured minus predicted plasma concentration) during and after TCI. Secondary outcomes included hemodynamic pharmacokinetic-pharmacodynamic (PK-PD) model, anesthetic depth (BIS), cardiac function (LVEF, SV), electrocardiographic PK-PD model (QTc, QTcd), and recovery profiles. While no significant differences in ΔC were observed during TCI, the Marsh model demonstrated significantly lower ΔC at all time points after TCI cessation (p < 0.05). Compared to the Schnider group, the Marsh group also showed higher BIS values, better preserved LVEF and SV, shorter QTc/QTcd intervals, reduced propofol requirements, and shorter recovery times (all p < 0.05). In conclusion, under the conditions of this study, in which propofol TCI was configured using total body weight for the Marsh model and lean body weight for the Schnider model, the Marsh model provided more accurate plasma concentration control, better hemodynamic stability, and improved recovery profiles compared with the Schnider model for anesthetic induction in obese cardiac surgery patients.