Daily Anesthesiology Research Analysis
Three studies stand out today in anesthesiology and perioperative medicine: a mechanistic BJA study reveals striatal D1 dopamine neurons modulate consciousness under sevoflurane but not propofol; a Bayesian network meta-analysis identifies granisetron and oxycodone as top options to prevent etomidate-induced myoclonus; and a large cohort links cumulative intraoperative hypotension to postoperative acute kidney injury after cardiac surgery.
Summary
Three studies stand out today in anesthesiology and perioperative medicine: a mechanistic BJA study reveals striatal D1 dopamine neurons modulate consciousness under sevoflurane but not propofol; a Bayesian network meta-analysis identifies granisetron and oxycodone as top options to prevent etomidate-induced myoclonus; and a large cohort links cumulative intraoperative hypotension to postoperative acute kidney injury after cardiac surgery.
Research Themes
- Neural mechanisms of anesthetic-induced loss and recovery of consciousness
- Perioperative hemodynamic management and renal outcomes
- Optimization of induction strategies and prevention of etomidate-induced myoclonus
Selected Articles
1. Striatal neurones expressing D1 dopamine receptors modulate consciousness in sevoflurane but not propofol anaesthesia in mice.
In mice, dorsal striatal D1 receptor neurons decreased activity before sevoflurane-induced LOC and recovered after emergence. Optogenetic activation triggered recovery of consciousness and cortical activation during steady sevoflurane anesthesia, while chemogenetic inhibition accelerated induction and delayed emergence; these manipulations had no effect under propofol. Findings indicate anesthetic-specific modulation of arousal circuitry.
Impact: This mechanistic study delineates an anesthetic-specific role of striatal D1 neurons, advancing understanding of how different agents induce and reverse unconsciousness.
Clinical Implications: Although preclinical, the results suggest potential for targeted neuromodulation to hasten emergence from volatile anesthesia and highlight that mechanisms of unconsciousness differ between agents.
Key Findings
- Population activity of striatal D1R neurons decreased before LOC and recovered after ROC under sevoflurane.
- Optogenetic activation induced ROC and cortical activation during steady-state sevoflurane anesthesia; chemogenetic inhibition accelerated induction (242.0→194.0 s, P=0.010) and delayed emergence (93.5→133.5 s, P=0.005).
- Chemogenetic activation accelerated emergence (107→81.3 s, P=0.011).
- No opto/chemogenetic effects were observed under propofol anesthesia.
Methodological Strengths
- In vivo fiber photometry with optogenetic and chemogenetic manipulation provides causal mechanistic evidence.
- Multi-modal assessment (EEG/EMG, righting reflex) strengthens behavioral-physiologic correlation.
Limitations
- Mouse model limits direct clinical translatability.
- Exact sample sizes and sex distribution are not specified in the abstract.
Future Directions: Test whether noninvasive neuromodulation targeting basal ganglia expedites emergence from volatile anesthesia in humans and map downstream circuits differentiating volatile vs i.v. agents.
BACKGROUND: Sevoflurane and propofol are the most widely used inhaled and i.v. general anaesthetics, respectively. The mechanisms by which sevoflurane and propofol induce loss of consciousness (LOC) remain unclear. Recent studies implicate the brain dopaminergic circuit in anaesthetic-induced LOC and the cortical-striatal-thalamic-cortical loop in decoding consciousness. We investigated the contribution of the dorsal striatum, which is a critical interface between the dopaminergic circuit and the cort
2. Comparative efficacy and safety of 20 intravenous pharmaceutical intervention for prevention of etomidate-induced myoclonus: a systematic review and Bayesian network meta-analysis.
Across 48 RCTs (n=4,768), granisetron and oxycodone ranked highest for preventing etomidate-induced myoclonus (OR≈0.01 vs placebo), including for moderate-to-severe events. Opioids overall had higher adverse event rates, though no severe AEs were reported. Sufentanil and remifentanil also performed well.
Impact: Provides the most comprehensive comparative evidence to date to guide prophylaxis against a common induction adverse effect.
Clinical Implications: Consider granisetron or oxycodone as leading options to reduce etomidate-induced myoclonus, balancing efficacy with the higher AE profile of opioids and individual patient risk.
Key Findings
- 48 RCTs (n=4,768) compared 20 IV interventions plus saline/placebo.
- Granisetron (OR 0.01, 95% CI 0.00–0.06) and oxycodone (OR 0.01, 95% CI 0.00–0.05) most effectively reduced overall EIM; top SUCRA ranks (94.4% and 89.7%).
- Sufentanil (76.5% SUCRA) and remifentanil (74.8%) also ranked highly.
- Opioids increased adverse events compared with controls; no severe AEs reported.
Methodological Strengths
- Broad, multi-database search and inclusion of 48 RCTs with Bayesian network meta-analysis enabling indirect comparisons.
- Subgroup analysis by myoclonus severity and safety synthesis across agents.
Limitations
- Certainty graded moderate-to-low for top agents; heterogeneity in dosing and outcome definitions.
- Potential publication bias and limited head-to-head trials for some comparisons.
Future Directions: Head-to-head RCTs comparing granisetron vs leading opioids with standardized dosing and safety endpoints; cost-effectiveness and patient-centered outcomes.
OBJECTIVE: To compare the efficacy and safety of pharmaceutical interventions to prevent etomidate-induced myoclonus (EIM), providing the optimal intervention for clinical practice. METHODS: PubMed, Embase, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Chinese National Knowledge Infrastructure, WanFang database, and SinoMed database were searched from the inception to sixth May 2024. We included randomized controlled trials (RCTs) comparing intravenous pharmaceutical interv
3. Intraoperative hypotension and its association with acute kidney injury in patients undergoing elective cardiac surgery: a large retrospective cohort study.
In 28,909 elective cardiac surgery patients, AKI occurred in 42.9%. Cumulative duration of intraoperative MAP <60 mmHg (episodes >2 min) was independently associated with higher AKI odds (OR 1.004 per minute; 95% CI 1.003–1.005). Findings support minimizing hypotension exposure time to mitigate renal risk.
Impact: Quantifies time-dependent hypotension risk for AKI in cardiac surgery, providing actionable targets for hemodynamic management and quality metrics.
Clinical Implications: Implement hemodynamic strategies to avoid sustained MAP <60 mmHg, including tighter vasoactive management and early detection/response protocols during bypass and off-pump phases.
Key Findings
- Retrospective cohort of 28,909 elective cardiac surgery patients (2009–2018).
- IOH defined as MAP <60 mmHg for >2 minutes; cumulative IOH duration recorded.
- AKI incidence 42.9%; each additional minute of IOH increased AKI odds (OR 1.004; 95% CI 1.003–1.005).
- Cumulative IOH duration was an independent risk factor for postoperative AKI.
Methodological Strengths
- Very large single-center cohort with standardized blood pressure definitions.
- Multivariable modeling to assess independent association of IOH duration with AKI.
Limitations
- Retrospective, single-center design limits causal inference and generalizability.
- Potential residual confounding (e.g., perfusion pressures during CPB, nephrotoxin exposure) not fully captured.
Future Directions: Prospective trials to test hypotension-avoidance protocols with time-under-threshold targets in cardiac surgery and evaluate downstream renal and long-term outcomes.
BACKGROUND: Intraoperative hypotension (IOH) is known to affect renal outcomes in noncardiac surgery. However, it is unclear whether intraoperative hypotension (IOH) causes postoperative acute kidney injury following cardiac surgery. OBJECTIVE: This study aimed to determine whether the duration of IOH during cardiac surgery is associated with the incidence of postoperative acute kidney injury (AKI) and identify its impact on long-term outcomes. DESIGN: Retrospective cohort study. SETTING: Academic univ