Daily Anesthesiology Research Analysis
Analyzed 73 papers and selected 3 impactful papers.
Summary
Three impactful anesthesiology studies stood out today: a secondary analysis of a large RCT used machine learning to identify which patients are most vulnerable to intraoperative hypotension if renin–angiotensin–aldosterone system inhibitors are continued; a randomized trial showed TLIP and retrolaminar blocks outperform paravertebral block for analgesia after lumbar disc surgery; and an openly shared fMRI dataset under graded propofol sedation enables investigation of covert consciousness during anesthesia.
Research Themes
- Personalized perioperative hemodynamic management
- Opioid-sparing regional anesthesia strategies
- Neural mechanisms of consciousness under anesthesia
Selected Articles
1. Impact of continuing renin-angiotensin-aldosterone system inhibitors before surgery on intraoperative hypotensive events: a secondary analysis of the STOP-or-NOT Trial.
In a secondary analysis of the STOP-or-NOT RCT, machine-learning-based heterogeneity of treatment effect revealed that the risk increase in intraoperative hypotension with continued RAAS inhibitors is not uniform. A high-risk subgroup (top 20%)—younger and with higher BMI—experienced the greatest hypotension risk difference, whereas a low-risk subgroup showed minimal impact.
Impact: This study operationalizes individualized perioperative management by quantifying who benefits from withholding RAAS inhibitors to avoid hypotension. It advances precision anesthesia through CATE-driven risk stratification.
Clinical Implications: Consider selective discontinuation of RAAS inhibitors in patients identified as high risk for intraoperative hypotension (e.g., younger, higher BMI) while allowing continuation in low-risk patients. Institutions can embed HTE-informed decision support into preoperative workflows.
Key Findings
- Significant heterogeneity of treatment effect for intraoperative hypotension with RAASi continuation was demonstrated in 2007 patients.
- High-risk subgroup (top 20%) showed a CATE risk difference of 0.172 and tended to be younger with higher BMI.
- Machine-learning-derived CATE enabled stratification into high-, medium-, and low-risk groups for tailored perioperative management.
Methodological Strengths
- Secondary analysis of a large multicenter randomized controlled trial with prespecified outcome definition.
- Use of modern machine-learning methods (CATE) to quantify heterogeneity of treatment effect.
Limitations
- Secondary analysis; not randomized to HTE-derived strategies and potential for residual confounding.
- Abstract truncation limits detailed characterization of all risk features; external validation needed.
Future Directions: Prospective trials testing HTE-guided RAASi management pathways and integration into clinical decision support to reduce hypotension without increasing postoperative complications.
BACKGROUND: The multicentre STOP-or-NOT trial has shown that continuation of renin-angiotensin-aldosterone inhibitors (RAASis) before major noncardiac surgery did not increase the rate of postoperative complications, but led to a higher incidence of intraoperative hypotension. However, the risk of intraoperative hypotension could vary significantly between patients. We evaluated whether there is heterogeneity in the risk of intraoperative hypotension among patients who continue vs those who discontinue RAASi therapy before major surgery. METHODS: We conducted a secondary analysis of the STOP-or-NOT trial. The primary outcome was intraoperative hypotension (defined as a mean arterial pressure <60 mm Hg) requiring vasopressor administration. We assessed for the presence of significant heterogeneity of treatment effect (HTE). When HTE was statistically significant, we estimated the conditional average treatment effect (CATE) using a machine learning approach. On the basis of CATE estimates, patients were stratified into three risk groups: high-risk (top 20%), low-risk (bottom 5%), and medium-risk (remaining 75%). RESULTS: Among 2007 patients, there was a statistically significant HTE for the risk of hypotension. Compared with the low-risk group, patients in the high-risk group (CATE risk difference, 0.172 [0.161-0.179]) were younger (62 vs 69 yr; P<0.001) and had a higher BMI (34 vs 27k m CONCLUSIONS: Our analysis supports the existence of significant heterogeneity in the risk of intraoperative hypotension associated with the continuation of RAASi therapy before major noncardiac surgery. CLINICAL TRIAL REGISTRATION: NCT03374449.
2. An open fMRI resource for studying human brain function and covert consciousness under anesthesia.
This openly shared fMRI dataset under graded propofol sedation includes mental imagery tasks that reveal instances of volitional imagery despite behavioral unresponsiveness. It enables mechanistic exploration of anesthesia-induced unconsciousness and covert consciousness with standardized, BIDS-compliant data.
Impact: Provides a rare, high-quality open dataset capturing covert consciousness signals under anesthesia, bridging clinical disorders-of-consciousness paradigms with anesthetic neuroscience.
Clinical Implications: While not immediately practice-changing, the dataset can inform development of biomarkers and monitoring strategies to detect covert consciousness or refine anesthetic depth assessment.
Key Findings
- An open fMRI dataset from 26 volunteers performing mental imagery and motor tasks under graded propofol sedation is released via OpenNeuro (BIDS-compliant).
- Dataset includes cases of volitional mental imagery despite behavioral unresponsiveness, enabling study of covert consciousness.
- Prior analyses using the dataset highlight anterior insula involvement in conscious access and asymmetric neural dynamics across loss and recovery of consciousness.
Methodological Strengths
- Standardized mental imagery paradigms with graded sedation levels in healthy volunteers.
- Openly shared, BIDS-formatted dataset enabling reproducibility and secondary analyses.
Limitations
- Small sample size and healthy volunteer population limit generalizability to surgical patients.
- Propofol-only paradigm and fMRI modality may not capture multimodal or anesthetic-agent–specific dynamics.
Future Directions: Extend to clinical cohorts (surgical or ICU), integrate EEG/fNIRS for multimodal decoding, and develop real-time classifiers for covert consciousness under anesthesia.
Anesthesia has revolutionized surgical practice and offers a controlled model to study the neurobiology of consciousness. Functional magnetic resonance imaging (fMRI) studies have shown that anesthesia primarily disrupts connectivity across association cortices, suggesting that impaired integration between higher-order brain regions underlies unconsciousness. However, traditional fMRI paradigms are limited in detecting covert consciousness. Here, we present an fMRI dataset acquired from 26 healthy volunteers performing mental imagery tasks (tennis, navigation, and hand squeeze) and a motor response task under graded propofol sedation. The dataset captures brain activity across varying sedation levels, including instances of volitional mental imagery despite behavioral unresponsiveness. Prior analyses using this dataset have investigated the anterior insula's role in conscious access and asymmetric neural dynamics during loss and recovery of consciousness. This openly available dataset, formatted according to BIDS standards and has been released via OpenNeuro, provides a resource for exploring the neural mechanisms of anesthesia and consciousness with the unique feature of mental imagery, traditionally used only during assessment of disorders of consciousness.
3. Comparison of paravertebral, thoracolumbar interfascial plane, and retrolaminar blocks for postoperative analgesia in lumbar disc herniation surgery: A randomized controlled trial.
In patients undergoing lumbar disc herniation surgery, TLIP and retrolaminar blocks provided superior analgesia at all measured time points versus paravertebral block and control, reduced opioid rescue, and improved early recovery. Motor block was most frequent with paravertebral block and lowest with retrolaminar block.
Impact: Directly informs block selection for spine surgery analgesia with a pragmatic RCT comparing three widely used techniques plus control.
Clinical Implications: Consider TLIP or retrolaminar blocks as part of multimodal analgesia for lumbar disc surgery to reduce opioid use and improve quality of recovery; retrolaminar may minimize motor block risk.
Key Findings
- TLIP and retrolaminar blocks achieved significantly lower VAS pain scores than paravertebral block and control at 0–24 hours postoperatively (P < .001).
- Rescue morphine consumption was significantly lower in TLIP and retrolaminar groups (P < .001).
- Quality of Recovery-40 scores were highest with TLIP and retrolaminar; motor block incidence was highest with paravertebral (26.7%) and lowest with retrolaminar (8.9%).
Methodological Strengths
- Prospective randomized controlled design with four arms including an active control.
- Ultrasound-guided blocks performed under expert supervision with multiple validated outcomes.
Limitations
- Single-center study with 24-hour follow-up; long-term analgesic benefits and functional outcomes not assessed.
- Blinding of interventions and assessors not detailed, potential performance/detection bias.
Future Directions: Multicenter, blinded trials assessing longer-term outcomes, cost-effectiveness, and integration into enhanced recovery pathways.
BACKGROUND: The goal of this prospective randomized controlled experiment was comparing the analgesic efficacy, opioid needs, and adverse effect profiles of paravertebral (PVB) block, thoracolumbar interfascial plane (TLIP) block, and retrolaminar (RLB) block in patients undergoing lumbar disc herniation surgery. METHODS: One hundred eighty-five adults (American Society of Anesthesiologists I-III) undergoing elective lumbar disc herniation surgery made up this single-center study. Among the exclusion criteria were coagulation problems, injection site infection, allergy to local anesthetics, and incapacity to provide informed consent. Patients were randomly assigned into 4 groups: control (systemic analgesia only), PVB, TLIP, and RLB (45 patients per group). An expert anesthesiologist supervised the ultrasonography during each block. The visual analog scale was used to measure postoperative pain at 0, 1, 2, 6, 12, and 24 hours after surgery. This was the primary outcome. Motor block incidence, rescue morphine consumption, and quality of recovery-40 scores at 24 hours were secondary objectives. Unfavorable incidents were noted. Analysis of variance and Kruskal-Wallis tests (P < .05) were used to examine the data. RESULTS: At every time point, the TLIP and RLB groups' visual analog scale scores were significantly lower than those of the PVB and control groups (P < .001). The TLIP and RLB groups consumed considerably less rescue morphine (P < .001). The TLIP and RLB groups had the highest quality of recovery-40 scores (P < .001). The PVB group had the highest incidence of motor block (26.7%), whereas the RLB group had the lowest rate (8.9%). There were no significant adverse effects noted. CONCLUSION: Compared to PVB and control group, TLIP and RLB provide better and longer postoperative analgesia, smaller opioid needs, and higher-quality recovery. Their importance in improved recovery regimens following lumbar disc herniation surgery is supported by their good safety profile.