Daily Anesthesiology Research Analysis
A double-blind RCT (n=200) shows that pre-emptive ketamine reduces the incidence of chronic post-thoracotomy pain—especially neuropathic features—without lowering in-hospital opioid use. A network meta-analysis finds no meaningful differences between TIVA, volatile anesthesia, and conscious sedation for endovascular stroke therapy outcomes. A meta-research study shows that large language models, including a specialized model, currently underperform expert-crafted search strings for anesthesiolog
Summary
A double-blind RCT (n=200) shows that pre-emptive ketamine reduces the incidence of chronic post-thoracotomy pain—especially neuropathic features—without lowering in-hospital opioid use. A network meta-analysis finds no meaningful differences between TIVA, volatile anesthesia, and conscious sedation for endovascular stroke therapy outcomes. A meta-research study shows that large language models, including a specialized model, currently underperform expert-crafted search strings for anesthesiology systematic reviews.
Research Themes
- Perioperative pain prevention and chronic postsurgical pain
- Anesthetic strategy for neurointerventional stroke care
- AI/LLMs in evidence synthesis for anesthesiology
Selected Articles
1. Perioperative ketamine to reduce and prevent acute and chronic post-thoracotomy pain: a randomized, double-blind, placebo-controlled clinical trial.
In a double-blind RCT of 200 thoracotomy patients, pre-emptive ketamine reduced the incidence of chronic post-thoracotomy pain—particularly neuropathic features—without reducing in-hospital opioid consumption or NRS scores beyond the immediate 6-hour period. The study supports ketamine’s role in preventing chronic postsurgical neuropathic pain after thoracotomy.
Impact: This trial addresses a major unmet need: prevention of chronic post-thoracotomy pain, a frequent and debilitating complication. The findings may change perioperative analgesic protocols for thoracic surgery.
Clinical Implications: Consider incorporating pre-emptive ketamine into thoracotomy analgesic pathways to reduce chronic neuropathic pain risk, with the understanding that acute opioid requirements may not decrease.
Key Findings
- Pre-emptive ketamine reduced coughing-related pain in the first 6 postoperative hours versus placebo.
- No difference in NRS pain scores at rest or with coughing on PODs 1–8 and no reduction in opioid consumption.
- Significantly lower incidence of chronic postoperative pain with neuropathic features (S-LANSS ≥12 at 30 days) in the ketamine group.
Methodological Strengths
- Randomized, double-blind, placebo-controlled design with trial registration (NCT03105765).
- Standardized neuropathic pain assessment using LANSS/S-LANSS at defined timepoints up to 90 days.
Limitations
- Single trial with limited detail on dosing regimen in the abstract; external generalizability needs confirmation.
- Telephone survey for S-LANSS at follow-up may introduce reporting bias; acute pain endpoints showed no sustained benefit.
Future Directions: Define optimal ketamine dosing/timing, explore patient subgroups most likely to benefit, and assess longer-term outcomes beyond 90 days and multimodal combinations.
BACKGROUND: Moderate to severe postoperative pain is common among patients following thoracotomy and serves as a risk factor for developing chronic post-thoracotomy pain (CPTP). This randomized controlled trial evaluated the effects of pre-emptively administered ketamine compared to placebo and standard care on both acute postoperative pain and CPTP. METHODS: Two hundred patients were enrolled in this prospective, randomized trial. The presence and severity of pain were assessed before surgery, first 6 hours after surgery, on postoperative days (PODs) 1-8, 30, and 90. For documentation of neuropathic pain, the Leeds Assessment Score for Neuropathic Symptoms and Signs (LANSS) was used pre- and postoperatively. The incidence and severity of CPTP was assessed by a telephone survey, the self-assessment LANSS (S-LANSS) 30 and 90 days after surgery. RESULTS: There was significant difference in numeric rating scale (NRS) pain scores when coughing in the first 6 hours after surgery, with less pain in the ketamine group. No difference was seen in NRS pain scores at rest and coughing between the ketamine and placebo group on PODs 1-8. There was no difference in the opioid consumption between the two groups. Thirty-four (18.7%) of the patients had a S-LANSS score ≥12 30 days following surgery, 12 (12.8%) in the ketamine group CONCLUSIONS: In summary, pre-emptive ketamine does not reduce opioid consumption and NRS scores after thoracotomy but more importantly it lowers significantly the incidence of chronic postoperative pain, especially neuropathic pain. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (NCT03105765).
2. Evaluating the utility of large language models in generating search strings for systematic reviews in anesthesiology: a comparative analysis of top-ranked journals.
Across 85 anesthesiology SRs, expert-crafted search strings recovered substantially more target studies than LLM-generated strings. A structured, PICO-aligned LLM (Meta-Analysis Librarian) outperformed a general-purpose LLM (ChatGPT 4o) but still lagged behind human-authored strategies.
Impact: This meta-research directly informs how anesthesiology teams should (and should not) leverage LLMs in evidence synthesis, a rapidly evolving and high-stakes methodological domain.
Clinical Implications: For systematic reviews and guidelines, retain information specialists and validated search methodologies; LLM outputs may be useful adjuncts but require expert oversight and validation.
Key Findings
- Original (human-authored) search strings achieved a median 65% retrieval rate, significantly outperforming LLMs.
- The specialized PICO-based Meta-Analysis Librarian (median 24%) outperformed ChatGPT 4o (median 6%) but remained inferior to expert strategies.
- Results highlight the current limitations of LLMs for PubMed retrieval in anesthesiology SRs.
Methodological Strengths
- Large comparative sample of 85 SRs from top anesthesiology journals.
- Objective benchmark using original SR search results and standardized, PICO-aligned prompts.
Limitations
- Evaluation limited to PubMed; performance across other databases remains unknown.
- Retrieval rate metric depends on original SR search results as the reference, which may themselves be imperfect.
Future Directions: Test hybrid human-LLM workflows, expand to multi-database environments, and refine domain-specific models trained on high-quality search strategies.
BACKGROUND: This study evaluated the effectiveness of large language models (LLMs), specifically ChatGPT 4o and a custom-designed model, Meta-Analysis Librarian, in generating accurate search strings for systematic reviews (SRs) in the field of anesthesiology. METHODS: We selected 85 SRs from the top 10 anesthesiology journals, according to Web of Science rankings, and extracted reference lists as benchmarks. Using study titles as input, we generated four search strings per SR: three with ChatGPT 4o using general prompts and one with the Meta-Analysis Librarian model, which follows a structured, Population, Intervention, Comparator, Outcome-based approach aligned with Cochrane Handbook standards. Each search string was used to query PubMed, and the retrieved results were compared with the PubMed retrieved studies from the original search string in each SR to assess retrieval accuracy. Statistical analysis compared the performance of each model. RESULTS: Original search strings demonstrated superior performance with a 65% (IQR: 43%-81%) retrieval rate, which was statistically different from both LLM groups in PubMed retrieved studies (p=0.001). The Meta-Analysis Librarian achieved a superior median retrieval rate to ChatGPT 4o (median, (IQR); 24% (13%-38%) vs 6% (0%-14%), respectively). CONCLUSION: The findings of this study highlight the significant advantage of using original search strings over LLM-generated search strings in PubMed retrieval studies. The Meta-Analysis Librarian demonstrated notable superiority in retrieval performance compared with ChatGPT 4o. Further research is needed to assess the broader applicability of LLM-generated search strings, especially across multiple databases.
3. Comparing General Anesthesia-Based Regimens for Endovascular Treatment of Acute Ischemic Stroke: A Systematic Review and Network Meta-Analysis.
Across 15 studies (n=3015), no significant differences were found between TIVA and volatile anesthesia—or versus conscious sedation—on 90-day functional recovery, mortality, successful recanalization, or recanalization time during endovascular stroke therapy. The analysis was underpowered for agent-specific effects.
Impact: Findings support flexibility in anesthetic strategy for EVT, focusing attention on workflow, monitoring, and patient selection rather than anesthetic class.
Clinical Implications: Both TIVA and volatile anesthesia (and conscious sedation) appear acceptable for EVT; choose based on patient factors, airway and hemodynamic control needs, and logistics, while recognizing current data are underpowered for agent-level differences.
Key Findings
- No significant difference between TIVA and volatile anesthesia in 90-day mRS≤2, mortality, recanalization success, or procedure time.
- No significant differences between conscious sedation and either TIVA or volatile on the same endpoints.
- Network meta-analysis suggests anesthetic regimen does not drive EVT outcomes, though the analysis was underpowered for agent-specific effects.
Methodological Strengths
- Comprehensive multi-database search and use of network meta-analysis to integrate varied comparisons.
- Large aggregate sample (n=3015) including both GA and conscious sedation comparators.
Limitations
- Only three studies directly compared TIVA vs volatile; heterogeneity and underpowering limit definitive conclusions.
- Mix of study designs; residual confounding and selection bias may remain.
Future Directions: Prospective randomized trials directly comparing anesthetic agents in EVT with stratification by patient and procedural factors; standardized peri-procedural management protocols.
BACKGROUND: Total intravenous anesthesia (TIVA)-based and volatile-based general anesthesia have different effects on cerebral hemodynamics. The current work compares these 2 regimens in acute ischemic stroke patients undergoing endovascular therapy. METHODS: We conducted a systematic literature search across MEDLINE, Embase, Cochrane, CINAHL, Web of Science, and Scopus. We identified English language studies including adult acute ischemic stroke patients managed with endovascular therapy under general anesthesia delineable into TIVA only and/or volatile only, and obtained categorical data for favorable functional outcomes using the modified Rankin scale (mRS ≤2), at 90 days after endovascular therapy. Odds ratios (OR) and standardized mean differences were calculated to inform a network meta-analysis approach, which permitted the inclusion of studies comparing a form of general anesthesia (ie, TIVA only or volatile only) to conscious sedation. RESULTS: The search rendered 6235 articles, of which 15 met inclusion criteria. Three studies directly investigated TIVA versus volatile, whereas 12 studies compared general anesthesia to conscious sedation. The total number of subjects was 3015 (conscious sedation: n = 1067; general anesthesia: n = 1948 [TIVA: n = 1212, volatile: n = 736]). No significant differences were identified between TIVA and volatile groups in 90-day neurological outcome (OR = 1.25, 95% confidence interval [CI], 0.81-1.91; P = .31), 90-day mortality (OR = 0.72, 95% CI, 0.42-1.24; P = .24), successful recanalization (OR = 1.33, 95% CI, 0.70-2.52; P = .39), or recanalization time (standardized mean difference = 0.03, 95% CI, -0.35 to 0.41; P = .88). Additionally, no significant differences were identified between the conscious sedation group and the TIVA group in 90-day neurological outcome (OR = 1.14, 95% CI, 0.84-1.53; P = .40), 90-day mortality (OR = 0.87, 95% CI, 0.62-1.23; P = .43), successful recanalization (OR = 0.76, 95% CI, 0.52-1.10; P = .15), or recanalization time (standardized mean difference = -0.18, 95% CI, -0.47 to 0.11; P = .23), and between the conscious sedation group and the volatile group in 90-day neurological outcome (OR = 1.42, 95% CI, 0.92-2.17; P = .11), 90-day mortality (OR = 0.63, 95% CI, 0.36-1.12; P = .11), successful recanalization (OR = 1.01, 95% CI, 0.52-1.94; P = .98), or recanalization time (standardized mean difference = -0.15, 95% CI, -0.52 to 0.23; P = .44). CONCLUSIONS: This network meta-analysis showed that the perioperative use of either general anesthesia-based regimen, or sedation, did not significantly impact various endovascular therapy-related outcomes. However, the current work was underpowered to detect differences in anesthetic agents, clinico-demographic characteristics, or procedural factors.