Daily Anesthesiology Research Analysis
Three impactful perioperative studies stand out today: a randomized, double-blind trial shows that adding dexmedetomidine-remifentanil to sevoflurane anesthesia in infants reduces volatile exposure but does not change neurodevelopment at 28–30 months; a large neurosurgical cohort links clindamycin prophylaxis to higher surgical site infection risk after clean craniotomy; and a mechanistic clinical study identifies 2-AG/MAGL-driven eicosanoid crosstalk as a driver of acute pain after total knee a
Summary
Three impactful perioperative studies stand out today: a randomized, double-blind trial shows that adding dexmedetomidine-remifentanil to sevoflurane anesthesia in infants reduces volatile exposure but does not change neurodevelopment at 28–30 months; a large neurosurgical cohort links clindamycin prophylaxis to higher surgical site infection risk after clean craniotomy; and a mechanistic clinical study identifies 2-AG/MAGL-driven eicosanoid crosstalk as a driver of acute pain after total knee arthroplasty, highlighting MAGL as a therapeutic target.
Research Themes
- Pediatric anesthesia neurodevelopmental safety
- Perioperative antibiotic prophylaxis and SSI risk
- Endocannabinoid–eicosanoid mechanisms in postoperative pain and novel targets
Selected Articles
1. Effects of Dexmedetomidine-Remifentanil on Neurodevelopment of Children after Inhalation Anesthesia: A Randomized Clinical Trial.
In a double-blind RCT of 400 infants/toddlers, adjunct dexmedetomidine–remifentanil reduced end-tidal sevoflurane by ~0.9 vol% but yielded no differences in full-scale IQ or behavior at 28–30 months versus sevoflurane alone. Anesthesia duration was similar between groups. The primary 5-year IQ endpoint is pending.
Impact: Addresses long-standing neurotoxicity concerns in pediatric anesthesia with rigorous randomization and clinically meaningful neurodevelopmental endpoints. Supports current practice by showing no early developmental harm despite reduced volatile exposure.
Clinical Implications: Clinicians need not alter anesthetic technique solely to mitigate putative neurotoxicity in infants; adjunct DEX–remifentanil can lower volatile concentration without changing early neurodevelopment. Continue to individualize based on hemodynamics and surgical needs while awaiting 5-year outcomes.
Key Findings
- End-tidal sevoflurane was lower with DEX–remifentanil adjunct vs control (1.8 vs 2.6 vol%; P<0.001).
- Full-scale IQ at 28–30 months did not differ (102.5 vs 103.6; mean difference −1.1; 95% CI −3.9 to 1.7; P=0.442).
- Child Behavior Checklist total scores were similar between groups.
- Anesthesia duration was comparable (77.1 vs 72.8 min; P=0.293).
Methodological Strengths
- Prospective, double-blind randomized design with assessor blinding.
- Standardized neurodevelopmental assessments and trial registration.
Limitations
- Primary endpoint at 5 years is pending; current results are secondary outcomes.
- Single-country setting and potential underpowering for small neurocognitive differences.
Future Directions: Report the prespecified 5-year IQ and comprehensive neurocognitive outcomes; evaluate dose–response relationships and applicability across different anesthetic regimens and healthcare settings.
BACKGROUND: Anesthetic exposure in young children raises concerns about neurodevelopmental safety, with preclinical evidence suggesting potential neurotoxicity of volatile anesthetics. This study aimed to assess whether the combination of dexmedetomidine and remifentanil, by reducing sevoflurane exposure, has any differential effect on neurodevelopmental outcomes in young children compared with sevoflurane alone. METHODS: This study was a prospective, double-blind, randomized clinical trial including children younger than 2 yr undergoing nonstaged, nonrepetitive surgeries. Participants received dexmedetomidine and remifentanil as adjuncts to sevoflurane (DEX-R group) or sevoflurane alone (control group). The study assessed their neurodevelopmental status at 28 to 30 months using the Korean Leiter International Performance Scale and the Child Behavior Checklist, as predefined secondary outcomes. The primary endpoint-full-scale IQ at 5 yr of age-will be reported after completion of long-term follow-up. RESULTS: Among 400 enrolled participants, 343 completed assessments (169 control, 176 DEX-R). There was no difference in the mean anesthesia duration between the control and DEX-R groups (77.1 min vs. 72.8 min; mean difference [95% CI], 4.4 [-3.8 to 12.6]; P = 0.293). The mean end-tidal sevoflurane concentration was significantly lower in the DEX-R group than in the control group (1.8 vol% vs. 2.6 vol%; mean difference [95% CI], -0.9 [-1.0 to -0.7] vol%; P < 0.001). The mean full-scale IQ score was 102.5 ± 11.5 in the DEX-R group and 103.6 ± 11.5 in the control group (mean difference, -1.1; 95% CI, -3.9 to 1.7; P = 0.442). No significant difference was observed in the Child Behavior Checklist total score between groups. CONCLUSIONS: The addition of dexmedetomidine and remifentanil to sevoflurane anesthesia was not associated with significant differences in neurodevelopmental outcomes at 28 to 30 months compared to sevoflurane alone.
2. Acute Pain After Total Knee Arthroplasty: 2-Arachidonoylglycerol Tone and Endocannabinoid/Eicosanoid Crosstalk.
In 90 TKA patients, higher intraoperative 2-AG in synovial fluid correlated with greater acute postoperative pain at rest and with ambulation, with stronger associations in females. Ex vivo MAGL inhibition increased 2-AG and reduced PGE2 in synovial tissue, positioning MAGL as a mechanistic node linking endocannabinoid and eicosanoid pathways in perioperative pain.
Impact: Provides mechanistic human data linking endocannabinoid tone to postoperative pain and identifies MAGL as a targetable enzymatic hub, offering a plausible pathway for non-opioid analgesic development.
Clinical Implications: Patients with elevated 2-AG tone may be at risk for worse acute pain after TKA; MAGL inhibition could reduce PGE2 biosynthesis and pain, meriting translational trials, potentially with sex-specific stratification.
Key Findings
- Synovial fluid 2-AG correlated with pain at rest (r=0.2644; P=.0157) and with ambulation (r=0.3856; P=.0005).
- CSF 2-AG correlated with pain at rest (r=0.3312; P=.0017) but not with ambulation.
- Associations were stronger in females than males.
- Ex vivo MAGL inhibition increased 2-AG (0.165→0.325 nmol/g; P=.0269) and reduced PGE2 (5.645→3.440 nmol/g; P=.0425) in synovial tissue.
Methodological Strengths
- Prospective human study with intraoperative sampling of CSF and synovial fluid.
- Mechanistic validation via ex vivo MAGL inhibition and COX-2 coexpression in human synovium.
Limitations
- Observational correlations cannot establish causality for clinical pain outcomes.
- Moderate sample size and sex-stratified analyses may be underpowered; ex vivo findings require in vivo confirmation.
Future Directions: Conduct randomized trials of MAGL inhibitors for postoperative analgesia, incorporate sex-specific stratification, and integrate perioperative 2-AG/PGE2 profiling to identify responders.
BACKGROUND: Total knee arthroplasty (TKA) is a surgical procedure that induces intense acute postoperative pain, but the mechanisms that amplify post-TKA pain remain incompletely understood. Endocannabinoids, such as 2-arachidonoylglycerol (2-AG), are endogenous lipids that can produce antinociceptive effects. However, hydrolysis of 2-AG by monoacylglycerol lipase (MAGL) generates arachidonic acid, the precursor to a host of eicosanoids that enhance pain. The presence of this metabolic pathway suggests that individuals with elevated 2-AG levels may be primed to develop greater postoperative pain. METHODS: The primary goal of this prospective study was to determine if intraoperative 2-AG levels in the synovial fluid (SF) and cerebrospinal fluid (CSF) of TKA patients are associated with the magnitude of acute postoperative pain at rest and with ambulation. The secondary goal was to determine whether 2-AG metabolism contributes to prostaglandin E2 (PGE2) biosynthesis in synovial tissue ex vivo. RESULTS: Ninety subjects were enrolled in the study. SF 2-AG was positively correlated with pain at rest (r = 0.2644; P = .0157) and with ambulation (r = 0.3856; P = .0005) while CSF 2-AG was associated with pain at rest (r = 0.3312; P = .0017) but not with ambulation (r = 0.1454; P =.1871). Stratification of the results by sex revealed positive correlations between 2-AG and pain in females, which were markedly weaker or not observed in males. Ex vivo analysis demonstrated coexpression of MAGL and cyclooxygenase-2 in synovial membranes, with MAGL inhibition by MJN110 elevating 2-AG levels (median, vehicle: 0.165 nmol/g vs MJN110: 0.325 nmol/g, P = .0269) and concomitantly reducing PGE2 (median, vehicle: 5.645 nmol/g vs MJN110: 3.440 nmol/g, P = .0425). CONCLUSIONS: Our findings demonstrate that patients presenting with an elevated 2-AG tone develop greater postoperative pain and position MAGL as an enzymatic node linking 2-AG metabolism with eicosanoid biosynthesis in perioperative human tissue.
3. Increased Risk of Surgical Site Infections With Clindamycin Prophylaxis in Clean Craniotomy.
Across 12,347 clean craniotomies, clindamycin prophylaxis was associated with higher SSI risk versus cefazolin (adjusted OR ~2.5; PSM OR 2.59) and higher 90-day revisions for infection, without differences in pathogen distribution. Findings support cefazolin as default prophylaxis even in patients with reported penicillin allergy, aligning with safety data on cefazolin cross-reactivity.
Impact: Large-scale, propensity-matched perioperative data provide actionable evidence against clindamycin prophylaxis for craniotomy, likely reducing SSI by steering practice toward cefazolin and penicillin-allergy delabeling strategies.
Clinical Implications: Adopt cefazolin as first-line prophylaxis for clean craniotomy; avoid clindamycin where possible. Implement penicillin allergy risk stratification/testing to enable cefazolin use, and reserve alternatives based on true allergy risk and local MRSA epidemiology.
Key Findings
- Among 12,347 patients, clindamycin use was associated with higher SSI risk (adjusted OR 2.52 [1.72–3.69]).
- Propensity score matching confirmed increased SSI (OR 2.59 [1.71–3.94]) and higher 90-day infection-related revision (OR 2.09 [1.23–3.54]).
- Overall SSI rate was 2.45%; common pathogens were Cutibacterium acnes (28.5%) and MSSA (24.5%), with no group differences.
Methodological Strengths
- Very large cohort with prospective SSI surveillance and detailed prophylaxis data.
- Robust analytical approach including multivariable adjustment and propensity score matching.
Limitations
- Retrospective design subject to residual confounding, including indication bias for antibiotic selection.
- Antibiotic dosing/timing details and allergy verification may be incomplete.
Future Directions: Prospective comparative studies or pragmatic trials of cefazolin vs alternatives in penicillin-allergy–labeled patients; implement and assess allergy delabeling pathways in neurosurgical populations.
BACKGROUND AND OBJECTIVES: Postoperative central nervous system infections remain a major complication following craniotomy, with reported incidence ranging from 2.2% to 9.6%. The administration of preoperative antibiotic prophylaxis, particularly cephalosporins, has significantly reduced these infections. However, in patients reporting a penicillin allergy, alternatives such as vancomycin or clindamycin are recommended despite ongoing concerns about their efficacy. Recent studies have associated clindamycin use with a higher risk of surgical site infections (SSI) in various surgical specialties. This study aimed to assess clindamycin impact on SSI prevention in clean craniotomy. METHODS: A retrospective analysis was conducted using a prospective surveillance database focused on SSI and antibiotic prophylaxis monitoring. Patients who underwent clean craniotomy between 2005 and 2020 were included. After univariate and multivariate analyses, we performed causal inference analysis with a propensity score matching to assess the excess risk of SSI. RESULTS: Among 12 347 patients, 93.8% received cefazolin and 6.2% clindamycin. The overall SSI rate was 2.45%. Clindamycin use significantly increased SSI risk in multivariate analysis (adjusted odds ratio adjusted: 2.52 [1.72-3.69]). The propensity score found increase of SSI rate (OR = 2.59 [1.71-3.94]) and of 90 days revision for infection (OR = 2.09 [1.23-3.54]). Other independent SSI risk factors included male sex, American Society of Anesthesiologists score ≥3, prolonged surgery, specific surgical diagnoses, and cerebrospinal fluid leakage, which was the strongest predictor (aOR = 38.51 [25.24-59.30]). The most frequently isolated pathogens were Cutibacterium acnes (28.5%) and methicillin-sensitive Staphylococcus aureus (24.5%). No significant differences were observed in bacterial distribution between antibiotic groups. CONCLUSION: Clindamycin use is associated with an increased risk of SSI in clean craniotomy. Its bacteriostatic nature, and the proven safety of cefazolin in penicillin-allergic patients support maintaining cefazolin as the preferred antibiotic for every clean craniotomy patient. The safety of modifying prophylaxis protocols should be prospectively evaluated to optimize postoperative infection prevention.