Daily Anesthesiology Research Analysis
Across anesthesiology-relevant studies, perioperative neurocognitive outcomes improved with targeted sedative choices: a meta-analysis showed esketamine reduces postoperative delirium and delayed neurocognitive recovery, while a randomized trial found dexmedetomidine sedation under regional anesthesia markedly lowers delirium, emergence agitation, and early POCD in older adults. Conversely, a randomized trial reported that adding perineural dexamethasone to ropivacaine for interscalene block pro
Summary
Across anesthesiology-relevant studies, perioperative neurocognitive outcomes improved with targeted sedative choices: a meta-analysis showed esketamine reduces postoperative delirium and delayed neurocognitive recovery, while a randomized trial found dexmedetomidine sedation under regional anesthesia markedly lowers delirium, emergence agitation, and early POCD in older adults. Conversely, a randomized trial reported that adding perineural dexamethasone to ropivacaine for interscalene block provided no additional analgesic benefit, underscoring the need to re-evaluate routine adjunct use.
Research Themes
- Perioperative neurocognitive protection with anesthetic adjuncts
- Optimization of sedation strategies under regional anesthesia in older adults
- Reappraisal of perineural steroid adjuvants for peripheral nerve blocks
Selected Articles
1. Impact of perioperative esketamine on the perioperative neurocognitive dysfunction: a systematic review and meta-analysis of randomised controlled studies.
Across 10 RCTs (n=854), perioperative esketamine halved the risk of postoperative delirium and reduced delayed neurocognitive recovery without increasing adverse events or length of stay; effects on 3-month neurocognitive outcomes were not significant. Pain on postoperative day 1 was also reduced.
Impact: Provides level I evidence that esketamine reduces short-term neurocognitive complications, directly informing anesthetic adjunct selection for high-risk patients.
Clinical Implications: Consider low-dose esketamine as part of multimodal anesthesia/analgesia to mitigate postoperative delirium and delayed neurocognitive recovery in adults, while counseling that long-term cognitive outcomes at 3 months may be unchanged.
Key Findings
- Reduced postoperative delirium: RR 0.46 (95% CI 0.30–0.71)
- Reduced delayed neurocognitive recovery: RR 0.41 (95% CI 0.21–0.78)
- No significant difference in 3-month postoperative neurocognitive disorder
- Lower pain severity on postoperative day 1; no increase in adverse events or hospital length of stay
Methodological Strengths
- Rigorous meta-analysis of RCTs with GRADE assessment
- Random-effects modeling and Cochrane risk-of-bias evaluation
Limitations
- Heterogeneity in dosing regimens and perioperative contexts
- Limited data on long-term (≥3 months) neurocognitive outcomes
Future Directions: Head-to-head dosing trials, standardized protocols, and longer follow-up are needed to define optimal esketamine regimens and their impact on long-term cognition.
OBJECTIVES: The effect of esketamine on perioperative neurocognitive dysfunction (PND) remains controversial. This systematic review and meta-analysis aimed to evaluate the impact of perioperative esketamine administration on PND. DESIGN: Systematic review and meta-analysis. DATA SOURCES: PubMed, EMBASE, Web of Science and Cochrane Library were searched from their inception to 25 April 2024. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included the randomised controlled trials (RCTs) that compared single or continuous intravenous infusion of esketamine to saline among adult surgical patients without pre-existing neurocognitive disorders. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted pertinent information from the included studies. Risk of bias was assessed using Cochrane's risk of bias criteria. Risk ratios (RRs) and their corresponding 95% CIs were synthesised using a random-effects model. The overall evidence quality was appraised using the Grading of Recommendations Assessment, Development and Evaluation framework. RESULTS: 10 RCTs were included in our meta-analysis, involving 854 surgical patients. Perioperative esketamine was associated with a reduced risk of postoperative delirium (POD) (relative risk (RR): 0.46, 95% CI: 0.30 to 0.71, p<0.001) and delayed neurocognitive recovery (dNCR) (RR: 0.41, 95% CI: 0.21 to 0.78, p<0.001). However, no statistically significant difference was found in the risk of postoperative neurocognitive disorder (post-NCD) at 3 months postsurgery between the esketamine and control groups (RR: 0.57, 95% CI: 0.19 to 1.73, p=0.40). Additionally, pain severity was reduced on postoperative day 1, with no difference in the risk of adverse events or length of hospital stay. CONCLUSION: Perioperative esketamine reduces the risk of short-term PND, including POD and dNCR, without significantly affecting the incidence of adverse events or length of hospital stay. However, no significant differences were observed in the risk of post-NCD at 3 months following surgery. This systematic review and meta-analysis offers valuable data for PND research and clinical drug intervention strategies. PROSPERO REGISTRATION NUMBER: CRD42024538438.
2. A Randomized Clinical Trial of Dexmedetomidine on Delirium, Cognitive Dysfunction, and Sleep After Non-Ambulatory Orthopedic Surgery With Regional Anesthesia.
In older adults undergoing major lower-limb surgery under regional anesthesia, dexmedetomidine sedation (vs propofol) dramatically reduced POD (4.8% vs 38.4%), ED (2.4% vs 38.4%), and early POCD (2.4% vs 56.4%). Dexmedetomidine also improved immediate postoperative sleep and lowered 3-month pain scores, at the cost of more bradycardia/hemodynamic instability.
Impact: Provides randomized, double-blind evidence that a specific sedative choice under regional anesthesia can substantially reduce neurocognitive complications and improve sleep and pain outcomes in older adults.
Clinical Implications: For elderly patients receiving regional anesthesia, consider dexmedetomidine sedation to lower POD/ED/early POCD and improve sleep; implement vigilant hemodynamic monitoring and bradycardia management protocols.
Key Findings
- POD reduced from 38.4% to 4.8% with dexmedetomidine
- ED reduced from 38.4% to 2.4%; early POCD reduced from 56.4% to 2.4%
- Improved immediate postoperative PSQI and lower 3-month painDETECT scores
- Increased intraoperative bradycardia/hemodynamic instability with dexmedetomidine; airway obstruction occurred in 2.4% vs 30.8%
Methodological Strengths
- Double-blind randomized controlled design with active comparator
- Validated tools for delirium (CAM), agitation (Riker), cognition, sleep, and pain
Limitations
- Single-center, modest sample size (n=80)
- Regional anesthesia context may limit generalizability to general anesthesia cases
Future Directions: Multicenter trials to confirm external validity, dose-finding to balance neurocognitive benefit and hemodynamic risk, and cost-effectiveness analyses.
BACKGROUND: Postoperative delirium (POD), emergence delirium (ED), and postoperative cognitive dysfunction (POCD) are disorders of the neuropsychiatric spectrum affecting the elderly during the postoperative period, potentially sharing a common pathophysiological pathway. Disrupted sleep postoperatively correlates with both POD and POCD, revealing overlapping risk factors. This study investigates the potential of dexmedetomidine anesthesia to reduce the incidence of POD (primary outcome), ED, POCD, impairment of sleep quality, and emergent chronic pain (secondary outcomes) in older adults undergoing major orthopedic surgery under regional anesthesia. METHODS: In this double-blind randomized control trial, patients scheduled for major lower limb orthopedic surgery under regional anesthesia were randomized to receive either dexmedetomidine or propofol for sedation at a 1:1 ratio. POD, ED, and POCD were assessed with the Confusion Assessment Method tool, the Riker Sedation-Agitation scale, and the European Battery of psychometric tests, respectively. Sleep quality was assessed using the Pittsburg Sleep Quality Index and chronic pain with the painDETECT tool. Assessments of all outcome variables were performed before surgery, and at 48 hours and 3 months postoperatively. RESULTS: A total of 80 patients (dexmedetomidine group n = 41) were enrolled in the study and completed the follow-up. POD, ED, and early POCD incidence were significantly lower in dexmedetomidine compared to propofol group (4.8% vs 38.4%, P = .001; 2.4% vs 38.4%, P < .001; 2.4% vs 56.4%, P < .001, respectively). Patients in the dexmedetomidine group reported improved sleep quality in the immediate postoperative period (lower PSQI score) and lower painDETECT scores at 3 months (4.4 ± 0.7 vs 13.4 ± 0.8, P < .001; 2.4 ± 0.9 vs 5.3 ± 0.9, P = .023, respectively). Intraoperative bradycardia and hemodynamic instability episodes were more common in the dexmedetomidine group while a single patient presented airway obstruction (2.4% vs 30.8%, P = .002) in the dexmedetomidine group. CONCLUSIONS: Sedation with dexmedetomidine resulted in a statistically and clinically important reduction in the incidence of POD, ED, and early POCD, while it improved self-reported postoperative sleep quality and reduced chronic pain scores in patients undergoing major elective lower limb surgery under regional anesthesia.
3. Postoperative Analgesia Effect Evaluation of Perineural Dexamethasone Plus Various Doses of Ropivacaine in Interscalene Brachial Plexus Block: A Randomized Controlled Trial.
In 140 patients undergoing shoulder arthroscopy with interscalene block and general anesthesia, adding 5 mg perineural dexamethasone to 0.25%, 0.5%, or 0.75% ropivacaine did not prolong analgesia duration nor improve pain scores or PONV compared with ropivacaine alone. Complication rates were similar.
Impact: Challenges a common practice of perineural steroid adjuvant use for interscalene block by showing no additive analgesic benefit across clinically used ropivacaine concentrations.
Clinical Implications: Routine perineural dexamethasone addition to interscalene block for shoulder arthroscopy may be unnecessary; focus on optimizing local anesthetic concentration/volume and multimodal systemic analgesia.
Key Findings
- No prolongation of analgesia with 5 mg perineural dexamethasone across 0.25%, 0.5%, 0.75% ropivacaine
- No significant differences in NRS pain scores or PONV between dexamethasone and control arms
- Similar intraoperative and postoperative complication rates among all groups
Methodological Strengths
- Randomized multi-arm comparison across clinically relevant ropivacaine concentrations
- Predefined primary endpoint (analgesia duration) with standardized ultrasound-guided technique
Limitations
- Single dose of dexamethasone (5 mg) tested; dose–response not explored
- General anesthesia co-administration may confound postoperative analgesic assessments
Future Directions: Evaluate different dexamethasone doses/routes (perineural vs IV), continuous catheter techniques, and patient-centered outcomes (rebound pain, function).
OBJECTIVES: Interscalene brachial plexus block (ISBPB) has gained popularity as a pain-relief method following shoulder arthroscopic surgery, significantly reducing the need for analgesics. This study was designed to evaluate whether the addition of dexamethasone to different effective concentrations of ropivacaine in ultrasound-guided ISBPB affects postoperative analgesic effect in patients undergoing shoulder arthroscopy surgery. MATERIALS AND METHODS: A total of 140 participants elected for shoulder arthroscopy under ISBPB and general anesthesia, randomized into 6 equal groups. Group A, B, and C received 10 mL 0.25%, 0.5%, and 0.75% ropivacaine mixed with 1 mL 0.9% saline, respectively. Likewise, groups A1, B1, and C1 received the same volumes of ropivacaine with 5 mg dexamethasone. The primary goal was to assess the duration of analgesia with ISBPB, with secondary objectives concerning postoperative nausea and vomiting (PONV) and numerical rating scale (NRS) pain scores. RESULTS: Across a range of ropivacaine concentrations, there was no significant difference in the analgesic efficacy between participants receiving dexamethasone treatment and those who did not. Notably, there was no demonstrable difference in the duration of analgesia among the treatment groups (group A vs. group A1: 510.13±262.39 min, 518.21±395.49 min; P =0.054); (group B vs. group B1: 672.42±306.63 min, 646.05±348.48 min; P =0.281); (group C vs. group C1: 724.42±384.14 min, 680.29±414.30 min; P =0.782). Furthermore, there was no significant difference in the incidence of intraoperative and postoperative complications. CONCLUSION: The present study indicated that the addition of dexamethasone to ropivacaine did not appear to provide any additional advantages in postoperative analgesic efficacy compared with the use of ropivacaine alone for patients undergoing shoulder arthroscopy surgery with ISBPB.