Daily ReportOct 31, 2026
Anesthesiology, October 31 edition
We read 24 papers and selected 3.
Summary
Today’s most impactful anesthesiology research centered on postoperative delirium prevention, hemodynamic optimization in older surgical patients, and opioid-sparing regional analgesia. The evidence included an updated meta-analysis of 22 randomized controlled trials, a prospective randomized trial showing that remimazolam improves hemodynamic stability without reducing delirium, and a randomized trial evaluating sequential lidocaine and liposomal bupivacaine for foot and ankle surgery.
Research Themes
- Postoperative delirium prevention and geriatric anesthesia
- Hemodynamic stability during induction of anesthesia
- Extended regional analgesia and functional recovery
Selected Articles
1. Effects of perioperative dexmedetomidine on postoperative delirium in older surgical patients: an updated meta-analysis of randomized controlled trials.
This PROSPERO-registered meta-analysis included 22 randomized controlled trials involving 4161 older surgical patients. Perioperative dexmedetomidine reduced postoperative delirium by approximately 44% and also reduced postoperative nausea and vomiting, but increased intraoperative and postoperative bradycardia and intraoperative hypotension.
Impact: The study provides the strongest aggregate evidence in this set that dexmedetomidine can prevent postoperative delirium, while clearly quantifying clinically important cardiovascular trade-offs. Its findings support risk-stratified rather than indiscriminate use in older patients.
Clinical Implications: Perioperative dexmedetomidine may be considered for delirium prevention in selected older surgical patients, particularly when bradycardia and hypotension can be actively monitored and managed. Dose selection and patient-specific cardiovascular risk assessment remain essential.
Key Findings
- Twenty-two randomized controlled trials involving 4161 patients were included.
- Dexmedetomidine reduced postoperative delirium incidence (RR 0.56, 95% CI 0.47-0.66; P < 0.00001; I² = 24%).
- Dexmedetomidine reduced postoperative nausea and vomiting but increased bradycardia and intraoperative hypotension.
Methodological Strengths
- Systematic integration of 22 randomized controlled trials with 4161 participants.
- Low statistical heterogeneity for the primary delirium outcome and prospective PROSPERO registration.
Limitations
- The included trials may differ in dexmedetomidine dose, timing, surgical populations, and delirium assessment protocols.
- The meta-analysis cannot fully establish the optimal dose or identify which cardiovascular-risk subgroups derive the greatest net benefit.
Future Directions: Future trials should compare standardized dosing strategies, incorporate patient-centered delirium severity and duration outcomes, and define cardiovascular safety thresholds for high-risk older adults.
STUDY OBJECTIVE: To evaluate the efficacy of perioperative intravenous dexmedetomidine in preventing postoperative delirium (POD) in older surgical patients. METHODS: A comprehensive literature search was performed across three authoritative databases: PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to July 7, 2026, included all available RCTs evaluating the effect of dexmedetomidine on POD in older surgical patients undergoing general anesthesia. The primary outcome was the incidence of POD. Secondary outcomes encompassed adverse events, including PONV, intraoperative and postoperative bradycardia and intraoperative and postoperative hypotension. The study was registered in the PROSPERO database under the identifier CRD420251001512. RESULTS: A total of 22 RCTs, involving 4161 patients, were included in the analysis.
2. Remimazolam versus propofol for elderly patients undergoing laparoscopic gastrointestinal surgery: a randomized trial concentrating on delirium and hemodynamic stability.
In this prospective randomized trial of 186 older adults, remimazolam at two induction doses did not reduce postoperative delirium compared with propofol. However, remimazolam provided better hemodynamic stability, with fewer treated hypotension and bradycardia events and lower vasopressor requirements, at the cost of slower loss of consciousness and extubation.
Impact: This clinically relevant negative result separates remimazolam’s hemodynamic advantages from an unproven delirium-prevention effect. It helps prevent overinterpretation of pharmacologic stability as evidence of improved postoperative cognitive outcomes.
Clinical Implications: Remimazolam may be a reasonable induction alternative for older patients at risk of hypotension or excessive vasopressor exposure, but it should not be selected solely to prevent postoperative delirium. Clinicians should anticipate slower induction and extubation.
Key Findings
- Among 186 patients, postoperative delirium occurred in 12.9% with remimazolam 0.15 mg/kg, 11.3% with remimazolam 0.3 mg/kg, and 6.5% with propofol; the difference was not statistically significant.
- Both remimazolam doses maintained higher mean arterial pressure after induction and intubation.
- Remimazolam reduced treated hypotension, bradycardia, and vasopressor requirements but prolonged loss of consciousness and extubation.
Methodological Strengths
- Prospective randomized three-arm comparison with a validated 3-Minute Diagnostic Interview for delirium assessment.
- Direct evaluation of both patient-centered cognitive outcome and clinically relevant hemodynamic outcomes.
Limitations
- The study was underpowered to exclude a clinically meaningful difference in delirium because the observed event rate was lower than expected.
- The trial involved a specific elderly laparoscopic gastrointestinal-surgery population, limiting generalizability to other procedures and frailer patients.
Future Directions: Larger, adequately powered multicenter trials should evaluate delirium severity and duration, recovery quality, and cost-effectiveness while stratifying patients by baseline cardiovascular and cognitive risk.
BACKGROUND: Postoperative delirium (POD) is a common complication in elderly surgical patients that can impede recovery. While remimazolam offers superior hemodynamic stability compared to propofol, its impact on POD incidence remains unclear. This randomized trial aimed to determine whether two induction doses of remimazolam are more effective than propofol in reducing POD and improving hemodynamic stability in older patients undergoing laparoscopic gastrointestinal surgery. METHODS: In this prospective trial, 186 patients (aged 60-80 years) were randomized to receive anesthesia induction with remimazolam 0.15 mg/kg (R1), remimazolam 0.3 mg/kg (R2), or propofol 1.5 mg/kg (P). The primary endpoint was the incidence of POD within 5 days post-surgery, assessed using the 3-Minute Diagnostic Interview for Confusion Assessment Method.
3. Sequential Lidocaine and Liposomal Bupivacaine for Popliteal Sciatic Nerve Block in Foot and Ankle Surgery: A Randomized Controlled Trial.
This blinded randomized trial compared sequential lidocaine followed by liposomal bupivacaine with single-injection ropivacaine in 80 adults undergoing foot and ankle surgery. The sequential regimen improved early motor scores and statistically reduced 24-hour pain, but the pain difference was below the prespecified threshold for clinical importance, and comparative safety remains uncertain.
Impact: The trial is valuable because it demonstrates a statistically positive but clinically modest analgesic result and a functional trade-off relevant to ambulatory regional anesthesia. Its cautious interpretation challenges claims that prolonged block duration automatically yields meaningful patient benefit.
Clinical Implications: Sequential lidocaine and liposomal bupivacaine may be considered investigationally when early motor recovery is prioritized, but routine adoption is premature. Clinicians should discuss uncertain functional and safety benefits, costs, and the possibility of local anesthetic systemic toxicity.
Key Findings
- Eighty adults were randomized; complete-case analysis included 37 patients in the lidocaine-liposomal bupivacaine group and 38 in the ropivacaine group.
- Twenty-four-hour resting pain was statistically lower with sequential lidocaine-liposomal bupivacaine, but the difference did not meet the prespecified threshold for clinical importance.
- Early motor function at 3 hours favored sequential treatment, while one suspected mild local anesthetic systemic toxicity event occurred after lidocaine.
Methodological Strengths
- Randomized design with blinding of participants and outcome assessors and prespecified coprimary outcomes.
- Assessment included both pain and early motor function, directly addressing the balance between analgesia and functional recovery.
Limitations
- The sample size was small, and the block providers were not blinded.
- The study was not powered to establish comparative safety, mobility outcomes, or cost-effectiveness, and complete-case analysis reduced the analyzed sample.
Future Directions: Larger multicenter trials should measure time to ambulation, falls, discharge readiness, prolonged pain, local anesthetic systemic toxicity, and cost-effectiveness, with follow-up extending beyond the first postoperative day.
BACKGROUND: In foot and ankle surgery, prolonged analgesia after popliteal sciatic nerve block (PSNB) may be accompanied by delayed motor recovery. The effects of sequential lidocaine and liposomal bupivacaine (LB), particularly on early motor function, remain uncertain. METHODS: Eighty adults undergoing foot and ankle surgery were randomized to preoperative 1.5% lidocaine (20 mL) followed by postoperative 0.665% LB (20 mL), or preoperative 0.5% ropivacaine (20 mL). Participants and outcome assessors were blinded; block providers were not. For the coprimary comparisons, resting pain was assessed at 24 hours using a 0-10 visual analog scale and motor function at 3 hours using the modified Bromage score. RESULTS: In complete-case analyses, 37 lidocaine-LB and 38 ropivacaine recipients were included.