Daily Anesthesiology Research Analysis
Analyzed 37 papers and selected 3 impactful papers.
Summary
Across perioperative medicine, three studies stand out: a multi-country analysis shows biological age (PhenoAge) robustly predicts postoperative mortality and complications beyond traditional risk factors; a randomized exploratory trial suggests combining preemptive analgesia with intranasal insulin reduces postoperative delirium in elderly fracture surgery; and a prospective study identifies mandibular condylar translation distance by ultrasound as a powerful predictor of difficult laryngoscopy in older adults.
Research Themes
- Biological age as a perioperative risk stratifier
- Metabolic and analgesic prehabilitation to prevent postoperative delirium
- Ultrasound-based airway assessment in the elderly
Selected Articles
1. Biological aging increases risk of postoperative morbidity and mortality: an international, multi-cohort study.
In >430,000 surgical patients across multiple countries, the biological age metric PhenoAge independently predicted 1-year mortality, cardiovascular events, and 30-day readmissions beyond chronological age, frailty, comorbidity burden, ASA status, and surgical complexity. Findings replicated across independent cohorts and were prospectively validated for early postoperative complications, supporting PhenoAge as a scalable perioperative risk stratifier.
Impact: This study robustly integrates biological aging into perioperative risk, demonstrating reproducibility across health systems and prospective validation, which advances precision risk stratification beyond chronological age.
Clinical Implications: PhenoAge, derived from routine labs, can identify high-risk patients for targeted prehabilitation, optimize perioperative planning, and inform shared decision-making, irrespective of chronological age.
Key Findings
- PhenoAge independently predicted 1-year mortality (UK Biobank OR 1.043, p<0.001), major adverse cardiovascular events (OR 1.041, p<0.001), and 30-day readmission (OR 1.02, p<0.001).
- “Fast Agers” had 49% higher mortality risk than “Normal Agers.”
- Results replicated in three independent cohorts (MOVER OR 1.03; Weill Cornell OR 1.036; INSPIRE OR 1.05; all p<0.001).
- Prospective validation showed PhenoAge predicted acute 3-day complications (OR 1.20; p=0.015).
Methodological Strengths
- Very large, international, multi-cohort design with external replication
- Comprehensive adjustment for confounders (age, frailty, comorbidity, ASA, surgical complexity) and prospective validation
Limitations
- Observational design precludes causal inference
- Generalizability to specific surgical subspecialties or non-represented populations may require further validation
Future Directions: Evaluate PhenoAge-guided prehabilitation and perioperative optimization strategies in interventional trials; assess integration with machine learning risk platforms and cost-effectiveness.
Biological age often diverges from chronological age, yet its independent impact on surgical outcomes remains poorly defined. We evaluated PhenoAge, a validated biological age metric, in an international multi-cohort study comprising over 430,000 surgical patients across the UK, USA, and South Korea. In the UK Biobank (N = 291,845), PhenoAge was a robust, independent predictor of 1-year mortality (OR 1.043; p < 0.001), major adverse cardiovascular events (OR 1.041; p < 0.001), and 30-day readmission (OR 1.02; p < 0.001), even after adjusting for chronological age, Fried Frailty Index, Charlson comorbidity score, American Society of Anesthesiologists (ASA) physical status, surgical complexity, and other common surgical risk factors. "Fast Agers" faced a 49% higher risk of mortality than "Normal Agers". The main findings were replicated across three independent international cohorts (MOVER OR 1.03; Weill Cornell OR 1.036; INSPIRE OR: 1.05; all p < 0.001), and validated prospectively at a large academic medical center, where PhenoAge predicted acute 3-day complications (OR 1.20; p = 0.015). As a scalable tool leveraging routine laboratory data, PhenoAge facilitates precision gerisurgery by identifying high-risk individuals for prehabilitation and biologically resilient candidates for complex procedures regardless of chronological age.
2. A prospective, randomized exploratory study: Association of preemptive analgesia combined with preoperative transnasal insulin therapy with reduced postoperative delirium in elderly patients undergoing lower extremity fracture surgery.
In elderly fracture surgery, a randomized exploratory trial found that combining preoperative intranasal insulin with a fascia iliaca block reduced postoperative delirium versus control (17.74% vs 38.71%). The combination also improved pain and sleep trajectories and favorably modulated insulin resistance and plasma p-tau, whereas intranasal insulin alone did not significantly reduce delirium.
Impact: The study suggests a feasible, multimodal preoperative strategy that targets both nociceptive and metabolic pathways to prevent postoperative delirium with supportive biomarker changes.
Clinical Implications: Preemptive fascia iliaca block combined with intranasal insulin may be considered as part of multimodal prehabilitation for high-risk elderly fracture patients to reduce delirium, pending confirmation in definitive RCTs.
Key Findings
- Postoperative delirium was lower in the insulin+preemptive analgesia group vs control (17.74% vs 38.71%; corrected P=0.009).
- Intranasal insulin alone did not significantly reduce delirium vs control (27.42%; corrected P=0.181).
- Combination therapy improved pain (lower NRS at P2, P4) and sleep (lower SRSS at P3), and reduced postoperative glucose, insulin resistance, and p-tau relative to control.
- p-tau increased postoperatively in control and insulin-alone groups but remained stable in the combination group; IR reduction occurred only with combination therapy.
Methodological Strengths
- Randomized, three-arm design with active regional anesthesia comparator
- Use of standardized delirium assessment (3D-CAM) and mechanistic biomarkers (IR, p-tau)
Limitations
- Exploratory, single-center nature with unclear power for clinical endpoints
- Combined intervention limits attribution of effects to individual components; short follow-up for delirium and no long-term cognitive outcomes
Future Directions: Conduct multi-center, adequately powered RCTs to confirm delirium reduction, parse component effects (insulin vs regional block), and assess long-term cognition and functional recovery.
OBJECTIVE: This exploratory study aimed to investigate whether combining preoperative intranasal insulin with pre-emptive analgesia is associated with a lower incidence of postoperative delirium (POD) in elderly patients undergoing lower extremity fracture surgery. METHODS: This prospective, randomized, exploratory trial involved 186 patients (aged ≥65 years and classified as ASA class II-III), who were allocated to one of three groups (n = 62): Group C (control: intranasal saline, 0.5 mL); Group I (insulin: intranasal insulin, 20 IU [0.5 mL]) and Group IP (insulin and pre-emptive analgesia: intranasal insulin as in Group I, plus a preoperative ultrasound-guided iliac fascia block with 0.375% ropivacaine [30 mL]). Intranasal administrations were given twice daily for two preoperative days and 20 min before anesthesia induction (five doses in total). The outcomes included NRS pain scores (at baseline [P1], 30 min after the intervention [P2] and 30 min after the third intranasal dose on day two [P4]), SRSS sleep scores (at baseline [P0] and on the night of the intervention [P3]), the incidence of postoperative delirium (assessed using the 3D-CAM on postoperative days one [T1], three [T2] and five [T3]), and serum biomarkers (insulin, glucose, insulin resistance [IR] and p-tau) at baseline [P1] and on postoperative day 1 [T1]). RESULTS: The incidence of POD was significantly lower in Group IP (17.74%) than in Group C (38.71%; corrected P = 0.009), while no significant difference was observed between Group I (27.42%) and Group C (corrected P = 0.181). For secondary exploratory outcomes, Group IP showed lower NRS scores at P2 and P4 (both nominal P < 0.001 vs. Group C) and lower SRSS scores at P3 (nominal P < 0.001 vs. Group C), suggesting potential improvements in pain and sleep. These patterns were not observed in Group I. Preoperative biomarkers were comparable across groups. Postoperatively, Group IP showed lower glucose (nominal P = 0.028), IR (nominal P = 0.001), and p-tau levels (nominal P < 0.001) compared with Group C, as well as lower insulin (nominal P < 0.001), IR (nominal P = 0.008), and p-tau (nominal P < 0.001) compared with Group I. Longitudinal analysis (T1 vs. P1) indicated an increase in p-tau in Group C and Group I (both nominal P < 0.001), whereas p-tau levels remained relatively stable in Group IP. A reduction in IR was observed only in Group IP (nominal P < 0.001). CONCLUSION: In this exploratory study, preoperative intranasal insulin alone showed no clear association with reduced POD or improved sleep. However, its combination with pre-emptive analgesia was associated with lower POD incidence, better pain and sleep profiles, and favorable biomarker changes. These hypothesis-generating findings warrant confirmation in future trials.
3. Prediction of difficult airways in elderly patients using bedside ultrasound: a prospective single-blind observational study.
In elderly surgical patients, bedside ultrasound metrics—especially mandibular condylar translation distance—accurately predicted difficult laryngoscopy (AUC 0.89) and difficult intubation (AUC 0.91). A six-predictor model combining ultrasound and clinical parameters achieved an optimism-corrected AUC of 0.924, supporting individualized preintubation risk stratification.
Impact: Provides a practical, noninvasive, and quantifiable approach to predict difficult airways in a high-risk elderly population, with strong discrimination and internal validation.
Clinical Implications: Incorporating MCTD and related ultrasound measures into preoperative airway assessment may improve planning (e.g., videolaryngoscopy availability, expert assistance) and reduce failed intubation risks in older adults.
Key Findings
- Difficult laryngoscopy and intubation occurred in 19.5% and 11.1% respectively among 226 elderly patients.
- Mandibular condylar translation distance had the best single-predictor performance (AUC 0.89 for difficult laryngoscopy; 0.91 for difficult intubation).
- A six-predictor combined model (including MCTD, HMDR, IID, TMD, MMS, sex) achieved an optimism-corrected AUC of 0.924.
- Lower MCTD, HMDR, IID, and male sex independently increased odds of difficult laryngoscopy.
Methodological Strengths
- Prospective, single-blind design with predefined ultrasound predictors and standardized outcomes
- Robust modeling with LASSO selection and bootstrap internal validation
Limitations
- Single-center study with internal but no external validation
- Operator dependency and potential variability in ultrasound acquisition; elderly-only sample limits generalizability
Future Directions: External multicenter validation, assessment of implementation workflows, and evaluation of impact on airway-related adverse events and resource allocation.
This prospective, single-blind observational study evaluated the predictive performance of selected ultrasound airway predictors and a combined prediction model for difficult laryngoscopy and difficult intubation in elderly patients. A total of 242 elderly patients scheduled for elective surgery under general anaesthesia with endotracheal intubation were enrolled. During the preanaesthesia phase, demographic information, classic clinical airway assessments, and ultrasound predictors were collected. The ultrasound predictors included mandibular condylar translation distance (MCTD), tongue thickness (TT), tongue volume (TV), hyomental distance in the extended position (HMDe), and hyomental distance ratio (HMDR). After anaesthesia induction, laryngoscopic views were graded, and intubation difficulty was scored. Diagnostic performance was assessed using receiver operating characteristic (ROC) curves. Least absolute shrinkage and selection operator (LASSO) logistic regression with tenfold cross-validation was used for variable selection. A multivariable logistic regression model was constructed for predicting difficult laryngoscopy, visualized as a nomogram, and internally validated using bootstrap resampling with 1000 repetitions. The final analysis included 226 elderly patients, 44 (19.5%) of whom experienced difficult laryngoscopy and 25 (11.1%) of whom experienced difficult intubation. MCTD showed the highest area under the ROC curve (AUC) among individual predictors for both difficult laryngoscopy (AUC 0.89; 95% CI: 0.84-0.94; P < 0.001) and difficult intubation (AUC 0.91; 95% CI: 0.86-0.97; P < 0.001). For difficult laryngoscopy, LASSO selected MCTD, HMDR, IID, TMD, MMS, and sex. In the multivariable model, lower MCTD, HMDR, IID, and male sex were independently associated with increased odds of difficult laryngoscopy. The six-predictor model showed an apparent AUC of 0.944 (95% CI: 0.914-0.974) and an optimism-corrected AUC of 0.924 (95% CI: 0.885-0.958). Several ultrasound measurements showed diagnostic value for predicting difficult laryngoscopy and difficult intubation in elderly patients. Mandibular condylar translation distance demonstrated the strongest individual ultrasound performance and remained an independent predictor of difficult laryngoscopy in the multivariable model. A combined model incorporating ultrasound and clinical airway parameters may provide individualized risk estimation for difficult laryngoscopy.Trial registration Retrospectively registered at www.chictr.org.cn (ChiCTR2300076196), 27 September 2023.