Daily Anesthesiology Research Analysis
Analyzed 78 papers and selected 3 impactful papers.
Summary
Three clinically oriented anesthesiology studies stand out today: a multicenter cohort identified a preoperative quantitative EEG connectivity marker that predicts postoperative delirium without persistent network changes at 3 months; a prospective cohort showed that PACU nurses’ structured clinical judgments outperform MAS and NEWS for predicting early complications; and a randomized trial demonstrated that ultrasound-confirmed early gastric emptying enables earlier sedated colonoscopy with better bowel preparation quality.
Research Themes
- Neurophysiological risk stratification for postoperative delirium
- Human-in-the-loop risk prediction at PACU discharge
- Point-of-care ultrasound to optimize timing and safety in sedated endoscopy
Selected Articles
1. Quantitative EEG changes preceding and following postoperative delirium: a prospective, multicenter, cohort study.
In older adults undergoing major surgery, reduced preoperative beta-band amplitude-based EEG connectivity predicted postoperative delirium, while no persistent resting-state quantitative EEG abnormalities were observed three months after surgery. These findings support EEG-based risk stratification without evidence of lasting network disruption.
Impact: It identifies a reproducible neurophysiological marker for postoperative delirium vulnerability using multicenter prospective data and modern EEG metrics.
Clinical Implications: Preoperative quantitative EEG, particularly beta-band amplitude-based connectivity, could augment delirium risk screening and guide targeted prevention strategies in older surgical patients.
Key Findings
- Among 330 surgical patients (≥65 years), 18% developed postoperative delirium.
- Future delirium patients showed significantly reduced preoperative beta amplitude-based connectivity (β = -0.36, pcorrected = 0.04).
- No persistent changes in resting-state quantitative EEG measures were observed three months after surgery, regardless of delirium occurrence.
Methodological Strengths
- Prospective multicenter cohort with non-surgical controls
- Use of multiple quantitative EEG metrics and linear mixed modeling
Limitations
- Observational design cannot establish causality
- Three-month follow-up may miss longer-term EEG alterations
Future Directions: Validate EEG-based risk markers across diverse populations, integrate with clinical risk scores, and test targeted delirium prevention guided by preoperative EEG.
BACKGROUND: Delirium occurs frequently after major surgery in older adults and is associated with long-term cognitive dysfunction. While postoperative delirium (POD) shows electroencephalographic (EEG) changes during the acute phase, it remains unclear whether quantitative EEG alterations precede or persist after POD. Identifying such patterns could reveal risk markers and mechanisms of long-term cognitive dysfunction. METHODS: In this prospective multicenter, cohort study, EEG recordings were obtained in patients aged ≥65 years before and three months after major elective surgery without pre-existent cognitive dysfunction, and in non-surgical controls. We analyzed quantitative EEG measures that show alterations during acute delirium, namely: relative power, phase-based and amplitude-based functional connectivity, spectral variability and signal complexity. Linear mixed models were used to assess effects of time, surgery, and POD on these EEG measures. RESULTS: Of 379 enrolled surgical patients, 330 had sufficient EEG data quality, of which 59 (18%) developed POD. Fifty-seven non-surgical controls were included and served as reference. At baseline, future POD patients exhibited significantly lower beta amplitude based connectivity (β= -0.36, pcorrected=0.04). No other EEG measures showed significant differences between groups at baseline. Three months after surgery, no persistent changes in quantitative EEG characteristics were observed in relation to POD occurrence or surgery alone. CONCLUSIONS: This study identified reduced preoperative beta amplitude-based connectivity as a possible marker of neurophysiological vulnerability for POD. However, the absence of significant longitudinal changes in quantitative EEG measures suggests that resting-state EEG networks may functionally recover or compensate in this cohort at three months postoperative.
2. Beyond discharge score: postoperative care unit nurses' clinical assessments improve postoperative risk stratification: A prospective cohort study.
In two PACUs, nurse clinical assessments outperformed MAS and NEWS in predicting complications within 72 hours of discharge among high-risk surgical patients, achieving higher discrimination and a high NPV. Structured clinical judgment should complement score-based discharge decisions.
Impact: It demonstrates added prognostic value of expert nurse judgment over widely used discharge scores, offering a pragmatic path to improve early postoperative safety.
Clinical Implications: Incorporate structured PACU nurse assessments into discharge criteria to enhance detection of patients at risk despite acceptable MAS/NEWS, potentially prompting closer monitoring or delayed discharge.
Key Findings
- MAS and NEWS had limited discrimination for early complications (AUC 0.555 and 0.589).
- PACU nurse assessments achieved higher discrimination (AUC 0.652, P=0.006) with NPV 93.8%.
- Patients rated as 'Potentially unstable' or 'Unstable' had higher complication risk despite meeting MAS criteria (OR 3.65, 95% CI 1.53–8.76).
Methodological Strengths
- Prospective two-centre cohort with predefined outcomes
- Use of AUC, OR, RR, and operating characteristics to quantify prognostic performance
Limitations
- Observational design with potential residual confounding
- Generalizability limited to two centres and high-risk populations
Future Directions: Develop standardized structured nurse assessment tools, validate across settings, and evaluate impact on outcomes and resource utilization when integrated into discharge algorithms.
BACKGROUND: Postoperative complications frequently occur within 24 h of surgery and are challenging to detect early. Tools such as the Modified Aldrete Score (MAS) and National Early Warning Score (NEWS) support postanaesthesia care unit (PACU) discharge decisions; however, their prognostic performance is uncertain. Clinical nurse assessments may offer additional value. OBJECTIVES: To compare the prognostic performance of MAS, NEWS, and PACU nurse clinical assessments in predicting early postoperative complications (within 72 h of PACU discharge) in high-risk surgical patients. DESIGN: Prospective, two-centre observational cohort. SETTING: Conducted in two PACUs in the Capital Region of Denmark. PATIENTS: Two hundred and forty high-risk adult surgical patients were included after elective or emergency procedures. Complications were defined according to Clavien-Dindo grade II to V. Patients with missing nurse assessments (n = 15) were excluded from analyses involving this variable. MAIN OUTCOME MEASURES: The primary outcome was the prognostic performance of MAS in identifying early postoperative complications. Secondary outcomes included the performance of NEWS and PACU nurse assessments. Early complications were defined as events occurring within 72 h of PACU discharge. RESULTS: MAS and NEWS showed limited predictive ability (AUC = 0.555 and 0.589, respectively). PACU nurse assessments were significantly associated with early complications (AUC = 0.652, P = 0.006). Patients rated as 'Potentially unstable' or 'Unstable' had a higher risk despite meeting MAS criteria: odds ratio (OR) = 3.65, 95% confidence interval (CI), 1.53 to 8.76; relative risk (RR) = 0.32, 95% CI, 0.15 to 0.70. The optimal threshold yielded 72.4% sensitivity, 61.2% specificity, 21.6% positive-predictive value (PPV), and 93.8% negative-predictive value (NPV). Early complications were associated with increased risk of subsequent complications: OR = 5.0, 95% CI, 1.8-14.1, P < 0.001. CONCLUSIONS: PACU nurse assessments outperformed MAS and NEWS in predicting early postoperative complications. Integrating structured clinical judgment into discharge decisions may enhance risk stratification and safety. TRIAL REGISTRATION: ClinicalTrials.gov: NCT06013891.
3. Ultrasonographic evaluation of gastric emptying and correlation of bowel preparation quality with different waiting times in patients undergoing colonoscopy with sedation: A randomized controlled clinical trial.
In a randomized trial of 134 sedated colonoscopy patients, ultrasound confirmed gastric emptying at 2–4 hours post-prep in all participants. Performing colonoscopy within 2–4 hours improved bowel preparation scores and satisfaction without increasing ultrasound-assessed aspiration risk in this selected low-risk cohort.
Impact: It integrates point-of-care gastric ultrasound with procedural timing to safely shorten the interval after bowel prep under sedation, improving preparation quality and patient experience.
Clinical Implications: In selected low-risk patients, adopting ultrasound-confirmed gastric emptying can allow earlier sedated colonoscopy (2–4 h post-prep) to enhance prep quality and satisfaction without added aspiration risk, informing fasting/timing protocols.
Key Findings
- All patients had ultrasound-confirmed gastric emptying at 2 or 4 hours after split-dose OSS.
- Bowel preparation scores were higher for 2–4 h timing vs 4–6 h (median 7.0 vs 6.0; P < 0.001).
- Patient satisfaction was higher in the 2–4 h group (median 10.0 vs 8.0; P < 0.001) without increased ultrasound-assessed aspiration risk.
Methodological Strengths
- Randomized controlled design in a clinically relevant sedated endoscopy setting
- Objective point-of-care gastric ultrasound to assess aspiration risk surrogate
Limitations
- Single-centre trial in a selected low-risk population limits generalizability
- Ultrasound-based assessment may not capture rare aspiration events
Future Directions: Multicentre trials including higher-risk patients to validate safety, and protocolized integration of gastric ultrasound into fasting/timing pathways.
STUDY OBJECTIVE: Quality of bowel preparation correlates with the time interval between its completion and colonoscopy in patients receiving colonoscopy. Previous studies focused primarily on awake patients, neglecting the risk of regurgitation and aspiration in those receiving sedation. We investigated the relationship between gastric emptying time, colonoscopy waiting time, and bowel preparation quality in patients undergoing colonoscopy with sedation. DESIGN: A prospective, randomized trial. SETTING: Endoscopy center. PATIENTS: 134 patients receiving colonoscopy with sedation. INTERVENTIONS: Gastric ultrasound assessment was initiated 2 or 4 h after completing the 3 L split-dose oral sulfate solution (OSS), followed by colonoscopy within 2-4 h (Group A) or 4-6 h (Group B) after confirming gastric emptying. MEASUREMENTS: The primary outcomes were full stomach rate at various timepoints and bowel preparation quality. Secondary outcomes included colonoscopy waiting time, operation time, terminal ileal intubation rate, polyp and adenoma detection rate, and overall satisfaction. MAIN RESULTS: Gastric emptying was confirmed at 2 or 4 h after bowel preparation in all patients. The bowel preparation score was significantly higher in Group A than in Group B (7.0 [6.0-8.0] vs 6.0 [5.0-7.0], P < 0.001), and patient satisfaction was also higher (10.0 [8.0-10.0] vs 8.0 [7.0-9.0], P < 0.001). CONCLUSIONS: Performing colonoscopy 2 h after 3 L split-dose OSS intake does not increase the risk of intraoperative regurgitation or aspiration as assessed by ultrasound in this selected, low-risk population. Colonoscopy performed within 2-4 h after bowel preparation completion yields superior bowel preparation quality compared to 4-6 h.