Daily ReportOct 13, 2026
Anesthesiology, October 13 edition
We read 67 papers and selected 3.
Summary
Today’s most impactful studies address three high-priority anesthesiology problems: preventable day-of-surgery cancellations, reliable interpretation of EEG network data during anesthesia, and safer early oral intake after general anesthesia. The findings combine health-system evidence, methodological advances, and clinical recovery data, with direct implications for perioperative pathways and research reproducibility.
Research Themes
- Perioperative system reliability and cancellation prevention
- EEG preprocessing validity in anesthesia and altered consciousness
- Early postoperative recovery and oral fluid intake
Selected Articles
1. Irreversible functional network deformation induced by preprocessing scheme order in multivariate EEG recordings.
This methodological study demonstrated that applying re-referencing before filtering can generate spurious cross-correlations in multivariate EEG recordings. The distortion was strongest and irreversible in signals with steep power spectra, including slow-wave sleep, anesthesia, postictal states, neonatal EEG, and vegetative states; filtering followed by re-referencing with surrogate correction was recommended.
Impact: The paper identifies a previously underappreciated source of systematic bias that can alter functional connectivity conclusions in anesthesia and disorders of consciousness. Its recommendations are immediately actionable for EEG acquisition pipelines, computational neuroscience, and reproducibility standards.
Clinical Implications: EEG studies used for anesthesia depth assessment, emergence research, epilepsy monitoring, and disorders of consciousness should prespecify preprocessing order and use surrogate-based correction when estimating functional connectivity. Existing datasets may require reanalysis before biological conclusions are accepted.
Key Findings
- Re-referencing followed by filtering produced spurious cross-correlations that increased with frequency band and depended on the signal power spectral exponent.
- For signals with power spectral exponent β ≥2, a pattern relevant to anesthesia and slow-wave sleep, the artificial correlations were reported to be irreversible.
- Filtering followed by re-referencing, combined with surrogate-corrected cross-correlations, was recommended for multivariate signals with β ≥2.
Methodological Strengths
- The analysis integrated human sleep EEG, controlled synthetic numerical models, and surrogate-based statistical testing.
- The two preprocessing schemes differed only in operation order, strengthening causal attribution of the observed distortion to preprocessing sequence.
Limitations
- The abstract does not provide the number of human participants or detailed effect estimates for all signal conditions.
- The findings were demonstrated in EEG and require validation across additional recording modalities, acquisition systems, and preprocessing implementations.
Future Directions: Future studies should establish community-wide preprocessing benchmarks, reanalyze published anesthesia and consciousness datasets, and determine how preprocessing artifacts affect clinical EEG biomarkers and machine-learning models.
INTRODUCTION: The analysis of Electroencephalographic recordings is non-trivial, the order in which filtering and re-referencing are applied during multivariate signal preprocessing has a critical and underappreciated consequence for functional network estimation. METHODS: Using EEG sleep recordings from healthy subjects, synthetic data from controlled numerical models (Nf-Tori and IAAFT surrogates), and surrogate-based statistical testing, we provide a quantitative comparison of two preprocessing schemes that differ solely in the order of filtering and re-referencing (filtering followed by re-referencing-FR, and re-referencing followed by filtering-RF). RESULTS: We show that the RF scheme induces spurious cross-correlations that increase systematically with the frequency band and are strongly modulated by the power spectral exponent β of the signal.
2. Incidence and reasons for cancellation on the day of elective surgery: a systematic review and meta-analysis.
This systematic review identified 58 studies and pooled 37 studies with a strict definition of day-of-surgery cancellation. The pooled cancellation incidence was 14% (95% CI 13–16%), with substantial heterogeneity; common drivers included patient-related issues, inadequate fasting, changes in medical condition, booking problems, missing equipment, and staffing shortages.
Impact: The study quantifies a large and globally relevant perioperative systems problem and organizes its causes into actionable patient, medical/anesthesia, administrative, and staffing domains. Its findings support targeted preoperative assessment and operational redesign rather than attributing cancellations solely to patients.
Clinical Implications: Hospitals should monitor day-of-surgery cancellations using a standardized definition, conduct timely pre-anesthetic assessment, verify fasting and equipment requirements in advance, and align staffing and operating-room capacity with scheduled cases. Local cause-specific interventions are likely to be more effective than a single universal strategy.
Key Findings
- Fifty-eight observational studies met the review criteria, and 37 studies with a strict day-of-surgery definition contributed to the pooled estimate.
- The pooled incidence of cancellation on the day of elective surgery was 14% (95% CI 13–16%), with substantial heterogeneity.
- Frequently reported reasons included patient decisions, inadequate fasting, medical-condition changes, booking problems, unavailable equipment, and insufficient staff.
Methodological Strengths
- The review used a random-effects meta-analysis, subgroup analyses, and Joanna Briggs Institute risk-of-bias appraisal.
- It applied a strict cancellation definition for the primary pooled estimate and categorized reasons into clinically actionable domains.
Limitations
- Definitions, healthcare systems, surgical specialties, and reason classifications varied substantially across studies.
- The pooled estimate was observational and heterogeneous, so it cannot establish causal effects of specific cancellation-prevention interventions.
Future Directions: Future research should use a consensus definition and standardized reason taxonomy, evaluate prospective pathway interventions, and report patient-centered outcomes, cost effects, and equity implications.
INTRODUCTION: Cancellation on the day of elective surgery is a persistent challenge that compromises operating theatre efficiency, wastes resources and delays patient care. Existing evidence is difficult to interpret because definitions of cancellation vary across studies and reported reasons are classified inconsistently. We aimed to estimate the incidence of cancellation on the day of surgery and synthesise the reported reasons for cancellation. METHODS: Databases were searched for observational studies reporting elective surgery cancellations. Studies explicitly defining cancellation on the day of surgery were included in a random-effects meta-analysis of proportions. Subgroup analyses examined variation by national income level and surgical speciality, with geographical region explored in supplementary analyses. Included studies were assessed for risk of bias using Joanna Briggs Institute critical appraisal tools.
3. Optimal volumes of early oral fluid intake in the post-anesthesia care unit for patients not under postoperative fasting orders: a meta-analysis and trial sequential analysis of clinical recovery and safety outcomes.
This systematic review included 13 studies involving 4,528 adults, including 11 randomized controlled trials. Early oral fluid intake in the post-anesthesia care unit reduced postoperative nausea and vomiting (RR 0.60, 95% CI 0.50–0.73; moderate-certainty evidence), and trial sequential analysis supported the robustness of this finding; evidence for thirst, satisfaction, discharge time, and rare aspiration events remained limited.
Impact: The study supports a practical shift away from routine prolonged fasting after anesthesia for appropriately selected adults. It combines meta-analysis, trial sequential analysis, and GRADE assessment, while appropriately emphasizing that rare aspiration complications remain underpowered outcomes.
Clinical Implications: In adults without postoperative fasting orders and after appropriate recovery assessment, PACU protocols may consider small, protocolized amounts of oral fluid to reduce postoperative nausea and vomiting. Patient selection, airway protection, consciousness, gastrointestinal function, and aspiration risk should be assessed before intake.
Key Findings
- Thirteen studies involving 4,528 adults were included, comprising 11 randomized controlled trials and 2 non-randomized studies.
- Early oral fluid intake reduced postoperative nausea and vomiting compared with delayed intake or standard fasting (RR 0.60, 95% CI 0.50–0.73; moderate certainty).
- Exploratory analyses suggested benefit with 20–49 mL and 100–199 mL volumes, while no aspiration events were observed; however, studies were not powered to exclude rare aspiration.
Methodological Strengths
- The review followed systematic search and dual-reviewer procedures, used random-effects models, and incorporated risk-of-bias assessment and GRADE certainty evaluation.
- Trial sequential analysis was used to assess whether the evidence for the primary outcome had crossed a monitoring boundary.
Limitations
- The included studies varied in timing, fluid type, volume, patient selection, and outcome assessment, producing substantial heterogeneity for several secondary outcomes.
- The sample was insufficient to determine the risk of rare aspiration or other uncommon serious adverse events.
Future Directions: Large multicenter trials should standardize eligibility, consciousness and airway-protection criteria, fluid type and volume, timing, and aspiration surveillance. Patient-reported thirst, comfort, recovery quality, and PACU discharge should be prespecified outcomes.
INTRODUCTION: Postoperative recovery in the post-anaesthesia care unit (PACU) is frequently complicated by thirst, oropharyngeal dryness, and postoperative nausea and vomiting (PONV). Early oral fluid intake has been proposed to alleviate these discomforts. However, its optimal timing and volume remain uncertain. We conducted a systematic review and meta-analysis with trial sequential analysis (TSA) to evaluate the safety and clinical outcomes of PACU-initiated early oral fluid intake in adults after general anaesthesia, focusing on administered fluid volume. METHODS: We systematically searched PubMed/MEDLINE, Embase, CENTRAL, Ovid, Web of Science, and Wanfang Database for studies published from January 2014 to December 2024. Eligible studies enrolled adults (≥18 years) recovering in the PACU after general anaesthesia who received early oral fluid intake versus delayed intake or standard fasting.