Daily Anesthesiology Research Analysis
Enhanced recovery programmes (ERPs) in cardiac surgery outperform fast-track-only strategies, reducing hospital/ICU length of stay and ventilation time. A mechanistic mouse study shows emergence from general anaesthesia is governed by probabilistic state switching rather than fixed inter-individual sensitivity. A meta-analysis links post–cardiac arrest hypocapnia to higher mortality and poor neurological outcomes, supporting normocapnia-targeted ventilation.
Summary
Enhanced recovery programmes (ERPs) in cardiac surgery outperform fast-track-only strategies, reducing hospital/ICU length of stay and ventilation time. A mechanistic mouse study shows emergence from general anaesthesia is governed by probabilistic state switching rather than fixed inter-individual sensitivity. A meta-analysis links post–cardiac arrest hypocapnia to higher mortality and poor neurological outcomes, supporting normocapnia-targeted ventilation.
Research Themes
- Enhanced recovery pathways in cardiac anesthesia
- Probabilistic neurodynamics of anesthesia emergence
- Ventilation targets after cardiac arrest
Selected Articles
1. Efficacy of enhanced recovery programmes for cardiac surgery: a systematic review and meta-analysis.
Across 18 studies (n=2625), implementing ERPs or fast-track pathways reduced hospital length of stay (−1.40 days), ICU length of stay (−13.22 h), and ventilation time (−4.68 h) versus usual care. ERPs showed additive benefit over fast-track alone for hospital stay reduction. Findings support comprehensive, multimodal perioperative pathways in cardiac surgery.
Impact: This PRISMA-compliant, PROSPERO-registered meta-analysis delineates the incremental value of ERPs beyond fast-track, quantifying reductions in hospital/ICU stay and ventilation time in cardiac surgery.
Clinical Implications: Cardiac surgery programs should adopt ERPs that include preoperative, intraoperative, and postoperative elements rather than relying on intraoperative fast-track strategies alone, to reduce resource use and expedite recovery.
Key Findings
- ERPs/FT reduced hospital length of stay by −1.40 days (95% CI −2.19 to −0.61).
- ICU stay and ventilation time decreased by −13.22 h and −4.68 h, respectively.
- ERPs provided additive benefit over FT for hospital LOS (ERP −2.11 days vs FT −0.30 days; P=0.003).
Methodological Strengths
- PRISMA-guided methodology with PROSPERO registration (CRD42022382409)
- Inclusion of randomized and prospective studies; random-effects meta-analysis
Limitations
- Heterogeneity in ERP/FT components and implementation across studies
- Outcomes focused on length of stay and ventilation time; limited long-term clinical endpoints
Future Directions: Standardize ERP components for cardiac surgery and test in multicenter RCTs with long-term outcomes (readmissions, complications, patient-reported outcomes).
BACKGROUND: The terms fast-track (FT) and enhanced recovery after surgery (ERAS) are often mistakenly used interchangeably. Fast-track cardiac anaesthesia focuses on perioperative strategies, whereas ERAS (or enhanced recovery programme [ERP]) encompasses a wider range of strategies designed to enhance overall recovery. Evidence is needed to demonstrate the additive value of ERP above FT in cardiac surgery. We conducted a meta-analysis to investigate the comparative efficacy of ERP and FT programmes in card
2. A probabilistic model of behavioural emergence from general anaesthesia in mice.
Repeated isoflurane exposures in genetically identical mice showed emergence times varying over two orders of magnitude without stable inter-individual differences; within-individual variability matched between-individual variability. A neuronal dynamics model of stochastic state switching reproduced observed variability, whereas standard PK-PD models failed.
Impact: Challenges the prevailing assumption that fixed patient sensitivity drives emergence variability, introducing a probabilistic framework with implications for managing delayed emergence.
Clinical Implications: Delayed emergence may be an inherent probabilistic event; clinicians should anticipate rare long emergence times despite standardized dosing and consider probabilistic risk communication and monitoring strategies.
Key Findings
- Emergence times spanned two orders of magnitude after identical isoflurane exposure.
- No stable inter-individual differences; within-individual variability equaled between-individual variability.
- Neuronal dynamics (stochastic state switching) model reproduced variability; standard PK-PD model did not.
- Individual anaesthetic sensitivity differences exist but do not predict emergence time across sessions.
Methodological Strengths
- Repeated-measures design in genetically identical mice across 10 sessions
- Comparative modeling with effect-site PK-PD vs neuronal dynamics models
Limitations
- Preclinical mouse model may limit generalizability to humans
- Focused on isoflurane; other anaesthetics not tested
Future Directions: Test probabilistic emergence predictions in humans, across agents and dosing paradigms, integrating EEG and behavioral endpoints to refine risk models for delayed emergence.
BACKGROUND: Time to emergence from general anaesthesia is highly variable between individuals. This variability has been attributed to individual differences in anaesthetic sensitivity. However, this hypothesis has not been verified experimentally. We explicitly test this hypothesis by quantifying emergence from anaesthesia repeatedly in the same individuals over time. METHODS: Genetically identical adult (12-24 weeks old) male (n=40) and female (n=20) C57BL/6J mice were exposed to 2 h of isoflurane (0.90
3. Association between arterial carbon dioxide tension and poor outcomes after cardiac arrest: A meta-analysis.
Across 14 cohorts and 3 RCTs (n=72,344), hypocapnia after cardiac arrest was associated with higher hospital mortality (OR 1.37) and poor neurological outcomes (OR 1.75). Hypercapnia increased hospital mortality in cohorts but was not linked to worse neurological outcomes; RCTs did not show harm from mild hypercapnia.
Impact: This large meta-analysis with protocol registration clarifies PaCO2–outcome relationships after cardiac arrest, informing ventilatory targets in post-resuscitation care.
Clinical Implications: Avoid hypocapnia during post–cardiac arrest ventilation; target normocapnia and be cautious with hyperventilation. Mild hypercapnia does not appear to worsen neurological outcomes based on RCTs.
Key Findings
- Hypocapnia associated with higher hospital mortality (OR 1.37; 95% CI 1.18–1.59).
- Hypocapnia associated with poor neurological outcomes (OR 1.75; 95% CI 1.04–2.96).
- Hypercapnia associated with higher hospital mortality in cohorts (OR 1.40), but not with poor neurological outcomes; RCTs showed no harm from mild hypercapnia.
Methodological Strengths
- Large pooled sample (n=72,344) including cohort studies and RCTs
- Protocol registered (INPLASY 2024100120) with systematic multi-database search
Limitations
- Heterogeneity in PaCO2 definitions, timing, and measurement across studies
- Observational designs dominate the evidence for some outcomes, with residual confounding likely
Future Directions: Conduct adequately powered RCTs comparing normocapnia vs mild hypercapnia post-arrest with standardized PaCO2 targets and continuous monitoring to determine causal effects on neurological outcomes.
BACKGROUND: Abnormal arterial carbon dioxide tension (PaCO METHODS: PubMed, Embase, and the Cochrane Library databases were searched through October 2024 to determine studies investigating the association between PaCO RESULTS: A total of 14 cohort studies and 3 RCTs comprising 72344 patients were included. Pooled analysis indicated that hypocapnia was associated with an increased risk of hospital mortality (nine cohort studies, OR 1.37; 95% CI, 1.18-1.59; P < 0.0001) and poor neurological outcomes (five cohort stu