Daily Anesthesiology Research Analysis
Three impactful anesthesiology papers stand out today: a multicenter RCT shows low-dose landiolol does not prevent postoperative atrial fibrillation (POAF) after cardiac surgery in non-Asian patients; a randomized trial finds a single preoperative hypnosis session reduces postoperative fatigue, emotional distress, and fentanyl use versus mindfulness in breast surgery; and intracranial EEG data indicate dexmedetomidine-induced unresponsiveness resembles N2 sleep more than propofol.
Summary
Three impactful anesthesiology papers stand out today: a multicenter RCT shows low-dose landiolol does not prevent postoperative atrial fibrillation (POAF) after cardiac surgery in non-Asian patients; a randomized trial finds a single preoperative hypnosis session reduces postoperative fatigue, emotional distress, and fentanyl use versus mindfulness in breast surgery; and intracranial EEG data indicate dexmedetomidine-induced unresponsiveness resembles N2 sleep more than propofol.
Research Themes
- Perioperative arrhythmia prevention in cardiac surgery
- Non-pharmacologic preoperative interventions for symptom control
- Neurophysiology of anesthetic-induced unconsciousness
Selected Articles
1. Low dose of landiolol does not prevent postoperative atrial fibrillation after cardiac surgery in non-Asian patients: a multicentre randomised study.
In a multicenter, double-blind RCT of 318 non-Asian adults undergoing cardiac surgery with CPB, a 24-hour low-dose landiolol infusion initiated in the ICU did not reduce ICU POAF incidence versus placebo and showed no differences in secondary outcomes or safety. These results challenge the generalizability of prior low-dose landiolol benefits observed in Asian cohorts.
Impact: This negative, well-powered RCT directly informs POAF prevention strategies and suggests that low-dose landiolol may not be effective across populations. It will likely recalibrate perioperative β-blocker practices and dosing assumptions outside Asia.
Clinical Implications: Do not rely on low-dose landiolol infusion as a stand-alone strategy to prevent POAF in older non-Asian patients after CPB; consider alternative or higher-intensity prophylaxis guided by existing guidelines and patient risk. Institutional protocols should reflect the lack of benefit at this dose.
Key Findings
- Low-dose 24-h landiolol infusion did not reduce ICU POAF incidence vs placebo (29.8% vs 31.9%; RR 0.93; P=0.77).
- No differences in secondary endpoints, including in-hospital and 30-day POAF, ICU/hospital length of stay, or safety outcomes.
- The trial enrolled 318 non-Asian patients ≥65 years with LVEF ≥40% undergoing elective CPB surgery.
Methodological Strengths
- Multicenter, double-blind, randomized, placebo-controlled design with intention-to-treat analysis
- Prospectively registered trial with clinically meaningful endpoints including 30-day outcomes
Limitations
- Evaluated only a low-dose, 24-hour infusion regimen; dose-response remains unknown in this population
- Conducted in non-Asian patients in France; findings may not apply to other settings or ethnic groups
Future Directions: Head-to-head trials comparing different landiolol doses or alternative β-blockers across diverse populations, with biomarker and rhythm-monitoring substudies to clarify mechanisms and identify responders.
BACKGROUND: Postoperative atrial fibrillation (POAF) affects 30% of patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Beta-blockers are the first-line agents recommended for POAF prevention. Landiolol, an ultra-short-acting, highly selective beta-1-blocker, has been shown to be effective in reducing POAF in Asian patients at a low dose of 2 μg kg METHODS: This multicentre, double-blind, randomised, placebo-controlled superiority trial was conducted from January 2021 to July 2023 at three hospitals in France. Participants were non-Asians ≥65 yr undergoing elective cardiac surgery with CPB and a left ventricular ejection fraction ≥40%. Treatment was started in the ICU and continued for up to 24 h, after which oral beta-blockers were administered. The primary endpoint was the incidence of POAF while in the ICU, analysed by intention to treat. Secondary outcomes included in-hospital and 30-day POAF, ICU and hospital length of stay, and safety outcomes. RESULTS: A total of 318 participants (mean age: 71 [range: 68-76] yr; 21.4% female) were randomised. POAF in ICU occurred in 51/160 (31.9%) participants who received placebo, compared with 47/158 (29.8%) who received a low-dose landiolol infusion (relative risk: 0.93 [95% confidence interval, 0.67-1.30]; P=0.77). No differences were observed in secondary endpoints, including in-hospital POAF and safety outcomes. CONCLUSIONS: In non-Asian patients undergoing cardiac surgery with CPB, a low-dose 24-h infusion of landiolol, used as a bridge to oral beta-blockers, did not reduce the incidence of postoperative atrial fibrillation. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT04607122).
2. Preoperative Hypnosis versus Mindfulness for Reducing Postoperative Symptoms in Breast Surgery: A Randomized Clinical Trial.
Among 203 women randomized to a single preoperative session, hypnosis reduced postoperative fatigue and emotional distress and lowered fentanyl consumption compared with mindfulness, without affecting pain, nausea, or discomfort. Benefits were greater in patients with higher preoperative anxiety, and no intervention-related adverse events were observed.
Impact: This pragmatic RCT supports a brief, scalable, nonpharmacologic intervention that improves patient-centered outcomes and reduces opioid exposure. It can be integrated into perioperative care pathways without added risk.
Clinical Implications: Consider offering a brief preoperative hypnosis session, especially for anxious patients, to reduce postoperative fatigue and emotional distress and limit opioid requirements after breast surgery.
Key Findings
- Preoperative hypnosis reduced postoperative fatigue (MD 6.4 on 100-mm VAS) and emotional distress (MD 5.7) compared with mindfulness.
- Postoperative fentanyl use was significantly lower with hypnosis (MD -0.03).
- No differences were observed in postoperative pain, nausea, or discomfort; effects were stronger in patients with higher preoperative anxiety.
Methodological Strengths
- Randomized controlled design with an active comparator (mindfulness)
- Predefined, patient-centered outcomes and objective analgesic consumption measures
Limitations
- Single center with outcomes measured primarily on the day of surgery
- Blinding of participants and providers was not feasible; effect sizes were modest
Future Directions: Evaluate implementation in diverse surgical populations, durability beyond the day of surgery, cost-effectiveness, and combination with multimodal ERAS pathways.
BACKGROUND: Breast cancer surgery is often associated with unpleasant postoperative symptoms, including pain, nausea, fatigue, and emotional distress, which can reduce quality of life and prolong recovery times. This study aimed to test the efficacy of preoperative hypnosis in reducing postoperative symptoms after breast cancer surgery. METHODS: A total of 203 women scheduled for breast cancer surgery at Oslo University Hospital in Oslo, Norway, participated in a randomized controlled trial. Patients were randomized to receive a single session of either preoperative hypnosis or mindfulness within 2 h before their scheduled surgery. Primary outcomes were postoperative pain, fatigue, nausea, discomfort, and emotional distress, measured using 100-mm visual analog scales on the day of surgery after recovery from general anesthesia. Additional measures included amount of intraoperative and postoperative anesthesia and analgesia, as well as surgery duration (extracted from patients' medical records). RESULTS: Patients receiving preoperative hypnosis reported significantly lower postoperative fatigue (mean difference [MD], 6.4; 95% CI, 0.40 to 12.4; Cohen's d = 0.30) and emotional distress (MD, 5.7; 95% CI, 0.24 to 11.2; d = 0.24) when compared to patients in a mindfulness control group. There was also a significant reduction in postoperative fentanyl use among those patients receiving preoperative hypnosis (MD, -0.03; 95% CI, -0.047 to -0.005; d = 0.54). Preoperative anxiety moderated the effect of hypnosis on postoperative emotional distress, showing a more pronounced benefit for patients with high levels of preoperative anxiety. However, no significant differences were found in postoperative pain, nausea, or discomfort between the hypnosis and mindfulness groups. No adverse events attributed to the interventions were reported. CONCLUSIONS: A brief preoperative hypnosis session before breast cancer surgery appears to be more effective than mindfulness in reducing postoperative fatigue, emotional distress, and fentanyl dose. Hypnosis stands out as a promising, nonpharmacologic, and safe intervention for reducing certain postoperative symptoms.
3. Dexmedetomidine produces more sleep-like brain activity compared with propofol in human participants.
In 34 epilepsy patients with intracranial EEG, dexmedetomidine produced unresponsiveness characterized by spectral and network features more closely resembling N2 sleep than propofol, which showed larger network entropy changes and more heterogeneous delta power. This provides mechanistic evidence that dexmedetomidine induces a sleep-like state.
Impact: Direct intracranial recordings in humans bridge anesthetic neurophysiology and natural sleep, informing sedative selection and goals (e.g., sleep-mimetic sedation) in perioperative and ICU settings.
Clinical Implications: When aiming to preserve sleep-like neurophysiology, dexmedetomidine may be preferable to propofol. This could influence strategies to mitigate sleep disruption and delirium risk during sedation.
Key Findings
- Dexmedetomidine-induced unresponsiveness resembled N2 sleep based on delta power and network entropy patterns.
- Propofol showed smaller, regionally heterogeneous delta power changes and larger increases in network entropy versus dexmedetomidine and sleep.
- Intracranial EEG in 34 patients provided high-resolution spectral and connectivity data across wake, sedated, and unresponsive states.
Methodological Strengths
- Use of intracranial EEG enables precise spectral and network analyses not possible with scalp EEG
- Within-subject comparisons across natural sleep and anesthetic states with standardized staging (OAA/S, polysomnography)
Limitations
- Epilepsy surgical candidates may limit generalizability to broader perioperative populations
- Observational design without randomization between anesthetics; modest sample size
Future Directions: Randomized cross-over studies linking sleep-like metrics to clinical outcomes (e.g., delirium, sleep quality) and testing tailored sedation protocols in ICU and intraoperative settings.
BACKGROUND: Dexmedetomidine is a selective α METHODS: Intracranial encephalography recordings were obtained in 34 patients with epilepsy being evaluated for seizure resection surgery. Band power, functional connectivity, and network entropy were measured during task-free periods just before surgery, during anaesthesia with either dexmedetomidine or propofol, and during overnight sleep. Anaesthesia stage (wake, sedated, unresponsive) was determined using the Observer's Assessment of Arousal/Sedation. Sleep was staged using standard polysomnography. RESULTS: Significant differences in delta power were observed during dexmedetomidine and propofol anaesthesia and during sleep. However, the magnitude of changes in delta power was smaller and regionally heterogeneous for propofol compared with dexmedetomidine and sleep, whereas changes in network entropy were larger for propofol compared with dexmedetomidine and sleep. Quantitative comparisons between changes in delta power and network entropy suggest that unresponsiveness under dexmedetomidine anaesthesia produces a similar brain state to that observed during N2 sleep. CONCLUSIONS: Although delta power, functional connectivity, and network entropy all showed changes during propofol, dexmedetomidine, and sleep, the magnitudes of these changes suggest that the effects of dexmedetomidine are more similar than those of propofol to sleep, specifically to N2 sleep.