Daily Anesthesiology Research Analysis
Analyzed 104 papers and selected 3 impactful papers.
Summary
Three rigorously designed perioperative studies stand out today: a multicenter randomized trial in Lancet shows that lower-intensity anticoagulation (low-dose UFH or LMWH) is noninferior to standard-dose UFH for ECMO with a trend to less bleeding; a JAMA Surgery randomized trial demonstrates noninferiority of single-encounter AR-guided lung nodule localization with markedly less radiation, pain, and delays; and a randomized trial in BMC Anesthesiology finds PPV-guided fluid therapy noninferior to LCVP-guided management during open hepatectomy.
Research Themes
- Anticoagulation strategy optimization for ECMO
- Augmented reality to streamline perioperative workflows
- Goal-directed hemodynamics in major hepatic surgery
Selected Articles
1. Standard-dose unfractionated heparin versus low-dose unfractionated heparin and low-molecular-weight heparin in extracorporeal life support (RATE): an open-label, randomised, non-inferiority trial.
In a multicenter randomized non-inferiority trial of 320 ECMO patients, both low-dose UFH and therapeutic LMWH were noninferior to standard-dose UFH for a composite of severe bleeding, severe thromboembolism, or 6‑month mortality. Lower-intensity strategies showed a trend toward less severe bleeding without an increase in thromboembolism, supporting reconsideration of anticoagulation targets in ECMO.
Impact: This is the first sufficiently powered randomized trial to compare anticoagulation intensities in ECMO, directly informing a ubiquitous ICU practice with potential to reduce bleeding harm.
Clinical Implications: Centers may safely consider lower-intensity anticoagulation (low-dose UFH or LMWH) during ECMO, balancing bleeding and thrombosis risks while monitoring local protocols and patient-specific indications.
Key Findings
- Low-dose UFH and therapeutic LMWH were noninferior to standard-dose UFH for the composite of severe bleeding, severe thromboembolic complications, or 6‑month mortality.
- Severe bleeding was numerically lower with low-dose UFH (58%) and LMWH (59%) than with standard-dose UFH (65%), without excess severe thromboembolism.
- All-cause mortality at 6 months was 50% (standard UFH), 42% (low-dose UFH), and 44% (LMWH).
- Noninferiority margin was an absolute risk difference of 7.5 percentage points; both interventions met this criterion.
Methodological Strengths
- Multicenter randomized non-inferiority design with intention-to-treat analysis
- Clinically meaningful composite endpoint with 6‑month follow-up
Limitations
- Open-label design could introduce performance bias
- Bleeding and thromboembolism differences were not statistically significant despite favorable trends
Future Directions: Head-to-head pragmatic trials comparing LMWH vs UFH with standardized bleeding definitions, and subgroup analyses (VV vs VA ECMO, surgical vs medical) to refine anticoagulation targets.
BACKGROUND: In patients receiving extracorporeal membrane oxygenation (ECMO), standard practice is full-dose intravenous unfractionated heparin (UFH) targeting an activated partial thromboplastin time of 2·0-2·5 times baseline to reduce thrombotic risk. This approach can increase bleeding without further reducing thrombosis compared with low-dose UFH. Robust evidence to guide anticoagulation targets is absent because anticoagulation targets in ECMO have never been assessed in a sufficiently powered randomised trial. We aimed to determine whether low-dose UFH or therapeutic low-molecular-weight heparin (LMWH) is non-inferior to standard-dose UFH in patients receiving ECMO. METHODS: In this open-label, three-arm, randomised, non-inferiority trial at seven Dutch intensive care units (ICUs), adults aged 18 years or older supported with veno-venous or veno-arterial ECMO at the ICU without vital indication for full-dose anticoagulation (eg, mechanical mitral valve) were randomly assigned to intravenous standard-dose UFH (activated partial thromboplastin time 2·0-2·5 times baseline), intravenous low-dose UFH (1·5-2·0 times baseline), or therapeutic subcutaneous LMWH. The primary outcome was a composite of severe bleeding during ECMO support, severe thromboembolic complications during ECMO support, or all-cause mortality at 6 months, and was assessed in all randomly assigned patients with deferred informed consent and 6-month follow-up data according to the intention-to-treat principle. Non-inferiority was met if the upper 95% CI limit for the absolute risk difference was less than 7·5 percentage points. This trial is registered at ClinicalTrials.gov (NCT04536272) and the Dutch trial register (NL7976). FINDINGS: Between Oct 22, 2020, and Sept 12, 2024, 330 patients were enrolled: 110 were randomly assigned to standard-dose UFH, 110 to low-dose UFH, and 110 to LMWH. Of 330 enrolled patients, 320 (225 [70%] males, 95 [30%] females; median age 56 years [IQR 45-65]; 255 [80%] White ethnicity) were analysed at 6 months. The composite primary outcome occurred in 87 (81%) of 107 patients with standard-dose UFH, 78 (72%) of 108 with low-dose UFH (absolute risk difference -9·1 percentage points [95% CI -20·3 to 2·1]), and 79 (75%) of 105 with LMWH (-6·1 percentage points [-17·2 to 5·0]), meeting non-inferiority for both interventions. The frequency of severe bleeding was lower with low-dose UFH and LMWH than with standard-dose UFH (63 [58%] patients and 62 [59%] vs 70 [65%]), without excess severe thromboembolic complications (11 [10%] and nine [9%] vs 12 [11%]), although these differences did not reach statistical significance. At 6 months, 54 (50%) patients in the standard-dose UFH group, 45 (42%) in the low-dose UFH group, and 46 (44%) in the LMWH group had died. INTERPRETATION: Low-dose UFH and therapeutic LMWH were non-inferior to standard-dose UFH. This finding supports reconsideration of anticoagulation targets in ECMO. Given the global expansion of ECMO, these findings suggest that reduced anticoagulation targets could substantially reduce bleeding-related harm. FUNDING: ZonMw.
2. Single-Encounter Augmented Reality-Guided Localization for Resection of Suspected Early-Stage Lung Cancer: A Randomized Clinical Trial.
Across 270 mITT patients, single-encounter AR-guided localization achieved noninferior surgical success versus standard CT-guided localization while markedly reducing radiation exposure, preprocedural pain, puncture time, and localization-to-incision delays. This streamlined OR-based workflow under general anesthesia may decongest CT suites and improve patient experience without compromising surgical margins.
Impact: This trial demonstrates a viable, less burdensome alternative to standard CT-guided localization with strong operational and patient-centered advantages, enabled by AR guidance.
Clinical Implications: Thoracic teams can consider AR-guided single-encounter localization to reduce radiation and streamline care, particularly for small nodules suitable for sublobar resection, while ensuring adequate margins.
Key Findings
- Noninferiority achieved for successful sublobar resection: 98.5% (AR) vs 99.3% (CT); risk difference −0.8 percentage points (95% CI, −2.7 to 3.9).
- Radiation exposure was substantially lower with AR (median 456.5 vs 1260.1 mGy·cm; P<.001).
- Preprocedural pain was lower with AR (NRS 0 vs 5; P<.001), with shorter puncture time (0.63 vs 6.50 minutes) and localization-to-incision interval (2.0 vs 33.5 minutes).
- Localization accuracy (error) did not differ significantly; pneumothorax occurred in 29.4% of CT-guided cases.
Methodological Strengths
- Randomized noninferiority design across five centers with mITT analysis
- Comprehensive secondary outcomes including radiation, PROs, and workflow metrics
Limitations
- Differences in anesthesia setting (general anesthesia in AR vs local for CT) may confound pain-related endpoints
- Study conducted in Chinese centers; generalizability to other health systems requires validation
Future Directions: External validation in diverse systems, cost-effectiveness analyses, and evaluation in more complex nodules (e.g., ground-glass, deep lesions) with standardized margin protocols.
IMPORTANCE: Preoperative localization is often required to achieve successful sublobar resection with adequate margins for computed tomography (CT)-detected pulmonary nodules suspicious for early-stage lung cancer. Conventional CT-guided localization involves a multiple-encounter workflow that may cause pain, radiation exposure, and complications. OBJECTIVE: To determine whether a single-encounter augmented reality (AR)-guided percutaneous localization strategy is noninferior to standard multiple-encounter CT-guided localization for achieving successful sublobar resection. DESIGN, SETTING, AND PARTICIPANTS: This randomized noninferiority trial was conducted at 5 centers in China between August 8, 2024, and September 30, 2025. Among 296 randomized patients, 270 were included in the modified intention-to-treat analysis (134 in AR; 136 in CT). Exclusion criteria included multiple nodules (≥2), unsafe percutaneous access, comorbidities limiting participation, or consent withdrawal. INTERVENTIONS: Single-encounter AR-guided percutaneous localization performed in the operating room under general anesthesia vs multiple-encounter CT-guided percutaneous localization performed in the CT suite under local anesthesia followed by transfer to the operating room for surgery. MAIN OUTCOMES AND MEASURES: The primary outcome was successful sublobar resection, defined as R0 resection with protocol-defined margin adequacy according to nodule type. Secondary outcomes included localization accuracy, radiation exposure, complications, patient-reported outcomes, and procedural efficiency. RESULTS: The median (IQR) age of the population was 59 (50-67) years, and 172 participants (63.7%) were female. Successful sublobar resection occurred in 132 of 134 AR-guided procedures (98.5%) and 135 of 136 CT-guided procedures (99.3%) (risk difference, -0.8 percentage points; 95% CI, -2.7 to 3.9), meeting the noninferiority criterion. There was no statistically significant difference in localization error between groups (median [IQR]: AR group, 3.0 [0.0 to 5.0]; CT group, 3.0 [2.0 to 6.0]). AR guidance was associated with lower radiation exposure (median [IQR], 456.50 [378.75 to 631.85] vs 1260.11 [1026.48 to 1544.53] mGy · cm; P < .001), lower preoperative pain (median [IQR] numeric rating scale, 0 [0-0] vs 5 [4-6]; P < .001), shorter puncture time (median [IQR], 0.63 [0.50 to 0.83] vs 6.50 [5.00 to 8.75] minutes; P < .001), and shorter localization-to-incision interval (median [IQR], 2.00 [1.50 to 2.00] vs 33.50 [18.00 to 63.00] minutes; P < .001). Pneumothorax occurred in 40 of 136 CT-guided cases (29.4%). CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, single-encounter AR-guided localization was noninferior to CT-guided localization for achieving successful sublobar resection and was associated with reduced radiation exposure, lower pain, shorter puncture time, and a shorter localization-to-incision interval, supporting its use as an alternative to CT-guided localization. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT06548451.
3. Pulse pressure variation-guided versus low central venous pressure-guided fluid management during elective open hepatectomy: a randomized non-inferiority trial.
In elective open hepatectomy, PPV-guided fluid therapy achieved noninferior intraoperative blood loss compared with conventional LCVP-guided management, with similar perfusion and renal metrics. PPV provides a physiologically grounded alternative to CVP targeting without compromising surgical field conditions.
Impact: This randomized trial challenges a long-standing practice (LCVP targeting) by showing that a dynamic preload/volume responsiveness metric (PPV) can safely achieve comparable blood loss.
Clinical Implications: For open hepatectomy, anesthesiologists can consider PPV-guided goal-directed therapy to minimize fluids while maintaining perfusion, especially where CVP targets are unreliable or impractical.
Key Findings
- PPV-guided strategy was noninferior to LCVP-guided management for intraoperative blood loss (mean difference −43 mL; 95% CI −169 to 83; noninferiority margin 98 mL).
- Total crystalloids/colloids, urine output, and serum lactate were similar between groups.
- Postoperative renal function at 24 hours (serum creatinine) did not differ, and surgical field grading was comparable.
Methodological Strengths
- Prospective randomized noninferiority design with predefined algorithms
- Clinically relevant primary endpoint (blood loss) and pragmatic secondary outcomes
Limitations
- Single-center study with modest sample size may limit generalizability
- Short-term outcomes; no assessment of longer-term complications or recovery
Future Directions: Multicenter trials incorporating enhanced recovery pathways and cost-effectiveness to confirm scalability of PPV-guided strategies in hepatic surgery.
BACKGROUND: Low central venous pressure (LCVP)-guided fluid management is widely used to reduce blood loss during liver resection; however, LCVP is an unreliable marker of preload. Pulse pressure variation (PPV) is a dynamic index of fluid responsiveness. This study evaluated whether a PPV-guided fluid management strategy is non-inferior to conventional LCVP-guided management in reducing intraoperative blood loss during elective open hepatectomy. METHODS: In this single-center, randomized, non-inferiority trial, adult patients (18-65 years) with American Society of Anesthesiologists physical status I-II scheduled for elective, non-donor open hepatic resection involving two or more segments were randomized to either an LCVP-guided group or a PPV-guided group. Fluid administration in both groups followed predefined hemodynamic algorithms. The primary outcome was intraoperative blood loss. Secondary outcomes included total intraoperative fluid administration, urine output, serum lactate concentrations, and postoperative renal function. Non-inferiority was assessed using a prespecified margin of 98 ml. RESULTS: Sixty-four patients (32 in each group) were included in the final analysis. Intraoperative blood loss was comparable between the LCVP and PPV groups (683 ± 276 ml vs. 726 ± 223 ml, respectively). The mean difference in blood loss was - 43 ml (95% confidence interval: -169 to 83 ml), with the upper limit remaining below the predefined non-inferiority margin, confirming non-inferiority of the PPV-guided strategy. Total crystalloid and colloid administration, urine output, surgical field grading, and perioperative serum lactate levels were similar between the two groups. Postoperative serum creatinine levels at 24 h did not differ significantly. CONCLUSIONS: PPV-guided fluid management was non-inferior to an LCVP-based strategy for reducing intraoperative blood loss during elective open hepatic resection, without evidence of compromised tissue perfusion. These findings suggest that PPV-guided fluid management may be a feasible alternative to CVP-targeted fluid management in this setting. TRIAL REGISTRATION: The trial was registered prospectively with the Clinical Trials Registry of India (CTRI/2018/01/011547; registered on 24 January 2018).