Daily Anesthesiology Research Analysis
Analyzed 66 papers and selected 3 impactful papers.
Summary
Three studies reshape perioperative thinking in anesthesiology: a meta-analysis shows opioid-free anesthesia yields comparable analgesia with less PONV but more bradycardia; a prospective mechanistic study links elevated TFPI after CPB to impaired thrombin generation; and a multicenter cohort quantifies severe bleeding risk after heart transplantation and its association with one-year mortality.
Research Themes
- Opioid-free anesthesia and multimodal analgesia
- Perioperative coagulation mechanisms after cardiopulmonary bypass
- Risk stratification and bleeding outcomes after heart transplantation
Selected Articles
1. The effect of opioid-free anesthesia on postoperative pain in orthopedic surgery: a systematic review and meta-analysis of randomized controlled trial.
Across seven RCTs in orthopedic surgery, opioid-free anesthesia achieved similar pain scores and morphine use compared to opioid-based anesthesia, while significantly reducing PONV and intraoperative hypotension and delaying time to first analgesic request. However, OFA increased intraoperative bradycardia, highlighting a safety trade-off, particularly with dexmedetomidine-based regimens.
Impact: This synthesis of RCTs provides higher-level evidence to guide adoption of opioid-sparing strategies, quantifying benefits (less PONV, hemodynamic stability) and risks (bradycardia). It informs anesthetic planning in high-volume orthopedic procedures where PONV reduction is a priority.
Clinical Implications: Consider OFA protocols to reduce PONV and hypotension in orthopedic patients, with proactive monitoring and mitigation of bradycardia (avoid high-dose dexmedetomidine, have anticholinergics/chronotropes ready). Tailor to patients at high risk of PONV and those in whom opioid minimization is desired.
Key Findings
- Postoperative pain intensity at PACU, 24 h, and 48 h did not differ between OFA and opioid-based anesthesia.
- OFA significantly reduced PONV risk (RR 0.37) and intraoperative hypotension (RR 0.56).
- Time to first analgesic request was prolonged by about 26 minutes with OFA, while 24-h morphine consumption was similar.
- OFA increased intraoperative bradycardia risk (RR 1.86).
Methodological Strengths
- Systematic review and meta-analysis of randomized controlled trials with PROSPERO registration
- Risk of bias and certainty assessed using Cochrane RoB 2.0 and GRADE
Limitations
- Modest total sample size (n=408) across seven trials may limit power for safety outcomes
- Heterogeneity in OFA protocols (e.g., dexmedetomidine dosing, adjuncts) and surgical procedures
Future Directions: Large, multicenter RCTs comparing standardized OFA versus opioid-based regimens should evaluate patient-centered outcomes (PONV, recovery trajectories) and cardiovascular safety, including protocolized dexmedetomidine dosing and monitoring.
BACKGROUND: Opioid-free anaesthesia (OFA) is increasingly recognized as a perioperative approach that may offer effective pain control with reduced risk of adverse effects. Considering that orthopaedic surgeries often lead to at least moderate postoperative pain, we assessed the effectiveness and safety of OFA in orthopaedic procedures. METHODS: We searched PubMed, ScienceDirect, ProQuest, and EuropePMC for relevant randomised controlled trials (RCT) and supplemented the data with citation tracking. Data were analysed using RevMan version 5.4. The risk of bias and the certainty of evidence were evaluated using the Cochrane Risk of Bias 2.0 tool and the GRADE approach. The study was registered on PROSPERO (CRD420251048348). RESULTS: Seven RCTs involving 408 patients were included. The intensity of postoperative pain measured in the post-anaesthesia care unit (mean difference [MD]: -0.08), at 24 hours (MD: -0.06), and at 48 hours (MD: -0.26) was not statistically significant. OFA reduced the risk of postoperative nausea and vomiting (PONV) (RR: 0.37; P = 0.00001) and prolonged the time to first request for analgesia (MD: 25.60 minutes; P = 0.00001). Twenty-four-hour morphine consumption was comparable across groups (MD: -0.28; P = 0.76). OFA reduced the incidence of intraoperative hypotension (risk ratio [RR]: 0.56; P = 0.02) but increased the risk of intraoperative bradycardia (RR: 1.86; P = 0.04). CONCLUSIONS: In orthopaedic surgery, OFA provides comparable pain control to opioid-based anaesthesia. It also reduced the incidence of postoperative nausea and vomiting and intraoperative hypotension, and prolonged the time to the first request for analgesia (statistically, but not clinically). However, the potential risk of bradycardia should be considered when using dexmedetomidine-based analgesics.
2. Postoperative reduction in thrombin generation induced by elevated levels of tissue factor pathway inhibitor in cardiac surgery: a prospective observational study.
In adults undergoing CPB, TFPI rose markedly at the end of surgery while thrombin generation decreased, with strong correlations between higher TFPI, prolonged whole-blood coagulation time, and reduced TG peaks. Neutralizing TFPI reversed TG suppression, implicating TFPI as a mechanistic driver of post-CPB hypocoagulability.
Impact: This study provides mechanistic evidence linking TFPI elevation to impaired thrombin generation after CPB, offering a targetable pathway for diagnosing or mitigating post-CPB coagulopathy.
Clinical Implications: Perioperative teams should recognize persistent TFPI-mediated anticoagulation after CPB as a contributor to bleeding risk. Viscoelastic/thrombin generation assays can guide hemostatic management; strategies that counteract TFPI effects may warrant exploration in refractory bleeding.
Key Findings
- TFPI increased from a median 18 ng/mL preoperatively to 54 ng/mL at the end of surgery (P<0.001).
- Peak thrombin generation decreased substantially at the end of surgery compared with preoperative values (P<0.001).
- TFPI correlated positively with whole-blood coagulation time (Rs=0.643) and negatively with TG peak (Rs=-0.624).
- Anti-TFPI antibody neutralized the reduction in peak thrombin generation.
Methodological Strengths
- Prospective sampling at predefined perioperative time points
- Use of complementary assays: thrombin generation, dielectric coagulometry, and antibody neutralization
Limitations
- Single-center observational design limits generalizability
- Clinical bleeding outcomes were not the primary endpoint
Future Directions: Interventional trials should test TFPI-modulating approaches or tailored hemostatic therapy based on thrombin generation to reduce bleeding after CPB.
PURPOSE: Tissue factor pathway inhibitor (TFPI) is an intrinsic anticoagulant factor, and its plasma concentration is elevated by heparin administration. Because several hours are required to return to normal range after heparin reversal, we investigated the role of TFPI in the inhibition of thrombin generation (TG) in patients undergoing cardiac surgery. METHODS: Blood samples were collected from adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) before, at the end of, and 1 day after surgery. Plasma concentration of TFPI, peak height of the TG assay (peak TG), and whole blood coagulation time by dielectric blood coagulometry using a Russell's viper venom cartridge system were evaluated. Nonparametric correlation was evaluated using Spearman's method, and time-dependent change was analyzed using repeated measures analysis of variance. RESULTS: The plasma concentration of TFPI was higher (54 [47-60] ng/mL vs. 18 [13-27] ng/mL; P < 0.001) and the peak TG value was lower (98.1 [48.9-148] nM vs. 268 [244-309]; P < 0.001) at the end of surgery than before surgery. Plasma TFPI concentration showed a positive correlation with whole blood coagulation time as measured by dielectric blood coagulometry (Rs = 0.643) and a negative correlation with peak TG (Rs = - 0.624). Anti-TFPI antibody neutralized reduction in peak TG. CONCLUSIONS: In patients undergoing cardiac surgery using CPB, the increase in plasma TFPI concentration at the end of surgery causes a reduction in TG and impairment of whole blood coagulation via a mechanism that includes inhibition of factor Xa activity.
3. Severe post-operative bleeding after heart transplantation.
In a two-center cohort of 446 adult heart transplant recipients, severe postoperative bleeding (UDPB ≥3) occurred in 25% and was independently associated with preoperative anemia, longer CPB duration, and pretransplant mechanical circulatory support. Severe bleeding nearly doubled one-year mortality (adjusted HR 1.91), underscoring a major modifiable risk domain.
Impact: This study quantifies bleeding burden and prognostic impact after heart transplantation in a leading anesthesiology journal, providing concrete risk factors that can inform perioperative strategies and resource allocation.
Clinical Implications: Optimize preoperative hemoglobin, minimize CPB duration when feasible, and enhance hemostatic vigilance in patients bridged with mechanical support. Consider targeted transfusion and coagulation management pathways for high-risk profiles to mitigate mortality.
Key Findings
- Severe postoperative bleeding (UDPB ≥3) occurred in 25% (112/446) of heart transplant recipients.
- Independent risk factors included mechanical circulatory support (adjOR 2.21), lower preoperative hemoglobin (adjOR 0.85 per g/dL), and longer CPB duration (adjOR 1.08 per 10 minutes).
- Severe bleeding was associated with higher 1-year mortality (35% vs 13%; adjusted HR 1.91, p=0.008).
Methodological Strengths
- Multicenter cohort with standardized bleeding definition (UDPB)
- Adjusted analyses using multivariable logistic and Cox regression
Limitations
- Retrospective observational design is prone to residual confounding
- Findings from two French referral centers may limit external generalizability
Future Directions: Prospective, multicenter studies should test targeted bleeding prevention bundles (e.g., preoperative anemia management, CPB strategies, coagulation optimization) and evaluate causal pathways.
BACKGROUND: Post-operative bleeding is frequent in cardiac surgery, but its incidence, risk factors and consequences remain largely unknown after heart transplantation. The main objective of this study was to describe the incidence of severe bleeding complications after adult heart transplantation. METHODS: We conducted an observational study including all adult patients who received a heart transplant between 2015 and 2022, in two French referral centers. The primary endpoint was the incidence of severe bleeding complications defined by a UDPB score ≥ 3 (Universal Definition of Perioperative Bleeding). Multivariable logistic regression was used to identify variables associated with the incidence of severe post-operative bleeding. The impact of severe post-operative bleeding on one-year mortality was evaluated using a multivariable Cox regression model. RESULTS: Among the 446 patients included, 112 (25%) developed severe bleeding. In multivariable analysis, long-term mechanical cardiac support (adjOR 2.21 [1.01-4.88]), preoperative hemoglobin (adjOR 0.85 [0.76-0.95]) and the duration of CPB (per 10min increase, adjOR=1.08 [1.03-1.15]) were associated with severe bleeding. Severe postoperative bleeding was associated with an increased mortality at one-year (35% vs 13%, p<0.001), with an adjusted HR of 1.91 (95% CI, 1.18-3.09, p=0.008). CONCLUSIONS: This study reports a high incidence of severe hemorrhagic complications following heart transplantation, particularly in patients with mechanical circulatory support. Bleeding complications were associated with a significant increase in morbidity and mortality. Larger-scale studies are needed to identify and evaluated potential prevention strategies.