Daily Anesthesiology Research Analysis
A double-blind RCT in total hip arthroplasty found no ROTEM evidence of fibrinolysis or clinical benefit from routine tranexamic acid, supporting more selective use. A multicenter Anesthesiology study showed higher standardized ICU admission ratios after rapid response activations were associated with better neurologic outcomes. A large external validation confirmed a dose-dependent association between red blood cell transfusion and postoperative AKI in cardiac surgery.
Summary
A double-blind RCT in total hip arthroplasty found no ROTEM evidence of fibrinolysis or clinical benefit from routine tranexamic acid, supporting more selective use. A multicenter Anesthesiology study showed higher standardized ICU admission ratios after rapid response activations were associated with better neurologic outcomes. A large external validation confirmed a dose-dependent association between red blood cell transfusion and postoperative AKI in cardiac surgery.
Research Themes
- Selective antifibrinolytic use guided by viscoelastic testing
- ICU triage metrics and outcomes after in-hospital rapid response
- Transfusion practices and renal risk in cardiac anesthesia
Selected Articles
1. The effect of tranexamic acid on blood coagulation in primary total hip arthroplasty using rotational thromboelastometry: a randomized controlled trial.
In 50 primary THA patients, prophylactic TXA did not alter ROTEM parameters, did not reveal perioperative fibrinolysis, and did not improve clinical outcomes compared with placebo. Findings support avoiding routine TXA when fibrinolysis is not present and suggest ROTEM-guided, selective use in high-risk cases.
Impact: This RCT challenges routine TXA use by showing no ROTEM or clinical benefit without demonstrable fibrinolysis, promoting precision antifibrinolytic therapy.
Clinical Implications: Consider viscoelastic testing to identify hyperfibrinolysis and reserve TXA for patients with ROTEM evidence or high-risk profiles, rather than universal prophylaxis in THA.
Key Findings
- ROTEM showed normal-range coagulability in all patients with no perioperative fibrinolysis (no ML >15%).
- No differences between TXA and placebo in NATEM/T-APTEM variables or clinical outcomes, including blood loss.
- Postoperative ROTEM indicated a trend toward accelerated coagulation (shorter CT, CFT; higher A10), independent of TXA.
Methodological Strengths
- Double-blind randomized controlled design with placebo control
- Mechanistic assessment using ROTEM (NATEM and T-APTEM) with preregistration (NCT03897621)
Limitations
- Single-center, small sample size (n=50), potentially underpowered for rare events or small clinical differences
- Findings may not generalize to patients with preexisting hyperfibrinolysis or different surgical settings
Future Directions: Large, pragmatic RCTs stratified by ROTEM-defined fibrinolysis are needed to define selective TXA indications and dosing, and to assess bleeding, thromboembolic events, and patient-centered outcomes.
BACKGROUND: Tranexamic acid (TXA), is commonly administered prophylactically to reduce blood loss in patients undergoing total hip arthroplasty (THA). However, its effect has never been studied. We hypothesized that no difference exists in the degree of fibrinolysis and blood loss between patients receiving prophylactic TXA and placebo. METHODS: This double-blinded randomized-controlled trial included 50 patients undergoing primary THA in 2021-2023. Clinicaltrials.gov (NCT03897621). Rotational-thromboelastometry (ROTEM) were performed to test blood coagulability using non citrated whole blood (NATEM) and blood treated with TXA (T-APTEM). The intervention group received TXA intravenously. The placebo group received 0.9% sodium chloride solution. The primary outcome measure was to quantitate the degree of fibrinolysis measured by maximum lysis (ML) demonstrated by ROTEM variables. Fibrinolysis was defined as ML (maximum lysis) > 15% within 1 h of testing. FINDINGS: Blood coagulability tested by ROTEM was within the normal range in all patients, and no difference was found between the TXA group and placebo group.NATEM and T-APTEM variables were similar in both groups and no patient developed fibrinolysis during the entire perioperative phases. At baseline, T-APTEM, compared with NATEM, showed shorter CT (746 ± 265 vs. 991 ± 237 p < 0.05) and greater ML (1.9 ± 2.2 vs. 0.8 ± 1, p < 0.05), suggesting some degree of acceleration of coagulation. Postoperatively, blood coagulability showed a tendency of acceleration with shorter CT (689 ± 188 vs. 828 ± 163, p < 0.05) and CFT (258 ± 101 vs. 293 ± 87 p < 0.05) and increased A10 (41 ± 9 vs. 38 ± 8, p < 0.05). Clinical outcomes, including blood loss, hematologic variables, and coagulation profile were similar between the two groups. INTERPRETATION: Normal range of blood coagulability in all patients, no significant differences between NATEM and T-APTEM variables, and similar clinical outcome between the two groups suggest that there is no definitive medical indication for TXA administration in patients undergoing THA without a preexisting fibrinolytic condition. Monitoring blood coagulability using ROTEM may be useful in guiding selective administration of TXA in high-risk patients. FUNDING: Department of Anesthesiology funding, Thomas Jefferson University Hospital. Support was provided solely from institutional and/or departmental sources.
2. Impact of the Standardized Intensive Care Unit Admission Ratio on Outcomes in Rapid Response System Activations: A Retrospective Multicenter Study in Japan.
Across 8,794 RRS activations, higher standardized ICU admission ratios were associated with lower odds of poor neurological outcome or death at 30 days, though the association with mortality alone was not significant. Findings suggest that greater ICU utilization after rapid responses may improve neurologic outcomes.
Impact: Introduces a standardized, risk-adjusted ICU admission metric (SIAR) and links institutional ICU utilization patterns to clinically meaningful outcomes after RRS activations.
Clinical Implications: Hospitals can benchmark SIAR to optimize post-RRS triage practices, potentially prioritizing ICU admission for patients at risk of neurologic deterioration while studying mechanisms and resource implications.
Key Findings
- Median ICU admission rate after RRS was 0.33; median SIAR was 0.98 across 35 institutions.
- Higher SIAR was significantly associated with lower odds of CPC ≥3 or death within 30 days (adjusted OR per 0.1 SIAR increase 0.94; P < 0.001).
- Association with 30-day mortality alone was not statistically significant in adjusted models.
Methodological Strengths
- Large multicenter cohort with 8,794 RRS activations and hospital-level clustering
- Risk-adjusted metric (SIAR) and GEE logistic regression addressing intra-hospital correlation
Limitations
- Retrospective observational design limits causal inference and is subject to residual confounding
- Potential heterogeneity in RRS criteria, ICU admission thresholds, and case mix across institutions
Future Directions: Prospective studies should test SIAR-informed triage pathways, evaluate mechanisms (e.g., timing/level of care), and quantify resource utilization versus outcome benefits.
BACKGROUND: Intensive care unit (ICU) admission rates after rapid response system (RRS) activation vary widely across institutions. This study examined institutional differences in ICU admission rates and their association with outcomes. METHODS: A multicenter retrospective observational study was conducted using a Japanese in-hospital emergency registry, including patients with RRS activation between 2018 and 2022. The ICU admission rate (ICU admissions/RRS activations) and the standardized ICU admission ratio (SIAR; actual/predicted ICU admissions) for each of 35 participating institutions were calculated. The association between SIAR and outcomes was assessed using generalized estimating equation logistic regression with hospital-level clustering. The primary outcome was death within 30 days, and the secondary outcome was a composite of Cerebral Performance Category (CPC) of 3 or higher or death within 30 days. Outcomes were defined as events occurring during hospitalization, within a maximum of 30 days after RRS activation. RESULTS: The study included 8,794 patients. The median ICU admission rate was 0.33 (interquartile range, 0.21 to 0.47), and the median SIAR was 0.98 (interquartile range, 0.75 to 1.17). In univariable analysis, SIAR showed a nonsignificant association with the incidence of death within 30 days (β = -0.05; 95% CI, -0.12 to 0.01; P = 0.108) and a significant negative association with the incidence of CPC of 3 or higher or death within 30 days (β = -0.15; 95% CI, -0.27 to -0.03; P = 0.015). In multivariable analysis, a 0.1-unit increase in SIAR was associated with an odds ratio of 0.98 (95% CI, 0.97 to 0.99; P = 0.104) for death within 30 days and 0.94 (95% CI, 0.92 to 0.96; P < 0.001) for CPC of 3 or higher or death within 30 days. CONCLUSIONS: Higher SIAR values were significantly associated with a lower incidence of CPC of 3 or higher or death within 30 days. Greater ICU utilization after RRS activation may improve outcomes, although underlying mechanisms require further study.
3. Blood transfusion and acute kidney injury after cardiac surgery: a retrospective observational study.
In 5,204 adults undergoing on-pump cardiac surgery, red blood cell transfusion showed a dose-dependent association with postoperative AKI, strongest when >2 units were transfused. The findings externally validate earlier work and underscore the need for restrictive, kidney-conscious transfusion strategies.
Impact: Provides robust external validation that the quantity of RBC transfusion independently elevates AKI risk after cardiac surgery, informing transfusion thresholds and patient blood management.
Clinical Implications: Adopt restrictive transfusion thresholds, minimize RBC units, and integrate AKI risk into intraoperative decision-making and consent; consider alternatives (cell salvage, antifibrinolytics when indicated).
Key Findings
- AKI occurred in 15.3% (798/5204) with KDIGO distribution: 77% stage 1, 11% stage 2, 12% stage 3.
- RBC transfusion (but not plasma or platelets) was significantly associated with AKI after adjustment using IPW logistic regression.
- Dose-response: 1–2 units increased probabilities of stage 1 AKI by 4% and stage 2–3 by 2%; >2 units increased stage 1 by 12% and stage 2–3 by 9%.
Methodological Strengths
- Large single-center cohort with detailed perioperative data and standardized KDIGO AKI criteria
- Causal modeling approach using inverse probability weighting to mitigate confounding
Limitations
- Retrospective design from a single center may limit generalizability and causal inference
- Nonemergent cases only; residual confounding from unmeasured factors possible
Future Directions: Prospective trials to test kidney-sparing transfusion strategies, integrate AKI risk prediction into PBM, and evaluate alternatives to RBC transfusion in cardiac surgery.
PURPOSE: Cardiac surgery-associated acute kidney injury (AKI) is linked to poor outcomes. An observational study from Copenhagen, Denmark identified perioperative red blood cell (RBC) transfusion as a modifiable risk factor for AKI, with a dose-dependent relationship between the number of RBC units transfused and the occurrence and severity of AKI. We aimed to externally validate those findings in a larger population. METHODS: We conducted a retrospective observational study of adult patients undergoing nonemergent on-pump cardiac surgery at Toronto General Hospital (Toronto, ON, Canada) between 2016 and 2021. Acute kidney injury was classified using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Data were analyzed using inverse probability weighted logistic regression. RESULTS: Among 5,204 patients, 798 developed AKI, with 77% classified as stage 1, 11% as stage 2, and 12% as stage 3. Patients with AKI were older, had lower preoperative hemoglobin levels and estimated glomerular filtration rates, longer cardiopulmonary bypass duration, and lower intraoperative hemoglobin levels. Red blood cells were administered to 37% of patients, with 14% receiving plasma and 32% platelets. Only RBC transfusion, alone or combined with other blood products, was significantly associated with AKI. The transfusion of 1-2 RBC units increased the probability of stage 1 AKI by 4% and stage 2-3 AKI by 2% compared with patients not receiving RBCs. The risk was especially pronounced with the transfusion of > 2 units of RBCs, which raised the probability of stage 1 AKI by 12% and stage 2-3 AKI by 9%. CONCLUSIONS: This study confirms previous findings that RBC transfusion is associated with postoperative AKI in cardiac surgery patients. The association was strongest among patients who received > 2 units of RBCs. Prospective studies are needed to determine the optimal strategies for transfusion in these patients and evaluate potential alternatives.