Is Tranexamic Acid Associated With Mortality or Multiple Organ Failure Following Severe Injury?

BACKGROUND: Tranexamic acid (TXA) administration is recommended in severely injured trauma patients. We examined TXA administration, admission fibrinolysis phenotypes, and clinical outcomes following traumatic injury and hypothesized that TXA was associated with increased multiple organ failure (MOF). METHODS: Two-year, single-center, retrospective investigation. Inclusion criteria were age ≥ 18 years, Injury Severity Score (ISS) >16, admitted from scene of injury, thromboelastography within 30 min of arrival. Fibrinolysis was evaluated by lysis at 30 min (LY30) and fibrinolysis phenotypes were defined as: Shutdown: LY30 ≤ 0.8%, Physiologic: LY30 0.81-2.9%, Hyperfibrinolysis: LY30 ≥ 3.0%. Primary outcomes were 28-day mortality and MOF. The association of TXA with mortality and MOF was assessed among the entire study population and in each of the fibrinolysis phenotypes. RESULTS: Four hundred twenty patients: 144/420 Shutdown (34.2%), 96/420 Physiologic (22.9%), and 180/410 Hyperfibrinolysis (42.9%). There was no difference in 28-day mortality by TXA administration among the entire study population (P = 0.52). However, there was a significant increase in MOF in patients who received TXA (11/46, 23.9% vs 16/374, 4.3%; P < 0.001). TXA was associated MOF (OR: 3.2, 95% CI 1.2-8.9), after adjusting for confounding variables. There was no difference in MOF in patients who received TXA in the Physiologic (1/5, 20.0% vs 7/91, 7.7%; P = 0.33) group. There was a significant increase in MOF among patients who received TXA in the Shutdown (3/11, 27.3% vs 5/133, 3.8%; P = 0.001) and Hyperfibrinolysis (7/30, 23.3% vs 5/150, 3.3%; P = 0.001) groups. CONCLUSIONS: Administration of TXA following traumatic injury was associated with MOF in the fibrinolysis shutdown and hyperfibrinolysis phenotypes and warrants continued evaluation.

Measurement of Retinal Microvascular Blood Velocity Using Erythrocyte Mediated Velocimetry.

Changes in retinal blood flow may be involved in the pathogenesis of glaucoma and other ocular diseases. Erythrocyte mediated velocimetry (EMV) is a novel technique where indocyanine green (ICG) dye is sequestered in erythrocyte ghosts and autologously re-injected to allow direct visualization of erythrocytes for in vivo measurement of speed. The purpose of this study is to determine the mean erythrocyte speed in the retinal microvasculature, as well as the intravisit and intervisit variability of EMV. Data from 23 EMV sessions from control, glaucoma suspect, and glaucoma patients were included in this study. In arteries with an average diameter of 43.11 µm ± 6.62 µm, the mean speed was 7.17 mm/s ± 2.35 mm/s. In veins with an average diameter of 45.87 µm ± 12.04 µm, the mean speed was 6.05 mm/s ± 1.96 mm/s. Intravisit variability, as measured by the mean coefficient of variation, was 3.57% (range 0.44-9.68%). Intervisit variability was 4.85% (range 0.15-8.43%). EMV may represent reliable method for determination of retinal blood speed, potentially allowing insights into the effects of pharmacologic agents or pathogenesis of ocular diseases.