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Background: The beneficial effects of estrogens on survival from hemorrhage have been suggested in some preclinical models. This study investigated the effects of ethynylestradiol-3-sulfate (EE-3-S) on coagulation, metabolism and survival in pigs following traumatic hemorrhage., Methods: Twenty-six pigs were randomized into: normal saline group (NS, n = 10), EE-3-S group (EE-3, n = 11) groups, and no resuscitation group (NR, n = 5). Femur fracture was performed in each pig's left leg, followed by hemorrhage of 55% of estimated blood volume and a 10-minute shock period. Afterward, pigs were resuscitated with a small volume of either NS alone (4 mL/kg) or EE-3-S with NS (1 mL/kg at concentration of 1 mg/mL, plus NS solution of 3 mL/kg). Pigs in NR group were not resuscitated with any fluid. All pigs were then monitored for 6 hours or until death, with hemodynamics and survival times recorded. Blood samples were taken during the study for measurements of oxygen metabolism (oxygen delivery, extraction, and consumption) and coagulation function (using Rotem with Extem reagents)., Results: All baseline measurements were similar among the three groups. In the NS group, femur fracture and hemorrhage immediately reduced mean arterial pressure (MAP, 74 ± 3 mm Hg to 44 ± 4 mm Hg) and increased heart rate (97 ± 5 bpm to 218 ± 14 bpm, both p < 0.05). Similar changes in MAP and heart rate were observed in the EE-3 and NR groups. There were no differences observed in changes of Rotem ® measurements or oxygen metabolism among the groups during the study. At 6 hours, four pigs in NS, four pigs in EE-3-S, and two pigs in the NR group survived to the end of the study. The mean survival times were similar among the NS (212 ± 43 minutes), EE-3 (212 ± 39 minutes), and NR (223 ± 63 minutes) groups ( p = 0.9845)., Conclusion: Following severe traumatic hemorrhage, hypotensive resuscitation with EE-3-S did not impact coagulation, metabolism, or survival in pigs., (Copyright © 2023 Written work prepared by employees of the Federal Government as part of their official duties is, under the U.S. Copyright Act, a “work of the United States Government” for which copyright protection under Title 17 of the United States Code is not available. As such, copyright does not extend to the contributions of employees of the Federal Government.)

Background: This study compared the resuscitation effects of platelets and fibrinogen concentrate (FC) on coagulation and hemodynamics in pigs with traumatic hemorrhage and reduced platelet counts., Methods: Thirty pigs (40 ± 3 kg) were anesthetized and catheterized with an apheresis catheter to remove platelets using the Haemonetics 9000 (Haemonetics, Braintree, MA). Afterward, a femur fracture was induced, followed by hemorrhage of 35% the estimated blood volume. Pigs were then randomized to be resuscitated with 5% human albumin (12.5 mL/kg), FC (250 mg/kg, 12.5 mL/kg), or platelets collected from apheresis (11.0 ± 0.5 mL/kg). Animals were monitored for 2 hours or until death. Blood samples were collected before (baseline [BL]) and after apheresis, after hemorrhage, and after resuscitation to assess changes in hemodynamics and coagulation using Rotem., Results: No change in mean arterial pressure (MAP) or heart rate (HR) was observed by platelet apheresis. Hemorrhage reduced MAP to 57% ± 5% and elevated HR to 212% ± 20% of BL (both p < 0.05). Resuscitation with albumin, FC, or platelets did not revert MAP or HR to BL. Platelet counts were reduced by apheresis from BL 383 ± 20 × 10/μL to 141 ± 14 × 10/μL and were reduced further after resuscitation with albumin (88 ± 18 × 10/μL) or FC (97 ± 13 × 10/μL, all p < 0.05), but improved with platelet resuscitation (307 ± 24 × 10/μL). Fibrinogen concentration was reduced by apheresis from BL 225 ± 9 mg/dL to 194 ± 8 mg/dL, fell after albumin infusion (134 ± 11 mg/dL), increased to 269 ± 10 mg/dL after FC resuscitation (all p < 0.05), and was not affected by platelet resuscitation. Rotem α-angle decreased from 79 ± 2 degrees to 69 ± 1 degrees by apheresis and hemorrhage (p < 0.05), and recovered similarly by resuscitation with FC (87 ± 1 degrees) or platelets (78 ± 2 degrees), but not by albumin (63 ± 3 degrees). Similar responses were observed in Rotem maximum clot firmness., Conclusion: In this traumatic hemorrhage swine model, low-volume resuscitation with FC or platelets was similarly effective in restoring coagulation.

Traumatic injury is one of the leading causes of death, with uncontrolled hemorrhage from coagulation dysfunction as one of the main potentially preventable causes of the mortality. Hypothermia, acidosis, and resuscitative hemodilution have been considered as the significant contributors to coagulation manifestations following trauma, known as the lethal triad. Over the past decade, clinical observations showed that coagulopathy may be present as early as hospital admission in some severely injured trauma patients. The hemostatic dysfunction is associated with higher blood transfusion requirements, longer hospital stay, and higher mortality. The recognition of this early coagulopathy has initiated tremendous interest and effort in the trauma community to expand our understanding of the underlying pathophysiology and improve clinical treatments. This review discusses the current knowledge of coagulation complications following trauma.

Background: Fibrinogen plays a central role in coagulation and falls to critical levels early after trauma. Administration of fibrinogen concentrate (FC) to improve hemostasis after severe bleeding seems beneficial, but it is unclear whether its use introduces excessive fibrinogen with a potential risk of thrombosis. This study investigated changes of endogenous fibrinogen metabolism from FC administration following traumatic hemorrhage in pigs., Methods: Anesthetized, instrumented pigs were randomized into lactated Ringer's (LR) solution only and LR plus FC groups (n = 7 each). Femur fracture of each pig's left leg was followed by hemorrhage of 60% total blood volume and resuscitation with LR (3× bled volume, LR group) or LR plus FC at 250 mg/kg (LR-FC group). Afterward, a constant infusion of stable isotopes 1-C-phenylalanine (phe, 6 hours) and d5-phe (3 hours) was performed with hourly blood sampling and subsequent gas chromatography-mass spectrometry analysis to quantify fibrinogen synthesis and breakdown rates, respectively. Blood gas and coagulation indices (thromboelastography) were measured on intermittent blood samples, and hemodynamics was continuously monitored. Animals were euthanized after the 6-hour isotope period., Results: Mean arterial pressure decreased by 50% after hemorrhage but improved after LR resuscitation in both groups. Hemorrhage and LR resuscitation reduced total protein, hematocrit, fibrinogen, and platelets to 50% of baseline values. Moreover, hemorrhage and resuscitation decreased fibrinogen concentration (207 ± 6 vs. 132 ± 7 mg/dL) and clot strength (72 ± 2 vs. 63 ± 2 mm) in both groups (p < 0.05). FC administration restored plasma fibrinogen concentrations and clot strength within 15 minutes, while no changes occurred in the LR group. Fibrinogen synthesis rates in the LR-FC group (1.3 ± 0.2 mg/kg/h) decreased versus the LR group (3.1 ± 0.5; p < 0.05), whereas fibrinogen breakdown rates were similar., Conclusion: Our data suggest an effective feedback mechanism that regulates host fibrinogen availability and thereby suggests that acute thrombosis from FC administration is an unlikely risk.

Background: This study compared coagulation function after resuscitation with Hextend and lactated Ringer's (LR) solution in pigs with tissue injury and hemorrhagic shock., Methods: Pigs were randomized into control (n = 7 each), LR, and Hextend groups. Femur fracture was induced using the captive bolt stunner at midshaft of the pigs' left legs, followed by hemorrhage of 60% total blood volume and resuscitation with either Hextend (equal to bled volume) or LR to reach the same mean arterial pressure. Pigs in the control group were not bled or resuscitated. Hemodynamics was monitored hourly for 6 hours. Blood samples were taken at baseline (BL), after hemorrhage, 15 minutes, 3 hours, and 6 hours after resuscitation for blood and coagulation measurements., Results: Mean arterial pressure decreased to 50% of BL by the 60% hemorrhage but returned to near BL within 1 hour after LR or Hextend resuscitation. Heart rate was increased (from 91 ± 4 beats per minute to 214 ± 20 beats per minute) by hemorrhage and decreased after resuscitation but remained elevated above BL in both groups. Resuscitation with Hextend (42 mL/kg) or LR (118 ± 3 mL/kg) reduced hematocrit, total protein, fibrinogen, and platelet counts, with greater decreases shown in the Hextend group. Clot strength was lower but returned to BL by 3 hours in the LR group, whereas it remained reduced for the 6-hour period after Hextend. The overall clotting capacity after LR was decreased after hemorrhage and resuscitation but returned to BL by 3 hours, whereas it remained low after Hextend for the 6-hour experiment period., Conclusion: After traumatic hemorrhage, coagulation function was restored within 6 hours with LR resuscitation but not with Hextend. The lack of recovery after Hextend is likely caused by greater hemodilution and possible effects of starches on coagulation substrates and further documents the need to restrict the use of high-molecular-weight starch in resuscitation fluids for bleeding casualties.

Hemorrhagic coagulopathy is a significant complication after traumatic injury, and much of the underlying mechanism remains unclear. We investigated the changes in fibrinogen metabolism and coagulation after a moderate hemorrhage and resuscitation. Pigs of either sex (weight, 40.9+/-0.8 kg) were anesthetized and instrumented with arterial and venous catheters and a thermodilution cardiac output catheter. Pigs were randomized into control (C; n=6), hemorrhage (H; n=6), and hemorrhage and resuscitation (H-LR; n=6) groups. Hemorrhage was induced by bleeding 35% of total blood volume for 30 min in H and H-LR groups. Resuscitation in H-LR group was performed using lactated Ringer's solution (LR) at 3 times the bled volume for 30 min. Fibrinogen metabolism was quantified using a primed constant infusion of 1-13C-phenylalanine (6 h) and d5-phenylalanine (4 h) and subsequent analysis by gas chromatograph-mass spectrometry, together with measurements of hemodynamics (hourly) and coagulation by thromboelastography (at baseline and 4 h after hemorrhage and resuscitation). Hemorrhage caused decreases in arterial pH and base excess, and an increase in arterial lactate content. Fluid resuscitation corrected these changes toward normal levels. Fibrinogen level was unchanged in C and decreased to 76%+/-4% in H and to 73%+/-3% in H-LR (both P<0.05, compared with baseline) after hemorrhage and resuscitation. Fibrinogen breakdown was increased from 3.0+/-0.4 mg kg-1 h-1 in C to 5.4+/-0.6 mg kg-1 h-1 in H and to 5.6+/-0.5 mg kg-1 h-1 in H-LR (both P<0.05, compared with control), but synthesis was unchanged. The clotting reaction time was unchanged in C and shortened to 93%+/-3% in H and to 91%+/-1% in H-LR (both P<0.05, compared with baseline). We conclude that hemorrhagic shock caused accelerated fibrinogen breakdown and coagulation. The LR resuscitation reduced tissue hypoxia indexes but did not affect the changes in fibrinogen metabolism and coagulation from hemorrhage. Thus, effective treatment of hemorrhage should include combining standard-of-care resuscitation with interventions to correct alterations in coagulation.

Introduction: This experimental in vitro study aimed to identify and characterize hypothermia-associated coagulopathy and to compare changes in mild to severe hypothermia with the quantitative measurement of rotational thromboelastometry (ROTEM) and multiple-electrode aggregometry (MULTIPLATE). Methods: Whole blood samples from 18 healthy volunteers were analyzed at the target temperatures of 37, 32, 24, 18, and 13.7°C with ROTEM (ExTEM, InTEM and FibTEM) and MULTIPLATE using the arachidonic acid 0.5 mM (ASPI), thrombin receptor-activating peptide-6 32 µM (TRAP) and adenosine diphosphate 6.4 µM (ADP) tests at the corresponding incubating temperatures for coagulation assessment. Results: Compared to baseline (37°C) values ROTEM measurements of clotting time (CT) was prolonged by 98% (at 18°C), clot formation time (CFT) was prolonged by 205% and the alpha angle dropped to 76% at 13.7°C (p < 0.001). At 24.0°C CT was prolonged by 56% and CFT by 53%. Maximum clot firmness was only slightly reduced by ≤2% at 13.7°C. Platelet function measured by MULTIPLATE was reduced with decreasing temperature (p < 0.001): AUC at 13.7°C −96% (ADP), −92% (ASPI) and −91% (TRAP). Conclusion: Hypothermia impairs coagulation by prolonging coagulation clotting time and by decreasing the velocity of clot formation in ROTEM measurements. MULTIPLATE testing confirms a linear decrease in platelet function with decreasing temperatures, but ROTEM fails to adequately detect hypothermia induced impairment of platelets. [ABSTRACT FROM AUTHOR]

Objectives: This study was designed to assess the stability and functional activity of fibrinogen concentrates subjected to the changes in temperature and duration observed in field conditions.Methods: Fibrinogen concentrate was stored at -20°C (12 vials), 22°C (12 vials), and 50°C with 80% humidity (12 vials), for up to 6 mo. At each temperature, three vials of fibrinogen concentrate were taken out at 0, 1, 3, and 6 mo and reconstituted. On analysis days, blood samples were taken from a single healthy donor to collect plasma samples. The donor plasma was mixed with commercial fibrinogen-deficient plasma to make fibrinogen-adjusted plasma (FAP). An aliquot of the reconstituted fibrinogen concentrate was used for quantification of stored fibrinogen content (using STA-R) and function (Rotem - Fibtem) in FAP.Results: At 22°C for 0, 1, 3, and 6 mo, there were no significant changes observed in fibrinogen content (1,223 ± 42 mg/vial, 1,286 ± 86 mg/vial, 1,234 ± 76 mg/vial, and 1,178 ± 64 mg/vial), prothrombin time (13.5 ± 0.1 s, 13.7 ± 0.6 s, 13.3 ± 0.4 s, and 13.7 ± 0.2 s), or activated partial thromboplastin time (31.1 ± 0.2 s, 32.0 ± 0.2 s, 31.5 ± 0.2 s, and 32.0 ± 0.8 s), respectively. There were also no significant changes observed in any of the Fibtem measurements. Similarly, no differences were observed in these variables over time at -20°C and 50°C with 80% humidity.Conclusions: Fibrinogen concentrate maintained its content and function when stored at -20°C to 50°C with up to 80% humidity for 6 mo. [ABSTRACT FROM AUTHOR]

Hemorrhagic coagulopathy is involved in the morbidity and mortality of trauma patients. Nonetheless, many aspects of the mechanisms underlying this disorder are poorly understood. We have therefore investigated changes in fibrinogen metabolism and coagulation function after a moderate hemorrhagic shock, using a new stable isotope approach. Twelve pigs were randomly divided into the control (C) and hemorrhage (H) groups. Hemorrhage was induced by bleeding 35% total blood volume over a 30-min period. A primed constant infusion of [1-13C]phenylalanine (Phe), d5-phenylalanine, and α-[1-13C]-ketoisocaproate (KIC) was given to quantify fibrinogen synthesis and breakdown, together with measurements of circulating liver enzyme activities and coagulation function. Mean arterial pressure was decreased by hemorrhage from 89 ± 4 mmHg in C to 47 ± 4 mmHg in H (P « 0.05), followed by a rebound to 68 ± 5 mmHg afterward. Fibrinogen fractional synthesis rate increased from 2.7 ± 0.2%/h in C to 4.2 ± 0.4%/h in H by Phe (P « 0.05) and from 3.1 ± 0.4%/h in C to 4.4 ± 0.5%/h in H by KIC (P « 0.05). Fibrinogen fractional breakdown rate increased from 3.6 ± 1.0%/h in C to 12.9 ± 1.8%/h in H (P « 0.05). The absolute breakdown rate accelerated from 3.0 ± 0.4 mg·kg-1·h-1 in C to 5.4 ± 0.6 mg·kg-1·h-1 in H (P « 0.05), but the absolute synthesis rate remained unchanged. These metabolic changes were accompanied by a reduction in blood clotting time to 92.7 ± 1.6% of the baseline value by hemorrhage (P « 0.05). No changes were found in liver enzyme activities. We conclude that the observed changes in coagulation after hemorrhagic shock are mechanistically related to the acute acceleration of fibrinogen degradation. [ABSTRACT FROM AUTHOR]