In vitro evaluation of hyperosmotic canine plasma suitable for infusion.

OBJECTIVE: To determine the characteristics of canine freeze-dried plasma (cFDP) as it is serially diluted with sterile water. DESIGN: In vitro experimental study. SETTING: Government blood and coagulation research laboratory. ANIMALS: cFDP from a commercial manufacturer. INTERVENTIONS: Ten units of cFDP were reconstituted to 100%, 90%, 80%, 70%, 60%, 50%, and 40% of the recommended volume with sterile water. The resultant solutions were analyzed for coagulation factor activity (factors II, V, VII, VIII, IX, X, and XII as well as antithrombin), fibrinogen concentration, prothrombin time, activated partial thromboplastin time, viscosity, osmolality, and kaolin-activated thromboelastography. MEASUREMENTS AND MAIN RESULTS: Viscosity, osmolality, and turbidity properties of plasma were increased in a reconstitution volume-dependent manner, with the 40% suggested volume generating approximately 2-fold increases in each. Similarly, factor activity levels and fibrinogen concentration increased by approximately 2-fold over this range in a concentration-dependent manner. Prothrombin time declined from 11.4 seconds at 100% volume to 10.9 seconds at 70% before increasing to 11.9 seconds at 40%. Activated partial thromboplastin time increased exponentially from 21.8 seconds at 100% rehydration to 100.0 seconds at 40%. R-time on TEG increased from 3.1 to 13.9 minutes at 50% rehydration, while alpha angle declined from 61.3° to 24.7° over the same range, and the maximum amplitude initially increased from 13.2 mm at 100% water to 18.6 mm at 70% water before dropping back down to 14.6 mm at 50% water. No clotting was observed with 40% rehydration. CONCLUSIONS: The creation of hyperosmotic plasma from cFDP appears feasible with preservation of concentrated coagulation factors, although there are some unexplained effects that happen to coagulation functions at the highest concentrations tested using only 40%-50% of recommended rehydration volume. Further studies are needed to evaluate the hyperosmotic product in vivo.

Comparison of assessment of coagulation in healthy dogs by the TEG 6s and TEG 5000 viscoelastic analyzers.

The TEG 6s (Haemonetics) point-of-care viscoelastic analyzer is portable, compact, simple to use, and has the potential for rapid viscoelastic analysis that can guide the treatment of veterinary patients at the site of care. Although approved for use in people, the TEG 6s has yet to be evaluated for hemostatic analysis in veterinary medicine. Citrated whole blood (CWB) was collected from 27 healthy dogs. An aliquot of CWB from each dog was diluted by 33% with an isotonic crystalloid, representing an in vitro model of hemodilution. Unaltered and diluted CWB samples were analyzed using 2 TEG 6s and 6 TEG 5000 (Haemonetics) analyzers. The 6 TEG 5000 analyzers ran duplicate analyses of either unaltered or diluted samples using 1 of 3 reagents (Haemonetics): Kaolin TEG, RapidTEG, or TEG Functional Fibrinogen. Duplicate TEG 5000 analyses were averaged and compared with a single TEG 6s analysis. Lin concordance correlation coefficient and Bland-Altman plots were used to evaluate agreement of reaction time, kinetic time, alpha angle, maximum amplitude (MA), and G value (G) for samples activated with Kaolin TEG, and agreement of MA for samples activated with RapidTEG between the 2 machines. Overall, agreement between the TEG 6s and TEG 5000 analyzers was poor. Viscoelastic measurements by the TEG 6s and TEG 5000 in healthy dogs were not all interchangeable. Agreement was satisfactory only for MA and G measurements of diluted blood samples activated with Kaolin TEG, and MA measurements for both unaltered and diluted blood samples activated with RapidTEG.

Hemoglobin-Based Oxygen Carrier for the Reconstitution of Canine Freeze-Dried Plasma in an In Vitro Model of Resuscitation.

Military working dogs (MWDs) are force multipliers that are at risk for severe trauma when employed on the battlefield. When in severe hemorrhagic shock, MWDs require both oxygen- carrying capacity and replacement of vascular volume and coagulation factors. The objective of this study was to evaluate the hemostatic capacity of canine freeze-dried plasma (cFDP) with a Food and Drug Administration (FDA)-approved hemoglobin- based oxygen carrier (HBOC) in an in vitro model of resuscitation. Whole blood (WB) was collected from 10 MWDs, and these samples were diluted by 10%, 25%, or 40% with either cFDP (reconstituted with water), HBOC, cFDP (reconstituted with HBOC), or an equal volume of a 1:1 ratio of cFDP (reconstituted with water) and HBOC. Hemostatic parameters were minimally changed based on evaluation of prothrombin time, activated partial thromboplastin time, fibrinogen and thromboelastography at the 10% and 25% dilutions, and parameters consistent with a hypocoagulability were seen at dilutions of 40%. Based on the results of this study, additional research is warranted to determine if cFDP reconstituted with HBOC is a viable resuscitation product in canine trauma.

Effects of refrigerated storage on hemostatic stability of four canine plasma products.

OBJECTIVE: To assess clotting times, coagulation factor activities, sterility, and thromboelastographic parameters of liquid plasma (LP), thawed fresh frozen plasma (FFP-T), and 2 novel formulations of freeze-dried plasma (FDP) stored refrigerated over 35 days. SAMPLE: 6 units of canine LP and FFP-T from a commercial animal blood bank and 5 units each of 2 formulations of canine FDP. PROCEDURES: Prothrombin time; activated partial thromboplastin time; activities of coagulation factors II, V, VII, VIII, IX, X, XI, and XII; and thromboelastographic parameters were determined for each product on days 0 (baseline), 3, 7, 14, 21, 28, and 35. For each day, a sample of each product was also submitted for aerobic bacterial culture. RESULTS: Small changes in coagulation factor activities and mild increased time to initial clot formation in LP and FFP-T were noted over the 35-day storage period. Activities of factor VIII in FDP1 and factor XII in FDP2 were < 50% at baseline but varied throughout. Compared with FFP-T, time to initial clot formation was increased and clot strength was preserved or increased for the FDPs throughout the study. One FDP had decreased pH, compared with other products. No plasma product yielded bacterial growth. CONCLUSIONS AND CLINICAL RELEVANCE: Liquid plasma and FFP-T would be reasonable to use when stored refrigerated for up to 35 days. Both FDP products showed variability in coagulation factor activities. Studies investigating the usefulness of these plasma products (FDPs) in dogs and the variable days of refrigerated storage (all products) are warranted. (Am J Vet Res 2020;81:964-972).

A study to assess a novel automated electrocardiogram technology in screening for atrial fibrillation.

INTRODUCTION: Atrial fibrillation is often asymptomatic and un-diagnosed in the community resulting in an increased risk of heart failure and stroke to those patients. We evaluated the effectiveness, tolerability, and accuracy of a novel six-channel electrocardiogram digital-health screening device, the RhythmPad, for the detection of atrial fibrillation. METHODS: Seven hundred and fifty-two participants attending the cardiology department were recruited. Two recordings were taken-a six-lead electrocardiogram using the RhythmPad device and a standard 12-lead electrocardiogram. Recorded traces were analyzed by two blinded cardiologists. The computer-generated automated diagnostic reports from both systems were also compared. Post-participation feedback was obtained from study participants using a three-part questionnaire. RESULTS: The sensitivity of the six-lead electrocardiogram compared to the 12-lead electrocardiogram, analyzed by two blinded cardiologists, for the detection of normal sinus rhythm was 95.9%, with a specificity of 97.2%. The sensitivity for the detection of atrial fibrillation using the six-lead ECG was 93.4%, with specificity 96.8%. The six-lead automated diagnostic report had a sensitivity and specificity of 97.5% and 98.6%, respectively, for correctly diagnosing normal sinus rhythm. For the correct diagnosis of atrial fibrillation, the six-lead automated diagnostic report had a sensitivity and specificity of 95.4% and 98.8%, respectively. A total of 95.4% of participants found RhythmPad to be comfortable, with only 0.5% preferring the 12-lead ECG device in comparison to six-lead ECG acquisitions. CONCLUSION: The RhythmPad digital health device and its automated diagnostic report were highly accurate in detecting atrial fibrillation when compared to a standard 12-lead electrocardiogram.

Potent Anti-Inflammatory and Pro-Resolving Effects of Anabasum in a Human Model of Self-Resolving Acute Inflammation.

Anabasum is a synthetic analog of Δ8 -tetrahydrocannabinol (THC)-11-oic acid that in preclinical models of experimental inflammation exerts potent anti-inflammatory actions with minimal central nervous system (CNS) cannabimimetic activity. Here we used a novel model of acute inflammation driven by i.d. UV-killed E. coli in healthy humans and found that anabasum (5 mg) exerted a potent anti-inflammatory effect equivalent to that of prednisolone in terms of inhibiting neutrophil infiltration, the hallmark of acute inflammation. These effects arose from the inhibition of the neutrophil chemoattractant LTB4 , while the inhibition of antiphagocytic prostanoids (PGE2 , TxB2 , and PGF2 α) resulted in enhanced clearance of inflammatory stimulus from the injected site. Anabasum at the higher dose of 20 mg possessed the additional properties of triggering the biosynthesis of specialized pro-resolving lipid mediators including LXA4 , LXB4 , RvD1, and RvD3. Collectively, we demonstrate for the first time a striking anti-inflammatory and pro-resolution effects of a synthetic analog of THC in healthy humans.