Shedding of the endothelial glycocalyx precedes leukocyte activation and adherence in acute inflammation. Rapid administration of crystalloid or colloid fluids for treating hemorrhagic shock may cause endothelial glycocalyx shedding, thereby increasing inflammation. This study aimed to compare the effect of different fluid treatments in a canine shock model on glycocalyx biomarker, hyaluronan, and inflammatory biomarkers. Greyhound dogs under general anesthesia subject to hemorrhage for 60 min were given 20 mL kg of either fresh whole blood (FWB), hydroxyethyl starch (HES) 130/0.4, 4% succinylated gelatin (GELO), or 80 mL kg of isotonic crystalloid (CRYST) over 20 min (n = 6 per group). Plasma biomarkers hyaluronan, interleukin (IL) 6, 8, 10, tumor necrosis factor-α, monocyte chemoattractant protein-1, keratinocyte chemokine-like, and atrial natriuretic peptide were measured at baseline, end of hemorrhage (Shock), end of fluid administration (T20), and then 40 (T60), 100 (T120), and 160 (T180) minutes later. Biomarker concentrations were compared between groups using the Kruskal-Wallis test or Fisher's exact test (measurable versus unmeasurable) (significance set at P < 0.05). Hyaluronan concentration peaked early in the CRYST group at T20, compared to HES (P = 0.005) and GELO (P = 0.018), and later in the GELO group at T60, compared to FWB (P < 0.001). The CRYST group had significantly more samples with measurable IL6 at T180 (P = 0.015), compared to GELO, and IL10 at T60, T120, and T180 (all P = 0.015), compared to FWB. There were no significant differences in other biomarker concentrations. In conclusion, rapid large-volume crystalloid administered for hemorrhagic shock was associated with increased hyaluronan and a greater inflammatory response.

Objective: To investigate the association between synthetic colloids and biomarkers of acute kidney injury (AKI) in dogs with hemorrhagic shock.Design: Experimental interventional study. Setting: University.Animals: Twenty-four healthy ex-racing Greyhounds. Interventions:Anesthetized Greyhounds subjected to hemorrhage for 60 min were resuscitated with 20 mL/kg of fresh whole blood (FWB), 6% hydroxyethyl starch (HES) 130/0.4, 4% succinylated gelatin (GELO), or 80 mL/kg of isotonic crystalloid (CRYST) over 20 min (n = 6 per treatment). Concentrations of biomarkers of AKI were measured at baseline, end of hemorrhage, and at 40 (T60), 100 (T120), and 160 (T180) min after fluid bolus. Biomarkers included neutrophil gelatinase-associated lipocalin in urine and serum (uNGAL; sNGAL), and urine cystatin C (uCYSC), kidney injury molecule-1 (uKIM), clusterin (uCLUST), osteopontin, gamma-glutamyl transferase, monocyte chemoattractant protein-1 (uMCP), interleukin-6, interleukin-8, protein (uPROT), hyaluronan, and F 2 -isoprostanes. Renal histology was scored for tubular injury and microvesiculation. Biomarker fold-change from baseline was compared between groups using Abbreviations: AKI, acute kidney injury; CRYST, balanced isotonic crystalloid; CSL, compound sodium lactate; FE Na , fractional excretion of sodium; FWB, fresh whole blood; GELO, 4% 133 mixed effects models (Bonferroni-Holm corrected P<0.05). Frequencies of histology scores were compared by Fisher's exact test. Measurements and main results:In dogs treated with GELO, uNGAL fold-change was markedly greater compared with all other groups at T60, T120, and T180 (all P<0.001), and uCYSC was greater at T60 compared with CRYST (P<0.001), and at T120 and T180 compared with all other groups (all P<0.001). Smaller, albeit significant, between-group differences in uKIM, uCLUST, uMCP, and urine protein concentration were observed across the FWB, GELO, and HES groups, compared with CRYST. The GELO group more frequently had marked tubular microvesiculation than the other groups (P = 0.015) although tubular injury scores were comparable. Conclusion:In dogs with hemorrhagic shock, GELO was associated with greater magnitude increases in urine biomarkers of AKI and more frequent marked tubular microvesiculation, compared with FWB, CRYST, and HES.

Background: Hemorrhagic shock and volume replacement can alter coagulation. Synthetic colloids, hydroxyethyl starch (HES), and gelatin, may enhance hypocoagulability. Our primary objective was to describe the effect of four fluid products on coagulation in canine hemorrhagic shock. Our secondary objective was to compare measurements of coagulation during shock to baseline in all dogs.Methods: Anesthetized greyhounds subjected to atraumatic hemorrhage for 60 min were administered 20 mL kg−1 of either fresh whole blood (FWB), 6% HES 130/0.4, 4% succinylated gelatin (GELO), or 80 mL kg−1 of isotonic crystalloid over 20 min (n = 6 per group). Platelet closure time (PCT), rotational thromboelastometry (ROTEM) and plasma coagulation assays were measured at baseline, end of hemorrhage (shock), and 40 (T60), and 160 (T180) min after study fluid. ROTEM parameters included clotting time (CT), clot formation time (CFT), alpha angle, maximum clot firmness (MCF), lysis index at 60 min (LI60), and thrombodynamic potential index (TPI) for INTEM, EXTEM, FIBTEM (MCF only), and APTEM (LI60 only) profiles. Plasma coagulation assays included prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen concentration and activities of factor VII (FVII), factor VIII (FVIII), and von Willebrand Factor antigen (vWF). Between-group differences were tested using linear mixed models with post-hoc between-group comparisons (Bonferroni-Holm corrected). Differences between baseline and shock were tested using paired t-tests. Significance was set at P < 0.05.Results: GELO showed longer PCT at T60, compared with FWB and CRYST, and at T180, compared with all other groups. HES showed longer EXTEM CT at T60, compared with all other groups. HES showed lower INTEM and EXTEM MCF at T60 and lower INTEM MCF at T180, compared with FWB. Some plasma coagulation assays showed greater hypocoagulability with HES. Comparing shock to baseline, EXTEM CT, INTEM CFT, EXTEM CFT, PT, and FVIII significantly increased and PCT, INTEM CT, INTEM MCF, EXTEM MCF, EXTEM LI60, EXTEM TPI, FIBTEM MCF, APTT, fibrinogen, FVII, and vWF significantly decreased.Conclusions: In dogs with hemorrhagic shock, volume replacement with GELO caused mild platelet dysfunction and HES was associated with coagulation changes consistent with hypocoagulability, beyond effects of hemodilution. Shock alone produced some evidence of hypocoagulability.

Objective To describe the clinical features of dogs treated for suspected anaphylaxis in Perth, Western Australia.Design Single-centre observational case series with retrospective and prospective phases.Methods This was a two-phase study of dogs with clinical suspicion of anaphylaxis presenting to the emergency service of a university teaching hospital. Dogs required evidence of, and appropriate treatment of, a type 1 hypersensitivity reaction as well as two or more organs affected (or cardiovascular signs alone) to be included. Phase 1 includes retrospective case series of 186 dogs (March 2006-December 2018. Phase 2 includes prospective descriptive case series of 46 dogs (October 2017-July 2018) focused on clinical signs. ResultsIn phase 1, 88 (47%) dogs had evidence of insect exposure prior to the acute event. One hundred forty (75%) dogs had dermatological signs, 141 (76%) had gastrointestinal signs and 129 (69%) had cardiovascular signs. Ninety-two (49%) dogs had vasoconstrictive shock (5 with bradycardia), 24 (13%) had vasodilatory shock, 8 (4%) had mixed vasodilatory and vasoconstrictive shock and 5 (3%) had unclassifiable shock. On focused abdominal ultrasound, 42 of 71 (59%) dogs had gallbladder wall oedema and 3 of 71 (4%) dogs had peritoneal free fluid. In phase 2, the distributions of insect exposure, organ dysfunction and sonographic abnormalities were similar to phase 1.Conclusion Dogs presenting with suspected anaphylaxis showed a broad range of presentations. Dermatological signs were absent in a proportion of dogs, vasoconstrictive shock was more frequent than vasodilatory and unique features of shock were identified. This study highlights the challenges of diagnosis based on presenting features alone.

Objective: To evaluate the effect of 6% hydroxyethyl starch (HES) 130/0.4, compared with a Hartmann's solution control (CRYST), on urine biomarkers of acute kidney injury (AKI) in dogs prescribed a fluid bolus.