Sodium pentobarbital dosages for exsanguination affect biochemical, molecular and histological measurements in rats.

Rodents are widely used for animal research in Egypt. Pentobarbital is the most common anesthetic agent; however overdoses may affect the experimental outcomes and limit the use of tissues. To investigate the effects of sodium pentobarbital overdoses during exsanguination, three groups (6 rats/group) of male and female rats were injected i.p. with 50, 100 and 150 mg/kg of sodium pentobarbital, then carotid exsanguination was performed immediately after loss of consciousness. Hypoxia-inducible factor 1-alpha (Hif1a) and tumor necrosis factor-alpha (Tnfa) mRNA expressions in liver and kidney organs were evaluated. As well as, serum aminotransferase activities (AST&ALT), glucose, urea, creatinine, malondialdehyde (MDA), reduced glutathione (GSH) and catalase (CAT) levels were determined. The histological alterations in liver, kidney and spleen were studied. It was found that Hif1a and Tnfa were significantly overexpressed in the studied organs and serum AST, glucose, creatinine and urea levels were significantly increased after sodium pentobarbital overdoses (100 and 150 mg/kg) compared to 50 mg/kg dose. Similarly, significant increase in MDA and GSH levels of liver, kidney and spleen were noticed. Results showed gender difference where Hif1a and Tnfa levels were significantly overexpressed at high dose of sodium pentobarbital of liver and kidney organs in female more than male rats. Since euthanasia protocol may influence the physiological variables and affect genes' expression, it is recommended to avoid sodium pentobarbital overdose during euthanasia as it may interfere with the biochemical, molecular and histological measurements.

Pilot Study of a Novel Swine Model for Controlling Junctional Hemorrhage Using the iTClamp in Conjunction With Hemostatic Agents.

Exsanguinating hemorrhage is a primary cause of battlefield death. The iTClamp is a relatively new device (FDA approval in 2013) that takes a different approach to hemorrhage control by applying mechanism wound closure. However, no previous studies have explored the feasibility of utilizing the iTClamp in conjunction with hemostatic packing. To fill this important gap in the literature, a novel swine model was developed, and a total of 12 trials were performed using QuikClot Combat Gauze or XSTAT sponges in conjunction with the iTClamp to treat arterial injuries through 5 cm or 10 cm skin incisions in the groin, axilla, or neck. First-attempt application success rate, application time, and blood loss were recorded. Hemostasis was achieved on all wounds, though reapplication was required in one Combat Gauze and three XSTAT applications. Application averaged ~50% slower for Combat Gauze (M = 41 seconds, 95%CI: 22-32 seconds) than for XSTAT (M = 27 seconds, 95%CI: 35-47 seconds). XSTAT application was faster than Combat Gauze for each wound location and size. The 10 cm wounds took ~10 seconds (36%) longer to close (M = 27 seconds, 95%CI: 35-47 seconds) than the 5 cm wounds (M = 27 seconds, 95%CI: 35-47 seconds). Blood loss was similar for Combat Gauze (M = 51 mL, 95%CI: 25-76 mL) and XSTAT (M = 60 mL, 95%CI: 30-90 mL). Blood loss was roughly twice as great for 10 cm wounds (M = 73 mL, 95%CI: 47-100 mL) than for 5 cm wounds (M = 38 mL, 95%CI: 18-57 mL). This pilot study supports the feasibility of a novel model for testing the iTClamp in conjunction with hemostatic packing towards controlling junctional hemorrhage.

Exsanguinating bleeding following tooth extraction in a 12-year-old girl: a rare case of acquired haemophilia A.

Acquired haemophilia A (AHA) is a life-threatening haemorrhagic disorder that occurs with various underlying conditions such as autoimmune disease, drug reactions, lymphoproliferative diseases, solid tumours and pregnancy/postpartum status. However, in half of all reported cases, the underlying disease is unknown. Most AHA cases develop in adults; paediatric/adolescent cases are extremely rare. The main clinical symptom is bleeding into the skin, muscles, soft tissues and/or mucous membranes. Here, we report the case of an otherwise healthy 12-year-old girl who presented with prolonged bleeding postexodontia. After being diagnosed with AHA, she was successfully treated with recombinant activated factor VII infusion and oral prednisolone. To avoid such unanticipated bleeding when performing dental extraction, preoperative haemostatic screening tests are recommended.

Mechanism of action of tranexamic acid in bleeding trauma patients: an exploratory analysis of data from the CRASH-2 trial.

INTRODUCTION: To investigate the mechanism of action of tranexamic acid (TXA) in bleeding trauma patients, we examined the timing of its effect on mortality. We hypothesised that if TXA reduces mortality by decreasing blood loss, its effect should be greatest on the day of the injury when bleeding is most profuse. However, if TXA reduces mortality via an anti-inflammatory mechanism its effect should be greater over the subsequent days. METHODS: Exploratory analysis, including per-protocol analyses, of data from the CRASH-2 trial, a randomised placebo controlled trial of the effect of TXA on mortality in 20,211 trauma patients with, or at risk of, significant bleeding. We examined hazard ratios (HR) and 95% confidence intervals for all-cause mortality, deaths due to bleeding and non-bleeding deaths, according to the day since injury. The CRASH-2 trial is registered as ISRCTN86750102 and ClinicalTrials.gov NCT00375258. RESULTS: The effect of TXA on mortality is greatest for deaths occurring on the day of the injury (HR all-cause mortality = 0.83, 0.73 to 0.93). This survival benefit is only evident in patients in whom treatment is initiated within 3 hours of their injury (HR ≤ 3 hours = 0.78, 0.68 to 0.90; HR > 3 hours = 1.02, 0.76 to 1.36). Initiation of TXA treatment within 3 hours of injury reduced the hazard of death due to bleeding on the day of the injury by 28% (HR = 0.72, 0.60 to 0.86). TXA treatment initiated beyond 3 hours of injury appeared to increase the hazard of death due to bleeding, although the estimates were imprecise. CONCLUSIONS: Early administration of tranexamic acid appears to reduce mortality primarily by preventing exsanguination on the day of the injury.

Efficacy of centhaquin as a small volume resuscitative agent in severely hemorrhaged rats.

Centhaquin has been reported to be an effective resuscitative agent. The present study was carried out to determine resuscitative effect of centhaquin when administered using a small volume of 3% hypertonic saline (HS) to hemorrhaged rats. Sprague-Dawley rats were anesthetized with urethane, and a pressure catheter SPR-320 was placed in the left femoral artery; another pressure-volume catheter SPR-869 was placed into the left ventricle. Hemorrhage was induced by withdrawing blood and mean arterial pressure (MAP) was maintained at 35 mm Hg for 30 minutes after which resuscitation was performed. Animals were divided in 2 groups: group A received HS and group B received centhaquin (0.05 mg/kg) dissolved in HS. The time by which MAP fell back to 35 mm Hg was observed at that time all animals were administered fresh blood. It was found that centhaquin significantly reduced blood lactate and improved cardiac output and MAP of hemorrhaged rats compared with HS. The time by which MAP fell back to 35 mm Hg in rats treated with HS was 55 ± 6 minutes, whereas it was 161 ± 14 minutes in centhaquin treated rats. Survival time following administration of fresh blood was 79 ± 7 minutes in vehicle-treated group, whereas it was 105 ± 9 minutes in centhaquin-treated rats. The total time of survival of rats treated with HS or centhaquin was 134 ± 12 minutes and 266 ± 16 minutes, respectively. Centhaquin, in small volume, maintained MAP of hemorrhaged rats for a considerable long time and improved the survival time.

Administration of fibrinogen concentrate in exsanguinating trauma patients is associated with improved survival at 6 hours but not at discharge.

BACKGROUND: Despite poor evidence and high costs, fibrinogen concentrate (FC) represents one of the most frequently used hemostatic agents in exsanguinating trauma. The aim was to assess whether the administration of FC in severely injured patients was associated with improved outcomes. METHODS: Patients documented in the Trauma Registry of the German Society for Trauma Surgery (primary admissions, Injury Severity Score [ISS] ≥16) who had received FC during initial care between emergency department (ED) arrival and intensive care unit admission (FC+) were matched with patients who had not received FC (FC-). RESULTS: The matched-pairs analysis yielded two comparable cohorts (n = 294 in each group) with a mean ISS of 37.6 ± 13.7 (FC+) and 37.1 ± 13.3 (FC-) (p = 0.73); the mean age was 40 ± 17 versus 40 ± 16 (p = 0.72), respectively. Patients were predominantly male (71.1% in both groups, p = 1.0). On emergency department arrival, hypotension (systolic blood pressure, ≤90 mm Hg) occurred in 51.4% (FC+) and 48.0% (FC-) (p = 0.41), and base excess was -7.4 ± 5.3 mmol/L for FC+ and was -7.5 ± 6.2 mmol/L for FC- (p = 0.96). Patients were administered 12.8 ± 14.3 (FC+) versus 11.3 ± 10.0 (FC-) packed red blood cell units (p = 0.20). Thromboembolism occurred in 6.8% (FC+) versus 3.4% (FC-) (p = 0.06), and multiple organ failure occurred in 61.2% versus 49.0% (p = 0.003), respectively. Whereas 6-hour mortality was 10.5% for FC+ versus 16.7% for FC- (p = 0.03), the mean time to death was 7.5 ± 14.6 days versus 4.7 ± 8.6 days (p = 0.006). The overall hospital mortality rate was 28.6% versus 25.5% (p = 0.40), respectively. CONCLUSION: This is the first study to investigate the effect of FC administration in bleeding trauma. In our large population of severely injured patients, the early use of FC was associated with a significantly lower 6-hour mortality and an increased time to death, but also an increased rate of multiple organ failure. A reduction of overall hospital mortality was not observed in patients receiving FC. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Polynitroxylated pegylated hemoglobin: a novel neuroprotective hemoglobin for acute volume-limited fluid resuscitation after combined traumatic brain injury and hemorrhagic hypotension in mice.

OBJECTIVE: Resuscitation of hemorrhagic hypotension after traumatic brain injury is challenging. A hemoglobin-based oxygen carrier may offer advantages. The novel therapeutic hemoglobin-based oxygen carrier, polynitroxylated pegylated hemoglobin (PNPH), may represent a neuroprotective hemoglobin-based oxygen carrier for traumatic brain injury resuscitation. HYPOTHESES: 1) PNPH is a unique non-neurotoxic hemoglobin-based oxygen carrier in neuronal culture and is neuroprotective in in vitro neuronal injury models. 2) Resuscitation with PNPH would require less volume to restore mean arterial blood pressure than lactated Ringer's or Hextend and confer neuroprotection in a mouse model of traumatic brain injury plus hemorrhagic hypotension. DESIGN: Prospective randomized, controlled experimental study. SETTING: University center. MEASUREMENTS AND MAIN RESULTS: In rat primary cortical neuron cultures, control bovine hemoglobin was neurotoxic (lactate dehydrogenase release; 3-[4,5-dimethylthiazol-2-yl-]-2,5-diphenyltetrazolium bromide assay) at concentrations from 12.5 to 0.625 µM, whereas polyethylene glycol-conjugated hemoglobin showed intermediate toxicity. PNPH was not neurotoxic (p<.05 vs. bovine hemoglobin and polyethylene glycol hemoglobin; all concentrations). PNPH conferred neuroprotection in in vitro neuronal injury (glutamate/glycine exposure and neuronal stretch), as assessed via lactate dehydrogenase and 3-[4,5-dimethylthiazol-2-yl-]-2,5-diphenyltetrazolium bromide (all p<.05 vs. control). C57BL6 mice received controlled cortical impact followed by hemorrhagic hypotension (2 mL/100 g, mean arterial blood pressure ∼35-40 mm Hg) for 90 min. Mice were resuscitated (mean arterial blood pressure>50 mm Hg for 30 min) with lactated Ringer's, Hextend, or PNPH, and then shed blood was reinfused. Mean arterial blood pressures, resuscitation volumes, blood gasses, glucose, and lactate were recorded. Brain sections at 7 days were examined via hematoxylin and eosin and Fluoro-Jade C (identifying dying neurons) staining in CA1 and CA3 hippocampus. Resuscitation with PNPH or Hextend required less volume than lactated Ringer's (both p<.05). PNPH but not Hextend improved mean arterial blood pressure vs. lactated Ringer's (p<.05). Mice resuscitated with PNPH had fewer Fluoro-Jade C positive neurons in CA1 vs. Hextend and lactated Ringer's, and CA3 vs. Hextend (p<.05). CONCLUSIONS: PNPH is a novel neuroprotective hemoglobin-based oxygen carrier in vitro and in vivo that may offer unique advantages for traumatic brain injury resuscitation.