Valproic acid improves survival and decreases resuscitation requirements in a swine model of prolonged damage control resuscitation.

BACKGROUND: Although damage control resuscitation (DCR) is routinely performed for short durations, prolonged DCR may be required in military conflicts as a component of prolonged field care. Valproic acid (VPA) has been shown to have beneficial properties in lethal hemorrhage/trauma models. We sought to investigate whether the addition of a single dose of VPA to a 72-hour prolonged DCR protocol would improve clinical outcomes. METHODS: Fifteen Yorkshire swine (40-45 kg) were subjected to lethal (50% estimated total blood volume) hemorrhagic shock (HS) and randomized to three groups: (1) HS, (2) HS-DCR, (3) HS-DCR-VPA (150 mg/kg over 3 hours) (n = 5/cohort). In groups assigned to receive DCR, Tactical Combat Casualty Care guidelines were applied (1 hour into the shock period), targeting a systolic blood pressure of 80 mm Hg. At 72 hours, surviving animals were given transfusion of packed red blood cells, simulating evacuation to higher echelons of care. Survival rates, physiologic parameters, resuscitative fluid requirements, and laboratory profiles were used to compare the clinical outcomes. RESULTS: This model was 100% lethal in the untreated animals. DCR improved survival to 20%, although this was not statistically significant. The addition of VPA to DCR significantly improved survival to 80% (p < 0.01). The VPA-treated animals also had significantly (p < 0.05) higher systolic blood pressures, lower fluid resuscitation requirements, higher hemoglobin levels, and lower creatinine and potassium levels. CONCLUSION: VPA administration improves survival, decreases resuscitation requirements, and improves hemodynamic and laboratory parameters when added to prolonged DCR in a lethal hemorrhage model

Development of a large animal model of lethal polytrauma and intra-abdominal sepsis with bacteremia

Background Trauma and sepsis are individually two of the leading causes of death worldwide. When combined, the mortality is greater than 50%. Thus, it is imperative to have a reproducible and reliable animal model to study the effects of polytrauma and sepsis and test novel treatment options. Porcine models are more translatable to humans than rodent models due to the similarities in anatomy and physiological response. We embarked on a study to develop a reproducible model of lethal polytrauma and intra-abdominal sepsis, which was lethal, though potentially salvageable with treatment.Methods Our laboratory has a well-established porcine model that was used as the foundation. Animals were subjected to a rectus crush injury, long bone fracture, liver and spleen laceration, traumatic brain injury and hemorrhage that was used as a foundation. We tested various colon injuries to create intra-abdominal sepsis. All animals underwent injuries followed by a period of shock, then subsequent resuscitation.Results All animals had blood culture-proven sepsis. Attempts at long-term survival of animals after injury were ceased because of poor appetite and energy. We shifted to an 8-hour endpoint. The polytrauma injury pattern remained constant and the colon injury pattern changed with the intention of creating a model that was ultimately lethal but potentially salvageable with a therapeutic drug. An uncontrolled cecal injury (n=4) group resulted in very early deaths. A controlled cecal injury (CCI; n=4) group had prolonged time prior to mortality with one surviving to the endpoint. The sigmoid injury (n=5) produced a similar survival curve to CCI but no animals surviving to the endpoint.Conclusion We have described a porcine model of polytrauma and sepsis that is reproducible and may be used to investigate novel treatments for trauma and sepsis.Level of evidence Not applicable. Animal study

Mesenchymal Stem Cell-Derived Exosomes Provide Neuroprotection and Improve Long-Term Neurologic Outcomes in a Swine Model of Traumatic Brain Injury and Hemorrhagic Shock

Combined traumatic brain injury (TBI) and hemorrhagic shock (HS) remains a leading cause of preventable death worldwide. Mesenchymal stem cell-derived exosomes have demonstrated promise in small animal models of neurologic injury. To investigate the effects of exosome treatment in a clinically realistic large animal model, Yorkshire swine underwent TBI and HS. Animals were maintained in shock for 2 h before resuscitation with normal saline (NS). Animals were then resuscitated either with NS (3 x volume of shed blood) or with the same volume of NS with delayed exosome administration (1 x 10(13) particles/4 mL) (n = 5/cohort). Exosomes were administered 9 h post-injury, and on post-injury days (PID) 1, 5, 9, and 13. Neurologic severity scores (NSS) were assessed for 30 days, and neurocognitive functions were objectively measured. Exosome-treated animals had significantly lower NSS (p \u3c 0.05) during the first five days of recovery. Exosome-treated animals also had a significantly shorter time to complete neurologic recovery (NSS = 0) compared with animals given NS alone (days to recovery: NS = 16.8 +/- 10.6; NS + exosomes = 5.6 +/- 2.8; p = 0.03). Animals treated with exosomes initiated neurocognitive testing earlier (days to initiation: NS = 9.6 +/- 0.5 vs. NS + exosomes = 4.2 +/- 0.8; p = 0.008); however, no difference was seen in time to mastery of tasks. In conclusion, treatment with exosomes attenuates the severity of neurologic injury and allows for faster neurologic recovery in a clinically realistic large animal model of TBI and HS

Early Single-Dose Treatment with Exosomes Provides Neuroprotection and Improves Blood-Brain Barrier Integrity in Swine Model of Traumatic Brain Injury and Hemorrhagic Shock

BACKGROUND: Administration of human mesenchymal stem cell (MSC)-derived exosomes can enhance neurorestoration in models of traumatic brain injury (TBI) and hemorrhagic shock (HS). The impact of early treatment with MSC-derived exosomes on brain injury in a large animal model remains unknown. We sought to evaluate the impact of early single-dose exosome treatment on brain swelling and lesion size, blood-based cerebral biomarkers, and blood-brain barrier (BBB) integrity. METHODS: Female Yorkshire swine were subjected to a severe TBI (12-mm cortical impact) and HS (40% estimated total blood volume). One hour into shock, animals were randomized (n=5/cohort) to receive either lactated Ringer\u27s (LR; 5mL) or LR + exosomes (LR+EXO; 1 x 10 exosome particles in 5 mL LR). Animals then underwent additional shock (1 hr) followed by normal saline resuscitation. After 6 hours of observation, brain swelling (% increase compared to the uninjured side) and lesion size (mm) were assessed. Cerebral hemodynamics and blood-based biomarkers of brain injury were compared. Immunofluorescence and RNA sequencing with differential gene expression and pathway analysis were used to assess the integrity of the peri-lesion BBB. RESULTS: Exosome-treated animals had significantly less (p \u3c 0.05) brain swelling and smaller lesion size. They also had significantly decreased (p \u3c 0.05) intracranial pressures and increased cerebral perfusion pressures. Exosome-treated animals had significantly decreased (p \u3c 0.05) albumin extravasation and significantly higher (p \u3c 0.05) laminin, claudin-5, and zonula occludens-1 levels. Differential gene expression and pathway analysis confirmed these findings. Serum glial fibrillary acidic protein levels were also significantly lower (p\u3c0.05) in the exosome-treated cohort at the end of the experiment. CONCLUSIONS: In a large animal model of TBI and HS, early treatment with a single dose of MSC-derived exosomes significantly attenuates brain swelling and lesion size, decreases levels of blood-based cerebral biomarkers, and improves BBB integrity. LEVEL OF EVIDENCE: Not applicable (pre-clinical study)

Early single-dose exosome treatment improves neurologic outcomes in a 7-day swine model of traumatic brain injury and hemorrhagic shock

BACKGROUND: Early single-dose treatment with human mesenchymal stem cell (MSC)-derived exosomes promotes neuroprotection and promotes blood-brain barrier (BBB) integrity in models of traumatic brain injury (TBI) and hemorrhagic shock (HS) in swine. The impact of an early single dose of exosomes on late survival (7-day), however, remains unknown. We sought to evaluate the impact of early single-dose exosome treatment on neurologic outcomes, brain lesion size, inflammatory cytokines, apoptotic markers, and mediators of neural plasticity in a 7-day survival model. METHODS: Yorkshire swine were subjected to a severe TBI (8-mm cortical impact) and HS (40% estimated total blood volume). After one hour of shock, animals were randomized (n=4/cohort) to receive either lactated Ringer\u27s (LR; 5mL) or LR + exosomes (LR+EXO; 1 × 10 exosome particles). After an additional hour of shock, animals were resuscitated with normal saline. Daily neurologic severity scores (NSS) were compared. At 7 days following injury, lesion size, inflammatory markers, and mediators of inflammation (NF-κB), apoptosis (BAX), and neural plasticity (BDNF) in brain tissue were compared between groups. RESULTS: Exosome-treated animals had significantly lower NSS (first 4 days; p \u3c 0.05) and faster neurologic recovery. At 7-days, exosome-treated animals had significantly smaller (p \u3c 0.05) brain lesion sizes. Exosome-treated animals also had significantly lower levels of inflammatory markers (IL-1, IL-6, IL-8, and IL-18) and higher granulocyte-macrophage colony stimulating factor (GM-CSF) levels compared to the control animals, indicating specific impacts on various cytokines. BAX and NF-κB levels were significantly lower (p \u3c 0.05) in exosome-treated animals, while BDNF levels were significantly higher (p \u3c 0.05) in the exosome-treated animals. CONCLUSIONS: In a large animal model of TBI and HS, early single-dose exosome treatment attenuates neurologic injury, decreases brain lesion size, inhibits inflammation and apoptosis, and promotes neural plasticity over a seven-day period. LEVEL OF EVIDENCE: Not applicable (pre-clinical study)