The role of nitric oxide in the efficacy of adenosine, lidocaine and magnesium (ALM) treatment of experimental hemorrhagic shock in rats

Background: Since nitric oxide (NO) plays multiple roles regulating the central nervous, cardiovascular and immune systems, our aim was to investigate the role of NO in the efficacy of 7.5% NaCl adenosine, lidocaine and magnesium (ALM) to improve mean arterial pressure (MAP) and heart rate (HR) following hemorrhagic shock (HS). Methods: Male Sprague-Dawley rats (101; 425±6g) were randomly assigned to 20 groups (n=4-n=8). HS (MAP<40mmHg) was induced by 20min pressure-controlled bleeding (∼40% blood volume), and the animal was left in shock (MAP 35-40mmHg) for 60min. NO synthase (NOS) inhibitor L-NAME was administered with a 0.3ml bolus of different combinations of 7.5% NaCl ALM active ingredients and hemodynamics were monitored for 60min. A number of specific NOS and NO inhibitors were tested. Results: 7.5% NaCl ALM corrected MAP after HS. In contrast, the addition of L-NAME to 7.5% NaCl ALM led to a rapid fall in MAP, sustained ventricular arrhythmias, and 100% mortality. Saline controls receiving 7.5% NaCl with L-NAME showed improved MAP with no deaths. None of the specific NOS and NO inhibitors mimicked L-NAME's effect on ALM. The addition of inducible (iNOS) inhibitor 1400W to 7.5% NaCl ALM failed to resuscitate, while NO scavenger PTIO and PI3K inhibitor Wortmannin reduced MAP recovery during 60min resuscitation. Conclusions: The ability of 7.5% NaCl ALM to resuscitate appears to be linked to one or more NO-producing pathways. Non-specific NOS inhibition with L-NAME blocked ALM resuscitation and led to cardiovascular collapse. More studies are required to examine NO site-specific contributions to ALM resuscitation

Immune dysfunction following severe trauma: A systems failure from the central nervous system to mitochondria

When a traumatic injury exceeds the body’s internal tolerances, the innate immune and inflammatory systems are rapidly activated, and if not contained early, increase morbidity and mortality. Early deaths after hospital admission are mostly from central nervous system (CNS) trauma, hemorrhage and circulatory collapse (30%), and later deaths from hyperinflammation, immunosuppression, infection, sepsis, acute respiratory distress, and multiple organ failure (20%). The molecular drivers of secondary injury include damage associated molecular patterns (DAMPs), pathogen associated molecular patterns (PAMPs) and other immune-modifying agents that activate the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic stress response. Despite a number of drugs targeting specific anti-inflammatory and immune pathways showing promise in animal models, the majority have failed to translate. Reasons for failure include difficulty to replicate the heterogeneity of humans, poorly designed trials, inappropriate use of specific pathogen-free (SPF) animals, ignoring sex-specific differences, and the flawed practice of single-nodal targeting. Systems interconnectedness is a major overlooked factor. We argue that if the CNS is protected early after major trauma and control of cardiovascular function is maintained, the endothelial-glycocalyx will be protected, sufficient oxygen will be delivered, mitochondrial energetics will be maintained, inflammation will be resolved and immune dysfunction will be minimized. The current challenge is to develop new systems-based drugs that target the CNS coupling of whole-body function

Pathophysiology of severe burn injuries: new therapeutic opportunities from a systems perspective

Severe burn injury elicits a profound stress response with the potential for high morbidity and mortality. If polytrauma is present, patient outcomes appear to be worse. Sex-based comparisons indicate females have worse outcomes than males. There are few effective drug therapies to treat burn shock and secondary injury progression. The lack of effective drugs appears to arise from the current treat-as-you-go approach rather than a more integrated systems approach. In this review, we present a brief history of burns research and discuss its pathophysiology from a systems’ perspective. The severe burn injury phenotype appears to develop from a rapid and relentless barrage of damage-associated molecular patterns (DAMPs), pathogen-associated molecular patterns (PAMPs) and neural afferent signals, which leads to a state of hyperinflammation, immune dysfunction, coagulopathy, hypermetabolism and intense pain. We propose that if the central nervous system (CNS) control of cardiovascular function and endothelial-glycocalyx-mitochondrial coupling can be restored early, these secondary injury processes may be minimized. The therapeutic goal is to switch the injury phenotype to a healing phenotype by reducing fluid leak and maintaining tissue O2 perfusion. Currently, no systems-based therapies exist to treat severe burns. We have been developing a small-volume fluid therapy comprising adenosine, lidocaine and magnesium (ALM) to treat hemorrhagic shock, traumatic brain injury and sepsis. Our early studies indicate that the ALM therapy holds some promise in supporting cardiovascular and pulmonary functions following severe burns. Future research will investigate the ability of ALM therapy to treat severe burns with polytrauma and sex disparities, and potential translation to humans

Why are bleeding trauma patients still dying? Towards a systems hypothesis of trauma

Over the years, many explanations have been put forward to explain early and late deaths following hemorrhagic trauma. Most include single-event, sequential contributions from sympathetic hyperactivity, endotheliopathy, trauma-induced coagulopathy (TIC), hyperinflammation, immune dysfunction, ATP deficit and multiple organ failure (MOF). We view early and late deaths as a systems failure, not as a series of manifestations that occur over time. The traditional approach appears to be a by-product of last century’s highly reductionist, single-nodal thinking, which also extends to patient management, drug treatment and drug design. Current practices appear to focus more on alleviating symptoms rather than addressing the underlying problem. In this review, we discuss the importance of the system, and focus on the brain’s “privilege” status to control secondary injury processes. Loss of status from blood brain barrier damage may be responsible for poor outcomes. We present a unified Systems Hypothesis Of Trauma (SHOT) which involves: 1) CNS-cardiovascular coupling, 2) Endothelial-glycocalyx health, and 3) Mitochondrial integrity. If central control of cardiovascular coupling is maintained, we hypothesize that the endothelium will be protected, mitochondrial energetics will be maintained, and immune dysregulation, inflammation, TIC and MOF will be minimized. Another overlooked contributor to early and late deaths following hemorrhagic trauma is from the trauma of emergent surgery itself. This adds further stress to central control of secondary injury processes. New point-of-care drug therapies are required to switch the body’s genomic and proteomic programs from an injury phenotype to a survival phenotype. Currently, no drug therapy exists that targets the whole system following major trauma

Clinical relevance of a p value: Does tranexamic acid save lives after trauma or postpartum hemorrhage?

[Extract] Tranexamic acid (TXA), an antifibrinolytic agent, has been widely publicized as saving lives after traumatic hemorrhage in the CRASH-2, MSATTERs, and PER-TRAX trials (2-5) and more recently after postpartum hemorrhage (PPH) in the World Maternal Antifibrinolytic (WOMAN) trial (6). Prophylactic administration of TXA is also increasingly used in major elective and emergency surgery to reduce excessive bleeding, transfusion requirements, and possible reexploration. (7

Adenosine, lidocaine and Mg2+ update: teaching old drugs new tricks

If a trauma (or infection) exceeds the body’s evolutionary design limits, a stress response is activated to quickly restore homeostasis. However, when the injury severity score is high, death is often imminent. The goal of this review is to provide an update on the effect of small-volume adenosine, lidocaine and Mg2+ (ALM) therapy on increasing survival and blunting secondary injury after non-compressible hemorrhagic shock and other trauma and infective/endotoxemic states. Two standout features of ALM therapy are: (1) resuscitation occurs at permissive hypotensive blood pressures (MAPs 50–60 mmHg), and (2) the drug confers neuroprotection at these low pressures. The therapy appears to reset the body’s baroreflex to produce a high-flow, hypotensive, vasodilatory state with maintained tissue O2 delivery. Whole body ALM protection appears to be afforded by NO synthesis-dependent pathways and shifting central nervous system (CNS) control from sympathetic to parasympathetic dominance, resulting in improved cardiovascular function, reduced immune activation and inflammation, correction of coagulopathy, restoration of endothelial glycocalyx, and reduced energy demand and mitochondrial oxidative stress. Recently, independent studies have shown ALM may also be useful for stroke, muscle trauma, and as an adjunct to Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA). Ongoing studies have further shown ALM may have utility for burn polytrauma, damage control surgery and orthopedic surgery. Lastly, we discuss the clinical applications of ALM fluid therapy for prehospital and military far-forward use for non-compressible hemorrhage and traumatic brain injury (TBI)

Lung protection after severe thermal burns with adenosine, lidocaine, and magnesium (ALM) resuscitation and importance of shams in a rat model

The management of severe burns remains a complex challenge. Adenosine, lidocaine, and magnesium (ALM) resuscitation therapy has been shown to protect against hemorrhagic shock and traumatic injury. The aim of the present study was to investigate the early protective effects of small-volume ALM fluid resuscitation in a rat model of 30% total body surface area (TBSA) thermal injury. Male Sprague–Dawley rats (320–340 g; n = 25)were randomly assigned to: 1) Sham (surgical instrumentation and saline infusion, without burn, n = 5), 2) Saline resuscitation group (n = 10), or 3) ALM resuscitation group (n = 10). Treatments were initiated 15-min after burn trauma, including 0.7 mL/kg 3% NaCl ± ALM bolus and 0.25–0.5 mL/kg/h 0.9% NaCl ± ALM drip, with animals monitored to 8.25-hr post-burn. Hemodynamics, cardiac function, blood chemistry, hematology, endothelial injury markers and histopathology were assessed. Survival was 100% for Shams and 90% for both ALM and Saline groups. Shams underwent significant physiological, immune and hematological changes over time as a result of surgical traums. ALM significantly reduced malondialdehyde levels in the lungs compared to Saline (P = .023), and showed minimal alveolar destruction and inflammatory cell infiltration (P < .001). ALM also improved cardiac function and oxygen delivery (21%, P = .418 vs Saline), reduced gut injury (P < .001 vs Saline), and increased plasma adiponectin (P < .001 vs baseline). Circulating levels of the acute phase protein alpha 1-acid glycoprotein (AGP) increased 1.6-times (P < .001), which may have impacted ALM's therapeutic efficacy. We conclude that small-volume ALM therapy significantly reduced lung oxidative stress and preserved alveolar integrity following severe burn trauma. Further studies are required to assess higher ALM doses with longer monitoring periods

Living in a hostile world: inflammation, new drug development, and coronavirus

We present a brief history of the immune response and show that Metchnikoff’s theory of inflammation and phagocytotic defense was largely ignored in the 20th century. For decades, the immune response was believed to be triggered centrally, until Lafferty and Cunningham proposed the initiating signal came from the tissues. This shift opened the way for Janeway’s pattern recognition receptor theory, and Matzinger’s danger model. All models failed to appreciate that without inflammation, there can be no immune response. The situation changed in the 1990s when cytokine biology was rapidly advancing, and the immune system’s role expanded from host defense, to the maintenance of host health. An inflammatory environment, produced by immune cells themselves, was now recognized as mandatory for their attack, removal and repair functions after an infection or injury. We explore the cellular programs of the immune response, and the role played by cytokines and other mediators to tailor the right response, at the right time. Normally, the immune response is robust, self-limiting and restorative. However, when the antigen load or trauma exceeds the body’s internal tolerances, as witnessed in some COVID-19 patients, excessive inflammation can lead to increased sympathetic outflows, cardiac dysfunction, coagulopathy, endothelial and metabolic dysfunction, multiple organ failure and death. Currently, there are few drug therapies to reduce excessive inflammation and immune dysfunction. We have been developing an intravenous (IV) fluid therapy comprising adenosine, lidocaine and Mg2+ (ALM) that confers a survival advantage by preventing excessive inflammation initiated by sepsis, endotoxemia and sterile trauma. The multi-pronged protection appears to be unique and may provide a tool to examine the intersection points in the immune response to infection or injury, and possible ways to prevent secondary tissue damage, such as that reported in patients with COVID-19

Specific pathogen-free (SPF) animal status as a variable in biomedical research: have we come full circle?

In this commentary, we discuss the pros and cons of using specific pathogen-free (SPF) animals in biomedical research, and present individual cases where altering the gut microbiome has dramatically changed the animal's basic physiology, immune/inflammatory functions and susceptibility to infection and disease. We argue that SPF manipulation of the microbiome-host relationship has itself become a confounding variable in biomedical research, which could have major implications to human translation

Conventional and specific-pathogen free rats respond differently to anesthesia and surgical trauma

Specific-pathogen free (SPF) animals were introduced in the 1960s to minimize disease and infection as variables in biomedical research. Our aim was to examine differences in physiological response in rat colonies bred and housed in a conventional versus SPF facility, and implications for research. Sprague-Dawley rats were anesthetized and catheterized for blood and pressure monitoring, and electrocardiogram (ECG) leads implanted. Hematology was assessed, and coagulation profile using rotational thromboelastometry. Health screening was outsourced to Cerberus Sciences. SPF rats had significantly lower pulse pressure (38% decrease), arrhythmias and prolonged QTc (27% increase) compared to conventional rats. No arrhythmias were found in conventional rats. SPF rats had significantly higher white cell, monocyte, neutrophil and lymphocyte counts, and were hyperfibrinolytic, indicated by EXTEM maximum lysis >15%. Independent assessment revealed similar pathogen exclusion between colonies, with the exception of Proteus in SPF animals. Returning to a conventional facility restored normal host physiology. We conclude that SPF animals displayed an abnormal hemodynamic, hematological and hemostatic phenotype in response to anesthesia and surgery, and provide a number of recommendations to help standardize research outcomes and translation