Safety and efficacy of human polymerized hemoglobin on guinea pig resuscitation from hemorrhagic shock.

For the past thirty years, hemoglobin-based oxygen carriers (HBOCs) have been under development as a red blood cell substitute. Side-effects such as vasoconstriction, oxidative injury, and cardiac toxicity have prevented clinical approval of HBOCs. Recently, high molecular weight (MW) polymerized human hemoglobin (PolyhHb) has shown positive results in rats. Studies have demonstrated that high MW PolyhHb increased O2 delivery, with minimal effects on blood pressure, without vasoconstriction, and devoid of toxicity. In this study, we used guinea pigs to evaluate the efficacy and safety of high MW PolyhHb, since like humans guinea pigs cannot produce endogenous ascorbic acid, which limits the capacity of both species to deal with oxidative stress. Hence, this study evaluated the efficacy and safety of resuscitation from severe hemorrhagic shock with high MW PolyhHb, fresh blood, and blood stored for 2 weeks. Animals were randomly assigned to each experimental group, and hemorrhage was induced by the withdrawal of 40% of the blood volume (BV, estimated as 7.5% of body weight) from the carotid artery catheter. Hypovolemic shock was maintained for 50 min. Resuscitation was implemented by infusing 25% of the animal's BV with the different treatments. Hemodynamics, blood gases, total hemoglobin, and lactate were not different before hemorrhage and during shock between groups. The hematocrit was lower for the PolyhHb group compared to the fresh and stored blood groups after resuscitation. Resuscitation with stored blood had lower blood pressure compared to fresh blood at 2 h. There was no difference in mean arterial pressure between groups at 24 h. Resuscitation with PolyhHb was not different from fresh blood for most parameters. Resuscitation with PolyhHb did not show any remarkable change in liver injury, inflammation, or cardiac damage. Resuscitation with stored blood showed changes in liver function and inflammation, but no kidney injury or systemic inflammation. Resuscitation with stored blood after 24 h displayed sympathetic hyper-activation and signs of cardiac injury. These results suggest that PolyhHb is an effective resuscitation alternative to blood. The decreased toxicities in terms of cardiac injury markers, vital organ function, and inflammation following PolyhHb resuscitation in guinea pigs indicate a favorable safety profile. These results are promising and support future studies with this new generation of PolyhHb as alternative to blood when blood is unavailable.

Blood Component Requirements and Erythrocyte Transfusion and Mortality Related to Hemoglobin Deficit in Phase III Trial of Hemoglobin-Based Oxygen Carrier: HBOC-201.

BACKGROUND: Hemoglobin-based oxygen carriers (HBOCs) may cause coagulopathy, changes in total hemoglobin (THb), and affect mortality. Low total hemoglobin concentrations [THb] during hemorrhage may worsen outcomes. STUDY QUESTION: The database of the Hemopure HEM-0115 phase III trial was queried to determine the use of platelets, plasma, or cryoprecipitate and compare transfusion requirements and coagulation studies between patients randomized to erythrocyte transfusion or HBOC-201 infusion. Modeling of hemoglobin (Hb) changes produced by HBOC-201, erythrocyte, and blood product administration were related to [THb], coagulopathy, and mortality. DATA SOURCES: Hemopure HEM-0115 phase III trial database. STUDY DESIGN: Retrospective and Novel Hemoglobin Deficit Formulas Tested Against Existing Database. RESULTS: The HBOC-201 database (n = 688) demonstrated less than 6% of subjects in both groups were administered non-Hb containing blood products (fresh frozen plasma, platelets, or cryoprecipitate) and low rates of coagulopathies in both erythrocyte and HBOC-201 arms. There were no differences in mortality in elective orthopedic patients administered up to 10 bags HBOC-201 (equivalent to 3 units erythrocytes). Low total [Hb] and lack of adequate oxygen carrying capacity was found to be an independent predictor of morbidity/mortality. CONCLUSIONS: The elective use of HBOC-201 for orthopedics versus erythrocytes demonstrated low incidence of blood product requirements in both cohorts and no differences in mortality up to the HBOC-201 equivalent of 3 units erythrocytes. High total Hb may be important to maintain in acute hemorrhage and [Hb] deficit, whereas later in recovery might not be as crucial. Future trauma trials may benefit from the use of HBOC-201 containing 13 g/dL in prehospital management, when erythrocytes are commonly not available.

From hemoglobin allostery to hemoglobin-based oxygen carriers.

Hemoglobin (Hb) plays its vital role through structural and functional properties evolutionarily optimized to work within red blood cells, i.e., the tetrameric assembly, well-defined oxygen affinity, positive cooperativity, and heterotropic allosteric regulation by protons, chloride and 2,3-diphosphoglycerate. Outside red blood cells, the Hb tetramer dissociates into dimers, which exhibit high oxygen affinity and neither cooperativity nor allosteric regulation. They are prone to extravasate, thus scavenging endothelial NO and causing hypertension, and cause nephrotoxicity. In addition, they are more prone to autoxidation, generating radicals. The need to overcome the adverse effects associated with cell-free Hb has always been a major hurdle in the development of substitutes of allogeneic blood transfusions for all clinical situations where blood is unavailable or cannot be used due to, for example, religious objections. This class of therapeutics, indicated as hemoglobin-based oxygen carriers (HBOCs), is formed by genetically and/or chemically modified Hbs. Many efforts were devoted to the exploitation of the wealth of biochemical and biophysical information available on Hb structure, function, and dynamics to design safe HBOCs, overcoming the negative effects of free plasma Hb. Unfortunately, so far, no HBOC has been approved by FDA and EMA, except for compassionate use. However, the unmet clinical needs that triggered intensive investigations more than fifty years ago are still awaiting an answer. Recently, HBOCs "repositioning" has led to their successful application in organ perfusion fluids.

Perfluorocarbon-based oxygen carriers: from physics to physiology.

Developing biocompatible, synthetic oxygen carriers is a consistently challenging task that researchers have been pursuing for decades. Perfluorocarbons (PFC) are fascinating compounds with a huge capacity to dissolve gases, where the respiratory gases are of special interest for current investigations. Although largely chemically and biologically inert, pure PFCs are not suitable for injection into the vascular system. Extensive research created stable PFC nano-emulsions that avoid (i) fast clearance from the blood and (ii) long organ retention time, which leads to undesired transient side effects. PFC-based oxygen carriers (PFOCs) show a variety of application fields, which are worthwhile to investigate. To understand the difficulties that challenge researchers in creating formulations for clinical applications, this review provides the physical background of PFCs' properties and then illuminates the reasons for instabilities of PFC emulsions. By linking the unique properties of PFCs and PFOCs to physiology, it elaborates on the response, processing and dysregulation, which the body experiences through intravascular PFOCs. Thereby the reader will receive a scientific and easily comprehensible overview why PFOCs are precious tools for so many diverse application areas from cancer therapeutics to blood substitutes up to organ preservation and diving disease.

The Dead Sea needs salt water massively bleeding patients need whole blood: The evolution of blood product resuscitation.

Whole blood, that is blood that is not manufactured into its component red blood cells (RBC) plasma, and platelets (PLT) units, was the mainstay of transfusion for many years until it was discovered that the component parts of a blood donation could be stored under different conditions thereby optimizing the storage length of each product. The use of low anti-A and -B titer group O whole blood (LTOWB) has recently been rediscovered for use in massively bleeding trauma patients. Whole blood has several advantages over conventional component therapy for these patients, including simplifying the logistics of the resuscitation, being more concentrated than whole blood that is reconstituted from conventional components, and providing cold-stored PLTs, amongst other benefits. While randomized controlled trials to determine the efficacy of using LTOWB in the resuscitation of massively bleeding trauma patients are currently underway, retrospective data has shown that massively bleeding recipients of LTOWB with traumatic injury do not have worse outcomes compared to patients who received conventional components and, in some cases, recipients of LTOWB have more favourable outcomes. This paper will describe some of the advantages of using LTOWB and will discuss the emerging evidence for its use in massively bleeding patients.

Opioid analgesics are the leading cause of adverse drug reactions in the obstetric population in South Korea.

Medication use during pregnancy is gradually increasing; however, the safety of this practice remains largely unknown.We investigated medications with the most adverse drug reactions (ADRs) among pregnant women and the clinical features of those medications.Reports of ADRs among pregnant women were extracted from the Korea Adverse Events Reporting System (January 2012-December 2015). We analyzed the data of drugs frequently reported to cause ADRs and their clinical features among 3 age groups.A total of 5642 ADRs among 3428 patients were analyzed. The number of ADR reports increased annually. The most common drug categories causing ADRs were analgesics, followed by gynecologic, uterotocolytic, anti-infective, antidiabetic, analgesic, and antihypertensive drugs. Analgesics comprised 6 opioids (morphine, fentanyl, hydromorphone, oxycodone, tramadol, pethidine) and an anti-pyretics (nefopam and ketorolac). As an individual drug, ritodrine (24.4%) was the most frequently reported, followed by morphine, 5-HT3 serotonin antagonist, nefopam, fentanyl, magnesium sulfate, insulin lispro, cefazedone, sodium chloride, hydromorphone, oxycodone, cefotetan, nifedipine, human insulin, tramadol, ketorolac, pethidine, methylergometrine, metoclopramide, and misoprostol (in that order). ADRs most frequently occurred in women aged 25 to 34 years, and the trend of ADR with the 20 most commonly reported medications significantly differed among the age groups (P = .011). In addition, the kind of common causative drugs was different among the age groups.Knowledge of medications and clinical conditions resulting in the highest ADR rates among pregnant women is necessary for medical practitioners to administer proper care.

Damage Control Resuscitation in polytrauma patient. / Damage Control Resuscitation en el paciente traumático.

Haemorrhagic shock is one of the main causes of mortality in severe polytrauma patients. To increase the survival rates, a combined strategy of treatment known as Damage Control has been developed. The aims of this article are to analyse the actual concept of Damage Control Resuscitation and its three treatment levels, describe the best transfusion strategy, and approach the acute coagulopathy of the traumatic patient as an entity. The potential changes of this therapeutic strategy over the coming years are also described.

Inhaled nitric oxide prevents systemic and pulmonary vasoconstriction due to hemoglobin-based oxygen carrier infusion: A case report.

Hemoglobin-based oxygen carriers (HBOCs) are used in extreme circumstances to increase hemoglobin concentration and improve oxygen delivery when allogenic red blood cell transfusions are contraindicated or not immediately available. However, HBOC-induced severe pulmonary and systemic vasoconstriction due to peripheral nitric oxide (NO) scavenging has stalled its implementation in clinical practice. We present a case of an 87 year-old patient with acute life-threatening anemia who received HBOC while breathing NO gas. This case shows that inhaled NO allows for the safe use of HBOC infusion by preventing HBOC-induced pulmonary and systemic vasoconstriction.

Proceedings From the Society for Advancement of Blood Management Annual Meeting 2017: Management Dilemmas of the Surgical Patient-When Blood Is Not an Option.

Vigilance is essential in the perioperative period. When blood is not an option for the patient, especially in a procedure/surgery that normally holds a risk for blood transfusion, complexity is added to the management. Current technology and knowledge has made avoidance of blood transfusion a realistic option but it does require a concerted patient-centered effort from the perioperative team. In this article, we provide suggestions for a successful, safe, and bloodless journey for patients. The approaches include preoperative optimization as well as intraoperative and postoperative techniques to reduce blood loss, and also introduces current innovative substitutes for transfusions. This article also assists in considering and maneuvering through the legal and ethical systems to respect patients' beliefs and ensuring their safety.

Long term safety and immunological effects of a nanobiotherapeutic, bovine poly-[hemoglobin-catalase-superoxide dismutase-carbonic anhydrase], after four weekly 5% blood volume top-loading followed by a challenge of 30% exchange transfusion.

The long-term safety and immunological effects of bovine poly-[haemoglobin-catalase-superoxide dismutase-carbonic anhydrase] in rats are studied by four-weekly 5% blood volume top-loading infusions followed by 30% blood volume exchange transfusion. There is no significant difference in growth, biochemistry and blood pressure between the control group receiving lactated ringer solution and those receiving the bovine poly-[haemoglobin-catalase-superoxide dismutase-carbonic anhydrase]. There is no significant change in mean arterial pressures (MAP) before and after each weekly top-loading infusion. After both the four weekly top-loading and the 30% exchange transfusions, the following safety and immune response evaluations are carried out. These include general studies on Ouchterlony double diffusion, total IgG and IgM, and complement activation. This is followed by quantitative measurements of specific antibodies against each of the following bovine components: Hb, CAT, SOD and CA in bovine poly-[haemoglobin-catalase-superoxide dismutase-carbonic anhydrase]. After the four weekly top-loading, each rat received a challenge of 30% blood volume exchange transfusion. The MAP, histamine and tryptase levels are tested before and after the 30% exchange transfusion. There are no anaphylactic reactions as shown by the MAP or histamine and tryptase. The results showed no safety problem nor adverse immune responses. All the rats survived when followed for one week after the 30% exchange transfusion.

High- and low-affinity PEGylated hemoglobin-based oxygen carriers: Differential oxidative stress in a Guinea pig transfusion model.

Hemoglobin-based oxygen carriers (HBOCs) are an investigational replacement for blood transfusions and are known to cause oxidative damage to tissues. To investigate the correlation between their oxygen binding properties and these detrimental effects, we investigated two PEGylated HBOCs endowed with different oxygen binding properties - but otherwise chemically identical - in a Guinea pig transfusion model. Plasma samples were analyzed for biochemical markers of inflammation, tissue damage and organ dysfunction; proteins and lipids of heart and kidney extracts were analyzed for markers of oxidative damage. Overall, both HBOCs produced higher oxidative stress in comparison to an auto-transfusion control group. Particularly, tissue 4-hydroxynonenal adducts, tissue malondialdehyde adducts and plasma 8-oxo-2'-deoxyguanosine exhibited significantly higher levels in comparison with the control group. For malondialdehyde adducts, a higher level in the renal tissue was observed for animals treated with the high-affinity HBOC, hinting at a correlation between the HBOCs oxygen binding properties and the oxidative stress they produce. Moreover, we found that the high-affinity HBOC produced greater tissue oxygenation in comparison with the low affinity one, possibly correlating with the higher oxidative stress it induced.

Preclinical In Vitro Safety Investigations of Submicron Sized Hemoglobin Based Oxygen Carrier HbMP-700.

Hemoglobin-based oxygen carriers (HBOCs) are being developed as oxygen and plasma volume-expanding therapeutics though their potential to promote oxidative tissue injury and nitric oxide (NO) scavenging combined with vasoconstriction has raised safety concerns. Therefore, we focused on these aspects during preclinical studies performed with the recently introduced hemoglobin microparticles (HbMP-700). Besides oxidative stress, we investigated possible vasoconstrictory influence of HBOCs as well as genetic toxicity. The novel developed HbMP-700 presented here provides a high oxygen affinity which prevents premature oxygen oversupply and avoids vasoconstriction of small blood vessels in vitro. The size of these particles is 700 nm (larger than 100 nm and smaller than 1000 nm) in order to prevent penetration through the blood vessel's endothelial gaps, NO-scavenging, and to avoid phagocytosis of large particles. We expect that the HbMP-700 meets the sophisticated requirements as a universal blood substitute.

Comprehensive Biochemical and Biophysical Characterization of Hemoglobin-Based Oxygen Carrier Therapeutics: All HBOCs Are Not Created Equally.

The development of hemoglobin (Hb)-based oxygen carriers (HBOCs) has been hampered because of safety concerns in humans. Chemical and/or genetic modifications of the Hb introduce varied structural and conformational constraint on the molecule that resulted in proteins with diverse allosteric responses, nitrosative and oxidative side reactions. Here, we present for the first time a comprehensive biochemical and biophysical comparison of human, bovine, and genetically engineered HBOCs that have been tested in humans. We evaluate oxygen equilibrium and ligand binding kinetics under different experimental conditions as well as their autoxidation kinetics, redox reactions, and heme release. We determined the effects of HBOCs on cellular redox states and mitochondrial respiration. Taken together, these experiments provide a better understanding of the relationship between the structure-function and oxidative reactivity of these proteins. One can therefore select independently among these diverse properties to engineer a safe and effective HBOC with improved biochemical/biophysical characteristics.

Microparticles in red cell concentrates prime polymorphonuclear neutrophils and cause acute lung injury in a two-event mouse model.

Red cell-derived microparticles (RMPs) are potential mediators of transfusion-related acute lung injury (TRALI). The aim of this study was to investigate the effects of microparticles present in red cell concentrates (RCC) on polymorphonuclear neutrophil (PMN) respiratory burst and acute lung injury (ALI) in mice. Microparticles (MPs) in RCC supernatant were quantified using flow cytometry. The priming activity of either isolated MPs or RCC supernatant toward human PMN was measured in vitro. Mice were injected with lipopolysaccharide (LPS), followed by an infusion of either isolated MPs or heat-treated RCC supernatant. The lungs were harvested to assess myeloperoxidase (MPO) activity, histology and pulmonary edema. Protein content in bronchoalveolar lavage fluid (BALF) was measured. The number of RMPs increased significantly during storage. Both isolated MPs and the supernatants from RCCs that had been stored for 28 and 35days effectively primed the PMN respiratory burst. The infusion of isolated MPs or supernatants that had been stored for >28days into LPS-treated mice caused ALI. The filtered supernatant resulted in significantly ameliorated mouse ALI. MPs that accumulate during RCC storage prime the PMN respiratory burst and cause ALI in a two-event mouse model.

Use of the blood substitute HBOC-201 in critically ill patients during sickle crisis: a three-case series.

BACKGROUND: Red blood cell (RBC) transfusion is an important treatment modality during severe sickle cell crisis (SCC). SCC patients who refuse, or cannot accept, RBCs present a unique challenge. Acellular hemoglobin (Hb)-based oxygen carriers (HBOCs) might be an alternative for critically ill patients in SCC with multiorgan failure due to life-threatening anemia. HBOC-201 (HbO2 Therapeutics) has been administered to more than 800 anemic patients in 22 clinical trials, but use of any HBOCs in critically ill sickle cell patients with organ failure is exceedingly rare. In the United States, HBOC-201 is currently only available for expanded access. CASE REPORT: We report three cases of HBOC-201 administered to critically ill sickle cell disease patients in SCC with multiorgan failure, either who refused RBCs (Jehovah's Witnesses) or for whom compatible RBCs were not available. RESULTS: Two patients received more than 20 units of HBOC-201, while the other received 6. The 27 units used in the third case equals the largest volume a patient has successfully received to date. All three patients survived to hospital discharge. CONCLUSION: These reports suggest that blood substitutes such as HBOC-201 can provide an oxygen bridge in SCC with multiorgan failure, until corpuscular Hb levels recover to meet metabolic demand, and highlight the compelling biochemical properties that warrant further investigation.

SANGUINATE™ (PEGylated Carboxyhemoglobin Bovine) Improves Cerebral Blood Flow to Vulnerable Brain Regions at Risk of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage.

BACKGROUND: Delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) has been linked to focal reductions in cerebral blood flow (CBF) and microvascular impairments in oxygen delivery. Effective therapies that restore flow and oxygen transport to vulnerable brain regions are currently lacking. SANGUINATE is a dual-action carbon monoxide-releasing and hemoglobin-based oxygen transfer agent with efficacy in animal models of focal brain ischemia and tolerability in patients with sickle cell disease. METHODS: We performed a safety and proof-of-principle study in 12 SAH patients at risk of DCI across three escalating doses (160, 240, and 320 mg/kg). We used 15O-PET (performed at baseline, after SANGUINATE and at 24 h) to evaluate efficacy for improving CBF and restoring flow-metabolism balance (assessed by oxygen extraction fraction [OEF]) to vulnerable regions (defined as baseline OEF ≥ 0.50). RESULTS: SANGUINATE resulted in a transient rise in mean arterial pressure (116 ± 15-127 ± 13 mm Hg, p = 0.001) that normalized by 24 h and allowed three patients with DCI to be weaned off vasopressors. No adverse events were noted during infusion. Global CBF did not rise (43 ± 8-46 ± 9 ml/100 g/min) although a trend was seen at the highest dose (45 ± 7-51 ± 9, p = 0.044). However, a significant 16% rise in regional CBF associated with reduction in OEF was seen in vulnerable regions, but did not persist at 24 h. CONCLUSIONS: We demonstrated that this novel agent can improve regional CBF and may improve oxygen supply-demand balance. Clinical studies (likely with repeat dosing) are required to evaluate whether this effect can prevent DCI or cerebral infarction.

Hemoglobin-based oxygen carriers promote systemic hyperfibrinolysis that is both dependent and independent of plasmin.

BACKGROUND: Hyperfibrinolysis plays an integral role in the genesis of trauma-induced coagulopathy. Recent data demonstrate that red blood cell lysis promotes fibrinolysis; however, the mechanism is unclear. Hemoglobin-based oxygen carriers (HBOCs) have been developed for resuscitation and have been associated with coagulopathy. We hypothesize that replacement of whole blood (WB) using an HBOC results in a coagulopathy because of the presence of free hemoglobin. MATERIALS AND METHODS: WB was sampled from healthy donors (n = 6). The clotting profile of each citrated sample was evaluated using native thromboelastography. Serial titrations were performed using both HBOC (PolyHeme) and normal saline (NS; 5%, 25%, and 50%) and evaluated both with and without a 75-ng/mL tissue plasminogen activator (tPA) challenge. Tranexamic acid (TXA) was added to inhibit plasmin-dependent fibrinolysis. Fibrinolysis was measured and recorded as lysis at 30 min (LY30), the percentage of clot LY30 after maximal clot strength. Dilution of WB with NS or HBOC was correlated using LY30 via Spearman rho coefficients. Groups were also compared using a Friedman test and post hoc analysis with a Bonferroni adjustment. RESULTS: tPA-provoked fibrinolysis was enhanced by both HBOC (median LY30 at 5%, 25%, and 50% titrations: 11%, 21%, and 44%, respectively; Spearman = 0.94; P < 0.001) and NS (11%, 28%, and 58%, respectively; Spearman = 0.790; P < 0.001). However, HBOC also enhanced fibrinolysis without the addition of tPA (1%, 4%, 5%; Spearman = 0.735; P = 0.001) and NS did not (1%, 2%, 1%; r = 0.300; P = 0.186. Moreover, addition of TXA did not alter or inhibit this fibrinolysis (WB versus 50% HBOC: 1.8% versus 5.7%, P = 0.04). There was no significant difference in fibrinolysis of HBOC with or without TXA (50% HBOC versus 50% HBOC + TXA: 5.6% versus 5.7%, P = 0.92). In addition, the increased fibrinolysis seen with NS was reversed when TXA was present (WB versus 50% NS: 1.8% versus 1.7%, P = 1.0). CONCLUSIONS: HBOCs enhance fibrinolysis both with and without addition of tPA; moreover, this mechanism is independent of plasmin as the phenomenon persists in the presence of TXA. Our findings indicate the hemoglobin molecule or its components stimulate fibrinolysis by both tPA-dependent and innate mechanisms.

Optimising Intravenous Volume Resuscitation of the Newborn in the Delivery Room: Practical Considerations and Gaps in Knowledge.

Volume resuscitation (VR) for the treatment of newborn shock is a rare but potentially lifesaving intervention. Conducting clinical studies to assess the effectiveness of VR in the delivery room during newborn stabilization is challenging. We review the available literature and current management guidelines to determine which infants will benefit from VR, the frequency of VR, and the choice of agents used. In addition, the potential role for placental transfusion in the prevention of newborn shock is explored.