Hemoglobin-based Oxygen Carriers Infusion Research Articles

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.

Beneficial effects of hemoglobin-based oxygen carriers on early resuscitation in rats with uncontrolled hemorrhagic shock

To investigate the early resuscitation effect of hemoglobin-based oxygen carriers (HBOC) in rats with uncontrolled hemorrhagic shock. 170 Sprague-Dawley (SD) rats were randomly divided into five groups: lactate Ringer solution (LR) control group, whole blood control group, and 0.5%, 2.0%, 5.0% HBOC groups, with 34 rats in each group. The uncontrolled hemorrhagic shock model in SD rats was reproduced by cutting off the splenic artery branch, and induced mean arterial pressure (MAP) reducing to 40 mmHg (1 mmHg = 0.133 kPa). The corresponding solution was infused after model reproduction in each group, maintaining MAP at 50 mmHg for 1 hour, then completely ligating and hemostasis, and maintaining MAP at 70 mmHg for 1 hour and 80 mmHg for 1 hour respectively, after maintaining MAP 80 mmHg, all were supplemented with LR to 2 times blood loss volume. The survival rate and blood loss rate were observed in 16 rats in each group, hemodynamics parameters including MAP, left ventricular systolic pressure (LVSP) and the maximum rate of left ventricular pressure rise (+dp/dt max) were determined in another 10 rats, and cardiac output (CO) and tissue oxygen supply (DO2) were observed in the rest 8 rats. (1) When resuscitation by LR alone, the blood loss rate of animals was as high as 60% to 70%. Compared with the LR control group, whole blood recovery could significantly reduce the blood loss rate before hemostasis in uncontrolled hemorrhagic shock rats [(46.6±4.5)% vs. (62.3±4.0)%, P < 0.01]; 0.5%, 2.0%, 5.0% HBOC could significantly decrease the blood loss rate, especially in 5.0% HBOC group with significant difference as compared with that in the LR control group [(45.6±4.1)% vs. (62.3±4.0)%, P < 0.01]. (2) When LR was used alone for resuscitation, the rats died quickly and survived for a short time. Only one rat survived for 12 hours, and no rat survived for more than 24 hours. Compared with the LR control group, whole blood resuscitation could improve the survival rate of uncontrolled hemorrhagic shock rats, and the survival time was significantly prolonged (hours: 20.4±4.6 vs. 3.5±1.1, P < 0.01); 0.5%, 2.0% and 5.0% HBOC also significantly prolonged the survival time of rats. The 5.0% HBOC group had the best effect, 4 rats survived in 24 hours, and the survival time was significantly longer than that of the LR control group (hours: 18.4±4.0 vs. 3.5±1.1, P < 0.01), and it was the same as the whole blood control group. (3) Compared with pre-shock, CO, DO2 and hemodynamic parameters of uncontrolled hemorrhagic shock rats were significantly decreased, and the above parameters were gradually increased with the prolongation of rehydration time. Compared with the LR control group, whole blood resuscitation could significantly increase CO and DO2, and improve hemodynamics in rats with uncontrolled hemorrhagic shock at different time points. Three concentrations of HBOC could also increase CO, DO2 and other hemodynamic parameters of rats at 1 hour of maintaining MAP of 80 mmHg after hemostasis and 1 hour and 2 hours after resuscitation. The effect of 5.0% HBOC group was more significant than that of the LR control group with statistically significant difference [CO (×10-3, L/min): 72.84±2.84 vs. 63.11±2.38 at 1 hour of maintaining MAP of 80 mmHg, 70.25±4.55 vs. 59.88±9.31 at 1 hour after resuscitation, 71.51±2.90 vs. 53.24±6.32 at 2 hours after resuscitation; DO2 (L×min-1×m-2): 271.9±13.5 vs. 159.1±25.4 at 1 hour of maintaining MAP of 80 mmHg, 261.0±15.0 vs. 145.7±20.1 at 1 hour after resuscitation, 249.6±12.0 vs. 107.4±18.2 at 2 hours after resuscitation; MAP (mmHg): 82.1±2.1 vs. 74.0±2.8 at 1 hour of maintaining MAP of 80 mmHg, 107.5±9.3 vs. 64.0±5.7 at 1 hour after resuscitation, 104.0±9.7 vs. 73.0±4.2 at 2 hours after resuscitation; LVSP (mmHg): 128.6±7.9 vs. 103.8±0.8 at 1 hour of maintaining MAP of 80 mmHg, 129.3±15.0 vs. 99.4±0.0 at 1 hour after resuscitation, 127.5±11.3 vs. 97.4±0.0 at 2 hours after resuscitation; +dp/dt max (mmHg/s): 6 534.2±787.6 vs. 5 074.0±71.7 at 1 hour of maintaining MAP of 80 mmHg, 5 961.5±545.4 vs. 4 934.5±510.2 at 1 hour after resuscitation, 5 897.4±350.5 vs. 4 534.7±489.2 at 2 hours after resuscitation, all P < 0.05]. HBOC infusion prolonged the survival time, increased survival rate, and improved hemodynamics, cardiac function and tissue oxygen supply in a dose-dependent manner in the early stage of uncontrolled hemorrhagic shock. The recovery effect of 5.0% HBOC was similar to that of the whole blood.

Balancing potential risks and benefits of hemoglobin‐based oxygen carriers

Hemoglobin-based oxygen carriers (HBOCs) are thought to have an adverse risk:benefit profile when compared to that of transfusing stored red blood cells (RBCs). However, there are clinical circumstances when RBC transfusion is not an option (e.g., patient refusal, unavailability owing to issues of compatibility or remote location). For these circumstances assessment of the risks of an HBOC should be compared to the risks of untransfused acute anemia. In this article we compare the risk of allowing a patient with severe anemia to have a further small decrease in hemoglobin (Hb) concentration to the risk of infusing an HBOC. We conclude that at Hb concentrations less than 6 g/dL, the risk of a further decrease in Hb concentration greatly exceeds the risk of HBOC infusion. Thus, we suggest that there may be a place for use of HBOCs when RBC transfusion is not an option.

Endothelial Dysfunction Enhances Vasoconstriction Due to Scavenging of Nitric Oxide by a Hemoglobin-based Oxygen Carrier

To date, there is no safe and effective hemoglobin-based oxygen carrier (HBOC) to substitute for erythrocyte transfusion. It is uncertain whether a deficiency of endothelial nitric oxide bioavailability (endothelial dysfunction) prevents or augments HBOC-induced vasoconstriction. Hemodynamic effects of infusion of PolyHeme (1.08 g hemoglobin/kg; Northfield Laboratories, Evanston, IL) or murine tetrameric hemoglobin (0.48 g hemoglobin/kg) were determined in awake healthy lambs, awake mice, and anesthetized mice. In vitro, a cumulative dose-tension response was obtained by sequential addition of PolyHeme or tetrameric hemoglobin to phenylephrine-precontracted murine aortic rings. Infusion of PolyHeme did not cause systemic hypertension in awake lambs but produced acute systemic and pulmonary vasoconstriction. Infusion of PolyHeme did not cause systemic hypertension in healthy wild-type mice but induced severe systemic vasoconstriction in mice with endothelial dysfunction (either db/db mice or high-fat fed wild-type mice for 4-6 weeks). The db/db mice were more sensitive to systemic vasoconstriction than wild-type mice after the infusion of either tetrameric hemoglobin or PolyHeme. Murine aortic ring studies confirmed that db/db mice have an impaired response to an endothelial-dependent vasodilator and an enhanced vasoconstrictor response to HBOC. Reduction in low molecular weight hemoglobin concentrations to less than 1% is insufficient to abrogate the vasoconstrictor effects of HBOC infusion in healthy awake sheep or in mice with reduced vascular nitric oxide levels associated with endothelial dysfunction. These findings suggest that testing HBOCs in animals with endothelial dysfunction can provide a more sensitive indication of their potential vasoconstrictor effects.

Glutaraldehyde-polymerized bovine hemoglobin and phosphodiesterase-5 inhibition*

Hemoglobin-based oxygen carriers (HBOC) of several types scavenge nitric oxide from the vasculature resulting in vasoconstriction and hypertension, both systemic and pulmonary. Phosphodiesterase-5 (PDE5) inhibitors promote nitric oxide activity and enhance vasodilation. The purpose of this study was to determine whether combined therapy of glutaraldehyde-polymerized bovine hemoglobin (HBOC) with a PDE5 inhibitor would counter the negative hemodynamic consequences of HBOC therapy alone, resulting in improved hemodynamics and oxygen delivery. A controlled, experimental study. A research laboratory at a university. Conscious male Sprague-Dawley rats. Glutaraldehyde-polymerized bovine hemoglobin (HBOC), sildenafil (PDE5 inhibitor), and lactated Ringer's solution (control). Infusion of the HBOC resulted in significant (p < 0.05) systemic and pulmonary vasoconstriction, with reduced cardiac output and reduced oxygen delivery to the periphery. Infusion of lactated Ringer's demonstrated no changes in the measured variables. Infusion of sildenafil alone reduced systemic and pulmonary artery blood pressure, while maintaining cardiac output and oxygen delivery. Combined HBOC and sildenafil infusion resulted in stable systemic blood pressure, cardiac output, and oxygen delivery. However, the addition of sildenafil to HBOC did not fully ameliorate the pulmonary vasoconstriction caused by HBOC. The HBOC used in this study resulted in pulmonary and systemic hypertension, reduced cardiac output, and oxygen delivery. These negative consequences of HBOC treatment can be largely overcome by combing HBOC treatment with a PDE5 inhibitor (sildenafil). Thus, these data support the continued investigation of combined HBOC and PDE5 inhibitor treatment in circumstances in which HBOC therapy is being considered.

Effects of hemoglobin‐based oxygen carriers (HBOCs) on nitric oxide (NO) levels in the spinotrapezius muscle and mesentery of the rat

Use of HBOCs has been limited by the side effect of increased mean arterial pressure (MAP). It is thought that HBOCs scavenge NO, leading to decreased [NO], arteriolar vasoconstriction, and increased vascular resistance and arterial pressure. Previous microcirculatory studies investigating effects of HBOC infusion have yielded contradictory results. The aim of this study was to compare responses of tissues with different metabolic activity to HBOC injection. Experiments were conducted in the spinotrapezius muscle or mesentery of anesthetized male Sprague‐Dawley rats. Preparations were loaded with 5 μM DAF‐2DA for 45 min. Cytosolic esterases convert DAF‐2DA to DAF‐2 which reacts with an oxygenated derivative of NO to form highly fluorescent DAF‐2T. The DAF‐2T signal was recorded with a digital CCD camera connected to a Zeiss fluorescence microscope. Vessel diameter, MAP and fluorescence were monitored under control conditions and after bolus i.v. injection of HBOC‐201 in 1, 10 and 100 μM plasma concentrations. HBOC‐201 increased MAP. There was vasoconstriction and an increase in DAF‐2T fluorescence in the spinotrapezius preparation, whereas no vasoconstriction or increase in DAF‐2T fluorescence was observed in the mesentery. These results suggest that metabolically active tissues like skeletal muscle have higher [NO] than less metabolically active tissues such as the mesentery. Support: HL18292.

Broadband diffuse optical spectroscopy assessment of hemorrhage- and hemoglobin-based blood substitute resuscitation

Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have been developed for replacement or augmentation of blood transfusion. It is important to monitor in vivo tissue hemoglobin content, total tissue hemoglobin [THb], oxy- and deoxy-hemoglobin concentrations ([OHb], [RHb]), and tissue oxygen saturation (S(t)O(2)=[OHb][THb]x100%) to evaluate effectiveness of HBOC transfusion. We designed and constructed a broadband diffuse optical spectroscopy (DOS) prototype system to measure bulk tissue absorption and scattering spectra between 650 and 1000 nm capable of accurately determining these tissue hemoglobin component concentrations in vivo. Our purpose was to assess the feasibility of using DOS to optically monitor tissue [OHb], [RHb], S(t)O(2), and total tissue hemoglobin concentration ([THb]=[OHb]+[RHb]) during HBOC infusion using a rabbit hypovolemic shock model. The DOS prototype probe was placed on the shaved inner thigh muscle of the hind leg to assess concentrations of [OHb], [RHb], [THb], as well as S(t)O(2). Hemorrhagic shock was induced in intubated New Zealand white rabbits (N=6) by withdrawing blood via a femoral arterial line to 20% blood loss (10-15 cckg). Hemoglobin glutamer-200 (Hb-200) 1:1 volume resuscitation was administered following the hemorrhage. These values were compared against traditional invasive measurements, serum hemoglobin concentration (sHGB), systemic blood pressure, heart rate, and blood gases. DOS revealed increases of [THb], [OHb], and tissue hemoglobin oxygen saturation after Hb-200 infusion, while blood total hemoglobin values continued did not increase; we speculate, due to hyperosmolality induced hemodilution. DOS enables noninvasive in vivo monitoring of tissue hemoglobin and oxygenation parameters during shock and volume expansion with HBOC and potentially enables the assessment of efficacy of resuscitation efforts using artificial blood substitutes.

Effects of the Resuscitation Fluid and the Hemoglobin Based Oxygen Carrier (HBOC) Excipient on the Toxicity of the HBOC: Ringer'sD,L-Lactate, Ringer'sL-Lactate, and Ringer's Ketone Solutions

Hemoglobin based oxygen carriers (HBOC) are resuspended in "excipients" consisting of Ringer's D,L-lactate containing antioxidants to prevent methemoglobin formation during storage. Investigators have reported cardiac arrhythmias following infusion of Ringer's D,L-lactate solution. Studies have shown that D-lactate stimulates human granulocytes to generate oxygen free radicals and L-lactate inhibits glycolysis. Patients receiving HBOC in Ringer's D,L-lactate excipient are also resuscitated or hemodiluted with Ringer's lactate solution. Oxygen-free radicals generated by Ringer's D,L-lactate and HBOC may oxidize nitric oxide in endothelial cells, causing the vasoconstrictor effects reported following HBOC infusion, and activate NF-kappab and the apoptotic cascade. The combination of Ringer's D,L-lactate and HBOC in Ringer's D,L-lactate excipient may be responsible for the severe adverse events observed in clinical studies of HBOC.Veech has recommended replacing the 27 mM of lactate in Ringer's with 27 mM D-betahydroxybutyrate (BHB). BHB reduces the generation of oxygen free radicals by mitochondria and human granulocytes.

Validation of oxygen saturation measurements in a canine model of hemoglobin-based oxygen carrier infusion.

This study was designed to validate oxygen saturation measurements from the NOVA CO-Oximeter (NOVA Biomedical Corporation, Waltham, MA), the i-STAT System (Sensor Devices, Waukesha, WI), and the Corning 170 blood gas analyzer (Bayer Corporation, East Walpole, MA) under conditions similar to the clinical application of a hemoglobin-based oxygen carrier (HBOC, hemoglobin glutamer-200 [bovine]; Oxyglobin, Biopure Corporation, Cambridge, MA). A canine model was used for both in vitro and in vivo experiments. In vivo experiments were conducted in a canine laboratory, and in vitro experiments were conducted in a tonometry laboratory. Study subjects were six mixed-breed dogs, each weighing approximately 30 kg. In the first set of experiments, the target blood po(2) levels were reached by tonometry. In the second set of experiments, quantitative measurements of total oxygen content with the LEXO2CON-K (HOSPEX Fiberoptics, Chestnut Hill, MA) were performed, immediately followed by measurements with the NOVA CO-Oximeter and the i-STAT system. HBOC was added in concentrations of 16.2, 32.5, 65, and 97.5 g/L. To analyze the clinical significance of the differences in the results obtained with the each investigated instrument, blood samples from dogs treated with HBOC after acute hemorrhagic shock were used. Oxygen saturation, oxygen content, and po(2) were measured. There was a strong correlation between the oxygen saturation values measured with the investigated instruments in samples after tonometry and known po(2). The total calculated oxygen content varied by 5% based on results generated by calculations using the investigated instruments. The results did not change with different oxygenation of the sample. The differences among methods were not significant when the HBOC concentration was 16.2 g/L. Higher concentrations of HBOC increased the difference between calculated and measured oxygen content; the i-STAT system demonstrated a greater deviation compared with the results of the other two instruments. Systemic oxygen uptake using the investigated instruments showed a high correlation with values based on LEXO2CON-K measurements (R = 0.97 for CO-Oximeter, R = 0.96 for Corning 170 blood gas analyzer, and R = 0.79 for i-STAT system). Systemic oxygen uptake values based on CO-Oximeter and Corning 170 blood gas analyzer data showed 75% accuracy; i-STAT system accuracy was 63% for control samples and 50% for samples after HBOC infusion.

Changes in circulating blood and plasma volume after hemoglobin-based oxygen carrier infusion and additional infusion of colloid solutions.

The aim of this study was to investigate the changes in circulating blood volume (CBV) after infusions of Hemoglobin glutamer-200 (bovine; Hb-200) in combination with 6% hetastarch in an animal model of acute posthemorrhagic anemia. Fifteen rabbits with a mean body weight of 2.2 +/- 0.2 kg were studied. After determination of the circulating plasma volume (CPV) and CBV, one third of the CBV was withdrawn via an arterial catheter. An equal volume of Hb-200 was then infused in the 5 animals in study group 1. In the remaining 10 animals, the same volume of 6% hetastarch solution was infused. Fifteen minutes after completion of the infusion, an additional infusion of 6% hetastarch at a dose equal to one third of the baseline CBV was performed in study group 1 and the control group. In study group 2, equal volumes of Hb-200 were infused. CPV measurements were performed at baseline, after hemorrhage, 5 and 15 minutes after volume replacement, and 1 and 15 minutes after hypervolemic hemodilution using the Evans blue dye dilution technique. The mean baseline CPV value was 53.4 +/- 1.1 mL/kg. The mean CBV at baseline was 90.8 +/- 4.9 mL/kg. After one third of the CBV was withdrawn, no differences in CBV or CPV were observed between the three groups. Replacement of one third of the CBV with Hb-200 significantly increased the CPV (73.7 +/- 1.8 mL/kg) when compared with the baseline level (53.5 +/- 1.8 mL/kg; n = 5; P < 0.05). The difference between the groups was first observed 15 minutes after infusion. CPV was significantly higher in study group 1 (87.0 +/- 2.2 mL/kg) compared with the other groups (80.2 +/- 2.6 mL/kg in the control group and 79.5 +/- 3.6 mL/kg in study group 2). After a second transfusion, the differences between the groups became more prominent. Study group 2 demonstrated the highest CPV and CBV. The two study groups demonstrated a statistically significant increase in circulating volumes compared with the control group. The magnitude of this difference was lower than expected based on in vitro colloid osmotic pressure measurements.

A novel approach to measuring circulating blood volume: the use of a hemoglobin-based oxygen carrier in a rabbit model.

Hemoglobin-based oxygen carriers (HBOC) may be ideal for monitoring circulating plasma volume (CV-P) and circulating blood volume (CV-B). We used an HBOC (Hemoglobin glutamer-200 [bovine], Oxyglobin; Biopure, Cambridge, MA) as an indicator for relative CV-B in the rabbit model. Accuracy of the technique was determined by comparison with the Evans blue dye (EBD) dilution technique in 19 anesthetized female New Zealand rabbits weighing 2.0 to 10.6 kg. The measurements were performed at baseline, after hemorrhage (1/3 of CV-B), normovolemic hemodilution (replacement of 1/3 CV-B by Hextend; Abbot Laboratories, North Chicago, IL), and hypervolemic hemodilution (additional infusion of Hextend(R) in a volume equal to 1/3 of CV-B). Hemoglobin concentration was measured by using a HemoCue photometer (HemoCue AB, Angelholm, Sweden). EBD concentration was analyzed by using linear regression to estimate Time 0 concentration; Time 0 was defined as EBD injection time. The difference between CV-P values determined by EBD and HBOC dilution was independent from the magnitude of the CV-P value. The relative bias was 1.29 mL, and the precision (one SD) was 2.82 mL. The difference did not reach statistical significance. Circulating plasma and blood volumes can be accurately estimated by plasma hemoglobin concentration measurements by using hemoglobin-based oxygen carrier infusion.

The Hemodynamic Effects of Cell-Free Hemoglobin During General and Epidural Anesthesia

Although hemoglobin-based oxygen carriers (HBOC) are now being investigated, the effects of HBOC solutions during regional anesthesia have never been analyzed. Therefore, we investigated the hemodynamic changes after HBOC infusion during general anesthesia and thoracic epidural anesthesia. Sheep were assigned to three different groups: a) a control group with six unanesthetized sheep; b) six sheep with a halothane anesthesia (2.0 vol. % in oxygen); and c) six awake sheep with a thoracic epidural anesthesia with bupivacaine. After a period of stabilization, all 18 animals received 100 mg/kg of the HBOC pyridoxalated hemoglobin polyoxyethylene conjugate. The infusion of the HBOC caused a significant increase in mean arterial pressure and pulmonary artery pressure in both the control and epidural anesthesia groups. Anesthesia with halothane reduced the effects of the HBOC-solution on mean arterial pressure but did not abolish the increase in pulmonary artery pressure. Our results demonstrate that vasoconstriction caused by HBOC solutions is not abolished by epidural anesthesia, but halothane anesthesia may alter the hemodynamic effects of HBOC solutions. Implications We evaluated the effects of epidural anesthesia and halothane anesthesia on the vasoconstrictive properties of a cell-free hemoglobin solution. The vasoconstriction caused by a cell-free hemoglobin solution was similar in unanesthetized sheep and sheep with thoracic epidural anesthesia and was reduced in sheep with halothane anesthesia.

Blood Substitutes: Oxygen-Carrying Acellular Fluids

Blood substitutes are acellular fluids that can transport and deliver oxygen to the tissues. The blood substitutes most likely to be available and effective for veterinary use are the hemoglobin-based oxygen carriers (HBOCs) containing modified human, mammalian, or recombinant hemoglobin. HBOCs can be stored at room temperature and do not require typing or crossmatching. Chemical modifications of hemoglobin affect its physiologic and pharmacologic properties and facilitate oxygen transport. Although many of the metabolic and toxicologic consequences of HBOC infusion are not fully understood, an approved product will likely be available in the near future.

Nitrosyl Hemoglobin Formation In-Vivo After Intravenous Administration of A Hemoglobin-Based Oxygen Carrier in Endotoxemic Rats

Interaction of hemoglobin-based oxygen carriers (HBOCs) with nitric oxide (NO) of endothelium or macrophage origin has been implicated in the observed vasoconstriction of some HBOC infusion. Definitive evidence supporting this interaction, in-vivo, has not been reported. We report here a confirmed in-vivo formation of nitrosyl Hb (HbNO), a product of Hb and NO reaction, in endotoxemic rats following intravenous administration of a HBOC. Male Sprague-Dawley rats were rendered endotoxemic by intravenous injection of lipopolysaccharide (LPS, 10mg/Kg), and five hours later HBOC (1.2gHb/Kg) was infused. Changes in blood pressure (BP) and HbNO levels were followed. HBOC infusion immediately reversed the hypotension of endotoxemia. In addition, HBOC infusion caused plasma HbNO formation determined by electron paramagnetic resonance spectroscopy. This is direct evidence of NO reaction with infused Hb. In conclusion, HBOC interacts in-vivo with NO directly in a model with increased NO. Whether this effect is prese...