Elimination of Hemoglobin and Lactate Dehydrogenase from Plasma in Normals and Patients with Intravascular Hemolysis

Renal Toxicodynamic Effects of Extracellular Hemoglobin After Acute Exposure

Plasma hemoglobin (Hb) is elevated in some hematologic disease states, during exposures to certain toxicants, and with the use of some medical devices. Exposure to free Hb can precipitate oxidative reactions within tissues and alter the normal physiological function of critical organ systems. As kidney structures can be highly sensitive to Hb exposures, we evaluated the acute dose dependent renal toxicologic response to purified Hb isolated from RBCs. Male Hartley guinea pigs (n = 5 per group) were dosed with 0.9% saline (2 ml), 15, 75, 150, or 300 mg of purified Hb, infused over a 2-h period. The primary endpoints of this study were to define toxicokinetic parameters after increasing doses of purified Hb, identify clinically recognized and experimental markers of acute kidney injury (AKI), and determine relevant toxicological parameters and potential causes of renal toxicity in this model. Experimental findings demonstrated a dose dependent increase in Cmax after a 2-h infusion, which correlated with an elevation in serum creatinine, renal Kim-1 mRNA expression and increased urinary Kim-1. Renal NGAL mRNA expression and urinary NGAL excretion were also increased in several groups, but these parameters did not correlate with exposure. Iron increased in the renal cortex as Hb exposure increased and its deposition colocalized with 4-hydroxy-nonenal and 8-Oxo-2-deoxyguanosine immune reactivity, suggesting oxidative stressors may contribute to AKI in animals exposed to Hb. The results presented here suggest that Cmax may effectively predict the risk of AKI in normal healthy animals exposed to Hb.

Emergency sternal intraosseous access for warm fresh whole blood transfusion in damage control resuscitation

BACKGROUND

Intraosseous (IO) vascular access is increasingly used as an emergency tool for achieving access to the systemic circulation in critically ill patients. The role of IO transfusion of blood in damage control resuscitation is however questionable due to possible inadequate flow rate and hemolysis. Some experts claim that IO transfusion is contraindicated. In this study, we have challenged this statement by looking at flow rates of autologous fresh whole blood reinfusion and hemolysis using two of the commonly used Food and Drug Administration-approved and Conformité Européenne (CE)-marked sternal needles. Additionally, the success rate of sternal access between the two devices is evaluated.

METHODS

Volunteer professional military personnel, were enrolled prospectively in a nonrandomized observational study design. We collected 450 mL of autologous whole blood from each participant. Participants were divided into the following three groups of 10: Tactically Advanced Lifesaving IO Needle (T.A.L.O.N.) IO, FAST1 IO, and intravenous group. The reinfusion was done by gravity only. Blood sampling was performed before blood collection and 30 minutes after reinfusion. Investigation of hemolysis was performed by measurements of haptoglobin and lactate dehydrogenase. Success rate was evaluated by correct aspiration of bone marrow.

RESULTS

Median reinfusion rate was 46.2 mL/min in the FAST1 group, 32.4 mL/min in the T.A.L.O.N. group, and 74.1 mL/min in the intravenous group. Blood samples from all participants were within normal ranges. There was no statistically significant difference in haptoglobin and lactate dehydrogenase between the groups. In the FAST1 group, 1 (9%) of 11 procedures failed. In the T.A.L.O.N. group, 4 (29%) of 14 procedures failed.

CONCLUSION

Although preferable, achieving peripheral venous access in the bleeding patient is a major problem. Our findings suggest that fresh whole-blood transfusion through the IO route is safe, reliable, and provide sufficient flow for resuscitation.

LEVEL OF EVIDENCE

Therapeutic/Care management study, level III.

Aortic valve replacement. A randomized study comparing Björk-Shiley and Lillehei-Kaster disc valves. Haematological evaluation

In this study, 79 randomized patients with either Björk-Shiley (B-S) or Lillehei-Kaster (L-K) aortic disc valves were re-admitted two years after operation for clinical, haemodynamic and haematological evaluation. This paper deals in particular with the haematological results. Cine-aortography was carried out in 76 patients and left ventricular catheterization via the transseptal approach was performed in 43 patients. Haemoglobin concentration, erythrocyte count, platlet count, reticulocyte count, plasma haemoglobin concentration, serum bilirubin, serum iron, serum haptoglobin and serum lactate dehydrogenase were studied in the patients. Postoperatively all patients had normal haemoglobin and erythrocyte count. Haptoglobin was absent or reduced in 43% of patients with B-S valves and in 65% of those with L-K valves. Serum lactate dehydrogenase activity (LDH) was abnormally elevated in 26% of patients in the B-S group and in 65% of those in the L-K group. Mean LDH was significantly higher in the L-K group compared with the B-S group (p less than 0.01). A highly significant linear correlation could be demonstrated between mean systolic pressure difference across the valve (delta pm) and LDH (p less than 0.001). This finding helps to explain why the L-K valves provoke more erythrocyte destruction than the B-S valves, since delta pm proved to be significantly higher in the L-K group. LDH was not significantly increased in 6 patients in whom a paravalvular leakage was demonstrated.

Leukocyte function after aortic valve replacement

Leukocyte function was studied in patients with prosthetic heart valves by oxygen consumption measurements during phagocytosis of polystyrene latex particles. The consumption reflects the phagocytotic capacity of the cells. In 38 patients with Starr-Edwards aortic ball valves the mean oxygen consumption was 3.95 nanoatoms per minute per 10(6) leukocytes, as compared to 4.15 in 50 healthy subjects, the difference not being statistically significant. The number of leukocytes per ml. of blood and the distribution of cell types was quite similar in the two groups, although slightly more younger cells were found in the patients. It is concluded that the capacity for phagocytosis is not significantly reduced after aortic ball valve implantation.

Changes in serum creatine kinase and hexose phosphate isomerase activity with exercise duration

In 18 groups of trained healthy male subjects (n = 166; age 17--42 years) the influence of type and duration of long-lasting exercise on the changes of creatine kinase (CPK) and hexose phosphate isomerase (PHI) activity in serum was studied. Above 65--70% of maximal aerobic capacity, a serum enzyme activity increase proportional to the exercise time was found with a different slope in each of the three exercise types examined [a) bicycle ergometer; b) ski race; c) impact-type exertion]. Work duration of more than 300 min induced in the third type of exertion an accelerated increase in serum CPK. A third degree equation best describes the changes in serum CPK for nine of our groups and five others from the literature. To ascertain the possible influence of intravascular hemolysis, sera were mixed with autologous erythrocyte hemolysates and enzyme activity measured. The findings are discussed with reference to critical aspects of the analytical methods, possible causes of serum enzyme changes, and possible use of enzyme measurements in evaluating adaptation of the organism to prolonged exercise.

Intravascular hemolysis in the late course of aortic valve

The degree of intravascular hemolysis was evaluated in 315 patients in the late course of aortic valve replacement. Starr-Edwards aortic ball valves of series 2300 caused significantly more hemolysis than did those of series 1200, as estimated from the serum lactate dehydrogenase levels. Smaller valves of series 2300 caused a higher degree of hemolysis than did the larger ones. Aortic disc valves induced a more moderate red cell destruction than did the ball valves, the Lillehei-Kaster significantly more than the Bjørk-Shiley prostheses. Crushing of red cells is thought to be a more important cause of hemolysis than shearing forces in turbulent blood. Hemolytic anemia represented a problem only in some patients with Starr-Edwards valve type 2300, although iron substitution was necessary also in some with other prostheses, since the hemoglobin-binding capacity of haptoglobin was exceeded in several patients. Valvular or paravalvular leakage was associated with stronger hemolysis in some patients, and should be suspected whenever the rate of red cell destruction increases. Longstanding intravascular hemolysis did not seriously affect renal function.

Platelet functions in patients with aortic ball valves

Platelet functions were studied in normal subjects and patients with single Staff-Edwards aortic ball valves of series 1200 and 2300. The most pronounced changes were found in platelet adhesiveness, measured with Hellem's modified method. The mean percentage of adhesive platelets was reduced from 71.8 in normal subjects to 50.9 in patients with valve type 1200 and to 27.2 in those with type 2300. An inverse correlation was found between platelet adhesiveness and the degree of intravascular hemolysis, as reflected by serum LDH levels. The mean bleeding time was significantly prolonged in patients with valve 2300, and the individual values correlated inversely to the adhesiveness. The mean values of platelet counts, or irreversible aggregation induced by collagen or epinephrine, and of platelet survival were all moderately-but significantly-reduced as compared to normal. The most important mechanism behind the disturbed platelet reactivity is probably mechanical damage of the platelets by the valve, whereas refractoriness of platelets toward ADP liberated from red cells as well as consumption of adhesive platelets by thrombus formation is thought to have limited influence on platelet behavior. Platelet function was altered to the same extent in patients with a history of arterial thromboembolic complications as in those without. The disturbed platelet reactivity may predispose to bleeding, but may also offer some protection against arterial thromboembolism.

Effects of dipyridamole and acetylsalicylic acid on platelet functions in patients with aortic ball-valve prostheses

The effects of dipyridamole and ASA on platelet functions were studied in patients with aortic ball-valve prostheses. Before ingestion, platelet adhesiveness was markedly reduced and platelet survival time slightly, but insignificantly shortened. ASA prolonged the bleeding time, reduced collagen-induced platelet aggregation, and inhibited secondary aggregation initiated by adrenalin. Similar effects were obtained with 2 Gm. of ASA alone as with 1 Gm. daily in combination with 225 mg. of dipyridamole. Platelet adhesiveness remained low. Depyridamole alone, 375 mg. daily, did not influence any of these parameters. The mean platelet half-life was prolonged from 3.52 to 3.72 days by each drug and to 4 days by the combined treatment. None of the differences was, however, statistically significant. A clinical study with ASA has been started in a larger series of patients to evaluate the effect on arterial thromboembolism.