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The American Journal of Case Reports Jan 2023BACKGROUND Fulminant hepatic failure (FHF) is commonly associated with elevated prothrombin time (PT) and international normalized ratio (INR). There is a commensurate...
A 36-Year-Old Woman with Acute Liver Failure Following Acetaminophen Overdose, Raised INR of 8.7, and Normal Blood Viscosity Measured by Rotational Thromboelastometry (ROTEM).
BACKGROUND Fulminant hepatic failure (FHF) is commonly associated with elevated prothrombin time (PT) and international normalized ratio (INR). There is a commensurate decline in pro- and anti-hemostatic factors, and hemostatic function is rebalanced, not reflected in INR. This report presents the case of a 36-year-old woman with FHF following acetaminophen overdose, an increased INR above 8.7, and normal blood viscosity measured by rotational thromboelastometry (ROTEM). CASE REPORT A 36-year-old woman presented with FHF following an acetaminophen overdose. On arrival, she was lethargic but arousable and followed commands. Her King's College Criteria for acetaminophen toxicity was 2 and her MELD score was 36. Her INR was unmeasurably high (>8.7). To evaluate whole-blood coagulation, a ROTEM analysis was performed. All parameters (CT, CFT, alpha-angle, A10, MCF) of the NATEM were within reference range. Despite the normal ROTEM, spontaneous bleeding was a concern. The patient received 5 units of cryoprecipitate and 9 units of FFP prior to a central venous line placement. She was started on molecular adsorbent recirculating system and continuous veno-venous hemodialysis, but died on day 7. CONCLUSIONS Patients with FHF can have normal whole-blood coagulation based on ROTEM even if INR levels are unmeasurably high. Viscoelastic tests such as ROTEM, which assesses whole-blood coagulation properties, are preferrable for coagulation monitoring in these patients. Blood product transfusion to correct coagulation abnormality, like FFP and cryoprecipitate, may be used based on the result of viscoelastic testing over conventional coagulation testing.
Topics: Female; Humans; Adult; Thrombelastography; International Normalized Ratio; Acetaminophen; Blood Viscosity; Blood Coagulation Disorders; Liver Failure, Acute
PubMed: 36718100
DOI: 10.12659/AJCR.938500 -
Canadian Medical Association Journal Oct 1964Viscosity of whole blood and plasma was measured in 258 apparently healthy subjects of both sexes from 5 to 60 years of age, and in 86 patients with unequivocal evidence...
Viscosity of whole blood and plasma was measured in 258 apparently healthy subjects of both sexes from 5 to 60 years of age, and in 86 patients with unequivocal evidence of chronic coronary heart disease. Children and young healthy females had the lowest viscosity readings. Healthy young and middle-aged males had significantly higher blood viscosity than females. Patients with coronary heart disease had significantly higher blood viscosity values than healthy groups of the same sex. It is suggested that the higher viscosity of whole blood and of plasma is a contributory factor in development of clinical manifestations of coronary heart disease and possibly of the basic vascular lesion itself.
Topics: Adolescent; Aging; Arteriosclerosis; Blood Viscosity; Child; Coitus; Coronary Artery Disease; Coronary Disease; Female; Geriatrics; Healthy Volunteers; Humans; Infant; Male; Middle Aged; Plasma; Sex; Statistics as Topic
PubMed: 14217258
DOI: No ID Found -
Biophysical Journal Apr 2023Increased blood viscosity in type 2 diabetes mellitus (T2DM) is a risk factor for the development of insulin resistance and diabetes-related vascular complications;...
Increased blood viscosity in type 2 diabetes mellitus (T2DM) is a risk factor for the development of insulin resistance and diabetes-related vascular complications; however, individuals with T2DM exhibit heterogeneous hemorheological properties, including cell deformation and aggregation. Using a multiscale red blood cell (RBC) model with key parameters derived from patient-specific data, we present a computational study of the rheological properties of blood from individual patients with T2DM. Specifically, one key model parameter, which determines the shear stiffness of the RBC membrane (μ) is informed by the high-shear-rate blood viscosity of patients with T2DM. At the same time, the other, which contributes to the strength of the RBC aggregation interaction (D), is derived from the low-shear-rate blood viscosity of patients with T2DM. The T2DM RBC suspensions are simulated at different shear rates, and the predicted blood viscosity is compared with clinical laboratory-measured data. The results show that the blood viscosity obtained from clinical laboratories and computational simulations are in agreement at both low and high shear rates. These quantitative simulation results demonstrate that the patient-specific model has truly learned the rheological behavior of T2DM blood by unifying the mechanical and aggregation factors of the RBCs, which provides an effective way to extract quantitative predictions of the rheological properties of the blood of individual patients with T2DM.
Topics: Humans; Diabetes Mellitus, Type 2; Blood Viscosity; Erythrocytes; Erythrocyte Aggregation; Rheology; Computer Simulation
PubMed: 36905122
DOI: 10.1016/j.bpj.2023.03.010 -
Journal of Medicine and Life Oct 2023Typhoid fever (TF) is a systemic infection caused by transmitted through contaminated water, food, or contact with infected individuals. In various infectious diseases,...
Typhoid fever (TF) is a systemic infection caused by transmitted through contaminated water, food, or contact with infected individuals. In various infectious diseases, blood viscosity (BV) is affected by changes in hemoglobin concentrations and acute phase reactants. Inflammatory responses can lead to elevated plasma protein levels and further affect BV. This study aimed to investigate BV changes in patients with acute TF. A cross-sectional study was performed involving 55 patients with acute TF compared to 38 healthy controls. BV and inflammatory parameters were measured in both groups. TF patients showed reduced blood cells compared to healthy controls (p=0.001). Additionally, plasma total protein (TP) levels significantly increased to 10.79±1.05 g/L in TF patients compared to 7.035±1.44 g/L in healthy controls (p=0.03). Hematocrit (HCT) levels were 11.67±2.89% in TF patients and 12.84±2.02% in healthy controls (p=0.07), suggesting a trend towards increased BV in TF patients. Elevated BV is involved in the pathogenesis of different inflammatory and infectious diseases. The increased BV in TF patients may raise the risk of complications. Therefore, monitoring BV might be a crucial tool in TF patients, mainly in the high-risk group, for early detection of cardiovascular complications.
Topics: Humans; Typhoid Fever; Cross-Sectional Studies; Blood Viscosity; Salmonella typhi; Communicable Diseases
PubMed: 38313175
DOI: 10.25122/jml-2023-0027 -
Journal of Applied Physiology... Apr 2016Sickle cell disease (SCD) is the most common cause of stroke in childhood and results primarily from a mismatch of cerebral oxygen supply and demand rather than arterial...
Sickle cell disease (SCD) is the most common cause of stroke in childhood and results primarily from a mismatch of cerebral oxygen supply and demand rather than arterial obstruction. However, resting cerebral blood flow (CBF) has not been examined in the general African American population, in whom obesity, hypertension, cerebrovascular disease, and diminished cerebrovascular reserve capacity are common. To better understand the underlying physiological substrate upon which SCD is superimposed, we measured CBF in 32 young (age 28 ± 10 yr), asymptomatic African American subjects with and without sickle cell trait (n= 14). To characterize the effects of chronic anemia, in isolation of sickle hemoglobin we also studied a cohort of 13 subjects with thalassemia major (n= 10), dyserythropoetic anemia (n= 1), or spherocytosis (n= 2). Blood was analyzed for complete blood count, hemoglobin electrophoresis, cell free hemoglobin, and lactate dehydrogenase. Multivariate regression analysis showed that oxygen content was the strongest predictor of CBF (r(2)= 0.33,P< 0.001). CBF declined rapidly in the second and third decades of life, but this drop was explained by reductions in cerebral gray matter. However, age effects persisted after correction for brain composition, possibly representing microvascular impairment. CBF was independent of viscosity, hemoglobin S%, and body mass index. Hyperoxia resulted in reduced CBF by 12.6% (P= 0.0002), and CBF changes were proportional to baseline oxygen content (r(2)= 0.16,P= 0.02). These data suggest that these hemoglobin subtypes do not alter the normal CBF regulation of the balance of oxygen supply and demand.
Topics: Adolescent; Adult; Anemia; Blood Cell Count; Blood Viscosity; Body Mass Index; Cerebrovascular Circulation; Child; Female; Gray Matter; Hemoglobins; Humans; Hyperoxia; L-Lactate Dehydrogenase; Male; Middle Aged; Oxygen; Young Adult
PubMed: 26796758
DOI: 10.1152/japplphysiol.00994.2015 -
Proceedings of the National Academy of... Jul 2011The viscosity of blood has long been used as an indicator in the understanding and treatment of disease, and the advent of modern viscometers allows its measurement with...
The viscosity of blood has long been used as an indicator in the understanding and treatment of disease, and the advent of modern viscometers allows its measurement with ever-improving clinical convenience. However, these advances have not been matched by theoretical developments that can yield a quantitative understanding of blood's microrheology and its possible connection to relevant biomolecules (e.g., fibrinogen). Using coarse-grained molecular dynamics and two different red blood cell models, we accurately predict the dependence of blood viscosity on shear rate and hematocrit. We explicitly represent cell-cell interactions and identify the types and sizes of reversible rouleaux structures that yield a tremendous increase of blood viscosity at low shear rates. We also present the first quantitative estimates of the magnitude of adhesive forces between red cells. In addition, our simulations support the hypothesis, previously deduced from experiments, of yield stress as an indicator of cell aggregation. This non-Newtonian behavior is analyzed and related to the suspension's microstructure, deformation, and dynamics of single red blood cells. The most complex cell dynamics occurs in the intermediate shear rate regime, where individual cells experience severe deformation and transient folded conformations. The generality of these cell models together with single-cell measurements points to the future prediction of blood-viscosity anomalies and the corresponding microstructures associated with various diseases (e.g., malaria, AIDS, and diabetes mellitus). The models can easily be adapted to tune the properties of a much wider class of complex fluids including capsule and vesicle suspensions.
Topics: Blood Viscosity; Cell Adhesion; Computer Simulation; Humans; Models, Biological; Molecular Dynamics Simulation; Rheology
PubMed: 21730178
DOI: 10.1073/pnas.1101210108 -
PloS One 2011Brain is one of the most energy demanding organs in mammals, and its total metabolic rate scales with brain volume raised to a power of around 5/6. This value is...
Brain is one of the most energy demanding organs in mammals, and its total metabolic rate scales with brain volume raised to a power of around 5/6. This value is significantly higher than the more common exponent 3/4 relating whole body resting metabolism with body mass and several other physiological variables in animals and plants. This article investigates the reasons for brain allometric distinction on a level of its microvessels. Based on collected empirical data it is found that regional cerebral blood flow CBF across gray matter scales with cortical volume V as CBF ~ V(-1/6), brain capillary diameter increases as V(1/12), and density of capillary length decreases as V(-1/6). It is predicted that velocity of capillary blood is almost invariant (~V(ε)), capillary transit time scales as V(1/6), capillary length increases as V(1/6+ε), and capillary number as V(2/3-ε), where ε is typically a small correction for medium and large brains, due to blood viscosity dependence on capillary radius. It is shown that the amount of capillary length and blood flow per cortical neuron are essentially conserved across mammals. These results indicate that geometry and dynamics of global neuro-vascular coupling have a proportionate character. Moreover, cerebral metabolic, hemodynamic, and microvascular variables scale with allometric exponents that are simple multiples of 1/6, rather than 1/4, which suggests that brain metabolism is more similar to the metabolism of aerobic than resting body. Relation of these findings to brain functional imaging studies involving the link between cerebral metabolism and blood flow is also discussed.
Topics: Animals; Blood Viscosity; Brain; Capillaries; Cerebral Cortex; Cerebrovascular Circulation; Humans; Mammals; Neurons; Organ Size
PubMed: 22053202
DOI: 10.1371/journal.pone.0026709 -
Revista Portuguesa de Cardiologia Jan 2020
Topics: Blood Viscosity; Coronary Artery Disease; Hemorheology; Humans; Microcirculation; Microvascular Angina
PubMed: 32156447
DOI: 10.1016/j.repc.2020.02.004 -
Clinical Hemorheology and... 2018Hematocrit increases during exercise and is usually decreased after regular training. However the interpretation of these facts is ambiguous since hematocrit is both a...
Hematocrit increases during exercise and is usually decreased after regular training. However the interpretation of these facts is ambiguous since hematocrit is both a determinant of oxygen supply and the major determinant of blood viscosity. Classically hematocrit was assumed to impair blood flow, but it has been evidenced to exert a biphasic effect on it. In order to cope with these two apparently opposite effects of hematocrit, hemorheologists have proposed the concept hematocrit/viscosity ratio (h/η). This h/η ratio is related to tissue oxygenation in vascular diseases (eg, POAD) but not in healthy subjects. h/η displays a bell-shaped curve as a function of hematocrit and the hematocrit value corresponding to the maximal h/η can be assumed to be a theoretically optimal hematocrit. We propose to analyse exercise-related alterations in hematocrit according to this theoretical approach, viscosity at high shear rate being reconstructed with Quemada's equation from actual plasma viscosity and red cell rigidity at various hematocrit levels. While theoretical and actual h/η are fairly correlated in athletes both before and after exercise, actual hematocrit is lower at rest and higher after exercise compared to the theoretical one. The main statistic correlate of these discrepancies between actual and predicted hematocrit is red cell rigidity. Submaximal exercise acutely decreases the h/η ratio (despite increasing both hematocrit and viscosity). This change is well predicted by the model and there is a strong correlation between predicted and actual h/η ratio. Endurance training tends to increase h/η and to reduce the discrepancy between predicted and actual hematocrit. Accordingly trained athletes have a higher h/η (both model-predicted and actual) than sedentary subjects, and a lower hematocrit, this lowering being rather correlated to training volume than to fitness improvement. On the whole, this approach suggests that homeostatic "viscoregulation" in athletes results in a fine tuning of h/η which seems to be a closely regulated parameter. Hematocrit alterations in this context are an adaptation involved in this regulation.
Topics: Adult; Blood Viscosity; Exercise; Female; Hematocrit; Hemorheology; Humans; Male
PubMed: 29710694
DOI: 10.3233/CH-189201 -
Sensors (Basel, Switzerland) Mar 2020Blood pumps have found applications in heart support devices, oxygenators, and dialysis systems, among others. Often, there is no room for sensors, or the sensors are...
Blood pumps have found applications in heart support devices, oxygenators, and dialysis systems, among others. Often, there is no room for sensors, or the sensors are simply unreliable when long-term operation is required. However, control systems rely on those hard-to-measure parameters, such as blood flow rate and pressure difference, thus their estimation takes a central role in the development process of such medical devices. The viscosity of the blood not only influences the estimation of those parameters but is often a parameter that is of great interest to both doctors and engineers. In this work, estimation methods for blood flow rate, pressure difference, and viscosity are presented using Gaussian process regression models. Different water-glycerol mixtures were used to model blood. Data was collected from a custom-built blood pump, designed for intracorporeal oxygenators in an in vitro test circuit. The estimation was performed from motor current and motor speed measurements and its accuracy was measured for: blood flow rate r = 0.98, root mean squared error (RMSE) = 46 mLmin; pressure difference r = 0.98, RMSE = 8.7 mmHg; and viscosity r = 0.98, RMSE = 0. 0.049 mPas. The results suggest that the presented methods can be used to accurately predict blood flow rate, pressure, and viscosity online.
Topics: Algorithms; Biomechanical Phenomena; Blood Viscosity; Glycerol; Hemorheology; Humans; Hydrodynamics; Normal Distribution; Pressure; Uncertainty; Water
PubMed: 32155844
DOI: 10.3390/s20051451