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Acta Otorrinolaringologica Espanola 2022Changes in blood viscoelastic properties have been proposed previosuly as etiopathogenesis for severe complications in COVID-19 and some cases of Sudden Deafness (SD)....
BACKGROUND
Changes in blood viscoelastic properties have been proposed previosuly as etiopathogenesis for severe complications in COVID-19 and some cases of Sudden Deafness (SD). This is an attempt to verify if SD cases in patients admitted for SARS-Cov-2 infection can be correlated.
PATIENTS AND METHODS
A prospective follow-up was carried out with COVID-19 patients, monitoring their blood viscosity (BV) at high shear rate (300 s) and inquiring them periodically for eventual hearing loss. This measurement was extended to cases bearing of SD in 2019 and 2020 without infection and a control group of healthy normoacoustic subjects.
RESULTS
The normality range was 4,16 ± 0,62 cps. 330 cases admitted for COVID-19 were evaluated from February 24th, 2020 to March 24th, 2021, 85 of them attended in ICU. After anamnesis and Audiometric Tone Thresholds developed as soon as possible, 9 SD were detected, all belonging to ICU group. The mean BV was 4,38 ± 0,43 cps in the ward group, 4,53 ± 0,39 cps in the ICU patients without SD, and 4,85 ± 0,52 cps in the cases with SD, with statistically significant differences. Highest BV elevations in the SD cases were detected between days 6 and 10 of hospital admission. In 2019 four cases consulted with SD, and another two did it in 2020 without a diagnosis of COVID-19, with normal BV values.
CONCLUSIONS
During SARS-Cov-2 infection, patients may show high BV and SS, although an inpatients control group and a larger sample volume are necessary to confirm the predisposition to hyperviscosity. The incidence of hearing damage is considerable if its possible appearance is taken into account, within the limitations of critical patients with COVID-19.
Topics: Blood Viscosity; COVID-19; Hearing Loss, Sudden; Humans; Prospective Studies; SARS-CoV-2
PubMed: 35397819
DOI: 10.1016/j.otoeng.2022.02.004 -
Applied Bionics and Biomechanics 2022The mechanical heart valve (MHV) is commonly used for the treatment of cardiovascular diseases. Nonphysiological hemodynamic in the MHV may cause hemolysis, platelet... (Review)
Review
The mechanical heart valve (MHV) is commonly used for the treatment of cardiovascular diseases. Nonphysiological hemodynamic in the MHV may cause hemolysis, platelet activation, and an increased risk of thromboembolism. Thromboembolism may cause severe complications and valve dysfunction. This paper thoroughly reviewed the simulation of physical quantities (velocity distribution, vortex formation, and shear stress) in healthy and dysfunctional MHV and reviewed the non-Newtonian blood flow characteristics in MHV. In the MHV numerical study, the dysfunction will affect the simulation results, increase the pressure gradient and shear stress, and change the blood flow patterns, increasing the risks of hemolysis and platelet activation. The blood flow passes downstream and has obvious recirculation and stagnation region with the increased dysfunction severity. Due to the complex structure of the MHV, the non-Newtonian shear-thinning viscosity blood characteristics become apparent in MHV simulations. The comparative study between Newtonian and non-Newtonian always shows the difference. The shear-thinning blood viscosity model is the basics to build the blood, also the blood exhibiting viscoelastic properties. More details are needed to establish a complete and more realistic simulation.
PubMed: 35498142
DOI: 10.1155/2022/9612296 -
Current Opinion in Hematology Nov 2022Hyperviscosity syndromes can lead to significant morbidity and mortality. Existing methods to measure microcirculatory rheology are not readily available and limited in... (Review)
Review
PURPOSE OF REVIEW
Hyperviscosity syndromes can lead to significant morbidity and mortality. Existing methods to measure microcirculatory rheology are not readily available and limited in relevance and accuracy at this level. In this review, we review selected hyperviscosity syndromes and the advancement of their knowledge using microfluidic platforms.
RECENT FINDINGS
Viscosity changes drastically at the microvascular level as the physical properties of the cells themselves become the major determinants of resistance to blood flow. Current, outdated viscosity measurements only quantify whole blood or serum. Changes in blood composition, cell number, or the physical properties themselves lead to increased blood viscosity. Given the significant morbidity and mortality from hyperviscosity syndromes, new biophysical tools are needed and being developed to study microvascular biophysical and hemodynamic conditions at this microvascular level to help predict those at risk and guide therapeutic treatment.
SUMMARY
The use of 'lab-on-a-chip' technology continues to rise to relevance with point of care, personalized testing and medicine as customizable microfluidic platforms enable independent control of many in vivo factors and are a powerful tool to study microcirculatory hemorheology.
Topics: Blood Viscosity; Hematologic Diseases; Hemorheology; Humans; Lab-On-A-Chip Devices; Microcirculation; Physicians
PubMed: 35916537
DOI: 10.1097/MOH.0000000000000735 -
Noro Psikiyatri Arsivi 2023Elevated proinflammatory status and alterations in blood flow, both of which are associated with the pathophysiology of schizophrenia, may be linked with an increased...
INTRODUCTION
Elevated proinflammatory status and alterations in blood flow, both of which are associated with the pathophysiology of schizophrenia, may be linked with an increased risk of cardiovascular diseases. However, such a relationship at different acute stages of schizophrenia has not been evaluated. We aimed to examine whether blood viscosity and systemic inflammatory status varied between first-episode schizophrenia (FES) and acute exacerbations of schizophrenia.
METHODS
Fifty-two patients with FES, 69 schizophrenia patients with acute exacerbation (S-AE) and 56 healthy controls (HC) were included in the study. Whole blood viscosity (WBV) was calculated according to de Simone's formula at low and high shear rates (LSR and HSR). Systemic immune-inflammation index (SII) and systemic inflammatory response index (SIRI) were calculated from hemogram screening data at admission.
RESULTS
When adjusted for age, WBV at both LSR and HSR were significantly decreased in both FES and S-AE groups compared to HCs. Systemic inflammatory response index was significantly higher in FES patients than in the S-AE and HC groups. Total cholesterol (TC) and WBV at HSR were correlated in patients. Total cholesterol predicted WBV at LSR in patients with FES whereas other independent variables including age and SIRI did not.
CONCLUSION
Both first and subsequent episodes of schizophrenia are associated with reduced blood viscosity. Increased inflammatory status may not fully explain such a relationship. Extrapolation of hemorheological characteristics in schizophrenia may help to stratify cardiovascular risk and reflect the pathophysiological process in the early and later stages of schizophrenia.
PubMed: 37645085
DOI: 10.29399/npa.28394 -
Frontiers in Neurology 2023The changes in blood viscosity can influence the shear stress at the vessel wall, but there is limited evidence regarding the impact on thrombogenesis and acute stroke....
BACKGROUND
The changes in blood viscosity can influence the shear stress at the vessel wall, but there is limited evidence regarding the impact on thrombogenesis and acute stroke. We aimed to investigate the effect of blood viscosity on stroke and the clinical utility of blood viscosity measurements obtained immediately upon hospital arrival.
METHODS
Patients with suspected stroke visiting the hospital within 24 h of the last known well time were enrolled. Point-of-care testing was used to obtain blood viscosity measurements before intravenous fluid infusion. Blood viscosity was measured as the reactive torque generated at three oscillatory frequencies (1, 5, and 10 rad/sec). Blood viscosity results were compared among patients with ischemic stroke, hemorrhagic stroke, and stroke mimics diagnosed as other than stroke.
RESULTS
Among 112 enrolled patients, blood viscosity measurements were accomplished within 2.4 ± 1.3 min of vessel puncture. At an oscillatory frequency of 10 rad/sec, blood viscosity differed significantly between the ischemic stroke (24.2 ± 4.9 ) and stroke mimic groups (17.8 ± 6.5 , < 0.001). This finding was consistent at different oscillatory frequencies (134.2 ± 46.3 vs. 102.4 ± 47.2 at 1 rad/sec and 39.2 ± 11.5 vs. 30.4 ± 12.4 at 5 rad/sec, Ps < 0.001), suggesting a relationship between decreases in viscosity and shear rate. The area under the receiver operating curve for differentiating cases of stroke from stroke mimic was 0.79 (95% confidence interval, 0.69-0.88).
CONCLUSION
Patients with ischemic stroke exhibit increases in whole blood viscosity, suggesting that blood viscosity measurements can aid in differentiating ischemic stroke from other diseases.
PubMed: 38107646
DOI: 10.3389/fneur.2023.1320773 -
Clinical Hemorheology and... 2022Elevated estimated blood viscosity (EBV), derived from hematocrit and globulins, is associated with thrombotic complications, organ failure, and higher mortality in...
BACKGROUND
Elevated estimated blood viscosity (EBV), derived from hematocrit and globulins, is associated with thrombotic complications, organ failure, and higher mortality in COVID-19 patients. Although informative, EBV does not account for cellular interactions or fibrinogen.
OBJECTIVE
Investigate whether patients with acute and recent COVID-19 have altered whole blood viscosity (WBV) when measured at both high and low shear rates using in vitro blood samples from patients.
METHODS
Cross-sectional study of 58 patients: 15 in the intensive care unit with acute COVID-19, 32 convalescent (9 < 8weeks [W] from acute infection, 23 > 8 W), and 11 controls without COVID-19. WBV was measured at high (300 s-1) and low (5 s-1) shear rates (HSR, LSR) using a scanning capillary viscometer.RESULTSAcute and convalescent patients < 8 W had mean WBV at LSR (16.0 centipoise [cP] and 15.1 cP) and HSR (5.1 cP and 4.7 cP). Mean WBV of convalescent > 8 W and control patients were 12.3 cP and 13.0 cP at LSR, and 4.1 cP and 4.2 cP at HSR. Acute and < 8 W patients had significantly higher WBV at both HSR and LSR compared to patients > 8 W (all p≤0.01). No significant differences in WBV were observed between acute and < 8 W patients, or between patients > 8 W and controls.
CONCLUSIONS
Hyperviscosity provides a possible explanation for thrombotic risk in acute and convalescent (< 8 W) patients. These findings have important implications for thromboprophylaxis.
Topics: Humans; Cross-Sectional Studies; COVID-19; Anticoagulants; Venous Thromboembolism; Blood Viscosity; Thrombosis; Thrombophilia
PubMed: 35466930
DOI: 10.3233/CH-221429 -
Clinical Kidney Journal Apr 2022Albumin is the most abundant protein in blood plasma and acts as a carrier for many circulating molecules. Hypoalbuminaemia, mostly caused by either renal or liver...
Albumin is the most abundant protein in blood plasma and acts as a carrier for many circulating molecules. Hypoalbuminaemia, mostly caused by either renal or liver disease or malnutrition, can perturb vascular homeostasis and is involved in the development of multiple diseases. Here we review four functions of albumin and the consequences of hypoalbuminaemia on vascular homeostasis. (i) Albumin is the main determinant of plasma colloid osmotic pressure. Hypoalbuminaemia was therefore thought to be the main mechanism for oedema in nephrotic syndrome (NS), however, experimental studies showed that intrarenal mechanisms rather than hypoalbuminaemia determine formation and, in particular, maintenance of oedema. (ii) Albumin functions as an interface between lysophosphatidylcholine (LPC) and circulating factors (lipoproteins and erythrocytes) and the endothelium. Consequently, hypoalbuminaemia results in higher LPC levels in lipoproteins and erythrocyte membrane, thereby increasing atherosclerotic properties of low-density lipoprotein and blood viscosity, respectively. Furthermore, albumin dose-dependently restores LPC-induced inhibition of vasodilation. (iii) Hypoalbuminaemia impacts on vascular nitric oxide (NO) signalling by directly increasing NO production in endothelial cells, leading to reduced NO sensitivity of vascular smooth muscle cells. (iv) Lastly, albumin binds free fatty acids (FFAs). FFAs can induce vascular smooth muscle cell apoptosis, uncouple endothelial NO synthase and decrease endothelium-dependent vasodilation. Unbound FFAs can increase the formation of reactive oxygen species by mitochondrial uncoupling in multiple cell types and induce hypertriglyceridemia in NS. In conclusion, albumin acts as an interface in the circulation and hypoalbuminaemia impairs multiple aspects of vascular function that may underlie the association of hypoalbuminaemia with adverse outcomes. However, hypoalbuminaemia is not a key to oedema in NS. These insights have therapeutic implications.
PubMed: 35371452
DOI: 10.1093/ckj/sfab194 -
Romanian Journal of Anaesthesia and... Dec 2021Blood rheology is an important determinant of blood flow but is probably one of the most neglected areas in clinical literature and practice. Blood viscosity changes...
Blood rheology is an important determinant of blood flow but is probably one of the most neglected areas in clinical literature and practice. Blood viscosity changes according to shear rates and depends on cellular and plasma factors. RBCs' aggregability and deformability are the main determinants of local flow characteristics in areas with lower and higher shear rates, but plasma viscosity is the main regulatory factor of flow resistance in the microcirculation. In individuals with altered blood rheology, the mechanical stress to vascular walls induces endothelial injury and vascular remodelling, and promotes atherosclerosis. Increased values of whole blood viscosity and plasma viscosity are correlated with cardiovascular risk factors and adverse cardiovascular events. The long-term effects of physical exercise can produce a hemorheological fitness that protects against cardiovascular diseases.
PubMed: 36844116
DOI: 10.2478/rjaic-2021-0007 -
Frontiers in Bioengineering and... 2021The association between blood viscosity and pathological conditions involving a number of organ systems is well known. However, how the body measures and maintains... (Review)
Review
The association between blood viscosity and pathological conditions involving a number of organ systems is well known. However, how the body measures and maintains appropriate blood viscosity is not well-described. The literature endorsing the function of the carotid sinus as a site of baroreception can be traced back to some of the earliest descriptions of digital pressure on the neck producing a drop in blood delivery to the brain. For the last 30 years, improved computational fluid dynamic (CFD) simulations of blood flow within the carotid sinus have demonstrated a more nuanced understanding of the changes in the region as it relates to changes in conventional metrics of cardiovascular function, including blood pressure. We suggest that the unique flow patterns within the carotid sinus may make it an ideal site to transduce flow data that can, in turn, enable real-time measurement of blood . The recent characterization of the PIEZO receptor family in the sinus vessel wall may provide a biological basis for this characterization. When coupled with other biomarkers of cardiovascular performance and descriptions of the blood rheology unique to the sinus region, this represents a novel venue for bioinspired design that may enable end-users to manipulate and optimize blood flow.
PubMed: 34178967
DOI: 10.3389/fbioe.2021.678048 -
Biomedicine & Pharmacotherapy =... Nov 2021In Covid-19, systemic disturbances may progress due to development of cytokine storm and dysregulation of and plasma osmolarility due to high release of pro-inflammatory... (Review)
Review
In Covid-19, systemic disturbances may progress due to development of cytokine storm and dysregulation of and plasma osmolarility due to high release of pro-inflammatory cytokines and neuro-hormonal disorders. Arginine vasopressin (AVP) which is involve in the regulation of body osmotic system, body water content, blood pressure and plasma volume, that are highly disturbed in Covid-19 and linked with poor clinical outcomes. Therefore, this present study aimed to find the potential association between AVP serum level and inflammatory disorders in Covid-19. It has been observed by different recent studies that physiological response due to fever, pain, hypovolemia, dehydration, and psychological stress is characterized by activation release of AVP to counter-balance high blood viscosity in Covid-19 patients. In addition, activated immune cells mainly T and B lymphocytes and released pro-inflammatory cytokines stimulate discharge of stored AVP from immune cells, which in a vicious cycle trigger release of pro-inflammatory cytokines. Vasopressin receptor antagonists have antiviral and anti-inflammatory effects that may inhibit AVP-induced hyponatremia and release of pro-inflammatory cytokines in Covid-19. In conclusion, release of AVP from hypothalamus is augmented in Covid-19 due to stress, high pro-inflammatory cytokines, high circulating AngII and inhibition of GABAergic neurons. In turn, high AVP level leads to induction of hyponatremia, inflammatory disorders, and development of complications in Covid-19 by activation of NF-κB and NLRP3 inflammasome with release of pro-inflammatory cytokines. Therefore, AVP antagonists might be novel potential therapeutic modality in treating Covid-19 through mitigation of AVP-mediated inflammatory disorders and hyponatremia.
Topics: Arginine Vasopressin; COVID-19; Drug Discovery; Humans; Inflammation; SARS-CoV-2; Water-Electrolyte Imbalance; COVID-19 Drug Treatment
PubMed: 34543987
DOI: 10.1016/j.biopha.2021.112193