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The Western Journal of Emergency... Mar 2019Oncologic emergencies may be seen in any emergency department and will become more frequent as our population ages and more patients receive chemotherapy. Life-saving... (Review)
Review
Oncologic emergencies may be seen in any emergency department and will become more frequent as our population ages and more patients receive chemotherapy. Life-saving interventions are available for certain oncologic emergencies if the diagnosis is made in a timely fashion. In this article we will cover neutropenic fever, tumor lysis syndrome, hypercalcemia of malignancy, and hyperviscosity syndrome. After reading this article the reader should be much more confident in the diagnosis, evaluation, and management of these oncologic emergencies.
Topics: Blood Viscosity; Emergencies; Emergency Treatment; Hematologic Diseases; Humans; Hypercalcemia; Neoplasms; Neutropenia; Tumor Lysis Syndrome
PubMed: 30881552
DOI: 10.5811/westjem.2018.12.37335 -
Journal of Clinical Pathology Sep 1985Erythrocyte deformability was formerly measured by its contribution to whole blood viscosity. It is now more commonly measured by filtration of erythrocytes through, or... (Review)
Review
Erythrocyte deformability was formerly measured by its contribution to whole blood viscosity. It is now more commonly measured by filtration of erythrocytes through, or aspiration into, pores of 3-5 microns diameter and by the measurement of shear induced erythrocyte elongation using laser diffractometry. Recent improvements in the technology for erythrocyte filtration have included the removal of acute phase reactants from test erythrocyte suspensions, ultrasonic cleaning and reuse of filter membranes, awareness of the importance of mean cell volume as a determinant of flow through 3 microns diameter pores, and the ability to detect subpopulations of less deformable erythrocytes. Measurements of erythrocyte elongation by laser diffractometry, using the Ektacytometer, are also influenced by cell size and need to be corrected for mean cell volume. These advances have greatly improved the sensitivity and specificity of rheological methods for measuring the deformability of erythrocytes and for investigating the mode of action of rheologically active drugs.
Topics: Blood Viscosity; Cell Separation; Erythrocyte Deformability; Erythrocytes; Hematologic Diseases; Humans; Membranes, Artificial; Optics and Photonics; Osmolar Concentration; Rheology; Temperature; Ultrafiltration
PubMed: 3900147
DOI: 10.1136/jcp.38.9.965 -
The Journal of Physiology Sep 2020Highlanders develop unique adaptative mechanisms to chronic hypoxic exposure, including substantial haemoglobin and haematocrit increases. However, a significant...
KEY POINTS
Highlanders develop unique adaptative mechanisms to chronic hypoxic exposure, including substantial haemoglobin and haematocrit increases. However, a significant proportion of populations living permanently at high altitude develop maladaptive features known as chronic mountain sickness (CMS). This study aimed to assess the effects of permanent life at high altitude on clinical and haemorheological parameters (blood viscosity and red blood cell aggregation) and to compare clinical and haemorheological parameters of dwellers from the highest city in the world according to CMS severity. Blood viscosity increased with altitude, together with haemoglobin concentration and haematocrit. At 5100 m, highlanders with moderate-to-severe CMS had higher blood viscosity mainly at high shear rate and even at corrected haematocrit (40%), with a lower red blood cell aggregation. Blood viscosity may contribute to CMS symptomatology but the increased blood viscosity in CMS patients cannot solely be explained by the rise in haematocrit.
ABSTRACT
Chronic mountain sickness (CMS) is a condition characterised by excessive erythrocytosis (EE). While EE is thought to increase blood viscosity and subsequently to trigger CMS symptoms, the exact relationship between blood viscosity and CMS symptoms remains incompletely understood. We assessed the effect of living at high altitude on haemoglobin, haematocrit and haemorheological parameters (blood viscosity and red blood cell aggregation), and investigated their relationship with CMS in highlanders living in the highest city in the world (La Rinconada, Peru, 5100 m). Ninety-three men participated in this study: 10 Caucasian lowlanders, 13 Andean highlanders living at 3800 m and 70 Andean highlanders living at 5100 m (35 asymptomatic, CMS score ≤5; 15 with mild CMS, CMS score between 6 and 10; 20 with moderate-to-severe CMS, CMS score >10). Blood viscosity was measured at native and corrected haematocrit (40%). Haemoglobin concentration and haematocrit increased with the altitude of residency. Blood viscosity also increased with altitude (at 45 s : 6.7 ± 0.9 mPa s at sea level, 14.0 ± 2.0 mPa s at 3800 m and 27.1 ± 8.8 mPa s at 5100 m; P < 0.001). At 5100 m, blood viscosity at corrected haematocrit was higher in highlanders with moderate-to-severe CMS (at 45 s : 18.9 ± 10.7 mPa s) than in highlanders without CMS (10.2 ± 5.9 mPa s) or with mild CMS (12.1 ± 6.1 mPa s) (P < 0.05). In conclusion, blood viscosity may contribute to CMS symptomatology but the increased blood viscosity in CMS patients cannot solely be explained by the rise in haematocrit.
Topics: Adaptation, Physiological; Altitude; Altitude Sickness; Blood Viscosity; Chronic Disease; Humans; Male; Peru
PubMed: 32445208
DOI: 10.1113/JP279694 -
Anesthesiology 1964
Review
Topics: Anesthesia; Anesthesia, General; Anesthesia, Spinal; Arteries; Blood Pressure; Blood Pressure Determination; Blood Viscosity; Brain; Cerebrospinal Fluid; Ganglionic Blockers; Heart; Hexamethonium Compounds; Humans; Hypotension; Hypotension, Controlled; Kidney; Liver; Mortality; Pentolinium Tartrate; Postoperative Care; Posture; Respiration; Respiratory Function Tests; Sympatholytics; Tachyphylaxis; Trimethaphan
PubMed: 14218200
DOI: 10.1097/00000542-196409000-00018 -
Medicine Dec 2023Lipoprotein(a) [Lp(a)] has been confirmed as a causal risk factor of atherosclerotic cardiovascular disease, but its role on circulation is not completely clear and is...
Lipoprotein(a) [Lp(a)] has been confirmed as a causal risk factor of atherosclerotic cardiovascular disease, but its role on circulation is not completely clear and is still being explored. Therefore, this study attempts to explore the relationship between Lp(a) and whole blood reducing viscosity (WBRV), to better understand the role of Lp(a) in circulatory and cardiovascular diseases. We retrospectively analyzed the data of consecutive subjects in the physical examination center of the Affiliated Hospital of Ningbo University Medical College from January 2022 to May 2022. Pearson or spearman correlation analysis was used to test the statistical relationship between 2 continuous variables according to whether they are normal; 131 participants were retrospectively enrolled in this study. The low-density lipoprotein concentration was associated with whole blood viscosity at low-shear (R = 0.220, P = .012), middle-shear (R = 0.226, P = .01), and high-shear viscosity (R = 0.212, P = .015), as well as plasma viscosity (RS = 0.207, P = .018). Lp(a) was not associated with whole blood viscosity at low, middle, and high shear rates, but was associated with WBRV at low shear (RS = 0.204, P = .019) and middle shear rates (RS = 0.197, P = .024). Lp(a) is associated with high WBRV, which may impart more insights into the role of Lp(a) in cardiovascular disease.
Topics: Humans; Blood Viscosity; Cardiovascular Diseases; Cross-Sectional Studies; Lipoprotein(a); Retrospective Studies; Risk Factors
PubMed: 38050213
DOI: 10.1097/MD.0000000000036236 -
Scientific Reports Jun 2023Blood viscosity may affect the mechanisms of stroke and early neurological deterioration (END). We aimed to investigate the relationship between blood viscosity, stroke...
Blood viscosity may affect the mechanisms of stroke and early neurological deterioration (END). We aimed to investigate the relationship between blood viscosity, stroke mechanisms, and END in patients with middle cerebral artery (MCA) infarction. Patients with symptomatic MCA atherosclerosis (≥ 50% stenosis) were recruited. Blood viscosity was compared across patients with different mechanisms of symptomatic MCA disease: in situ thrombo-occlusion (sMCA-IST), artery-to-artery embolism (sMCA-AAE), and local branch occlusion (sMCA-LBO). END was defined as four points increase in the National Institutes of Health Stroke Scale score from baseline during the first week. The association between blood viscosity and END was also evaluated. A total of 360 patients (76 with sMCA-IST, 216 with sMCA-AAE, and 68 with sMCA-LBO) were investigated. Blood viscosity was highest in patients with sMCA-IST, followed by sMCA-AAE and sMCA-LBO (P < 0.001). Blood viscosity was associated with END in patients with MCA disease. Low shear viscosity was associated with END in patients with sMCA- LBO (adjusted odds ratio, aOR 1.524; 95% confidence interval, CI 1.035-2.246), sMCA- IST (aOR 1.365; 95% CI 1.013-1.839), and sMCA- AAE (aOR 1.285; 95% CI 1.010-1.634). Blood viscosity was related to END in patients with stroke caused by MCA disease.
Topics: Humans; Middle Cerebral Artery; Blood Viscosity; Stroke; Infarction, Middle Cerebral Artery; Atherosclerosis
PubMed: 37296267
DOI: 10.1038/s41598-023-36633-z -
Whole blood viscosity in microvascular angina and coronary artery disease: Significance and utility.Revista Portuguesa de Cardiologia Jan 2020Whole blood viscosity (WBV) is the intrinsic resistance of blood flow in vessels, and when elevated induces endothelial shear stress and endothelial inflammation and can...
INTRODUCTION AND OBJECTIVES
Whole blood viscosity (WBV) is the intrinsic resistance of blood flow in vessels, and when elevated induces endothelial shear stress and endothelial inflammation and can accelerate the atherosclerotic process. This study aims to compare WBV levels in patients with microvascular angina (MVA), patients with coronary artery disease (CAD), and normal controls, and to identify the relationship between WBV and high-sensitivity C-reactive protein as a marker of inflammation in MVA and CAD.
METHODS
A total of 573 patients were studied. The MVA group consisted of 189 subjects, the CAD group consisted of 203 subjects, and the control group consisted of 181 age- and gender-matched individuals. WBV was calculated from hematocrit and plasma protein concentration at a low shear rate (0.5 s) and high shear rate (208 s) by a validated equation.
RESULTS
Patients with CAD and MVA had significantly higher WBV at both low and high shear rates compared to the control group. Correlation analysis revealed a significant relationship between high-sensitivity C-reactive protein and WBV at low (r=0.556; p<0.001) and high shear rates (r=0.562) in the CAD group and at low (r=0.475) and high shear rates (r=0.493) in the MVA group.
CONCLUSIONS
Overall, this study demonstrated a significant and independent association between blood viscosity and the existence of endothelial inflammation and the atherosclerotic process.
Topics: Aged; Blood Viscosity; C-Reactive Protein; Case-Control Studies; Coronary Artery Disease; Female; Hematocrit; Humans; Inflammation; Male; Microvascular Angina; Middle Aged; Non-Randomized Controlled Trials as Topic; Retrospective Studies; Serum Albumin, Human; Serum Globulins
PubMed: 32156449
DOI: 10.1016/j.repc.2019.04.008 -
Journal of Internal Medicine Apr 2006The increase of plasma and blood viscosity is usually associated with pathological conditions; however, elevation of both parameters often results in increased perfusion... (Review)
Review
The increase of plasma and blood viscosity is usually associated with pathological conditions; however, elevation of both parameters often results in increased perfusion and the lowering of peripheral vascular resistance. In extreme haemodilution, blood viscosity is too low and insufficient to maintain functional capillary density, a problem that in experimental studies is shown to be corrected by increasing plasma viscosity up to 2.2 cP. This effect is mediated by mechanotransduction-induced nitric oxide (NO) production via shear stress in the endothelium as shown by microelectrode perivascular measurements of NO concentration. Moderate elevations of blood viscosity by increasing haematocrit ( approximately 10%) result in comparable reductions of blood pressure and peripheral vascular resistance, an effect also NO-mediated as it is absent after Nomega-nitro-L-arginine methyl ester treatment and in endothelial nitric oxide synthase-deficient mice. These findings show that the rheological properties of plasma affect vessel diameter in the microcirculation leading to counterintuitive responses to the changes in blood and plasma viscosity. Application of these findings to haemorrhagic shock resuscitation leads to the concept of hyperosmotic-hyperviscous resuscitation as a modality for maintaining the recovery of microvascular function.
Topics: Animals; Blood Viscosity; Hemorheology; Hemorrhage; Homeostasis; Humans; Hypertension; Hypotension; Mechanotransduction, Cellular; Nitric Oxide; Resuscitation
PubMed: 16594904
DOI: 10.1111/j.1365-2796.2006.01622.x -
Diving and Hyperbaric Medicine Mar 2020Prolonged cold-water immersion (CWI) has the potential to cause significant hypothermia and haemoconcentration; both of which have previously been shown to independently...
INTRODUCTION
Prolonged cold-water immersion (CWI) has the potential to cause significant hypothermia and haemoconcentration; both of which have previously been shown to independently increase blood viscosity in vitro. The purpose of this study was to determine the effect of CWI on blood viscosity and examine the relative contribution of decreased blood temperature and haemoconcentration.
METHODS
Ten healthy volunteers were immersed to mid-sternum in 10°C water for 90 minutes. Gastrointestinal (GI) temperature, haematocrit (Hct), and blood viscosity were measured pre- and post-CWI.
RESULTS
CWI caused mean (SD) GI temperature to decrease from 37.5 (0.3)°C to 36.2 (0.7)°C (P < 0.05). CWI also caused mean Hct to increase from 40.0 (3.5)% to 45.0 (2.9)% (P < 0.05). As a result of the haemoconcentration and decreased GI temperature during CWI the mean blood viscosity increased by 19% from 2.80 (0.28) mPa·s⁻¹ to 3.33 (0.42) mPa·s⁻¹ (P < 0.05). However, when the pre-CWI blood sample was measured at the post-CWI GI temperature (36.2°C) there was no significant difference in the blood viscosity when compared to the pre-CWI (37.5°C) blood sample (2.82 (0.20) mPa·s-1 and 2.80 (0.28) mPa·s-1 respectively). Furthermore, the changes in Hct and blood viscosity during CWI were significantly correlated with an r = 0.84.
CONCLUSION
The results of the current study show that prolonged, severe CWI causes a significant 19% increase in blood viscosity. In addition, the results strongly suggest that almost all of the increased blood viscosity seen following CWI is the result of haemoconcentration, not decreased blood temperature.
Topics: Blood Viscosity; Body Temperature; Exercise; Female; Humans; Hypothermia; Immersion; Male; Temperature; Water
PubMed: 32187614
DOI: 10.28920/dhm50.1.24-27 -
Soft Matter Jan 2022Sickle cell anemia (SCA) is a disease that affects red blood cells (RBCs). Healthy RBCs are highly deformable objects that under flow can penetrate blood capillaries...
Sickle cell anemia (SCA) is a disease that affects red blood cells (RBCs). Healthy RBCs are highly deformable objects that under flow can penetrate blood capillaries smaller than their typical size. In SCA there is an impaired deformability of some cells, which are much stiffer and with a different shape than healthy cells, and thereby affect regular blood flow. It is known that blood from patients with SCA has a higher viscosity than normal blood. However, it is unclear how the rigidity of cells is related to the viscosity of blood, in part because SCA patients are often treated with transfusions of variable amounts of normal RBCs and only a fraction of cells will be stiff. Here, we report systematic experimental measurements of the viscosity of a suspension varying the fraction of rigid particles within a suspension of healthy cells. We also perform systematic numerical simulations of a similar mixed suspension of soft RBCs, rigid particles, and their hydrodynamic interactions. Our results show that there is a rheological signature within blood viscosity to clearly identify the fraction of rigidified cells among healthy deformable cells down to a 5% volume fraction of rigidified cells. Although aggregation of RBCs is known to affect blood rheology at low shear rates, and our simulations mimic this effect an adhesion potential, we show that such adhesion, or aggregation, is unlikely to provide a physical rationalization for the viscosity increase observed in the experiments at moderate shear rates due to rigidified cells. Through numerical simulations, we also highlight that most of the viscosity increase of the suspension is due to the rigidity of the particles rather than their sickled or spherical shape. Our results are relevant to better characterize SCA, provide useful insights relevant to rheological consequences of blood transfusions, and, more generally, extend to the rheology of mixed suspensions having particles with different rigidities, as well as offering possibilities for developments in the field of soft material composites.
Topics: Anemia, Sickle Cell; Blood Viscosity; Erythrocytes; Humans; Rheology; Viscosity
PubMed: 34931640
DOI: 10.1039/d1sm01299a