Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BLOOD”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources
PubMed1997

Peripheral-blood stem-cell transplantation versus autologous bone marrow transplantation in Hodgkin's and non-Hodgkin's lymphomas: a new matched-pair analysis of the European Group for Blood and Marrow Transplantation Registry Data. Lymphoma Working Party of the European Group for Blood and Marrow Transplantation.

PURPOSE: To address the question of short-term and long-term advantages of peripheral-blood stem-cell transplantation (PBSCT) over autologous bone marrow transplantation (ABMT), we have reviewed the data of 3,214 patients with lymphoma, 2,859 undergoing ABMT, and 355 undergoing PBSCT. PATIENTS AND METHODS: Analysis of prognostic factors for progression-free survival (PFS) was conducted separately for non-Hodgkin's lymphoma (NHL) (N = 1,915) and Hodgkin's disease (HD) (N = 1,299). In multivariate analysis, the relevant factors were status at transplant for NHL and sex, size of largest mass at transplant, status at transplant, and conditioning regimen for HD. The pair analysis was carried out by matching NHL and HD patients separately by their prognostic factors. Additionally, NHL patients were matched for histology, whereas both HD and NHL patients were matched for date of transplant. With this method, 454 patients were matched in the NHL group and 256 were matched in the HD group. RESULTS: The overall survival (OS) and PFS unexpectedy were better for ABMT versus PBSCT patients in the HD group (OS, 65.3% at 4 years for ABMT v 52.7% for PBSCT; P = .0198). There was no difference in OS or PFS in the NHL group (OS, 56.6% at 4 years for ABMT v 52.7% for PBSCT; P = .4148). The overall relapse or progression rate at 4 years for NHL was 42% after ABMT and 49.2% after PBSCT (P = .1220); for HD, it was 40% and 58.6%, respectively (P = .0164). Transplant-related mortality was lower, but not significantly, with PBSCT: 7.0% for ABMT versus 3.5% for PBSCT in NHL (P = .1356) and 7% for ABMT versus 4.7% for PBSCT in HD (P = .6056). Hematologic recovery occurred faster significantly with PBSCT irrespective of disease. CONCLUSION: This study confirms the advantage of PBSCT in terms of hematopoietic reconstitution, but it fails to show any superiority in the long term. Poorer results for both progression free and overall survival observed in HD patients who are receiving PBSCT are unexplained and should be confirmed with randomized studies.

Adult↗
PubMed1998

Incidence and outcome of hepatic veno-occlusive disease after blood or marrow transplantation: a prospective cohort study of the European Group for Blood and Marrow Transplantation. European Group for Blood and Marrow Transplantation Chronic Leukemia Working Party.

To determine the incidence and outcome of hepatic veno-occlusive disease (VOD) after blood or marrow transplantation (BMT), we prospectively evaluated all consecutive patients receiving a BMT during a 6-month period in participating EBMT centers. All of them were evaluated for occurrence of VOD according to previously defined clinical criteria. The clinical course, outcome, value of prophylactic and therapeutic interventions, and the influence of previously described risk factors were analyzed. During the study period, 1,652 BMT were performed in 73 centers. VOD was diagnosed in 87 patients (5.3%; 95% confidence interval [CI], 4.2% to 6.4%). Fifty-six of 631 allogeneic BMT (8.9%) and 31 of 1,010 autologous BMT (3.1%) developed this complication (P <.0001). VOD was classified as mild in 7 (8%), moderate in 56 (64.4%), and severe in 24 (27.6%) cases. Sixteen patients died of VOD (corresponding to 1% of the whole series, 18.4% of VOD patients, and 66.7% of severe VOD). The use of unfractionated heparin did not significantly decrease the incidence of VOD. Independent variables associated with an increased risk of VOD were allogeneic BMT (relative risk [RR], 2.8; P <.001), pre-BMT elevation of serum aspartate aminotransferase (RR, 2.4; P =.001), high-dose cytoreductive therapy (RR, 2.3; P =.003), Karnofsky performance score less than 90% (RR, 2.7; P =.006), and prior abdominal radiation (RR, 2.9; P =.03). In conclusion, this prospective study shows that (1) the incidence of VOD is lower than that reported in smaller studies from single centers, (2) about one fourth of cases of VOD progress to severe disease, (3) main risk factors have a major impact on incidence of VOD, and (4) the use of prophylactic unfractionated heparin does not seem to reduce the incidence of VOD.

Adult↗
PubMed2005

One hundred consecutive hepatobiliary resections for biliary hilar malignancy: preoperative blood donation, blood loss, transfusion, and outcome.

BACKGROUND: Many reports on blood loss and transfusion requirements during hepatectomy for metastatic liver cancer or hepatocellular carcinoma have been published; however, there are no reports on these issues in hepatectomy for biliary hilar malignancy. The aim of this study was to review our experience with blood loss and perioperative blood requirements in 100 consecutive hepatectomies for biliary hilar malignancy. METHODS: One hundred consecutive hepatectomies with en bloc resection of the caudate lobe and extrahepatic bile duct for hilar malignancies were performed, including 81 perihilar cholangiocarcinomas and 19 advanced gallbladder carcinomas involving the hepatic hilus. Fifty-eight hilar resections were combined with other organ and/or vascular resection. Data on preoperative blood donation, intraoperative blood loss, and perioperative transfusion were collected and analyzed. RESULTS: Preoperative autologous blood donation was possible in 73 patients (3.4 +/- 1.2 U). Intraoperative blood loss was 1850 +/- 1000 mL (range, 677-5900 mL), and it was < 2000 mL in 62 patients. Intraoperatively, only 7 of the 73 patients (10%) who donated blood received transfusion of unheated, homologous blood products (packed red blood cells or fresh frozen plasma), whereas 18 the 23 patients (67%) without donation received homologous transfusions. Only 16 patients received transfusion postoperatively, and overall, 35 patients received unheated homologous blood products. Total serum bilirubin concentrations after hepatectomy in patients receiving autologous blood transfusion only was similar to those in patients who did not receive transfusion. The incidence of postoperative complications was higher in the 35 patients who received perioperative homologous transfusion than in 65 patients who did not (94% vs 52%; P <.0001). The mortality rate (including all deaths) was 3% (myocardial infarction, intra-abdominal bleeding, and liver failure, 1 patient each). CONCLUSIONS: Despite the technical difficulties arising from hepatectomy for biliary hilar malignancy, approximately two thirds of hepatectomies can be performed in an experienced center without perioperative homologous blood transfusion using preoperative blood donation.

Adult↗
PubMed1998

Collagen-induced whole blood platelet aggregation in patients undergoing surgical procedures associated with minimal to moderate blood loss.

Intraoperative bleeding due to platelet disorders is a persistent problem. Therefore, a screening assay to identify patients who are likely to bleed as a result of platelet dysfunction would be useful in formulating decisions about patient care. A previous study indicated that preoperative collagen-induced whole blood platelet aggregation predicts bleeding in patients undergoing surgery with cardiopulmonary bypass, a procedure associated with substantial blood loss. In the current study, we assessed the ability of the same whole blood platelet aggregation test to predict blood loss in patients undergoing surgical procedures not associated with substantial blood loss. The study included 369 adult patients (165 men and 204 women). Patients were categorized in three groups depending on the invasiveness of the operation and the expected blood loss. The intraoperative estimated blood loss value, obtained from the operative report in the patient record, increased significantly with increasing surgical invasiveness. Patients with excessive blood loss (defined as blood loss at or above the 75th or 90th percentile of the estimated blood loss values of patients undergoing procedures of similar invasiveness) had similar platelet aggregation values as patients who did not experience excessive blood loss. Thus, for patients undergoing operations not associated with substantial blood loss, the results of preoperative collagen-induced whole blood platelet aggregation are not effective in identifying patients likely to experience excessive blood loss.

Blood Coagulation Tests↗
PubMed2006

Relationships between blood rheology and age, body mass index, blood cell count, fibrinogen, and lipids in healthy subjects.

We investigated the relationships between blood rheology assessed by microchannel method and the various hemorheologic factors in healthy subjects. One hundred seventy-six healthy volunteers (90 men and 86 women, mean age; 32.9+/-11.3 years) were participated in this study. Body weight, body mass index, red blood cell count, hematocrit, hemoglobin, white blood cell count, and platelet count, plasma fibrinogen, and fasting serum lipid and lipoprotein concentrations were measured. In order to assess blood rheology, blood passage time was determined by a microchannel method (Micro Channel Array Flow Analyzer). Age, body mass index, red blood cell count, hematocrit, hemoglobin, white blood cell count, total cholesterol, low-density lipoprotein cholesterol, and triglyceride were positively correlated with blood passage time in all subjects, respectively (p<0.01) and high-density lipoprotein cholesterol was inversely correlated with blood passage time (p<0.01). However, platelet count, and fibrinogen were not correlated with blood passage time. The present study showed that increased age, body mass index, red blood cell count, white blood cell count, total cholesterol, low-density lipoprotein cholesterol, and triglyceride and decreased high-density lipoprotein cholesterol were associated with impaired blood rheology measured by microchannel method in healthy subjects, suggesting that aging, obesity, erythrocytosis, leukocytosis, and dyslipidemia may be related to hemorheological disorders. This microchannel method may be useful to study blood rheology which may be associated with various risk factors of cardiovascular disorders.

Adolescent↗
PubMed1997

Nucleated red blood cells in cord blood of singleton term neonates.

OBJECTIVE: This study aims to establish normal values for nucleated red blood cells in term singletons and factors associated with their elevation. STUDY DESIGN: Cord blood was prospectively collected from term singleton gestations from Feb. 1 to July 31, 1995. Umbilical vein white blood cells and nucleated red blood cells were counted and umbilical arterial pH was determined. Medical records provided maternal and neonatal information. RESULTS: Cord blood from 1112 cases was obtained and evaluated for nucleated red blood cells per 100 white blood cells. Nine outliers were censored (nucleated red blood cells per 100 white blood cells = 126 to 830); five cases were excluded because of missing data. The mean value of nucleated red blood cells per 100 white blood cells was 8.55, the SD was 10.27, and the range was 0 to 89. The value did not very by maternal tobacco or drug use, anemia, fetal presentation, or mode of delivery. Both maternal diabetes and meconium were associated with elevated values, p < 0.01. Apgar scores and cord pHs showed trends toward inverse proportionality to the number of nucleated red blood cells per 100 white blood cells. CONCLUSION: The mean number of nucleated red blood cells per 100 white blood cells was 8.55, with a wide range and SD. Elevated values may be associated with markers of intrauterine hypoxia such as meconium, lower Apgar scores, and lower pH values.

Adolescent↗
PubMed1996

Sexual maturation and racial differences in blood pressure in girls: the National Heart, Lung, and Blood Institute Growth and Health Study.

OBJECTIVE: To evaluate racial differences in blood pressure in girls aged 9 to 10 years in the National Heart, Lung, and Blood Institute Growth and Health Study (NGHS) and to evaluate the extent to which racial differences in blood pressure are explained by other factors, including sexual maturation and body size. METHODS: The NGHS enrolled 539 black and 616 white girls aged 9 years, and 674 black and 550 white girls aged 10 years. Racial differences in blood pressure were examined. Relationships of stage of sexual maturation, height, and skinfold thickness with systolic and diastolic blood pressure were evaluated by multiple regression analysis. RESULTS: The black girls had significantly higher systolic (102.0 +/- 8.90 vs 100.5 +/- 9.42 mm Hg, p <0.001) and diastolic (58.0 +/- 12.0 vs 56.5 +/- 12.51 mm Hg, p <0.01) blood pressures than the white girls. The black girls were also more advanced in sexual maturation and were taller (142.9 +/- 7.94 vs 139.6 +/- 7.05, p <0.001) and heavier (39.6 +/- 11.24 vs 35.3 +/- 8.73 kg, p <0.001) than the white girls. Both systolic and diastolic blood pressure were significantly correlated with level of maturation, height, weight, and sum of skinfolds. Stage of maturation was found to account for the difference in blood pressure between black girls and white girls. In a multiple regression analysis, controlling for height (for diastolic blood pressure) and for both height and sum of skinfolds (for systolic blood pressure) eliminated the effects of race and stage of maturation on blood pressure. CONCLUSION: Racial differences in blood pressure were observed for 9- and 10-year-old girls and are explained by the fact that black girls were more mature than white girls. The effect of sexual maturation on blood pressure appears to operate through height and body fat. The effect of obesity may be more important for systolic than for diastolic blood pressure. Continuation of racial differences in blood pressure may result in a higher prevalence of hypertension for black women.

Adipose Tissue↗
PubMed2002

A randomised controlled trial of the effect of anticipation of a blood test on blood pressure.

Blood pressure is affected by situational anxiety, such as the white coat effect. We hypothesised that blood pressure would also be affected by anticipation of a blood test. Volunteer subjects were recruited on the campus of Birmingham University. Subjects were randomly assigned to intervention and control groups. After a period of rest, three seated blood pressure measurements were taken at 1-min intervals using an electronic sphygmomanometer. Between the second and third measurements subjects in the intervention group were told that a blood test would be carried out after the last measurement. No blood test was carried out. Three blood pressure measurements were made in all 213 randomised subjects. Analysis was by intention-to-treat. In the control group mean systolic and diastolic blood pressure fell in successive measurements. Between the second and third measurements mean systolic blood pressure fell by 1.4 mm Hg in the control group and rose by 2.6 mm Hg in the intervention group (difference 4.0 mm Hg, P < 0.0001). A rise in diastolic blood pressure between the second and third measurements did not reach statistical significance. It was concluded that anticipation of a blood test affects measured systolic blood pressure in volunteers. The practice of taking blood tests at the same time as measuring blood pressure may potentially bias estimations of blood pressure.

Adolescent↗
PubMed1994

Blood to brain and brain to blood passage of native horseradish peroxidase, wheat germ agglutinin, and albumin: pharmacokinetic and morphological assessments.

Native horseradish peroxidase (HRP) and the lectin wheat germ agglutinin (WGA) conjugated to HRP are protein probes represented in the blood-brain barrier (BBB) literature for elucidating morphological routes of passage between blood and brain. We report the application of established pharmacokinetic methods, e.g., multiple-time regression analysis and capillary depletion technique, to measure and compare bidirectional rates of passage between blood and brain for radioactive iodine-labeled HRP (I-HRP), WGA-HRP (I-WGA-HRP), and the serum protein albumin (I-ALB) following administration of the probes intravenously (i.v.) or by intracerebroventricular (i.c.v.) injection in mice. The pharmacokinetic data are supplemented with light and electron microscopic analyses of HRP and WGA-HRP delivered i.v. or by i.c.v. injection. The rates of bidirectional movement between blood and brain are the same for coinjected I-HRP and I-ALB. Blood-borne HRP, unlike WGA-HRP, has unimpeded access to the CNS extracellularly through sites deficient in a BBB, such as the circumventricular organs and subarachnoid space/pial surface. Nevertheless, blood-borne I-WGA-HRP enters the brain approximately 10 times more rapidly than I-HRP and I-ALB. Separation of blood vessels from the neocortical parenchyma confirms the entry of blood-borne I-WGA-HRP to the brain and sequestration of I-WGA-HRP by cerebral endothelial cells. Nearly half the I-WGA-HRP radioactivity associated with cortical vessels is judged to be subcellular. Light microscopic results suggest the extracellular pathways into the brain available to blood-borne native HRP do not represent predominant routes of entry for blood-borne WGA-HRP. Ultrastructural analysis further suggests WGA-HRP is likely to undergo adsorptive transcytosis through cerebral endothelia from blood to brain via specific subcellular compartments within the endothelium. Entry of blood-borne I-WGA-HRP, but not of I-ALB, is stimulated with coinjected unlabeled WGA-HRP, suggesting the latter may enhance the adsorptive endocytosis of blood-borne I-WGA-HRP. With i.c.v. coinjection of I-WGA-HRP and I-ALB, I-WGA-HRP exists the brain more slowly than I-ALB. The brain to blood passage of I-WGA-HRP is nil with inclusion of unlabeled WGA-HRP, which does not alter the exist of I-ALB. Adsorptive endocytosis of i.c.v. injected WGA-HRP appears restricted largely to cells lining the ventricular cavities, e.g., ependymal and choroid plexus epithelia. In summary, the data suggest that the bidirectional rates of passage between brain and blood for native HRP are comparable to those for albumin.

Animals↗
PubMed1993

Local cerebral blood flow and glucose utilization after blood exchange with a hemoglobin-based O2 carrier in conscious rats.

The effects of a blood exchange on cerebral blood flow and glucose utilization were studied. A near to total blood exchange (hematocrit < 3%) was achieved in conscious rats by isovolemic hemodilution. Ultrapurified, polymerized, bovine hemoglobin (UPBHB) served as a blood substitute. Local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCGU) were measured in 34 brain structures of conscious rats by means of the ido[14C]antipyrine and the 2-[14C]-deoxy-D-glucose methods. A group of rats without blood exchange served as control. After blood exchange LCBF increased from 36 to 126% in the different brain structures resulting in a nearly doubled mean cerebral blood flow (+82%). LCGU increased only moderately by 0-24%. Significant increases in LCGU were observed in 16 brain structures. Mean cerebral glucose utilization slightly increased (+14%). The relationship between LCGU and LCBF was found to be tight both in the control group (r = 0.95) as well as after blood replacement (r = 0.94), although it was reset to a higher overall LCBF-to-LCGU ratio. The profound increases in LCBF observed after blood exchange, which were not paralleled by comparable increases in LCGU, might be explained by a reduction of blood viscosity after blood exchange. Additional effects of blood exchange observed in the present study were an increase of mean arterial blood pressure and a decline of heart rate. The results indicate that replacement of blood with the hemoglobin-based oxygen carrier UPBHB appears to meet the cerebral circulatory and metabolic demands of the brain tissue.

Animals↗
PubMedDate not supplied

Blood pressure changes during adolescence and subsequent adult blood pressure level.

Serial data were analyzed for blood pressure recorded between the ages of 9 to 18 years for 278 children and for a subset of this group whose blood pressure was measured at the age of 30 +/- 5.0 years (n = 93). Blood pressures were measured by auscultation over the antecubital fossa with the participant seated. Systolic blood pressure was recorded when the first sound was heard, and diastolic blood pressure was recorded when all sounds disappeared (fifth phase). A linear regression model was fitted to the data for each individual, and adjustments were made for regression toward the mean using maximum likelihood procedures. There were no significant correlations between the estimated initial values of blood pressure and the rate of change from 9 to 18 years of age. The associations between the levels of blood pressure at 9 years of age and at 30 years of age were significant for systolic blood pressure only in male subjects and were not significant for diastolic blood pressure in either sex. The correlations between the rate of blood pressure change from 9 to 18 years of age and blood pressure levels at 30 years of age were nonsignificant. When the initial values and the rate of change in blood pressure from 9 to 18 years of age were taken into account simultaneously, they accounted for approximately 20% of the variation in systolic blood pressure levels at 30 years of age. This finding indicates that children with higher blood pressure levels at about 9 years of age and with rapid increases in blood pressure during pubescence may have an increased risk of becoming hypertensive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2003

Assessment of acid-base status and plasma lactate concentrations in arterial, mixed venous, and portal blood from dogs during experimental hepatic blood inflow occlusion.

OBJECTIVE: To determine the effects of extended experimental hepatic blood flow occlusion (ie, portal triad clamping [PTC]) in dogs by measuring acid-base status and plasma lactate concentrations in arterial, mixed venous, and portal blood and evaluating the relationship between metabolic and concurrent hemodynamic changes. ANIMALS: 6 healthy Beagles. PROCEDURE: During anesthesia with isoflurane, cardiac output and arterial blood pressure were measured. Arterial, mixed venous, and portal blood samples were collected simultaneously for blood gas analyses and plasma lactate measurements before PTC and at 8-minute intervals thereafter. RESULTS: PTC resulted in severe hemodynamic and metabolic alterations. Eight minutes after PTC, significant decreases in cardiac index from a baseline value of 3.40 +/- 0.27 to 1.54 +/- 0.26 L/min/m2 and in mean arterial blood pressure from a baseline value of 74 +/- 6 to 43 +/- 6 mm Hg were recorded. After PTC, results indicative of lactic acidosis were found in portal blood at 16 minutes, in mixed venous at 32 minutes, and in arterial blood at 48 minutes. Significant differences in measured variables were also found between arterial and portal blood samples, between mixed venous and portal blood samples, and between arterial and mixed venous blood samples after PTC, compared with differences at baseline. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of mixed venous blood is preferable to analysis of arterial blood in the assessment of metabolic derangement. In a clinical setting, occluded portal blood is released to the systemic circulation, and the degree of reperfusion injury may depend on the metabolic status of pooled portal blood.

Acid-Base Equilibrium↗
PubMed1995

Average blood loss and the risk of requiring perioperative blood transfusion in 506 orthognathic surgical procedures.

PURPOSE: This study quantifies the estimated blood loss in seven groups of orthognathic surgical procedures and the risk of requiring perioperative blood transfusion, and identifies the factors relating to blood loss and need for transfusion. PATIENTS AND METHODS: The records of 506 consecutive patients who underwent various orthognathic surgical procedures under hypotensive anesthesia from 1987 to 1990 were analyzed retrospectively. All procedures were performed by the authors in the same hospital setting. Patients were placed in seven groups based on the operation(s) performed, including single-jaw and double-jaw procedures. Estimated blood loss was calculated for each group and was correlated with patients' sex, age, and year of surgery, and whether they autodonated blood. The volume of intravenous (IV) fluids given was also recorded. RESULTS: Average estimated blood loss for all groups was 273.23 mL. Double-jaw procedures resulted in more blood loss than single-jaw procedures. Men and boys had a higher average blood loss than women and girls, but average blood loss was not affected significantly by patients' age or year of surgery. Only four patients (0.8%) received blood transfusions, and their average estimated blood loss was 975 mL. The percentage of patients autodonating increased from 10.4% in 1987 to 54.9% in 1990. There was no significant difference in the percentage of autodonators by surgical procedure. CONCLUSIONS: The need for blood transfusion in this study was extremely low. Factors contributing to this are believed to be use of hypotensive anesthesia; a single surgical team; and a constant surgical setting. Patients having double-jaw surgery are at greater risk for blood loss than those having single-jaw procedures, and should be so advised, along with the risks of blood transfusion. The authors believe that under the conditions of this study the use of autodonation is not necessary, with the possible exception of complex double-jaw procedures involving small patients.

Adolescent↗
PubMed1993

Blood transfusions in hip fracture patients: implications for blood conservation programs.

To address the potential role of innovative blood conservation interventions in nonelective surgery, we reviewed blood transfusions and blood losses during hospitalization of patients undergoing open reduction internal fixation of an intratrochanteric hip fracture. Sixty-four orthopaedic patients consecutively admitted over a 3-year interval were analyzed for transfusion needs by calculating red blood cell (RBC) volume lost during hospitalization. Overall, 39 (61%) patients received blood. We found that the "transfusion-trigger" was higher for females compared to males. Fifteen (23%) of 64 patients were identified to have been transfused with RBC volumes in excess of RBC volumes lost. The remaining 49 patients determined to be untransfused or to be transfused appropriately received 1.4 +/- 2.1 blood units (M +/- SD). Of these, 30 (60%) received < or = 1 U. We found no evidence that patients who received blood transfusions in excess of blood losses benefited compared to those whose blood replacement was less than blood lost. We conclude that innovative blood conservation interventions such as recombinant human erythropoietin (EPO) therapy can be incorporated into this nonelective surgical setting and may permit a significant percentage of hip fracture patients to avoid homologous blood transfusion. An algorithm for physician education programs that can address blood transfusion practices is provided so that patients can benefit from new blood conservation approaches.

Aged↗
PubMedDate not supplied

Evaluation of blood recirculation in catheters for haemodialysis and its relation to blood circuit pressures.

The objectives of this study were to evaluate the degree of blood recirculation (REC) in venous catheters for dual lumen haemodialysis, and its relation to the drop in arterial line pressure and return venous pressure during haemodialysis. A total of 25 catheters were evaluated (15 temporary 15 cm catheters, and 10 permanent tunnelled 32 cm catheters). REC was calculated using a blood temperature monitor. With blood flow stabilised at 250 ml/min,the session was initiated and the following was determined: real blood flow, drop in arterial line pressure (pre-pump pressure), positive pressure and blood recirculation. Mean blood recirculation in the total of catheters was 6.4 +/- 3%, mean real blood flow was 230 +/- 9 ml/min. Mean blood pressure was -146 +/- 52 mmHG. Mean positive pressure was 127 +/- 47 mmHG. A strong correlation was found between real flow and arterial pressure (r = 0.79, p < 0.01), and between arterial pressure and blood recirculation (r = -0.57, p < 0.01). Comparing the variables studied, a lower degree of REC (5.2+/-2 vs. 8.5+/-3, p < 0.01), a higher real blood flow (234 +/- 7 vs. 223 +/- 7, p < 0.01) and a lower drop in arterial pressure (-127 +/- 49 vs. -180 +/- 40, p < 0.05) were found in temporary catheters than in permanent catheters. No differences were observed in positive pressure. As a conclusion, these results suggest that blood recirculation is lower in temporary catheters than in permanent tunnelled catheters. This is related to a lower drop in pre-pump blood pressure and a higher real blood flow. However, positive pressure does not seem to influence the degree of blood recirculation in venous dual lumen catheters for haemodialysis.

Arteriovenous Shunt, Surgical↗
PubMed1992

Some characteristics of blood shed into the Solcotrans postoperative orthopaedic drainage/reinfusion system.

OBJECTIVE: To assess the suitability of blood shed into the Solcotrans orthopaedic autotransfusion system as a source of autologous blood for transfusion. DESIGN: Blood samples were taken from patients after surgery and from shed blood within the Solcotrans units. SETTING: Surgery was performed at a public hospital. PATIENTS: All six patients underwent total knee replacements. MAIN OUTCOME MEASURES: Measurements were made of haemoglobin, haematocrit, platelets, pH, potassium, plasma haemoglobin, fibrinogen, D-dimer, plasminogen activator, thromboplastin and fibrinopeptide A. The non-activated partial thromboplastin time was estimated. Shed blood was compared with homologous whole blood to assess the thrombogenic potential of shed blood in vitro. RESULTS: The haemoglobin and haematocrit levels of the shed blood were significantly lower than venous blood (P = 0.008). Levels of potassium in shed blood were normal although there was significant haemolysis. Shed blood was depleted of clotting factors, with increased levels of D-dimer (16-128 g/L). Activation of the coagulation pathway within the shed blood was shown by a shortened non-activated partial thromboplastin time (90-120 s), and detectable levels of thromboplastin. Propionibacterium acnes was isolated from one of the units. CONCLUSION: Reinfusion of large volumes of shed blood should probably be avoided, but use of the Solcotrans orthopaedic transfusion system in conjunction with other autologous transfusion practices can reduce the patient's requirement for homologous blood.

Blood Coagulation Tests↗
PubMed1987

Increases in brain tumor and cerebral blood flow by blood-perfluorochemical emulsion (Fluosol-DA) exchange.

It has been suggested that oxygen-carrying blood substitutes, perfluorochemical (PFC) emulsions, can increase blood flow and oxygen delivery to poorly perfused tumor regions. Local cerebral blood flow was measured in male Wistar rats bearing intracranial Walker 256 tumor with and without blood-PFC exchange using [14C]iodoantipyrine (IAP) and quantitative autoradiographic techniques. The exchange transfusion was performed in two groups of awake animals breathing 100% oxygen: (a) complete blood-PFC exchange, hematocrit 4%; and (b) partial blood-PFC exchange, hematocrit 20-25%. The tissue/blood partition coefficient for IAP was determined in a separate set of experiments under identical conditions and was used in calculating blood flow. Cerebral blood flow increased approximately 2-fold following complete blood-PFC exchange and 1.5-fold by the partial exchange. A similar 1.5-fold increase in flow was measured in intraparenchymal tumors following partial exchange; however, a flow increase was not identified in the meningeal extension of the tumors. The increase in cerebral blood flow is consistent with an autoregulatory response of the central nervous system vasculature to maintain an adequate supply of oxygen to central nervous system tissue. Presumably, the increase in blood flow to the intracerebral tumor reflects the autoregulatory response of the host tissue. The effect of blood-PFC exchange on blood flow and drug delivery to tumor may depend on the particular tumor and its site of growth (host tissue). The tissue/blood partition coefficient for IAP increased from 0.8 to 1.0 and 1.4 following partial and complete blood-PFC exchange, respectively. This change in the partition coefficient reflects the change in the intravascular fraction of IAP that is bound to plasma proteins. The enhanced therapeutic effect that has been reported in some experimental tumor models may result from a higher tissue/blood equilibrium distribution ratio (due to reduced plasma protein binding) resulting in a higher tissue exposure to certain drugs following PFC administration.

Animals↗
PubMed2000

How much blood is really lost in total knee arthroplasty?. Correct blood loss management should take hidden loss into account.

In total knee arthroplasty (TKA) the total blood loss is composed of 'visible' blood loss from the surgical field and wound drainage, and blood loss into the tissues which is hidden. Blood management should be aimed at addressing the total blood loss. The measured loss is generally an underestimation of the 'true' loss, which can be calculated. Sixty-three TKAs were prospectively studied at the Avon Orthopaedic Centre, Bristol, UK. All but two TKAs were performed under a tourniquet. Thus the intraoperative blood loss was usually zero. Reinfusion of drained blood was carried out when appropriate. The drainage and volume reinfused were recorded. None of the patients studied received a bank blood transfusion. All patients had FBC including haematocrit (Hct) pre- and post-operatively. Each patients height and weight were recorded pre-operatively. The true total blood loss was calculated using height, weight and pre- and post-op Hct. Subtracting the visible loss gives the hidden loss. As the object of the study was to determine the proportion of blood loss that is hidden, rather than document blood loss in general, seven patients with very large blood losses were excluded from the study to minimise the effect of haemodilution on our calculation. The threshold chosen was 1.5 l. In TKA, the mean total calculated blood loss was 1474 ml. The mean hidden loss was 735 ml. It can be seen that the hidden loss is 50% of the total loss, making the true loss following TKA twice the volume usually recorded. This is due to bleeding into the tissues and haemolysis when reinfusion is carried out. It is concluded that when planning blood management after TKA, account should be taken of the probable substantial hidden blood loss.

Journal Article↗