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PubMed1977

Blood pressure and heart rate regulating capacity of the carotid sinus during changes in blood volume distribution in man.

The influence of changes in blood volume distribution on the carotid baroreflex was studied in 18 subjects. Blood volume distribution was changed by varying the pressure around the lower body above and below ambient, thereby varying the amount of blood pooled in this region and exerting a secondary influence on the central blood volume. The carotid arterial stretch receptors were stimulated by varying the pressure in air-tight box enclosing the neck. To obtain a standardized carotid sinus stimulus (SCS) the pressure in the box was varied sinusoidally between - 10 and - 40 mmHg with a fixed freqency of 0.03 Hz. The effects on heart rate and blood pressure were assessed by harmonic analysis performed off-line on a digital computer. During lower body negative pressure of -40 mmHg (LBNP -40), i.e. during a procedure known to reduce the central blood volume, SCS induced an augmented effect on the blood pressure regulating capacity but not on the heart rate response. Expressing the blood pressure regulating capacity as peak-to-peak changes in systolic arterial pressure, the response during LBNP -40 mmHg was almost twice the control value. The opposite stimulus-lower body postive pressure-influenced the SCS-induced effects only slightly but on the average a minor reduction in both blood pressure and heart rate regulating capacity was found compared with the control condition, though the difference did not reach significant levels. The results support the hypothesis that changes in blood volume distribution modify the function of the carotid baroreflex, possibly via intrathoracic receptors sensitive to changes in central blood volume and/or central venous pressure.

Adult↗
PubMed1995

Acute cocaine administration alters posttraumatic blood pressure and cerebral blood flow in rats.

Cocaine abuse is widespread, and it is possible that its two main pharmacological actions, sympathomimetic and local anesthetic, could influence the blood pressure and cerebral blood flow response to brain injury, which occurs with increased frequency in drug abusers. We tested this hypothesis in ventilated barbiturate-anesthetized rats. Brain injury was induced using the fluid-percussion method, and cortical blood flow was measured using laser-Doppler flowmetry. Saline, cocaine, methamphetamine, or lidocaine was administered 10 min before injury. Upon injury, both cocaine- and saline-pretreated rats showed a similar acute hypertensive phase, which was followed by a period of more pronounced hypotension in the cocaine group (68 +/- 4 vs. 100 +/- 6 mmHg). Cortical blood flow increased dramatically 3-15 s following injury-induced hypertension in both the cocaine and saline groups (approximately 230-260%), but then fell below preinjury values within minutes. At 1 h postinjury, the blood flow in the saline group was 53 +/- 6% of the preinjury value, while in the cocaine group, flow was 74 +/- 7% of preinjury baseline. Similar to the cocaine-treated animals, methamphetamine also caused a more pronounced hypotensive event, but blood flow was not significantly different from saline controls. Lidocaine did not alter posttraumatic blood pressure but did significantly elevate blood flow throughout the 1-h postinjury period. At 60 min posttrauma, blood flow in the lidocaine group was 80 +/- 10% of the preinjury value. The mechanism by which cocaine alters blood pressure and blood flow after injury is not entirely certain.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Evaluation of noninvasive blood pressure monitoring devices Spacelabs 90202 and 90207 versus resting and ambulatory 24-hour intra-arterial blood pressure.

This study evaluated the accuracy of blood pressure values provided by the Spacelabs 90202 and 90207 devices in comparison with intra-arterial recording in 19 subjects at rest and in nine subjects in ambulatory conditions (Oxford method). At rest Spacelabs monitors reflected intra-arterial systolic blood pressure values very closely but overestimated to a considerable extent intra-arterial diastolic blood pressure (Spacelabs-intra-arterial differences, -0.8 +/- 9.2, NS, and 9.1 +/- 8.8 mm Hg, p less than 0.01, for systolic and diastolic blood pressures, respectively). In ambulatory conditions Spacelabs-intra-arterial average differences in 24-hour values were +0.4 +/- 5.1 mm Hg for systolic blood pressure (NS) and +14.0 +/- 2.9 mm Hg for diastolic blood pressure (p less than 0.01) when group data were considered. The performance of both Spacelabs devices was worse when assessed in individual subjects or for each hourly interval. In spite of these differences between noninvasive and intra-arterial absolute blood pressure values, however, Spacelabs 90202 and 90207 monitors were able to faithfully reflect directional hour-to-hour changes in intra-arterial blood pressure (chi 2 = 18.2 and chi 2 = 23.1 for systolic and diastolic blood pressures, respectively, p less than 0.01). No differences were found between the performance of the two Spacelabs devices. Thus, although the absolute accuracy of blood pressure values provided by these monitors in ambulatory subjects is still limited, they seem to be suitable for studies aimed at assessing 24-hour blood pressure profiles quantitatively as well as qualitatively.

Adolescent↗
PubMed1977

Change in liver blood flow and blood content in dogs during direct and reflex alteration of hepatic sympathetic nerve activity.

A mean decrease of 60% in liver blood volume was recorded by a plethysmographic technique during electrical stimulation of the hepatic nerves in anesthetized, vagotomized dogs. A decrease in pressure in the vascularly isolated carotid sinus to 40 mm Hg, from a mean control of 144 mm Hg, decreased liver blood volume by a mean of 16%; arterial blood pressure increased by a mean of 77 mm Hg. Carotid sinus hypotension was accompanied by respective mean increases of 16% and 1.4% in hepatic arterial and portal venous blood flows, and of 45% and 22% in arterial and portal resistances. Increase in sinus pressure to 240 mm Hg increased liver blood volume by a mean of 20%; arterial blood pressure decreased by 90 mm Hg. Sinus hypertension was accompanied by respective mean decreased of 10% and 1.5% in hepatic arterial and portal venous blood flows, and of 44% and 18% in arterial and portal resistances. Interruption of afferent vagal traffic from cardiopulmonary receptors was maximally effective in decreasing liver blood volume at a carotid sinus pressure of 40 mm Hg and was ineffective at carotid sinus pressures greater than 160 mm Hg. Combined withdrawal of carotid and cardiopulmonary vasomotor inhibition decreased liver blood volume by 42%; of this 37% was due to the cardiopulmonary and 63% to the carotid baroreflex. The study showed the canine liver to function as a blood reservoir by active mobilization of a portion of its blood volume.

Animals↗
PubMed2004

Relationship between blood pressure measurements recorded on patients' charts in family physicians' offices and subsequent 24 hour ambulatory blood pressure monitoring.

BACKGROUND: In most western countries 20% of adults have hypertension. Reports in the literature suggest that from 31 to 86% of treated patients are not at recommended target levels. However it is important to consider how we are determining whether targets are unmet and the degree to which they are unmet. Our underlying hypothesis is that white coat effect is partially responsible for the reported low rates of control of hypertension by primary care practitioners. METHODS: The study population consists of 1142 patients who are being assessed for enrollment in two community-based randomized controlled trials. Patients must have essential hypertension, be on antihypertensive medication, and must not have met their blood pressure targets. We are reporting on the proportion of patients who have not achieved target, and the degree to which they have not achieved their target. We also report on the mean daytime blood pressures on 24 hour ABPM and compare these to mean blood pressures found on the patients' charts. RESULTS: We identified 3284 patient charts of patients with hypertension. Of these, 1142 were determined to be "out of control" (did not achieve target) and 436 agreed to undergo 24 hour ABPM for final determination of eligibility. Overwhelmingly (95.8% of the time) it was the systolic blood pressure that was not under control. However, most of the patients who had not achieved target according to our criteria were within 10 mmHg of the recommended targets. Isolated systolic blood pressure was the best predictor of elevated mean daytime blood pressure on 24 hour ABPM. CONCLUSIONS: At least 35% of patients had not achieved target blood pressure levels and this is primarily due to lack of control of systolic blood pressure. The best predictor of continuing hypertension on 24 hour ABPM was the mean systolic blood pressure on the patients chart. However, only 69% of patients who were uncontrolled according blood pressures recorded in the chart were uncontrolled according to 24 hour ABPM criteria. This suggests that the white coat effect makes blood pressure measurements in the doctor's offices, at least as currently done, not sufficiently accurate for determining treatment endpoint.

Adult↗
PubMed2006

Blood donors' motivation and attitude to non-remunerated blood donation in Lithuania.

BACKGROUND: In the Soviet period, the blood donation system operated in Lithuania exclusively on a remunerative basis. After joining the EU, Lithuania committed itself to meeting the EU requirements to provide all consumers within its boundaries with safe blood products made from voluntary unpaid blood donations. However, the introduction of a non-remunerated donation system may considerably affect donors' motivation and retention. Thus the aim of the current research was to determine blood donation motives among the present donors and investigate their attitude towards non-remunerated donation. METHODS: A questionnaire survey of 400 blood donors. Survey data processed using SPSS statistical analysis package. Statistical data reliability checked using Fisher's exact test (p < 0.05). RESULTS: Paid donors comprised 89.9%, while non-paid ones made 10.1% of the respondents. Research findings show that 93 per cent of the paid donors give blood on a regular basis; while among the non-remunerated donors the same figure amounted merely to 20.6 per cent. The idea of the remuneration necessity is supported by 78.3 per cent of the paid donors, while 64.7 per cent of the non-remunerated respondents believe that remuneration is not necessary. The absolute majority of the paid donors (92%) think they should be offered a monetary compensation for blood donation, while more than half of the non-remunerated donors (55.9) claim they would be content with a mere appreciation of the act. Provided no remuneration were offered, 28.44 per cent of the respondents would carry on doing it, 29.6 per cent would do it only in emergency, 29.6 per cent would donate blood merely for their family or friends, and 12.3 per cent would quit it completely. CONCLUSION: Most respondents admitted having donated blood for the following reasons: willingness to help the ill or monetary compensation. Majority would consent to free blood donation only in case of emergency or as a family replacement, which leads to a conclusion that provided monetary remuneration is completely terminated part of the currently active paid donors would withdraw from this activity, which might seriously affect the national supply of blood and its products.

Adult↗
PubMed2006

Economics of blood screening: in search of an optimal blood screening strategy.

The objectives of this retrospective study were to assess the economic impact that the practice of 'family replacement donor system' has on the operational costs of a rural blood bank and to rationalize efficient blood screening protocols with a view to minimizing blood screening costs without compromising blood safety. Prevalence of transfusion-transmissible infections such as HIV, hepatitis B and syphilis were ascertained from records of 870 potential donors screened over a period of 6 months. Costs of screening tests were approximated by summing up costs of materials used per test. Overhead and labour costs were not factored in. Average and marginal costs of a fully-screened blood unit were calculated using different blood screening protocols. The average and marginal costs of a fully-screened blood unit vary greatly depending on the order in which screening tests are conducted. Although the variation in average costs per blood unit among different protocols is narrow, US 29.44 dollars to US 33 dollars, the variation in marginal costs is significantly wider ranging from US 22.79 dollars to US 51.85 dollars. Overall, 78 (9%) of the potential donors had HIV infection while 25 (3.2%) had hepatitis B infections and nine (1.2%) donors had syphilis. Co-infection rate was very low at 1.4%. The study shows that it is possible to prioritize blood screening tests for the selection of safe blood donors simply and cost-effectively in a developing country hospital. In the face of rapid rises in health-care spending, it is very important that essential health services such as blood screening are safely delivered with as little expenditure of financial resources as possible. To make sound economic decisions, average cost is not what matters but marginal cost, the cost of one more test.

AIDS Serodiagnosis↗
PubMed2005

Evaluation of a point-of-care blood analyzer and determination of reference ranges for blood parameters in rockfish.

OBJECTIVE: To compare values of blood parameters in rockfish obtained by use of a point-of-care portable blood analyzer with values determined by a veterinary diagnostic laboratory, calculate reference ranges for various blood parameters in black rockfish, and compare values of blood parameters in clinically normal fish with those of fish with clinical abnormalities. DESIGN: Prospective study. ANIMALS: 41 captive adult black rockfish (Sebastes melanops) and 4 captive adult blue rockfish (Sebastes mystinus). PROCEDURE: Rockfish were anesthetized with tricaine methanesulfonate for collection of blood samples. Heparinized blood samples were immediately analyzed with a point-of-care analyzer. Blood sodium, potassium, chloride, urea nitrogen, and glucose concentrations; Hct; pH; partial pressure of carbon dioxide; total carbon dioxide concentration; bicarbonate concentration; base excess; and hemoglobin concentration were determined. A microhematocrit technique was used to determine PCV, and a refractometer was used to estimate total plasma protein concentration. Paired heparinized blood samples were transported to a veterinary diagnostic laboratory for analyses. RESULTS: Data obtained with the point-of-care analyzer were reproducible; however, values for most blood parameters were significantly different from those obtained by the veterinary diagnostic laboratory. Fish with poor body condition had several blood parameter values that were lower than corresponding values in clinically normal fish. CONCLUSIONS AND CLINICAL RELEVANCE: Point-of-care blood analyses may prove useful in rockfish. Point-of-care data for a large number of clinically normal fish must be obtained for reference ranges to be calculated, and further assessments of clinically abnormal fish are necessary to determine the relevance of the data.

Animals↗
PubMed1995

Insulin-mediated increase in calf blood flow is not related to blood pressure levels in patients with type 2 diabetes mellitus.

An association between insulin resistance and blood pressure levels has been found both in non-diabetic subjects and in type 2 diabetic patients. In non-diabetic subjects, infusion of insulin increases skeletal muscle blood flow, and it has been suggested that an attenuated flow-response to insulin may cause insulin resistance and may also serve as a mechanism relating insulin resistance to elevated blood pressure. We wanted to explore whether these findings could be extended to patients with type 2 diabetes. The effect of insulin infusion during a hyperinsulinaemic euglycaemic glucose clamp investigation on calf blood flow and its relationship to average diastolic blood pressure (DBPAVG), insulin sensitivity (GFRIlbm), body fat and total exercise capacity (TEC) was examined in 11 patients with type 2 diabetes. We found that insulin infusion increased median calf blood flow from 2.3 to 2.7 ml/min.100 g (p = 0.01). The change in blood flow (delta flow) did not correlate to the subjects' average blood pressure levels or their insulin sensitivity. Significant correlations between delta flow and leg fat %, fasting and clamp-insulin levels and total exercise capacity were observed. In conclusion, we found that insulin infusion increased calf blood flow significantly in patients with type 2 diabetes. However, our hypothesis that a negative correlation exists between blood pressure levels and insulin stimulated blood flow, was invalidated. Leg fat was identified as an important predictor of delta flow, GDRILBM and TEC in these patients.

Aged↗
PubMed1992

Blood pressure and intracranial pressure-volume dynamics in severe head injury: relationship with cerebral blood flow.

Increased brain tissue stiffness following severe traumatic brain injury is an important factor in the development of raised intracranial pressure (ICP). However, the mechanisms involved in brain tissue stiffness are not well understood, particularly the effect of changes in systemic blood pressure. Thus, controversy exists as to the optimum management of blood pressure in severe head injury, and diverging treatment strategies have been proposed. In the present study, the effect of induced alterations in blood pressure on ICP and brain stiffness as indicated by the pressure-volume index (PVI) was studied during 58 tests of autoregulation of cerebral blood flow in 47 comatose head-injured patients. In patients with intact autoregulation mechanisms, lowering the blood pressure caused a steep increase in ICP (from 20 +/- 3 to 30 +/- 2 mm Hg, mean +/- standard error of the mean), while raising blood pressure did not change the ICP. When autoregulation was defective, ICP varied directly with blood pressure. Accordingly, with intact autoregulation, a weak positive correlation between PVI and cerebral perfusion pressure was found; however, with defective autoregulation, the PVI was inversely related to cerebral perfusion pressure. The various blood pressure manipulations did not significantly alter the cerebral metabolic rate of oxygen, irrespective of the status of autoregulation. It is concluded that the changes in ICP can be explained by changes in cerebral blood volume due to cerebral vasoconstriction or dilatation, while the changes in PVI can be largely attributed to alterations in transmural pressure, which may or may not be attenuated by cerebral arteriolar vasoconstriction, depending on the autoregulatory status. The data indicate that a decline in blood pressure should be avoided in head-injured patients, even when baseline blood pressure is high. On the other hand, induced hypertension did not consistently reduce ICP in patients with intact autoregulation and should only be attempted after thorough assessment of the cerebrovascular status and under careful monitoring of its effects.

Blood Pressure↗
PubMed2004

[Effects of nitrendipine on circadian variation of blood pressure in inpatients with renal parenchymal hypertension: assessment by ambulatory blood pressure monitoring].

OBJECTIVE: To study the effect of once-daily administration of a nitrendipine tablet 10 mg on 24-hour ambulatory blood pressure in inpatients with renal parenchymal hypertension. METHODS: Sixteen patients participated in the present study, and one patient was withdrawn because the baseline office blood pressure was less than 140/90 mmHg. In the baseline period, ambulatory blood pressure was monitored every 30 minutes for 30 hours. After the baseline measurement, nitrendipine 10 mg was orally administered once daily every morning for 7 days. The 30-hour ambulatory blood pressure monitoring was repeated after Day 6. RESULTS: Fifteen patients (aged 64.9 +/- 15.0 years) completed the study protocol. Baseline office blood pressure was 157.9 +/- 17.5/84.7 +/- 12.5 mmHg (mean +/- SD). Nitrendipine 10 mg tablets significantly reduced both systolic blood pressure (SBP) and diastolic blood pressure (DBP) at least for 11 hours after administration compared with those at baseline. The rate of "Decrease" (reduction in blood pressure > or = 20/10 mmHg and/or achieved blood pressure < 140/90 mmHg at trough point) was 60.0% (9/15). Eleven patients were considered as effective cases at peak point (maximal reduction in blood pressure > or = 20/10 mmHg). The rate of "Decrease" in effective cases at peak point was 72.7% (8/11). CONCLUSION: These results suggest that a once-daily administration of nitrendipine 10 mg tablets is effective for the 24-hour control of blood pressure in patients with renal parenchymal hypertension.

Administration, Oral↗
PubMed2003

[The effect of reinfusion of mediastinal blood drained after coronary surgery on coagulation, fibrinolysis and volume of blood products transfused].

The aim of the study was to assess the effect of reinfusion of shed mediastinal blood on coagulation and volume of blood products transfused postoperatively. In the first retrospective part of the study, two groups of patients were compared with regard to postoperative blood loss and volume of blood products transfused postoperatively. The study group comprised 260 patients who received drained mediastinal blood. The control group comprised 277 patients who did not receive drained mediastinal blood postoperatively. Volumes of blood lost and transfused were similar in both groups (Tab. 2). The percentage of patients who avoided homologous transfusions was slightly lower in the study group, but the difference did not reach statistical significance (Fig. 1). Two subgroups with drainage higher than usual were compared and no significant differences were found (Tab. 3). In the second prospective part, the effect of postoperative autotransfusion on coagulation and fibrinolysis was studied. The study (autotransfusion) group consisted of 39 patients. The control group consisted of 28 patients. Coagulation tests done in both groups are listed in Tab. 1. Statistically significant differences were disclosed for prothrombin time preoperatively (p = 0.024), activated partial thromboplastin time preoperatively (p = 0.0029), and after 4 (p = 0.0046) and 8 hours (p = 0.0238) from surgery. The most notable differences were found for D-dimers. The level of D-dimers 4 hours after operation and reinfusion of mediastinal blood rose to an average of 22617 ng/mL, in comparison with 3419 ng/mL after 4 hours from surgery in the control group (statistically significant). However, after deduction of D-dimers transfused with mediastinal blood, the mean corrected concentration of D-dimers was 7000 ng/mL and was not significantly higher than in the control group (Tab. 4). The consecutive levels of D-dimers in the study group, though significantly higher than in the control group, tended to decrease, indicating that reinfusion did not contribute to activation of fibrynolysis (Fig. 2). It was therefore concluded that reinfusion of shed mediastinal blood allowed for a slight reduction in the volume of blood products transfused in the study group and did not affect coagulation.

Blood Coagulation Tests↗
PubMed1991

[Relation of mass screening blood pressure to usual 24-hour working day blood pressure variation and left ventricular hypertrophy].

Fifty-three regularly employed hypertensive men (HT group) aged 38 to 68 years, whose blood pressure measured at a health evaluation clinic was systolic blood pressure (SBP) greater than or equal to 160 mmHg and/or diastolic pressure (DBP) greater than or equal to 95, and 21 age-matched normal controls (NC group), whose SBP was less than 140 and DBP was less than 90 had their blood pressure monitored over 24 hours during a usual working day. Age and clinical pressure were 53.1 +/- 7.1 years (mean +/- SD) and 147 +/- 18/97 +/- 10 mmHg (SBP/DBP) in the HT group, and 52.7 +/- 8.9 and 117 +/- 8/78 +/- 7 in the NC group. In the HT group, blood pressure during work (146/96 mmHg) was similar to clinical blood pressure, while blood pressure at home (135/89 mmHg) was considerably lower than clinic measured values. In contrast, blood pressure variabilities in the NC group during non-sleep hours were less, and clinical measurement was lower than that at home (122/80 mmHg), and during work (126/82 mmHg). For those examined by echocardiogram (46 in HT and 21 in NC), end-diastolic left ventricular wall thickness (LVT), and left ventricular mass index (LVMI) correlated most strongly with pressure during work by partial correlation analysis with age as a covariant (LVT:: SBP: r = 0.47, DBP: r = 0.53 both p less than 0.001, and LVMI:: SBP: r = 0.29, DBP: r = 0.25 both p less than 0.25). Clinical blood pressure as well as blood pressure at home and during sleep correlated significantly with LVT. These findings suggest that the blood pressure measurements obtained at a mass screening clinic, although infrequent, have important implications in relation to cardiac organ damage and for providing an estimate of blood pressure during work for hypertensives.

Adult↗
PubMed1990

The use of autologous blood. The National Blood Resource Education Program Expert Panel.

The risk of transmitting disease through blood transfusions continues to fall as additional blood donor screening and testing measures are implemented. Nevertheless, when a blood transfusion is needed during the perioperative period, autologous blood is the safest option for eligible patients. Three methods for obtaining autologous blood to use during or after a planned surgical procedure are preoperative autologous blood donation, perioperative blood salvage, and acute normovolemic hemodilution. These techniques can be used alone or in combination to decrease or eliminate a patient's exposure to homologous blood. However, because all transfusions carry some health risk and blood administration costs, autologous blood should not be collected or reinfused indiscriminately. Autologous blood services should be used for eligible patients who are likely to require a transfusion but should not be employed for minor procedures in which transfusion is unlikely.

Blood Donors↗
PubMed1979

Human red blood cells with normal or improved oxygen transport function prepared and frozen in the primary polyvinyl chloride plastic blood collection container.

This is a report a a new system for freezing human red blood cells in the same polyvinyl chloride plastic container in which the blood is collected and separated into components. This polyvinyl chloride plastic collection bag with integrally attached transfer packs for blood collection, component separation, red blood cell biochemical modification, freezing, storage, and post-thaw dilution before washing, represents a major advancement in the freeze-preservation process. The label with the donor's blood type and identification number affixed to the bag at the time of collection remains in place throughout the freezing and thawing process. The transfused red blood cells are of superior quality, and the processing cost is less than with other methods of freeze-preservation. There is a lower risk of contamination with these red blood cells because manipulation of the product is kept at a minimum. "Rejuvenation", a bioengineering process by which outdated red blood cells can be salvaged, can be incorporated into the preservation process using one of the attached transfer packs of the primary collection bag. This process has been introduced as a possible means of alleviating the dramatic blood shortages which occur periodically. Red blood cells may also be "rejuvenated" after storage in the liquid state to increase their 2,3 DPG and ATP levels to 150 to 200% of normal, and these red blood cells with improved oxygen transport function have been administered to anemic patients with and without cardiopulmonary insufficiency, patients undergoing cardiopulmonary bypass and treatment with hypothermia during cardiac surgery, and in instances where nonhemolytic transfusion reactions might be expected.

Adenosine Triphosphate↗
PubMed1994

Increase in blood pressure reproducibility by repeated semi-automatic blood pressure measurements in the clinic environment.

OBJECTIVE: To evaluate whether increasing the number of blood pressure readings obtained in the clinic environment increases the blood pressure reproducibility. PATIENTS: Thirteen mild essential hypertensive patients studied in the outpatient clinics, following withdrawal of antihypertensive treatment for 4 weeks. METHODS: The systolic and diastolic blood pressures were measured three times, using a mercury sphygmomanometer, with the patient in the sitting position. Measurements were then performed with the patient in the lying position using an oscillometric device (SpaceLabs 90202 or 90207). The device was operated semi-automatically at 3-min intervals until 25 readings had been collected. The same procedure was repeated 4 weeks later. The systolic blood pressure, diastolic blood pressure and heart rate were averaged by considering a progressively greater number of readings, from 1 to 25. The reciprocal of the standard deviation (1/SD) of the mean difference after 4 weeks was taken as the measure of reproducibility. RESULTS: 1/SD increased progressively as the number of semi-automatic blood pressure readings from which the average was calculated increased. For a similar number of blood pressure readings the reproducibility was similar for semi-automatic readings to that for automatic readings obtained by 24-h ambulatory blood pressure monitoring. CONCLUSION: Multiple blood pressure readings obtained semi-automatically in the outpatient clinics increase blood pressure reproducibility and make the value similar to that obtained by ambulatory blood pressure monitoring. The advantage of an increase in reproducibility for studies on antihypertensive drugs thus depends on the number of readings, and can also be obtained by semi-automatic measurements in the clinic environment.

Adult↗
PubMed1996

[Reduction of homologous blood in elective cardiac surgery with miscellaneous autologous blood transfusion--especially with short-term predonation method].

The efficacy of homologous blood reduction in consecutive elective cardiac surgery by four different autologous transfusion methods was described. One hundred forty patients were divided into five different groups. No autologous blood transfusion in group A (22 cases), intraoperative autotransfusion with Cell Saver in group B (24 cases), additional intraoperative hemodilution method in group C (25 cases), additional preoperative predonation two weeks before operation in group D (15 cases), and predonation one week before operation with recombinant human erythropoietin administration in group E (55 cases) were performed. In group E, the criterion for patient selection of predonation was widely indicated (hemoglobin > 10 g/dl, body weight > 40 kg) and the period of the predonation technique was shorter compared with previous reports. The total homologous blood transfusion volume and the rate of the patients without homologous blood in each groups was 2216 +/- 1888 ml, 14.3% in group A, 2297 +/- 1789 ml, 4.2% in group B, 774 +/- 1043 ml, 36% in group C, 399 +/- 683 ml, 64.3% in group D, 135 +/- 276 ml, and 76.3% in group E, respectively. There were significant differences between group A, B or C and group D (p < 0.01), group A, B or C and group E (p < 0.001), and group D and group E (p < 0.05) with total homologous blood volume and between group A or B and group D (p < 0.01), group A or B and group E (p < 0.001), group B and group C (p < 0.05), and group C and group E (p < 0.01) with the rate of the patients without homologous blood. The reduction of homologous blood volume by patients was 1500 ml by the intraoperative hemodilution method, 370 ml by the preoperative prodonation technique, and 260 ml with predonation using erythropoietin. Ten of the thirteen patient (76.9%) who required homologous blood transfusion in group E had anemia (Hb < 12 g/dl) at preoperative blood pooling or postoperative massive bleeding (total mediastinal drainage > 1000 ml). Elongation of the predonation period before operation or postoperative autotransfusion of mediastinal shed blood and intraoperative aprotinin administration in such patients should be considered to reduce homologous blood transfusion.

Aged↗
PubMed1997

[Effect of processed blood volume, leukocyte count and concentration of CD34-positive cells in peripheral blood on efficiency of stem cell apheresis].

Despite many published studies no parameter could be identified yet to acceptably and individually predict collection results in stem cell apheresis. We analyzed leukocyte counts and processed blood volume, absolute and relative CD34+ cell counts, and overall collection efficiency in 120 patients with hematological and solid malignancies (354 leukaphereses using the Cobe Spectra cell separator, a median of 3 per patient, span 1-9). Stem cells were mobilized into peripheral blood by conventional chemotherapy followed by daily doses of G-CSF. CD34+ progenitor cell counts were monitored through multiparametric flow cytometry. Blood and collection flows varied in the range of 45-90 ml/min and 0.7-1.5 ml/min, respectively. CD34+ progenitor cells were enriched 38-fold in the apheresis product as compared to peripheral blood at a processed blood volume lower than one total blood volume. Efficiency continuously declined, on to a 25-fold concentration at a processed blood volume above the 3-fold total blood volume. Total collection efficiency, calculated from the absolute content of CD34+ progenitor cells in peripheral blood and apheresis concentrate (a parameter for progenitor cell mobilization during the apheresis), reached a plateau at a processed blood volume above the 3-fold total blood volume. However, variation among individual patients was high. The concentration rate of CD34+ cells at a leukocyte count below 5,000/microliter averaged 50 and declined continuously to 8 at leukocyte counts between 45,000 and 50,000/microliter. To summarize, in 70% of patients with leukocyte counts below 5,000/microliter and CD34+ progenitor cell counts above 10,000/ml, more than 1.5 x 10(6) progenitors per kg body weight could be collected in a single leukapheresis. According to the presented data, the variation in overall collection efficiency is mainly due to: 1) varying mobilization of progenitors during the apheresis procedures itself and 2) dependence on peripheral leukocyte counts.

Antigens, CD34↗