Manual Blood Research Articles

Automated blood pressure measurement in atrial fibrillation

The measurement of blood pressure in atrial fibrillation is considered as difficult and uncertain, and current guidelines recommend the use of the auscultatory method. The accuracy of automated blood pressure monitors in atrial fibrillation remains controversial. A systematic review and meta-analysis was performed of studies comparing automated (oscillometric or automated Korotkov) versus manual auscultatory blood pressure measurements (mercury or aneroid sphygmomanometer) in patients with sustained atrial fibrillation. Twelve validations were analyzed (566 patients; five home, three ambulatory and three office devices). Pooled correlation coefficients between automated and manual blood pressure measurements were stronger for SBP than DBP (r = 0.89 versus 0.76, P < 0.001). Automated measurements were higher than manual measurements [pooled average SBP difference 0.5 mmHg, 95% confidence interval (CI) -0.9, 1.9; DBP 2.5 mmHg, 95%CI -0.6, 5.7). The mean difference was within 5 mmHg in six and four (SBP and DBP, respectively) of six validations. The SD of mean difference was within 8 mmHg in two and three (SBP and DBP, respectively) of four validations. The proportion of absolute automated-manual differences within 5 mmHg was at least 65% in four and two (SBP and DBP, respectively) of eight validations. Three studies showed no impact of heart rate on the automated-manual blood pressure differences. There is limited evidence and significant heterogeneity in the studies that validated automated blood pressure monitors in atrial fibrillation. These monitors appear to be accurate in measuring SBP but not DBP. Given that atrial fibrillation is common in the elderly, in whom systolic hypertension is more common and important than diastolic hypertension, automated monitors appear to be appropriate for self-home but not for office measurement.

Comparison Study of the Rates of Manual Peripheral Blood Smear Review From 3 Automated Hematology Analyzers, Unicel DxH 800, ADVIA 2120i, and XE 2100, Using International Consensus Group Guidelines

In the clinical laboratory, it is important both to reduce the number of peripheral blood slide reviews to save time and money and to avoid reporting false results. To determine differences in the slide review rates of 3 widely used automated hematologic analyzers, the Unicel DxH 800 (Beckman Coulter Inc, Fullerton, California), ADVIA 2120i (Siemens Diagnostics, Tarrytown, New York), and XE 2100 (Sysmex, Kobe, Japan), using International Consensus Group for Hematology Review guidelines. A total of 1485 samples were tested, and 300 were manually reviewed. Slide review rates, sensitivity, specificity, and false-positive and false-negative rates were estimated using consensus group rules and compared using χ(2) tests, Fisher exact tests, or generalized estimating equations. Unicel DxH 800, ADVIA 2120i, and XE 2100 showed 22.8%, 20.2%, and 28.6% slide review rates; 14.3%, 14.3%, and 9.7% false-negative rates; and 13.7, 11.3%, and 17.3% false-positive rates, respectively. All analyzers showed significantly higher false-negative rates than that of the consensus group (2.9%). False-negative rates were higher than the recommended levels. Among 3 automated hematologic analyzers, XE 2100 showed the highest rate of slide review. Because the present study clearly shows that the slide review rates have distinct characteristics among the studied analyzers, each individual laboratory should consider selecting the most appropriate analyzer according to clinical characteristics. Analyzers with high sensitivity may be advantageous in outpatient settings for screening patients, whereas analyzers with high specificity may be beneficial in inpatient settings for efficient patient care.

The great myth of office blood pressure measurement

Clinical practice guidelines have traditionally recommended manual blood pressure (BP) measurement in the office setting as the standard method for diagnosing hypertension. In reality, manual BP in routine clinical practice is relatively inaccurate, over-diagnoses hypertension by provoking office-induced increases in BP and correlates poorly with both the awake ambulatory BP and target organ damage. The most recent guidelines recommend 24-h ambulatory BP and home BP for diagnosing hypertension. The advent of automated office BP (AOBP) represents a third alternative to conventional manual BP measurement, one that maintains the role of office BP readings in the diagnosis and management of hypertension. AOBP has three basic principles: multiple readings taken using a fully automated sphygmomanometer with the patient resting quietly alone. AOBP eliminates office-induced hypertension such that the cut-point for a normal AOBP is the same as for the awake ambulatory BP and home BP. As compared to routine manual office BP, AOBP provides more accurate BP readings, is more consistent during repeated office visits and in different settings and correlates better with both the awake ambulatory BP and target organ damage. The advantages of AOBP over manual BP measurement support its use in routine clinical practice.

Assessment of brain glucose metabolism with input function determined from brain PET images by means of Bayesian ICA and MCMC methods

Positron emission tomography (PET) imaging has the capability to produce regional or parametric images of physiological aspects in a tissue of interest. Apart from the acquired PET data, the concentration of the radiotracer supplied to the tissue through the vascularization has to be known as the input function (IF). IF can be obtained by manual or automatic blood sampling and cross calibrated with PET. These procedures are cumbersome, invasive and generate uncertainties. In the present work, we determine IF from internal artery in fluorodeoxyglucose (18F-FDG) brain images by means of Independent Component Analysis (ICA) based on Bayesian theory and Monte Carlo Markov Chain (MCMC) sampling method (BICA, Bayesian ICA). Dynamic brain images were decomposed with BICA into image sequences of blood and tissue components. A region of interest was drawn around the internal artery in the blood image to determine BICA-IF. BICA-IF was therefore corrected for spillover of radioactivity emission from tissue, then it was normalized with three plasma samples to correct for partial volume and blood to plasma radioactivity ratio. BICA-IF was found comparable to IF determined by blood sampling, and rCMRG values in several brain structures obtained with BICA-IF and sampled IF showed a bias of 6.4% which was attributed to the difference in the time sampling of 4s for sampled IF versus 15s for BICA-MC-IF at early times. In conclusion, BICA is a strong approach in image decomposition to extract blood curves in a noninvasive way.

Exponential error reduction in pretransfusion testing with automation

Protecting the safety of blood transfusion is the top priority of transfusion service laboratories. Pretransfusion testing is a critical element of the entire transfusion process to enhance vein-to-vein safety. Human error associated with manual pretransfusion testing is a cause of transfusion-related mortality and morbidity and most human errors can be eliminated by automated systems. However, the uptake of automation in transfusion services has been slow and many transfusion service laboratories around the world still use manual blood group and antibody screen (G&S) methods. The goal of this study was to compare error potentials of commonly used manual (e.g., tiles and tubes) versus automated (e.g., ID-GelStation and AutoVue Innova) G&S methods. Routine G&S processes in seven transfusion service laboratories (four with manual and three with automated G&S methods) were analyzed using failure modes and effects analysis to evaluate the corresponding error potentials of each method. Manual methods contained a higher number of process steps ranging from 22 to 39, while automated G&S methods only contained six to eight steps. Corresponding to the number of the process steps that required human interactions, the risk priority number (RPN) of the manual methods ranged from 5304 to 10,976. In contrast, the RPN of the automated methods was between 129 and 436 and also demonstrated a 90% to 98% reduction of the defect opportunities in routine G&S testing. This study provided quantitative evidence on how automation could transform pretransfusion testing processes by dramatically reducing error potentials and thus would improve the safety of blood transfusion.

Accuracy and precision of vessel area assessment: Manual versus automatic lumen delineation based on full‐width at half‐maximum

To evaluate the accuracy and precision of manual and automatic blood vessel diameter measurements, a quantitative comparison was conducted, using both phantom and clinical 3D magnetic resonance angiography (MRA) data. Since diameters are often manually measured, which likely is influenced by operator dependency, automatic lumen delineation, based on the full-width at half-maximum (FWHM), could improve these measurements. Manual and automatic diameter assessments were compared, using MRA data from a vascular phantom (geometry obtained with μCT) and clinical MRA data. The diameters were manually assessed by 15 MRA experts, using both caliper and contour tools. To translate the experimental results to clinical practice, the precision obtained using phantom data was compared to the precision obtained with clinical data. A diameter error <10% was obtained with resolutions above 2, 3, and 5 pixels/diameter for the automatic FWHM, contour, and caliper methods, respectively. Using phantom data, precision of the manual methods was low (error >20%), even at high resolutions, while precision for the automatic method was high (error <3%) when using more than 2 pixels/diameter. A similar trend was found with clinical data. The results obtained clearly demonstrate improvement in the accuracy and precision of vessel diameter measurements with use of the automatic FWHM-based method.

New approach to measurement of blood pressure in the office

Automated office blood pressure (AOBP) measurement has important advantages over conventional manual office blood pressure (MOBP) readings. AOBP requires the use of a fully automated sphygmomanometer which takes multiple readings with the patient resting alone. By following these three principles of AOBP, it is possible to obtain office readings which are similar to home BP and to the awake ambulatory BP recorded with 24-h BP monitoring. All three methods of automated BP measurement define hypertension as a BP≥135/85mmHg. The correlation between the awake ambulatory BP (a recognized gold standard for predicting future cardiac events in relation to BP status) and AOBP is significantly stronger than it is for routine MOBP. AOBP eliminates office-induced hypertension (white coat hypertension) and correlates with target organ damage significantly stronger than does routine MOBP. After 100 years of manual BP measurement with the mercury sphygmomanometer, it is now time to adopt AOBP for use in routine clinical practice in order to achieve a more accurate assessment of a patient's BP status and future cardiovascular risk.

Arm Complications After Manual Whole Blood Donation and Their Impact

Arm complications after whole blood donation occur in approximately 30% of donations. The 2 most common arm complications are contusion/hematoma (23%) and arm pain (10%). A variety of arm complications were evaluated from a national donor complication database, clinical studies, and review of the literature. The incidence of nerve injuries, arterial punctures, contusions/hematomas, and other complications were based on observations and reports at blood drives, interviews 3 weeks after donations, and donor reports of outside medical care. The clinical course of each complication is described.

Evaluation of an Automated Digital Imaging System, Nextslide Digital Review Network, for Examination of Peripheral Blood Smears

Several automated digital imaging systems have been introduced in recent years to improve turnaround time and proficiency in examining peripheral blood smears in hematology laboratories. To evaluate a new automated digital imaging system, Nextslide Digital Review Network (Nextslide), for examination of peripheral blood smears. We evaluated 479 peripheral blood smears, of which 247 (51.6%) were included for comparison of Nextslide and manual white blood cell differential counts and morphology evaluation, 204 (42.6%) were included for comparison of Nextslide and CellaVision (DM96) differential counts, and 28 (5.8%) were neonatal samples examined for enumeration of nucleated red blood cells. Results from both method comparisons showed excellent correlation for all major white blood cell classes with correlation coefficients ranging from 0.70 to 0.99. Evaluation of white blood cell, red blood cell, and platelet morphology also showed good correlation among methods. White blood cell preclassification capability in the system was evaluated for rate and accuracy. Leukopenic samples demonstrated markedly decreased review time with Nextslide. Enumeration of nucleated red blood cells showed good correlation among methods. Our evaluation of Nextslide shows excellent correlation when compared with conventional manual differentials and CellaVision (DM96) differentials for evaluation of peripheral blood smears.

Conversion of arterial input functions for dual pharmacokinetic modeling using Gd‐DTPA/MRI and 18F‐FDG/PET

Reaching the full potential of magnetic resonance imaging (MRI)-positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) in MRI, into a (18)F-fluorodeoxyglucose ((18)F-FDG) AIF in PET, and vice versa. The AIFs from both modalities were obtained from manual blood sampling in a F98-Fisher glioblastoma rat model. They were well fitted by a convolution of a rectangular function with a biexponential clearance function. The parameters of the biexponential AIF model were found statistically different between MRI and PET. Pharmacokinetic MRI parameters such as the volume transfer constant (K(trans)), the extravascular-extracellular volume fraction (ν(e)), and the blood volume fraction (ν(p)) calculated with the Gd-DTPA AIF and the Gd-DTPA AIF converted from (18)F-FDG AIF normalized with or without blood sample were not statistically different. Similarly, the tumor metabolic rates of glucose (TMRGlc) calculated with (18) F-FDG AIF and with (18) F-FDG AIF obtained from Gd-DTPA AIF were also found not statistically different. In conclusion, only one accurate AIF would be needed for dual MRI-PET pharmacokinetic modeling in small animal models.

Combining image-derived and venous input functions enables quantification of serotonin-1A receptors with [carbonyl-11C]WAY-100635 independent of arterial sampling

image- derived input functions (IDIFs) represent a promising technique for a simpler and less invasive quantification of PET studies as compared to arterial cannulation. However, a number of limitations complicate the routine use of IDIFs in clinical research protocols and the full substitution of manual arterial samples by venous ones has hardly been evaluated. This study aims for a direct validation of IDIFs and venous data for the quantification of serotonin-1A receptor binding (5-HT(1A)) with [carbonyl-(11)C]WAY-100635 before and after hormone treatment. Fifteen PET measurements with arterial and venous blood sampling were obtained from 10 healthy women, 8 scans before and 7 after eight weeks of hormone replacement therapy. Image-derived input functions were derived automatically from cerebral blood vessels, corrected for partial volume effects and combined with venous manual samples from 10 min onward (IDIF+VIF). Corrections for plasma/whole-blood ratio and metabolites were done separately with arterial and venous samples. 5-HT(1A) receptor quantification was achieved with arterial input functions (AIF) and IDIF+VIF using a two-tissue compartment model. Comparison between arterial and venous manual blood samples yielded excellent reproducibility. Variability (VAR) was less than 10% for whole-blood activity (p>0.4) and below 2% for plasma to whole-blood ratios (p>0.4). Variability was slightly higher for parent fractions (VARmax=24% at 5 min, p<0.05 and VAR<13% after 20 min, p>0.1) but still within previously reported values. IDIFs after partial volume correction had peak values comparable to AIFs (mean difference Δ=-7.6 ± 16.9 kBq/ml, p>0.1), whereas AIFs exhibited a delay (Δ=4 ± 6.4s, p<0.05) and higher peak width (Δ=15.9 ± 5.2s, p<0.001). Linear regression analysis showed strong agreement for 5-HT(1A) binding as obtained with AIF and IDIF+VIF at baseline (R(2)=0.95), after treatment (R(2)=0.93) and when pooling all scans (R(2)=0.93), with slopes and intercepts in the range of 0.97 to 1.07 and -0.05 to 0.16, respectively. In addition to the region of interest analysis, the approach yielded virtually identical results for voxel-wise quantification as compared to the AIF. Despite the fast metabolism of the radioligand, manual arterial blood samples can be substituted by venous ones for parent fractions and plasma to whole-blood ratios. Moreover, the combination of image-derived and venous input functions provides a reliable quantification of 5-HT(1A) receptors. This holds true for 5-HT(1A) binding estimates before and after treatment for both regions of interest-based and voxel-wise modeling. Taken together, the approach provides less invasive receptor quantification by full independence of arterial cannulation. This offers great potential for the routine use in clinical research protocols and encourages further investigation for other radioligands with different kinetic characteristics.

Plasma Cortisol and noradrenalin concentrations in pigs: automated sampling of freely moving pigs housed in the PigTurn®versus manually sampled and restrained pigs

AbstractMinimising the effects of restraint and human interaction on the endocrine physiology of animals is essential for collection of accurate physiological measurements. Our objective was to compare stress-induced cortisol (CORT) and noradrenalin (NorA) responses in automated vs manual blood sampling in pigs. A total of 16 pigs (30 kg) were assigned to either: (i) automated blood sampling via an indwelling catheter using a novel-penning system called PigTurn®which detects the pig's rotational movement and responds by counter-rotating, allowing free movement while preventing catheter twisting; (ii) automated sampling while exposed to visual and auditory responses of manually sampled pigs; or (iii) manual sampling by jugular venipuncture while pigs were restrained in dorsal recumbency. During sampling of (i), personnel were not permitted in the room; samplings of (ii) and (iii) were performed simultaneously in the same room. Blood samples were collected every 20 min for 120 min and measured for CORT (ng ml−1) using mass spectrometry and NorA (pg ml−1) using High Performance Liquid Chromatography (HPLC). Effects of treatment and time were computed with mixed models adjusted by Tukeypost hoc. CORT and NorA concentrations were lowest in group (i) followed by group (ii), which were not different. However, CORT and NorA levels in manually sampled animals (iii) were highest compared to automated methods (i) and (ii). Plasma concentrations across time were not different for CORT, but NorA concentration at time 0 min was higher than at 120 min. The presence of visual and auditory stimuli evoked by manual sampled animals did not affect non-handled pigs’ responses. Restraint and manual sampling of pigs can be extremely stressful while the automated blood sampling of freely moving pigs, housed in the PigTurn®was significantly less stressful for the animals.

Comparison of Two Methods for the Determination of the Effects of Ionizing Radiation on Blood Cell Counts in Mice

A reliable technique is needed to determine the effect of ionizing radiation on white blood cell (WBC) counts. Facilities that utilize automated methods can provide this service. However, utilizing external facilities can introduce additional variables, such as differences between time of sample collection and time of sample processing, which may affect the results. The purpose of the present study was to determine whether an automated method at an external facility can accurately determine radiation-induced changes in total WBC, lymphocyte and granulocyte counts when samples are analyzed at periods of time up to 24 hours after collection and stored either at room temperature or at 4oC. To accomplish this, we compared automated blood cell counts determined at an external facility with our manual blood cell counts processed immediately after sample collection or 24 h after sample collection and stored either at room temperature or 4°C from mice exposed to 2 Gy proton or 2 Gy gamma radiation. Our results show a close correlation and good agreement between the two methods, indicating that neither a delay of 24 hours in sample processing nor storage temperature affected white blood cell counts. Analysis of the effects of radiation on blood cell counts by either manual or automated cell counts revealed a statistically significant decrease in lymphocyte and granulocyte counts at different days post-irradiation, with no statistically significant difference between the methods employed; therefore both manual and automated blood cell counts are reliable methods to determine the effects of ionizing radiation in blood cells.

Masked hypertension and prehypertension: diagnostic overlap and interrelationships with left ventricular mass: the masked hypertension study

Masked hypertension (MHT) and prehypertension (PHT) are both associated with an increase in cardiovascular disease (CVD) risk, relative to sustained normotension. This study examined the diagnostic overlap between MHT and PHT, and their interrelationships with left ventricular (LV) mass index (LVMI), a marker of cardiovascular end-organ damage. A research nurse performed three manual clinic blood pressure (CBP) measurements on three occasions over a 3-week period (total of nine readings, which were averaged) in 813 participants without treated hypertension from the Masked Hypertension Study, an ongoing worksite-based, population study. Twenty-four-hour ambulatory blood pressure (ABP) was assessed by using a SpaceLabs 90207 monitor. LVMI was determined by echocardiography in 784 (96.4%) participants. Of the 813 participants, 769 (94.6%) had normal CBP levels (<140/90 mm Hg). One hundred and seventeen (15.2%) participants with normal CBP had MHT (normal CBP and mean awake ABP ≥135/85 mm Hg) and 287 (37.3%) had PHT (mean CBP 120-139/80-89 mm Hg). 83.8% of MHT participants had PHT and 34.1% of PHT participants had MHT. MHT was infrequent (3.9%) when CBP was optimal (<120/80 mm Hg). After adjusting for age, gender, body mass index (BMI), race/ethnicity, history of high cholesterol, history of diabetes, current smoking, family history of hypertension, and physical activity, compared with optimal CBP with MHT participants, LVMI was significantly greater in PHT without MHT participants and in PHT with MHT participants. In this community sample, there was substantial diagnostic overlap between MHT and PHT. The diagnosis of MHT using an ABP monitor may not be warranted for individuals with optimal CBP.

Intraclass correlation in practice: Assessment of reliability of manual blood pressure measurement among assessors in a clinical trial

Background : To ensure the reliability of manual blood pressure (BP) readings in a clinical trial, sources of error due to measurement must be reduced as much as possible. Apart from following standard procedure for BP measurement and ensuring good equipments, the measurement errors that come from the assessors themselves should be assessed. Objective : To demonstrate the use of two-way random effects, interactions absent, absolute agreement (Type A), single measures (Type 1) intraclass correlation coefficient (ICC) in the assessment of reliability of manual BP readings among assessors involved in a clinical trial using manual BP measurement, by using an interrater reliability study conducted by the authors as an example study. Methods : The steps involved in obtaining ICC in the study were discussed. Sample size given the number of assessors in the study was calculated. BP was measured using regularly maintained mercury sphygnomanometers, following recommendations by Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) for BP measurement in office setting. The outcomes were systolic and diastolic BP readings. A type of ICC, two-way random effects, interactions absent, absolute agreement (Type A), single measures (Type 1) ICC was chosen for the analysis and specifically discussed. Pre-requisite assumptions for ICC were meticulously checked and described. The interrater reliability for systolic and diastolic BP readings as expressed by ICC (single measure) were presented with confidence interval (CI). The ICCs obtained in the example study were discussed and concluded. The flaws of the study were also criticised. Results : The interrater reliability for systolic and diastolic BP measurements as expressed by ICC (single measure) were 0.87 (95% confidence interval [CI] 0.722, 0.956) and 0.77 (95% CI 0.560, 0.918) respectively. Conclusion : We demonstrated the steps required to obtain ICC. Since the use of manual BP measurement using mercury sphygmomanometer is still considered as gold standard of BP measurement, it is important that studies in which the BP outcome is measured using such method conduct interrater reliability studies properly.

Intraclass correlation in practice: Assessment of reliability of manual blood pressure measurement among assessors in a clinical trial

Intraclass correlation in practice: Assessment of reliability of manual blood pressure measurement among assessors in a clinical trial

Conventional versus automated measurement of blood pressure in the office (CAMBO) trial

Effective strategies to identify office-induced hypertension in routine clinical practice are required to improve diagnosis and management of hypertension. To compare the quality and accuracy of automated office blood pressure (AOBP) measurement using the BpTRU device with manual office blood pressure (MOBP) in routine clinical practice using awake ambulatory blood pressure (AABP) as the gold standard. Primary care practices in Eastern Canada were allocated by cluster randomization to use of AOBP (36 practices, 52 physicians) or to MOBP (31 practices, 36 physicians) in patients with systolic hypertension. The last routine MOBP reading pre-enrolment was compared to the blood pressure (BP) at the first visit after enrollment and after 2 years of follow-up. The primary outcome measure was the mean difference between the AABP and MOBP versus AOBP. The mean (95% confidence interval) decrease in systolic BP from pre- to post-enrollment was greater (P < 0.001) at the first visit in the 252 AOBP patients [-14.3 (-16.6, -12.0)] compared to the 209 MOBP patients [-8.0 (-2.2, -5.8)]. At Year 2, AOBP decreased by -16.3 (-18.6, -14.1) compared to a decrease in MOBP of -12.4 (-14.7, -10.1) (P = 0.02). The mean difference between systolic AABP and MOBP at the first post-enrollment office visit [-7.3 (-9.7, -4.9)] was greater (P < 0.001) than the difference for AOBP [-1.8 (-4.0, 0.4)]. At Year 2, these differences were -5.2 (-7.5, -3.0) for MOBP and -2.8 (-4.9, -0.7) for AOBP (P = 0.13). AOBP virtually eliminated office-induced hypertension. The decrease in MOBP was attributed to participation in a research study and not to any specific intervention.

Preparing students to competently measure blood pressure in the real-world environment: A comparison between New Zealand and the United Kingdom

This research sought to evaluate the contribution of simulation to the development of a fundamental nursing skill, blood pressure measurement. Year one nursing students at UCOL, New Zealand ( n = 75) and the University of Huddersfield, England ( n = 55) completed questionnaires about their confidence/competence levels in blood pressure measurement at the conclusion of the simulation sessions, and again after their first clinical placement. Registered nurses who worked with those students ( n = 22 UCOL, n = 21 University of Huddersfield) also completed assessments of the students’ competence with both electronic and manual blood pressure during their placement. On completion of the simulation sessions 60% of the UCOL students considered themselves competent or confident/competent in blood pressure measurement compared with just 16% of those at the University of Huddersfield. Reports of registered nurse supervision of students undertaking blood pressure measurement on clinical placement varied, but it was clear that students often undertook blood pressure measurement without a registered nurse in attendance to check technique, or the accuracy of their recording.

Feasibility and safety of multicomponent apheresis donation

Background and Objectives Modern apheresis devices offer the possibility to collect blood components that are well standardized, as compared with those available with manual whole blood donations. Recent technologic advances in multicomponent donation have made possible the development of systems that can collect different blood components from the same donor during one apheresis session. Red blood cells (RBCs) can be concurrently collected with plasma or platelets (PLTs).Materials and Methods A PLT yield of ≥2 × 1011 per unit according to European guidelines can be targeted by the algorithm of the blood cell separators after entering donor specific parameters such as body weight, height and blood counts. Furthermore, two units of RBCs can also be collected during one apheresis session provided that the donor fulfils the eligibility criteria for that procedure.Results The haemoglobin content of apheresed RBCs after addition of additive solution is higher than the minimal European requirement of whole blood derived RBCs of 40 g per unit due to standardization. Automated blood cell separators permit predictable collection of blood components with consistent yields and volumes. Repeat apheresis donors accept multicomponent donation and consent to concurrent component collection in &gt;90% of the procedures. The results of a national survey showed that approximately 75% were willing to give an additional RBC unit four times per year. This allows blood centres to increase the number of units colleted at low extra costs. Collecting an additional RBC unit in plateletpheresis causes extra costs of approximately 20€ for disposables and work load compensating the production costs with respect to the selling price. The incidence of acute adverse events in multicomponent apheresis was reported with less than 1%. Small, female donors with lower pre‐donation haematocrit were at higher risk for adverse events, especially when RBCs were collected. Double unit RBC collection showed to be safe if special eligibility criteria were respected.Conclusion Previous definitions of blood component yield and volume as well as the flexibility to collect those multicomponents allow the blood centre to collect those components that maximize donors’ contribution and to meet the demands of its area hospitals for blood components. Blood transfusion services are progressively increasing their reliance on apheresis technology to optimize the number of blood components collected per donor visit and to reduce the number of donors a patient is exposed to. The use of these systems has shown at the same time that multicomponent donations have been well tolerated by the donors and are cost‐effective.

Blood Pressure Monitoring in the Assessment of Old Patients with Acute Stroke

Most patients have elevated blood pressure in the early phase of acute stroke that it often returns to normal within approximately seven-days. Most available data on the pattern of blood pressure in acute stroke are based on manual blood pressure measurements. The aims of the present study were to assess with 24 h blood pressure monitoring the pattern of blood pressure in acute stroke, and the change in blood pressure during the first week of event in very old patients. We studied 99 patients with acute stroke (58 males), mean age 83 ± 6 years (range 70-97). Casual blood pressure and 24 h blood pressure monitoring were recorded within 24 h of admission, and then after six- to seven-days. Casual blood pressure before beginning the 24 h blood pressure monitoring was 154 ± 23/80 ± 15 mmHg and the average 24 h blood pressure was 147 ± 20/74 ± 11 mmHg. One-week after stroke, casual blood pressure decreased by 15/7 mmHg, whereas 24 h blood pressure decreased by only 7/2 mmHg (P<0·01). Blood pressure decreased remarkably only in those with admission elevated systolic blood pressure. The change in 24 h systolic blood pressure after one-week correlated to the 24 h admission systolic blood pressure (R=0·47; P<0·01). Casual blood pressure may overestimate blood pressure in stroke patients. Very old patients with stroke exhibit a mild increase in blood pressure during the acute phase, and blood pressure decreases spontaneously only in those with elevated blood pressure levels. Use of 24 h blood pressure monitoring may be helpful in elderly patients with acute stroke.