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At least 19 recordsLinked to original sources
PubMed1995

[New aspects in evaluating the hypertensive patient: measuring blood pressure in the physician's office--ambulatory blood pressure monitoring--blood pressure self-measurement].

The "average" blood pressure of hypertensives, which is held responsible for the adverse effects of hypertension is poorly reflected by causal readings (CR), which are taken as a surrogate. CR do not only differ from average blood pressures, but also fail to give information on blood pressure variability. According to white coat effect and blood pressure variability a satisfying classification of severity and consecutively of prognosis cannot be done in an individual. Furthermore CR fail to inform us sufficiently about therapeutic effects in single patients. To improve we have to change to blood pressure judgements which are based on many instead of occasional readings. Ambulatory blood pressure monitoring (ABM) is a possibility to overcome this weakness. Compared to casual readings the average of the ambulatory readings is higher reproducible and does not depend on placebo treatment. In spite of this advantage a general substitution of CR by ABM is impossible because the number of equipment available is too small, nobody wants to cover the costs, the procedure is inconvenient, and up till now we miss guidelines how to proceed in the daily routine. Blood pressure self-monitoring is an additional way to improve the weakness of CR. The amount of blood pressure readings needed for a satisfying judgement of blood pressure are taken and registered by the patients. The self recorded data can be used as a valuable data base to calculate average blood pressure and blood pressure variability and drug effects. Mean values of twice daily recordings of a month are highly reproducible and do highly correlate to average ABM recordings of the day.

Antihypertensive Agents↗
PubMed1991

Lactate analyzer with continuous blood sampling for monitoring blood lactate during physical exercise.

To monitor changes in the concentration of blood lactate during physical exercise, we used an automated lactate analyzer based on an electro-enzymatic method with continuous blood sampling through a catheter. The lactate concentration was measured every 2 min; between measurements, the instrument was calibrated with a lactate standard. Ascorbic acid, bilirubin, hemoglobin, creatinine, uric acid, and glucose did not interfere with the measurements. The lactate concentrations in blood samples from apparently healthy subjects before and after exercise correlated well (r = 0.993) with results by the conventional enzymatic method. We measured the blood lactate concentrations in nine apparently healthy volunteers during exercise on a treadmill with an increasing workload. The point at which lactate concentrations started to increase was detected easily. Thus, the lactate analyzer is suitable for monitoring changes in blood lactate concentrations during exercise.

Autoanalysis↗
PubMed1998

Use of a neonatal blood pressure cuff to monitor blood pressure in the adult finger--comparison with a standard adult arm cuff.

BACKGROUND: There are few suitable methods for monitoring blood pressure continuously (or intermittently) for research in adult stroke patients, who are ill but do not justify invasive intensive care monitoring. METHOD: We tested a neonatal arm blood pressure in adults by placing it on the forefinger ("finger cuff"). We compared the repeatability of the finger cuff with blood pressure measured by a standard adult arm cuff using the oscillometric technique in 168 ambulatory outpatients attending a cerebrovascular disease clinic. RESULTS: The mean difference between sequential mean blood pressure readings with the finger cuff was 0.55 mm Hg (95% confidence interval (CI) -14.36 to 15.47 mm Hg), and for the arm cuff was 3.31 mm Hg (95% CI -23.33 to 16.71 mm Hg). Measurements made with the arm cuff were shown to affect subsequent arm cuff readings made within a few minutes of the first. The mean difference between the finger cuff and arm cuff mean blood pressure readings was 0.03 mm Hg (95% CI -26.07 to 26.14 mm Hg) and agreement was better when the blood pressure was measured with the finger cuff first rather than the arm cuff. However, although there was no difference in the mean blood pressure recordings both systolic and diastolic blood pressure measurements differed systematically between arm and finger cuff. CONCLUSION: The reproducibility of sequential blood pressure measurements made with the finger cuff was better than with the arm cuff. The performance of the finger cuff compared with that of the arm cuff was sufficiently good to encourage use of the finger cuff in research involving automatic intermittent monitoring to observe sequential blood pressures over time in stroke patients. However, measurements of systolic and diastolic pressure were not the same with the two cuffs and further work on calibration of the finger cuff would be useful.

Adolescent↗
PubMed2000

[Use of platelet function analyzer PFA-100 and whole blood aggregometry to monitor blood platelet sensitivity to acetylsalicylic acid (aspirin). Is it possible to reliably monitor antiplatelet treatment using routine laboratory diagnostic methods?].

Introduction of the antiplatelet agents of new generations and the occurrence of the phenomenon of "aspirin-resistance" triggered the search for better, simpler and more reliable routine diagnostic methods to monitor platelet reactivity. Our objective was to evaluate the usefulness and reliability of two simple methods: platelet function analyzer (PFA-100) and whole blood platelet aggregometry for monitoring of platelet function in 18 healthy blood donors and 35 patients with ischaemic heart disease (IHD) subjected to small doses/75 mg and 150 mg a day) of acetylsalicylic acid (aspirin). In 50% of healthy blood donors the intake of 75 mg ASA a day resulted in the prolongation of PFA-100 collagen/epinephrine closure time (CEPI = (relevant to reduced platelet reactivity) of over 150 s, whereas 75% donors responded to 150 mg ASA-. Otherwise, the daily dose of 150 mg ASA resulted in a prolonged CEPI merely in 23% of in IHD patients. At both doses ASA completely inhibited the arachidonic acid-induced whole blood platelet aggregation in all healthy donors and in all but 3 IHD patients. Collagen-induced platelet aggregation was only negligibly affected by either dose of ASA. Our results point that the simultaneous monitoring of the PFA-100 collagen/epinephrine closure time and whole blood platelet aggregometry (Chrono-Log) enables to reliably evaluate the inhibition of platelet function by ASA and discriminate the partial or complete platelet insensitivity to aspirin. The phenomenon of more frequent platelet aspirin-resistance in IHD patients requires to be verified in randomised clinical prospective studies.

Adult↗
PubMed2001

Characteristics of a new fully programmable blood sampling device for monitoring blood radioactivity during PET.

The first performance tests of a new fully programmable blood sampling device for monitoring blood radioactivity during positron emission tomography (PET) are described. Blood is withdrawn through 1-mm internal diameter tubing using an infusion pump which can be operated at rates varying from 0 to 600 ml/h. Activity in blood is measured by a 6-cm-thick bismuth germanate crystal connected to a photomultiplier tube and multichannel analyser (MCA) which are positioned within 6 cm lead shielding. Positioning of the tubing is an exact and simple procedure. The minimal readout time of the MCA is 1 s. Two independent energy windows can be set. Operation of the pump and MCA is fully controlled by a PC, i.e. sampling time, interval time and pump rate can be varied at any time during the PET scan by user-defined scripts. A number of characteristics of the new system were studied, such as sensitivity, dead time, linearity, effect of background radiation and pump rate as a function of input pressure. In addition, dispersion was measured as a function of pump rate. Finally, first clinical results were compared with manual samples. The sensitivity equalled 0.7 and 0.2 cps/Bq for 511- and 1022-keV 30% energy windows, respectively, and the system dead time was 500 ns. The system remained linear within 2% with activity concentrations up to 2.5 MBq/cc. Short-term reproducibility was better than 3% for a 1-h period. Long-term reproducibility was about 5% (ISD), which was mainly caused by variation in the diameter of the tubing. If the device was positioned in such a way that maximum shielding was directed towards the patient, the effects of background radiation from the patient on the measured activity concentration for clinically relevant conditions was minimal (<3%). Pump rate varied with input pressure, but remained constant for a given pressure. Dispersion constants smaller than 0.14 s(-1) were observed for pump rates higher than 300 ml/h, indicating that the system dispersion is small. Clinical data showed an excellent agreement to within 3% (ISD) between the results obtained with the new system and manual samples. With the continuous blood sampler radioactivity in blood can be measured accurately during the entire course of the PET scan. Furthermore, the system is fully programmable allowing adjustment of all parameters during a single PET scan.

Algorithms↗
PubMed1992

[Development of automated lactate analyzer with continuous blood sampling for monitoring blood lactate and its application for the testing of physical exercise].

The anaerobic threshold is useful for estimating the intensity of physical exercise. It is shown as either an increase in blood concentrations of lactate or a disproportionate increase in ventilation. We developed a lactate analyzer based on an electroenzymatic method with a continuous blood sampling system through a double-lumen catheter. Ascorbic acid, bilirubin, hemoglobin, creatinine, uric acid, and glucose did not interfere the results. The lactate concentrations in blood samples from healthy subjects during physical exercise correlated well (r = 0.993) with results measured by the conventional enzymatic method. We measured the concentrations of blood lactate with a use of this lactate analyzer to see the anaerobic threshold in nine healthy volunteers during exercise on a treadmill with an increasing workload. The point at which lactate concentrations started to increase was detected easily. The anaerobic threshold identified as a disproportionate increase in ventilation was seen at almost the same time. We conclude that the lactate analyzer, with a continuous blood sampling system, can measure precisely concentrations of lactate in blood and can detect the anaerobic threshold during physical exercise.

Adult↗
PubMed2002

Ambulatory versus conventional methods for monitoring blood pressure during pregnancy.

BACKGROUND: Hypertensive disorders are among the most common medical complications of pregnancy and a leading cause of maternal and perinatal morbidity and mortality world-wide. Blood pressure measurement plays a central role in the screening and management of hypertension during pregnancy. In recent years the validity of conventional (clinic) blood pressure measurement has been questioned and efforts have been made to improve the technique with ambulatory automated devices that provide a large number of measurements over a period of time, usually a 24-hour period. OBJECTIVES: To assess whether the use of ambulatory blood pressure monitoring during pregnancy improves subsequent maternal and feto-neonatal outcomes, women-newborn quality of life or use of health service resources, compared with conventional (clinic) blood pressure measurements. These effects will be assessed for the following subgroups: (1) Women at low or average risk of hypertensive disorders of pregnancy (unselected). (2) Women defined as high risk of hypertensive disorders of pregnancy. (3) Women with hypertension without other signs of pre-eclampsia. (4) Women with established pre-eclampsia. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register, MEDLINE, LILACS and EMBASE were searched. Date of last search: July 2001. SELECTION CRITERIA: All randomised trials comparing ambulatory blood pressure monitoring versus conventional (clinic) blood pressure monitoring in pregnancy. Quasi-random designs will be excluded. DATA COLLECTION AND ANALYSIS: Two reviewers evaluated all potentially relevant articles, examined each study for possible inclusion and assessed the methodological quality using the Cochrane guidelines. MAIN RESULTS: No trials included. REVIEWER'S CONCLUSIONS: There is no randomised controlled trial evidence to support the use of ambulatory blood pressure monitoring during pregnancy. Randomized trials with adequate design and sample sizes are needed to evaluate the possible advantages and risks of ambulatory blood pressure monitoring during pregnancy, in particular in hypertensive pregnant women. These trials should evaluate not only clinical outcomes, but also use of health care resources and women's views.

Blood Pressure Monitoring, Ambulatory↗
PubMed2004

Undetected, uncontrolled blood pressure in type 2 diabetes: self-monitored blood pressure profiles.

OBJECTIVES: To construct a novel and clinically relevant means of representing self-monitored blood pressure (SMBP). METHODS: Patients treated to an office blood pressure (BP) < 130/80 mmHg measured their BP at home for 14 days using an Omron IC semi-automatic portable monitor with memory. SMBP data were transferred from the monitor to a computer to produce graphic profiles (SMBPp) that depict the hourly variation in BP throughout a "typical" or modal day. RESULTS: Office BP and SMBP data from 66 subjects with type 2 diabetes and hypertension (HTN), who completed a previous study of intensified management, were analyzed based on European Society of Hypertension-European Society of Cardiology (ESH-ESC) classifications. Patients were classified as Optimal (6), Normal (12), High Normal (15), Isolated systolic HTN (29) and Grades 1, 2 or 3 HTN (4). SMBP disagreed in 32 cases, placing 29 patients in higher risk categories. Analysis by SMBPp of the 33 patients originally classified as Optimal, Normal or High Normal showed that on average 50 +/- 31% of their systolic SMBP values exceeded ESH-ESC thresholds for HTN (135 mmHg). It also revealed that 74 +/- 21% of their SMBP values exceeded the treatment goal (< 25 mmHg) for high-risk patients with type 2 diabetes. CONCLUSIONS: SMBPp allowed for a definitive measurement of the dynamic daily BP changes. It produced compelling evidence of persistent patterns of BP fluctuations among patients with normal office BP whose uncontrolled HTN would have remained undetected.

Adult↗
PubMedDate not supplied

Computation of time-specified tolerance intervals for ambulatorily monitored blood pressure.

Hypertension is an important risk factor for strokes, heart attacks, and other vascular diseases. Pharmacologic treatment of high blood pressure reduces the incidence of these complications and prolongs life, so there is a strong incentive to identify and treat individuals with high blood pressure. The development of automatic instrumentation for noninvasive and ambulatory blood pressure monitoring makes it possible to follow the time course of blood pressure variations continuously in healthy peer groups to be used as a reference standard as well as in potentially hypertensive subjects. For clinical applications, tolerance intervals should be substituted, whenever possible for prediction limits. When only hybrid data (time series of data collected from a group of subjects) are available, such a tolerance interval can be difficult to determine following a parametric approach similar to the procedure used for the computation of prediction intervals when consideration of both within-subject and among-subjects variances is wanted. The authors have developed a nonparametric method for the computation of such tolerance intervals. Because the method is based on bootstrap techniques, it does not require the assumption of normality or symmetry in the data and is thus more appropriate when dealing with small samples. The method was used to establish time-qualified reference limits for series of blood pressure and heart rate values monitored automatically in healthy individuals of both genders. The use of these tolerance intervals may eliminate many false-positive and false-negative diagnoses that might be obtained when relying on time-unspecified single samples. These limits can serve as a reference for comparisons of a given subject's blood pressure series over time, yielding nonparametric measures of extent and timing of any blood pressure excess or deficit. Such indices can then be used for an objective and positive definition of health, for the screening and diagnosis of disease, and for gauging responses to treatment.

Adult↗
PubMed2001

Influence of parity and age on ambulatory monitored blood pressure during pregnancy.

Studies based on casual blood pressure measurements concluded that both age and parity have significant effects on blood pressure during pregnancy. We have tested these results on clinically healthy normotensive women who were systematically studied by ambulatory blood pressure monitoring during their pregnancies. We analyzed 1254 blood pressure series sampled for 48 consecutive hours every 4 weeks from the first obstetric visit (usually within the first trimester of pregnancy) until delivery in 205 normotensive pregnant women. Data were divided for comparative analysis by parity (nulliparous versus multiparous), age (</=25, 26 to 30, 31 to 35, and >/=36 years), and trimester of gestation. Circadian parameters established by population multiple-component analysis were compared between groups with a nonparametric test. Effects of age and parity on blood pressure were also tested by ANOVA. A highly statistically significant circadian pattern described by a model that includes components with periods of 24 and 12 hours is demonstrated for systolic and diastolic blood pressure for all groups of pregnant women in all trimesters (always P<0.001). There was no significant difference in 24-hour mean among groups divided by parity at any age or stage of pregnancy (always P>0.160). A trend of increasing blood pressure with age was found for diastolic but not systolic blood pressure. Although statistically significant, differences in the 24-hour mean of diastolic blood pressure among groups divided by age were always <1.5 mm Hg. Data obtained from systematic ambulatory monitoring in normotensive pregnant women indicate the lack of differences in blood pressure according to parity. The small, although significant, increase in diastolic blood pressure with age may have little influence in the proper identification of women with gestational hypertension. Reference thresholds for blood pressure to be used in the early identification of hypertensive complications in pregnancy could thus be developed as a function of rest-activity cycle and gestational age, independent of parity or maternal age.

Adult↗
PubMedDate not supplied

A diary model for monitoring blood pressure in the elderly.

Activity can significantly change blood pressure. Twenty four hour ambulatory blood pressure monitoring (Holter method) was introduced to optimize diagnosis and the changes in blood pressure. It was flanked by the purpose to use diaries to correlate symptoms and pressure changes, pressure changes and psychophysical activity, life style and drugs. The diary model adopted by us for 380 elderly subjects between 65 and 85 years old is divided into four main sections: 1. general activities (8 items); 2. situational variations (7 items); 3. correlation between symptoms and pressure changes; 4. drug treatment and pressure changes. The aim of our study was to assess the compliance of the elderly to keeping a diary. Our results showed that compliance was satisfactory in 352/380 subjects (93%).

Adult↗
PubMed2002

Modeling the circadian variability of ambulatorily monitored blood pressure by multiple-component analysis.

The use of a set of new end points derived from ambulatory blood pressure monitoring (ABPM), in addition to the blood pressure (BP) values themselves, has been advocated to improve the sensitivity and specificity in diagnosing hypertension and to evaluate a person's response to treatment. An adequate estimation of rhythmic parameters depends, however, on the ability to describe properly the circadian pattern of BP variability. The purpose of this study was to identify a simple model that could characterize sufficiently well the circadian pattern of BP in normotensive healthy volunteers sampled by ambulatory monitoring. We studied 278 clinically healthy Spanish adults (184 men), 22.7 +/- 3.3 yr of age, without medical history of hypertension and mean BP from ambulatory profiles always below 135/85 mmHg for systolic/diastolic BP, who underwent sequential ABPM providing a total of 1115 series of BPs and heart rates (HRs), sampled on each occasion at 0.5h intervals for 48 h. Subjects were assessed while adhering to their usual diurnal activity and nocturnal sleep routine, without restrictions but avoiding the use of medication. The circadian rhythm in BP and HR for each subject was established by multiple-component analysis. A statistically significant 24h component is documented for 97% of the BP profiles, with a significant second (12h) harmonic documented in 65% of the profiles. Other ultradian harmonic components were significant in less than 20% of the profiles. A statistically significant increase in the coefficient of determination (percent of overall variability explained by the function fitted to the data) was only obtained after including the periods of 24 and 12 h for BP, and periods of 24, 12, and 6 h for HR in the model components. Although other ultradian components can be demonstrated as statistically significant in a small percent of subjects, a rather simple model including only the two first harmonics of the 24h period describes sufficiently well, at the specified sampling rate, the circadian pattern of BP in normotensive subjects. Departure from this model could characterize overt pathology, as recently demonstrated in the diagnosis of preeclampsia.

Adult↗
PubMed2002

The validity of the Medisafe self-monitoring blood glucose system.

Self-monitoring blood glucose (SMBG) meters are widely used in the management of diabetes. The new SMBG meter Medisafe, which is based on the optoelectric colorimetry method, has been introduced. The objective of this study was to validate the Medisafe SMBG meters in comparison with the reference autoanalyzer (Hitachi 717) and to assess the repeatability of the instrument as well as variations of tip replacement. Samples of capillary and venous blood from 299 patients were tested. The correlation coefficients between the Medisafe-measured capillary and venous blood glucose levels and the reference autoanalyzer venous plasma glucose levels were 0.976 and 0.975, respectively. The range of differences from the reference value was examined; only 4% was in excess of +/- 20% of the reference laboratory value, and more than 40% of the values were within 5% of the reference laboratory value. Moreover, repeatability of the Medisafe capillary blood samples measured in three patients with three different blood glucose levels was determined. The coefficients of variation of blood glucose values are within 5%. In addition, the results of mean and SEM from each replication in three patients and glucose measurement from different lots of tips showed no significant difference (p > 0.05). It is concluded that the Medisafe SMBG meter has shown good results in terms of validity and repeatability. Furthermore, it provides safety from blood contamination, which is recommended in countries with a high prevalence of human immunodeficiency virus.

Adolescent↗
PubMed2002

Portable blood glucose meters as a means of monitoring blood glucose concentrations in dogs and cats with diabetes mellitus.

The use of portable blood glucose meters (PBGM) has become common in veterinary medicine as a rapid means of monitoring animals' blood glucose in a variety of medical conditions. These hand-held monitors allow for diagnostic and therapeutic decisions to be made quickly and relatively inexpensively using only a small amount of blood. Both in conditions resulting in hyperglycemia, such as diabetes mellitus, and in those resulting in hypoglycemia, such as sepsis or the presence of an insulinoma, veterinarians have come to rely on PBGM to provide critical information on the status of their animal patients. In particular, PBGM are frequently used to measure individual blood glucose values in an animal over a period to create a blood glucose curve when evaluating the effectiveness of insulin therapy in diabetic dogs and cats.

Animals↗
PubMed1998

Monitoring blood levels of selected drugs. Remember to factor in the many confounding variables.

Appropriate use of various pharmacologic agents involves not only awareness of therapeutic indications and side effects but also familiarity with clinical use and timing of blood level monitoring. The effective as well as the toxic level of antiepileptic drugs varies widely among patients, so the patient's response is more important than the serum drug level. These agents may interact with other disease states, other drugs, and even other antiepileptic agents. Because of digoxin's long half-life and the effect of physical exercise on serum concentration, the timing of serum collection is important. The usefulness of measuring amiodarone serum concentrations is controversial, but findings may help identify patients at risk for side effects related to the drug. Procainamide has a very short half-life and concentrations change over a short period, so blood levels of this agent should be measured before administration of a dose. The dose of levothyroxine required to restore a normal thyroid hormone level varies with age, coexistent conditions, and use of other medications. After the appropriate dose is determined, follow-up monitoring yearly is necessary (more often in the elderly). Efficacy and toxicity of theophylline are directly related to serum concentrations, and a reduced target level of 5 to 15 micrograms/mL has recently been suggested. Proper monitoring is important, because metabolic changes and drug interactions can cause either subtherapeutic or toxic levels.

Anti-Arrhythmia Agents↗
PubMed2000

Infrastructure for monitoring blood transfusion practice in New South Wales hospitals.

OBJECTIVES: To determine the existing infrastructure for monitoring blood transfusion practices in New South Wales hospitals. DESIGN: A questionnaire survey conducted in August 1998. PARTICIPANTS: All healthcare facilities known to have used blood products from the Australian Red Cross Blood Service--New South Wales in the 12 months before the survey. MAIN OUTCOME MEASURES: Existence of a transfusion committee and policies and procedures to ensure appropriate use and issue of blood products; monitoring expiry rates of red blood cells, platelets and fresh frozen plasma; using a maximum blood ordering schedule (MBOS); and measuring the crossmatch to transfusion ratio (CT ratio). RESULTS: 224 hospitals were surveyed and 144 responses were received (64%). Twenty-five hospitals (17%) had a transfusion committee; 60 (42%) monitored expiry rates of red cells, and 39 (27%) and 42 (29%), respectively, monitored these rates for platelets and fresh frozen plasma. Thirty-three hospitals (23%) used an MBOS and 43 (30%) measured the CT ratio. However, over 70% of the larger hospitals (> 200 beds) had all these aspects of transfusion infrastructure in place, and 35% had transfusion committees. CONCLUSIONS: Our survey showed that, overall, there was a lack of transfusion infrastructure in NSW hospitals. However, most of the hospitals with more than 200 beds had infrastructure in place to monitor transfusion practices, but only a minority had established transfusion committees.

Blood Specimen Collection↗