The Norwegian office-, home-, and ambulatory blood pressure study (NOHA)

OBJECTIVES

To evaluate the use of ambulatory blood pressure monitoring in comparison with home and office blood pressure in every-day general practice.

METHODS

In a multicenter survey sixty-two practitioners previously unfamiliar with ambulatory blood pressure monitoring performed a total of 1162 (mean 18 +/- 16; range 3-94) 24-h ambulatory- and home blood pressure measurements in normotensive subjects or patients with untreated or treated hypertension.

RESULTS

In subjects with office blood pressure <140/90 mmHg average 24-h ambulatory blood pressure (Tenso 24 monitors) was 126/79 mmHg, home blood pressure (Tenso Plus semiautomatic sphygmomanometers) was 128/ 84 mmHg, and office blood pressure (standard sphygmomanometer) was 130/82 mmHg. Patients with office blood pressure > or = 140/90 mmHg had 24-h ambulatory blood pressure averaging 141/88 mmHg, home blood pressure 149/93 mmHg, and office blood pressure 157/95 mmHg. The difference between office-, home-, and ambulatory blood pressure increased with age. Expected differences were found between the three blood pressure modalities according to indication of examination (borderline -, "white-coat" -, and therapy refractory hypertension). Indices of hypertension related end-organ damage were positively correlated with home and ambulatory blood pressure but not with office blood pressure. Overall the performance of home- and ambulatory blood pressure in this general practice setting was similar to that seen by specialized blood pressure units.

CONCLUSION

This study demonstrates the practical utility of home- and ambulatory blood pressure measurement in every-day general practice. Both methods are easy to introduce and the quality of blood pressure data obtained in every-day general practice are comparable to those obtained in hypertension clinics and trial centers.

Interest of home blood pressure measurements (HBPM) to establish degree of hypertensive control

AIMS

To establish the validity and clinical value of home blood pressure measurements (HBPM) in the treatment follow-up of patients with essential hypertension to rule out or to confirm poor control of blood pressure obtained in the doctor's office with a mercury sphygmomanometer.

MATERIAL AND METHODS

Observational, cross-sectional study was carried out to validate HBPM in treated hypertensive patients poorly controlled by office-based casual blood pressure measurements. Measurements were made on 2 consecutive days with six readings taken per day. To do this, 2 x 2 tables were drawn up to validate the HBPM using ABPM as the reference method. Sensitivity (S), specificity (Sp), positive probability quotient (+PQ) and negative probability quotient (-PQ) were calculated. The study population (n = 149) was selected by consecutive sampling of the hypertensive patients seen in the Vallada Health Centre. Only 124 patients could be evaluated.

RESULTS

Values obtained with HBPM were: S 97.3% (95% CI 90.4-99.7%), Sp 62.7% (48.1-75.9%), +PQ 2.61 (1.82-3.73) and -PQ 0.04 (0.01-0.71).

CONCLUSIONS

Home monitoring of blood pressure is a useful alternative to ABPM to rule out office-based poor control of hypertensive patients, but not to confirm it.

Pulse‐wave morphology and pulse‐wave velocity in healthy human volunteers: Examination conditions

OBJECTIVE

Applanation tonometry for pulse-wave analysis (PWA) and determination of pulse-wave velocity (PWV) is a non-invasive method for assessment of the central aortic pressure waveform and indices of arterial stiffness. The objective of this study was to examine the influence of eating and smoking on PWA and PWV measurements in order to establish standard examination conditions. Furthermore, intra- and interobserver reproducibility and the effects of varying the site of measurements were observed.

MATERIAL AND METHODS

Duplicate measurements of the radial pressure waveform and of the brachial and aortic PWV on the right and left side of the body were recorded in 23 healthy subjects by two trained observers. Measurements were performed in the fasting state and 3 h after a high-calorie meal, and before and 1 h after smoking a cigarette.

RESULTS

Intake of a high-calorie meal as well as smoking caused significant changes in both PWA and PWV parameters and an inter-arm difference was observed. Intra- and interobserver reproducibility was good.

CONCLUSIONS

Pulse-wave measurements by applanation tonometry should be undertaken in the same arm during fasting and smoking abstinence.

DYNAMIC LATERALIZATION: HOSTILITY, CARDIOVASCULAR REGULATION, AND TACHISTOSCOPIC RECOGNITION

This experiment tested a hypothesis linking the right cerebral regulation of hostility and cardiovascular arousal. It also replicates related research regarding hostility, cardiovascular regulation, and auditory recognition (Shenal Harrison, 2003) through the visual modality. Thirty low- and high-hostile participants (n = 30) were identified using the Cook Medley Hostility Scale (CMHS). Only right-handed male participants with no significant medical or psychological history completed the experiment. All participants completed the cold pressor paradigm. Cardiovascular measures (systolic blood pressure [SBP] and diastolic blood pressure [DBP]) were recorded and tachistoscopic lexical recognition procedures were administered before and after the physical stressor. The primary finding of this research was greater left cerebral activation (decreased cardiovascular reactivity) following the tachistoscopic lexical recognition tasks and greater right cerebral activation following the painful (cold pressor) stressor.

NEAR-CONTINUOUS, NONINVASIVE BLOOD PRESSURE MONITORING IN THE OUT-OF-HOSPITAL SETTING

OBJECTIVES

This study was conducted to test out-of-hospital performance of a noninvasive radial artery tonometry device to assess blood pressure (BP), providing readings every 10-12 seconds. The primary objective was to determine the correlation between noninvasive BPs calculated with radial artery tonometry and standard oscillometric cuff methods. The secondary objective was to determine whether the difference observed between the two techniques was consistent over the range of BPs measured.

METHODS

This prospective trial enrolled adults transported by helicopter (n = 9 patients), fixed-wing airplane (n = 1), or ground vehicle (n = 10) of a single transport service. Patients had BP assessed simultaneously, by both standard automatic cuff and radial artery tonometry device, every 5 minutes. Data were assessed with correlation coefficients, and Bland-Altman techniques were utilized to assess for bias over the range of mean arterial pressures (MAPs) encountered. For all tests, p was set at 0.05.

RESULTS

No major problem with radial artery tonometry device field performance was noted. There were 139 pairs of MAP assessments in 20 patients. The correlation coefficient for the two assessment modalities was 0.96. Bland-Altman bias plot and Pitman's test (p = 0.11) revealed good correlation between the two assessment mechanisms over the entire range of MAPs (42 to 163 mm Hg) encountered in the study.

CONCLUSION

The radial artery tonometry device provided MAP assessments that were highly correlated with readings from a standard oscillometric device. The radial artery tonometry device performed well in a variety of patient types and in multiple transport vehicles, and there was no sign that its performance was adversely affected by the out-of-hospital setting.

Factors affecting the accuracy of volume-oscillometric blood pressure measurement during partial pressurization of the wrist

We compared the volume-oscillometric responses of the airbag pressure sensor and the contact force sensor across and along the radial artery on the wrist during partial pressurization by an airbag. Because of the anatomic structure and non-uniform pressurization pressure distribution, elongated and shifted oscillometric pressure waveform envelope variations are observed. For the contact force sensors directly above the radial artery, S-shaped pressurization curves can be seen possibly due to temporal softening of the radial artery stiffness at near zero transmural pressure. These differences in the shape of oscillometric envelope as well as pressurization curve may be the leading factors for inaccuracies of volume-oscillometric blood pressure measurement by partial pressurization method using an airbag.

[Arterial pressure dynamics in patients during prosthetic stomatological reception]

During prosthetic stomatological reception with the help of portable arterial pressure monitor Kardiotechnika-04AD-01 there were examined patients with normal blood pressure and arterial hypertension. The data were received confirming dependence of arterial pressure lifting with personal anxiety level. Conclusion was drown that close patient's examination was necessary before prosthetic stomatological reception.

Kinetics and persistence of cardiovascular and locomotor effects of immobilization stress and influence of ACTH treatment

Stress triggers crucial responses, including elevated blood pressure and heart rate (HR), to handle the emergency and restore homeostasis. However, continuation of these effects following cessation of the stress is implicated with many stress-related disorders. Here, we examine the kinetics and persistence of cardiovascular and locomotor responses to single and repeated immobilization stress (IMO), with and without prior treatment with adrenocorticotropic hormone (ACTH). Radiotelemetry probes were implanted into male Sprague-Dawley rats to continually monitor mean arterial pressure (MAP), HR and locomotor activity. Rats were subjected to IMO for 2 h daily (10 a.m. to noon, 6 consecutive days). The first IMO induced the greatest change in MAP (about 30 mm Hg) and HR (about 200 bpm). Following each IMO, MAP and HR were elevated during the remaining light phase and in the subsequent dark phase, HR was lower than prior to IMO. We further examined whether elevation of ACTH to a level similar to IMO will elicit similar effects, and if it will alter subsequent responses to IMO. Injection of ACTH (13 IU/kg, s.c.) triggered a short-lived rise in MAP, and decreased HR. After six daily injections of ACTH and recovery time (8 days), rats were immobilized as above. The cardiovascular responses were similar during the IMO, but the ACTH-pretreated group displayed differences following cessation of the IMO. In addition, IMO led to a large reduction of locomotor activity during the dark (normally active) phase to levels similar to the light phase. Following the IMOs, locomotor activity recovered more slowly in the ACTH-pretreated group. The study revealed that IMO-triggered cardiovascular and locomotor responses are evident after termination of the stress. In addition, prior exposure to ACTH delayed recovery in cardiovascular and locomotor functions following cessation of stress.

Bispectral index monitoring for nurse-administered propofol sedation during upper endoscopic ultrasound: a prospective, randomized controlled trial

Bispectral index monitoring (BIS) is a quantitative assessment of brain cortical activity. The aim of this study was to determine if BIS-guided nurse-administered propofol sedation would decrease by > or = 20% both recovery time and propofol dose compared to standard propofol sedation for endoscopic ultrasound (EUS). Prospectively, eligible outpatients were randomized to BIS-guided or standard propofol sedation during EUS. Propofol was given by nurses in intermittent boluses with sedation targeted at a BIS score of < 65-75. For the control group, the nurse was blinded to BIS scores and sedation was titrated to a modified observer's assessment of alertness/sedation scale (MOAA/S) score < or = 3. Of 50 patients enrolled, data for 44 randomized to BIS-guidance (n = 24) and the control group (n = 20) were evaluated. Between the BIS-guided and control group there was no difference between the mean procedure duration, total propofol dose, recovery time, mean intraoperative MOAA/S, and mean BIS score. Compared to standard propofol sedation for EUS, BIS-guided propofol sedation offers no significant decrease in postprocedure recovery times or propofol doses.

[Design of the software system of the platform for long-term blood pressure monitoring]

In this study, a platform for long-term and non-invasive blood pressure monitoring is proposed, Its software system and the functions of different program modules in the software system are introduced together with the development methods of the main modules.

Correlation between intrasac pressure measurements of a pressure sensor and an angiographic catheter during endovascular repair of abdominal aortic aneurysm

PURPOSE

To establish a correlation between intrasac pressure measurements of a pressure sensor and an angiographic catheter placed in the same aneurysm sac before and after its exclusion by an endoprosthesis.

METHODS

Patients who underwent endovascular abdominal aortic aneurysm repair and received an EndoSure wireless pressure sensor implant between March 19 and December 11, 2004 were enrolled in the study. Simultaneous readings of systolic, diastolic, mean, and pulse pressure within the aneurysm sac were obtained from the catheter and the sensor, both before and after sac exclusion by the endoprosthesis (Readings 1 and 2, respectively). Intrasac pressure measurements were compared using Pearson's correlation and Student's t test. Statistical significance was set at p<0.05.

RESULTS

Twenty-five patients had the pressure sensor implanted, with simultaneous readings (i.e., recorded by both devices) obtained in 19 patients for Reading 1 and in 10 patients for Reading 2. There was a statistically significant correlation for all pressure variables during both readings, with p<0.01 for all except the pulse pressure in Reading 1 (p<0.05). Statistical significance of pressure variations before and after abdominal aortic aneurysm exclusion was coincident between the sensor and catheter for diastolic (p>0.05), mean (p>0.05), and pulse (p<0.01) pressures; the sole disagreement was observed for systolic pressure, which varied, on average, 31.23 mmHg by the catheter (p<0.05) and 22 mmHg (p>0.05) by the sensor.

CONCLUSION

The excellent agreement between intrasac pressure readings recorded by the catheter and the sensor justifies use of the latter for detection of post-exclusion abdominal aortic aneurysm pressurization.

Invasive intravascular hemodynamic monitoring: technical issues

There is a lot of discussion in the literature about the best way to manage hemodynamic problems, but no algorithm can be useful unless the hemodynamic measurements that are used in the algorithms are valid. Yet, studies repeatedly have shown that physicians and nurses do not have a strong knowledge of the principles of measurements. Key factors in the use of transducers are zeroing, leveling, and calibrating. An understanding of the concept of transmural pressure is key to avoiding many potential artifacts related to variations in pleural pressure. The location of the proper place for measurement on the actual waveform can also be a source of error. This article covers these points as well as some suggestions for trouble-shooting.

Abdominal compartment syndrome: clinical aspects and monitoring

Markedly elevated intra-abdominal pressures will result in predictable hemodynamic consequences related to compromised venous return. When the hemodynamic abnormalities are associated with organ dysfunction of failure, patients suffer from the abdominal compartment syndrome. At-risk patients should be routinely monitored for intra-abdominal hypertension, and a multidisciplinary care paradigm should be established. Vigorous resuscitation of both surgical and medical patients highly correlates with IAH and ACS risk. Vigilance, prompt diagnosis, and intervention for abdominal compartment syndrome will reduce the morbidity and mortality in critically ill. Future challenges include altering resuscitation strategies to reduce ascites formation, earlier diagnosis of organ dysfunction, and intra-organ monitoring techniques.

Effect of the shapes of the oscillometric pulse amplitude envelopes and their characteristic ratios on the differences between auscultatory and oscillometric blood pressure measurements

INTRODUCTION

Oscillometric noninvasive blood pressure (NIBP) devices determine pressure by analysing the oscillometric waveform using empirical algorithms. Many algorithms analyse the waveform by calculating the systolic and diastolic characteristic ratios, which are the amplitudes of the oscillometric pulses in the cuff at, respectively, the systolic and diastolic pressures, divided by the peak pulse amplitude. A database of oscillometric waveforms was used to study the influences of the characteristic ratios on the differences between auscultatory and oscillometric measurements.

METHODS

Two hundred and forty-three oscillometric waveforms and simultaneous auscultatory blood pressures were recorded from 124 patients at cuff deflation rates of 2-3 mmHg/s. A simulator regenerated the waveforms, which were presented to two NIBP devices, the Omron HEM-907 [OMRON Europe B.V. (OMCE), Hoofddorp, The Netherlands] and the GE ProCare 400 (GE Healthcare, Tampa, Florida, USA). For each waveform, the paired systolic and paired diastolic pressure differences between device measurements and auscultatory reference pressures were calculated. The systolic and diastolic characteristic ratios, corresponding to the reference auscultatory pressures of each oscillometric waveform stored in the simulator, were calculated. The paired differences between NIBP measured and auscultatory reference pressures were compared with the characteristic ratios.

RESULTS

The mean and standard deviations of the systolic and diastolic characteristic ratios were 0.49 (0.11) and 0.72 (0.12), respectively. The systolic pressures recorded by both devices were lower (negative paired pressure difference) than the corresponding auscultatory pressures at low systolic characteristic ratios, but higher than the corresponding auscultatory pressures at high systolic pressures. Conversely, the differences between the paired diastolic pressure differences were higher at low diastolic characteristic ratios, compared with those at high diastolic characteristic ratios. The paired systolic pressure differences were within +/-5 mmHg for those waveforms with systolic characteristic ratios between 0.4 and 0.7 for the Omron and between 0.3 and 0.5 for the ProCare. The paired diastolic pressure differences were within +/-5 mmHg for those waveforms with diastolic characteristic ratios between 0.4 and 0.6 for the Omron and between 0.5 and 0.8 for the ProCare.

DISCUSSION AND CONCLUSION

The systolic and diastolic paired oscillometric-auscultatory pressure differences varied with their corresponding characteristic ratios. Good agreement (within 5 mmHg) between the oscillometric and auscultatory pressures occurred for oscillometric pulse amplitude envelopes with specific ranges of characteristic ratios, but the ranges were different for the two devices. Further work is required to classify the different envelope shapes, comparing them with patient conditions, to determine if a clearer understanding of the different waveform shapes would improve the accuracy of oscillometric measurements.

Sympathetic peripheral vasoconstriction may be measured using an artifact of the Finapres volume clamp technique

OBJECTIVES

The objective of this work was to test the hypothesis that the Finapres underestimates blood pressure during sympathetic peripheral vasoconstriction.

METHODS

Measurements were made simultaneously with two Finapres devices and one radial artery tonometer during the onset of periodic lower body negative pressure in healthy volunteers. The Finapres is believed to underestimate blood pressure during sympathetic peripheral vasoconstriction, but tonometry is not considered to be influenced. A lower blood pressure recording was therefore expected from the Finapres during the induced sympathetic vasoconstriction. To test the association with autonomic activity the time course of the difference between the two measurement techniques was compared with the induced change in heart rate.

RESULTS

In averaged results from 10 volunteers the Finapres and tonometer both showed a drop in blood pressure with the vacuum onset. A significantly larger drop was recorded by the Finapres. The result is consistent with an underestimate of blood pressure by the Finapres during the autonomic stimulation. The time course of the difference between the two measures of blood pressure follows the induced changes in heart rate, providing further evidence that the differences relate to autonomic activity.

CONCLUSION

Measurement of the difference may be a convenient method for monitoring the neurological component of peripheral vasoactivity. It is argued that the difference is insensitive to peripheral vasoactivity mediated by local endothelial or myogenic mechanisms.

Validation of the HEM-780REL with easy wrap cuff for self-measurement of blood pressure according to the European Society of Hypertension International Protocol

OBJECTIVE

We tested the accuracy of the HEM-780REL automatic blood pressure monitor with Easy Wrap Cuff.

METHODS

We used the International Protocol for validation of blood pressure measuring devices developed by the Working Group on Blood Pressure Monitoring of the European Society of Hypertension. Thirty-three adults over the age of 30 years participated to have 11 total participants in each of the three required blood pressure ranges for systolic and diastolic blood pressure. Sequential blood pressure readings were taken independently by trained observers using a mercury standard with appropriate size cuff. A third observer performed measurements with the test device. Analyses were performed according to International Protocol specifications for the 99 pairs of measurements. The device was given a pass/fail recommendation based on bands of accuracy compared with the mercury standard (within 5, 10, or 15 mmHg), as well as number of readings per participant within 5 mmHg.

RESULTS

The mean blood pressure difference was 0.52+/-7.7 mmHg for systolic blood pressure and 0.39+/-4.7 mmHg for diastolic blood pressure. Twenty-four out of 33 participants had two out of three readings within 5 mmHg of the mercury standard for systolic blood pressure. Twenty-seven out of 33 participants had two out of three readings within 5 mmHg of the mercury standard for diastolic blood pressure. The device received a passing grade both for accuracy of individual measurements and for accuracy for individuals.

CONCLUSION

The HEM-780REL with Easy Wrap Cuff performs accurately according to the standards of the International Protocol.

Accuracy of the HoMedics BPA-300, a home blood pressure monitor using the auscultatory method

PURPOSE

To determine whether the HoMedics Model BPA-300 meets American Association for the Advancement of Medical Instrumentation (AAMI) accuracy standards.

METHOD

Simultaneous auscultatory measurements by two observers using a mercury manometer were obtained in participants during measurement with the HoMedics Model BPA-300. Triple measurements were obtained after a minimum of 5 min of rest and 1 min between readings.

RESULTS

In total, 132 participants had 396 nurse-measured blood pressures (BP) and 385 successful systolic and 383 diastolic monitor readings. The initial auscultation systolic BP was less than 100 mmHg in 17 participants (12.9%), between 100 and 160 mmHg in 108 participants (81.8%), and greater than 160 mmHg in seven (5.3%) of participants. The average difference between the observers and device was 0.6+/-4.3 mmHg for systolic and 0.5+/-4.3 mmHg for diastolic-measured BPs by AAMI method 1, which met this guideline. The average difference between observers and device by AAMI method 2 was 0.9+/-4.0 mmHg for systolic and 0.5+/-3.9 mmHg for diastolic-measured BP, which met this guideline.

CONCLUSION

The HoMedics Model BPA-300 meets AAMI accuracy standards using methods 1 and 2.

Evaluation of the SCHILLER BR-102 plus noninvasive ambulatory blood pressure monitor according to the International Protocol introduced by the Working Group on Blood Pressure Monitoring of the European Society of Hypertension

OBJECTIVE

To evaluate the SCHILLER BR-102 plus (Schiller AG, Baar, Switzerland) noninvasive ambulatory blood pressure recorder according to the International Protocol for validation of blood pressure measuring devices in adults introduced by the Working Group on Blood Pressure Monitoring of the European Society of Hypertension.

METHOD

One SCHILLER BR-102 plus blood pressure recorder was tested by a validation team, consisting of three persons: two observers (nurses) and a doctor, acting as supervisor and 'expert'. The European Society of Hypertension International Protocol comprises two phases. Fifteen participants were recruited for the first phase and, following a successful test, a further 18 persons (giving a total of 33) were recruited additionally. For phase 1, five of the 15 participants had systolic blood pressure and diastolic blood pressure in each of the ranges: low, medium and high. For phase 2, 11 of the 33 participants (including the first 15 participants) had systolic blood pressure and diastolic blood pressure in each of the ranges. The mercury standard for validation was preferred over the optional Sphygmocorder. Because the SCHILLER BR-102 plus has the oscillometric method as backup to the basic auscultatory measurement, both systems of measurement were subjected to individual validations.

RESULTS

Results obtained show that the SCHILLER BR-102 plus noninvasive ambulatory blood pressure recorder meets all the requirements specified in the International Protocol for both oscillometric and auscultatory methods.

CONCLUSION

On the basis of these results, the SCHILLER BR-102 plus can be recommended for ambulatory blood pressure measurement in clinical practice using both auscultatory and oscillometric modes.

Evaluation and effects of the Omron 725 CIC device for measuring blood pressure in a hypertension clinic

BACKGROUND

We compared the Omron 725 CIC device (Omron Healthcare Inc., Vernon Hills, Illinois, USA), which is designed to register the blood pressure on the arm, with a mercury sphygmomanometer. In addition, we evaluated the possible impact that this device might have on the decisions made in a hypertension clinic.

METHODS

Patients (n=183) older than 18 years (range 18-84 years) with a wide range of systolic (87-197 mmHg) and diastolic (48-108 mmHg) blood pressures were included. Some of the standards of the Association for the Advancement of Medical Instrumentation and of the British Hypertension Society were used to evaluate the results of the automated device in clinical practice.

RESULTS

Using Bland-Altman analysis, an underestimation of both measures was observed with the automated Omron 725 CIC device; the systolic pressure was 3.6+/-8.8 mmHg too low with a very wide range of -13.7 to 20.9 and the diastolic pressure was also 4.4+/-6.3 mmHg too low with a range of -8.1 to 16.9. Clinical decisions could have been changed in 24 of the 116 hypertensive patients (20.6%) if the readings of the automated device had been used instead of using the readings of a mercury sphygmomanometer. These could have included modifying the dosage or changing the medicine used.

CONCLUSION

The blood pressure measurements by Omron 725 CIC are different from those of blood pressure readings taken with a mercury sphygmomanometer and this could affect clinical decisions in the diagnosis and follow-up of a hypertensive patient in an office environment.

Validation of the Welch Allyn Spot Vital Signs blood pressure device according to the ANSI/AAMI SP10: 2002. Accuracy and cost-efficiency successfully combined

OBJECTIVES

To validate a significantly lower priced, new-generation blood pressure device by using the ANSI/AAMI SP10:2002 Standard evaluation.

METHODS

The Spot Vital Signs device evaluation was performed using the procedure specified in the SP10: 2002 American National Standard. Both obese and hypertensive participants were overrepresented in the study population.

RESULTS

The mean+/-standard deviation for the device readings compared with auscultation by paired, trained, blinded observers for systolic blood pressure was -1.0+/-4.1 mmHg; for diastolic blood pressure it was -0.4+/-6.1 mmHg. These passed AAMI criteria. The device, at a cost well below those of comparable professional-quality (vs. self measurement) electronic blood pressure devices, was extremely accurate.

CONCLUSIONS

The Welch Allyn Spot Vital Signs device provides a cost-effective alternative for medical-care delivery sites where accuracy and cost are both high priorities. The study population was oversampled for obese and hypertensive patients, the major target groups in whom blood pressure must be able to be recorded accurately to optimize diagnosis and management of cardiovascular disease.

Clinical evaluation of the Welch Allyn SureBP algorithm for automated blood pressure measurement

OBJECTIVES

To clinically evaluate an inflation-based algorithm incorporated into a new automated blood pressure monitor manufactured by Welch Allyn, Inc.

METHODS

Device evaluation was performed according to the Association for the Advancement of Medical Instrumentation standard. An overabundance of patients with hypertension (32) were part of the 110 total participants. The data were also analyzed as described in the British Hypertension Society protocol.

RESULTS

The mean error and standard deviation for systolic blood pressure were -0.9 mmHg+/-7.2; for diastolic blood pressure -2.2 mmHg+/-6.7. These passed the Association for the Advancement of Medical Instrumentation standard requirements. By British Hypertension Society data analysis, the device achieved an AA grading. Over 90% of the cycles' blood pressure values were obtained during inflation.

CONCLUSIONS

The SureBP inflation-based algorithm successfully passed the Association for the Advancement of Medical Instrumentation standard requirements and achieved an AA rating by British Hypertension Society data analysis. The monitor has great advantages for patient comfort and speed of readings (average 15 s per reading). As the population studied was skewed by including a much larger than needed number of patients with hypertension, clinicians can have added confidence in this new technology.

Validation of an oscillometric home blood pressure monitor in an end-stage renal disease population and the effect of arterial stiffness on its accuracy

OBJECTIVES

Increased arterial stiffness, common in end-stage renal disease patients, has been shown to affect the correspondence between oscillometric and mercury sphygmomanometer blood pressure readings. The purpose of this study was to validate an oscillometric home blood pressure monitor in an end-stage renal disease population and to determine the effect of arterial stiffness on its accuracy.

METHODS

Blood pressure measurements were taken with the Microlife 3AC1-1PC (Microlife; Taipei, Taiwan), an oscillometric home blood pressure monitor, and a mercury sphygmomanometer in 33 patients as specified by the European Society of Hypertension Validation Protocol. Radial pulse wave analyses were also performed.

RESULTS

On the basis of European Society of Hypertension criteria, the Microlife 3AC1-1PC received a passing score for systolic and diastolic blood pressures. On average, the oscillometric monitor overestimated diastolic blood pressure by 2.4 mmHg (P=0.005, SD=4.5 mmHg) and there was a trend towards overestimation of systolic blood pressure as well (1.3 mmHg, P=0.09, SD=4.4 mmHg). A positive correlation was found between arterial stiffness, as assessed by augmentation index and pulse pressure, and the diastolic blood pressure difference between the device and the mercury sphygmomanometer (r=0.54, P=0.003; and r=0.65, P=0.001, respectively). Diastolic blood pressure was negatively correlated with the diastolic blood pressure difference (r=-0.49, P=0.003). No significant relationship was found between the systolic blood pressure difference and augmentation index, pulse pressure or systolic blood pressure.

CONCLUSION

The Microlife 3AC1-1PC was shown to accurately measure blood pressure in patients with end-stage renal disease. As arterial stiffness increased and diastolic blood pressure fell, diastolic blood pressure was increasingly overestimated.

[Orthostatic hypotension and hypertension lying down: a clinical dilemma. 56-year-old patient with multiple system atrophy]

A 56-year-old patient with multisystem atrophy of Parkinson type presents himself with severe, symptomatic and orthostatic hypotension and concomitant arterial hypertension while in a recumbent position. Etiology and pathophysiology of orthostatic hypotension and concomitant hypertension in recumbent position is discussed as it relates to this specific patient. Specific indications for antihypertensive therapies and other potential therapeutic options are also discussed.

Comparison of noninvasive oscillometric and intra-arterial blood pressure measurements in hyperacute stroke

OBJECTIVES

This study aims to compare automatic oscillometric blood pressure recordings with simultaneous direct intra-arterial blood pressure measurements in hyperacute stroke patients to test the accuracy of oscillometric readings.

METHODS

A total of 51 first-ever stroke patients underwent simultaneous noninvasive automatic oscillometric and intra-arterial blood pressure monitoring within 3 h of ictus. Casual blood pressure was measured in both arms using a standard mercury sphygmomanometer on hospital admission. Patients who received antihypertensive medication during the blood pressure monitoring were excluded.

RESULTS

The estimation of systolic blood pressure (SBP) using oscillometric recordings underestimated direct radial artery SBP by 9.7 mmHg (95% confidence interval: 6.5-13.0, P<0.001). In contrast, an upward bias of 5.6 mmHg (95% confidence interval: 3.5-7.7, P<0.001) was documented when noninvasive diastolic blood pressure (DBP) recordings were compared with intra-arterial DBP recordings. For SBP and DBP, the Pearson correlation coefficients between noninvasive and intra-arterial recordings were 0.854 and 0.832, respectively. When the study population was stratified according to SBP bands (group A: SBP<or=160 mmHg; group B: SBP>160 mmHg and SBP<or=180 mmHg, group C: SBP>180 mmHg), higher mean DeltaSBP (intra-arterial SBP-oscillometric SBP) levels were documented in group C (+19.8 mmHg, 95% confidence intervals: 12.2-27.4) when compared with groups B (+8.5 mmHg, 95% confidence intervals: 2.7-14.5; P=0.025) and A (+5.9 mmHg, 95% confidence intervals: 1.8-9.9; P=0.002).

CONCLUSION

Noninvasive automatic oscillometric BP measurements underestimate direct SBP recordings and overestimate direct DBP readings in acute stroke. The magnitude of the discrepancy between intra-arterial and oscillometric SBP recordings is even more prominent in patients with critically elevated SBP levels.

In vitro and in vivo evaluation of an oscillometric device for monitoring blood pressure in dialysis patients

BACKGROUND

Nowadays, an increasing number of dialysis machines lodge a blood pressure (BP) measuring device, whose accuracy has a clear implication for the patients' clinical management.

METHODS

An automated oscillometric sphygmomanometer (HD-BPM by Gambro Dasco) used during haemodialysis was submitted to both in vitro and in vivo tests, in order to evaluate some modifications aimed at improving measurement accuracy and consistency. The results were compared with those obtained by another oscillometric monitor (BX-100 by Colin). Three steps of evaluation were followed. First, the maintenance of the overall accuracy requirements prescribed by ANSI/AAMI SP-10 standard was verified. Then, an in vitro validation was carried out by using a test simulator. Finally, during a multi-centre field trial, 392 BP measurement sessions on 53 dialysis patients were collected. Every session consisted of two consecutive intra-dialysis measurements by the oscillometric monitors, each one performed simultaneously to an auscultatory measurement. A comparison with the intra-arterial method was performed as well.

RESULTS

When compared with an in vivo data set previously collected, the HD-BPM accuracy complied with required limits. Second, the internal repeatability with respect to the simulator was satisfactory (SD of the differences between device and simulator readings: HD-BPM: systolic = 5.7, diastolic = 4.2; BX-100: systolic = 4.2, diastolic = 5.5 mmHg). Moreover, the comparison between oscillometric and auscultatory methods during in vivo trial gave similar results for the two monitors, even if systolic pressure SD exceeds the limit recommended by ANSI/AAMI SP-10 (mean value of the differences +/- SD: HD-BPM: systolic = 0.5 +/- 9.0, diastolic = 1.5 +/- 6.9; BX-100: systolic = 3.1 +/- 8.2, diastolic = -2.0 +/- 7.6 mmHg).

CONCLUSIONS

These data underline the importance of performing accuracy evaluations for BP monitors in the conditions where they normally work, by using well-accepted protocols.

Novel Way to Confirm Successful Endovascular Repair of a Thoracic Aortic Aneurysm Using a Remote Wireless Pressure Sensor

Due to the continuous risk of rupture from endoleaks after endoluminal graft repair of thoracic aneurysms, the need for lifelong postoperative surveillance has become necessary. Patients are put at a lifetime risk of radiation exposure and may be at an increased risk of contrast induced nephropathy from routine contrast use during follow-up computed tomography for postoperative surveillance of endoluminal grafts. Measuring aneurysm sac pressures using remote wireless pressure sensor may provide a noninvasive method to detect endoleak, procedural success, and long-term stent graft stability.

Identifying physiological measurements for medical monitoring: implications for autonomous health care in austere environments

In a patient who has lost a significant amount of blood, avoiding cardiovascular collapse and impending circulatory shock depends on the ability to maintain adequate arterial blood pressure in the presence of significant central hypovolemia. Our analysis of hemodynamic, autonomic, and metabolic data obtained from healthy human subjects exposed to progressive reduction in central blood volume and supported by data from trauma patients provide evidence to support the following conclusions: 1. Because of autonomically-mediated compensatory mechanisms, standard vital signs can remain unchanged or change too late, when cardiovascular collapse is imminent. 2. Currently proposed closed-loop resuscitation and oxygen delivery systems controlled by arterial blood pressure and SpO2 may prove inadequate for early intervention decision-support. 3. Continuous capture of PP, ECG R-wave amplitude, indices of HRV, cardiac BRS, and/or muscle PO2 could improve the sensitivity of closed-loop resuscitation and oxygen delivery by providing earlier indications of clinical status.

Measuring orthostatic hypotension with the Finometer device: is a blood pressure drop of one heartbeat clinically relevant?

OBJECTIVE

The role of orthostatic hypotension in falls in older people is generally accepted. Because of the high degree of intra- and interobserver variability in conventional measurements of orthostatic hypotension, application of continuous measurement systems has been proposed. The clinical relevance of a blood pressure drop lasting one heartbeat, however, is unknown. We therefore investigated which time average of continuous-finger-blood-pressure measurement (Finometer) showed the best association between orthostatic hypotension and falls. This was also compared with conventional sphygmomanometer measurements.

METHODS

In 217 geriatric outpatients supine and standing (finger) blood pressure to diagnose orthostatic hypotension was monitored with Finometry (beat-to-beat and 1, 5, 10, 15, 20 and 30 s averages) and sphygmomanometry. History of fall incidents (previous year) was registered.

RESULTS

The best association (C=0.22, P=0.003) with falls history was found for the 5-s average of Finometry, whereas falls and orthostatic hypotension assessed by sphygmomanometry did not correlate. The odds ratio of a fall according to orthostatic hypotension using the 5-s average was 2.54 (95% CI: 1.37 to 4.71).

CONCLUSIONS

Orthostatic hypotension and falls are correlated when using Finometry, with the best association found when using 5-s averages. As the etiology of falls is often multifactorial, orthostatic hypotension and falls are poorly correlated, irrespective of the method or time average that is applied.

Direct measurement of intra-abdominal pressure with a solid microtranducer

OBJECTIVE

To describe a direct intra-abdominal pressure (IAP) measurement technique using a solid microsensor comparing its values with the ones simultaneously obtained by means of Kron's technique. Comparative study between two different methods to measure intra-abdominal pressure in a multidisciplinary intensive care unit of a university hospital.

METHODS

In 11 critical patients considered irreversibly ill, IAP was simultaneously measured via Kron's technique (IAPK) and by direct measure (IAPC) through an abdominal tap with a Codman microsensor, inserted through it. Several measurements were obtained at different PEEP levels (0, 10 and 20 cm of H20) and bed inclination (0 degrees , 40 degrees and 60 degrees ).

RESULTS

92 simultaneous measurements of IAPK and IAPC were made. The difference between both measurements (mean +/- SD) were: 0.286 +/- 0.938 mmHg. The correlation coefficient was r = 0.98. Bland-Altman plot showed a narrow distribution: 95% of the differences were between 1.87 mmHg of each averaged value. No complications with IAPC measurements were found.

CONCLUSIONS

Direct IAP measurement with a Codman microsensor allows continuous monitoring without urinary tract manipulation, is simple to use and to calibrate, minimally invasive and appropriate for patients at risk to develop abdominal compartmental syndrome. Due to its cost it should be reserved for selected critical patients where standard techniques are contraindicated or can be inaccurate.

Effect of Continuous and Pulsatile Flow Left Ventricular Assist on Pulsatility in a Pediatric Animal Model of Left Ventricular Dysfunction: Pilot Observations

Pediatric ventricular assist devices are being developed that can produce pulsatile flow (PF) or continuous flow (CF). An important aspect of choosing between these two modes is understanding the consequences of each mode on pediatric vascular pulsatility. Differences in vascular pulsatility generated by PF and CF operation of the 3-inch pediatric cardiopulmonary assist system (pCAS, Ension, Inc., Pittsburgh, PA) were investigated while providing left atrium-to-aorta left ventricular assist (LVA), using an infant animal model of left ventricular dysfunction. Hemodynamic data were digitally recorded with the pCAS providing LVA at incremental flow rates while operating in continuous mode, pulsatile mode at 100 bpm, and pulsatile mode at 140 bpm. These data were used to calculate vascular input impedance (Zart), energy equivalent pressure, and surplus hemodynamic energy as indices of pulsatility for partial (50% of maximum) and maximum LVA flow. Both CF and PF LVA by the pCAS resulted in favorable hemodynamic rectification of left ventricular dysfunction while generating equivalent flows. PF LVA maintained a greater degree of pulsatility compared with CF, as evidenced by increasing energy equivalent pressure and a lesser drop in surplus hemodynamic energy with increasing pCAS flow. Differences in Zart modulus and phase were indiscernible. The selection of flow mode may have long-term consequences on Zart and end-organ perfusion affecting clinical outcomes in pediatric patients.

Conservative treatment of an acute compartment syndrome of the thigh

Compartment syndromes of the thigh after blunt trauma without any fracture are rare. Most surgeons recommend operative treatment. There are different rules for compartment syndromes of the thigh in young athletes after blunt trauma compared to compartment syndromes at other locations [(1) the large volume of the quadriceps muscle, (2) its relatively elastic fascia, (3) the direct proximal contact to the hip muscles which allows extravasation of fluid out of the compartment)]. We present a case of conservative treatment of elevated intra-compartmental pressure (ICP) of the anterior thigh after blunt trauma and the follow-up until return to sport. Conservative treatment of a compartment syndrome of the thigh after blunt trauma in a young patient without fracture or vascular damage was successful without short-term sequelae. Recovery of muscle strength is delayed but return to sport is possible. Depending on the severity the diagnosis and follow-up with ICP measurements and MRI is necessary. There is a very good chance for excellent outcome without any risk of surgery. However, a long healing time is possible.

The Effect of Left Ventricular Function and Drive Pressures on the Filling and Ejection of a Pulsatile Pediatric Ventricular Assist Device in an Acute Animal Model

Penn State is currently developing a 12-mL, pulsatile, pneumatically driven pediatric ventricular assist device intended to be used in infants. After extensive in vitro testing of the pump in a passive-filling, mock circulatory loop, an acute animal study was performed to obtain data with a contracting ventricle. The objectives were to determine the range of pneumatic pressures and time required to completely fill and empty the pediatric ventricular assist device under various physiologic conditions, simulate reductions in ventricular contractility and blood volume, and provide data for validation of the mock circulatory loop. A 15-kg goat was used. The cannulation was achieved via left thoracotomy from the left ventricle to the descending aorta. The pump rate and systolic duration were controlled manually to maintain complete filling and ejection. The mean ejection time ranged from 280 ms to 382 ms when the systolic pressure ranged from 350 mm Hg to 200 mm Hg. The mean filling time ranged from 352 ms to 490 ms, for the diastolic pressure range of -60 mm Hg to 0 mm Hg. Esmolol produced a decrease in left ventricular pressure, required longer pump filling time, and reduced LVAD flow.

The occurrence of the alerting response is independent of the method of blood pressure measurement in hypertensive patients

OBJECTIVE

Current guidelines stress the need for more than one measurement of blood pressure in the hypertensive patient. The frequency with which the first blood pressure significantly exceeds subsequent blood pressures (alerting response) is unknown. Participants in a hypertension treatment trial before initiation of therapy were included in post-hoc analyses to investigate the alerting response separately for trained nurse blood pressure measurements with mercury sphygmomanometer and measurements taken by an Omron 705 CP automated device.

BASIC METHODS

A total of 313 participants were included. Each participant had three nurse blood pressure readings before a 24-h automated blood pressure monitoring device was attached, and three Omron measurements at the time the automated blood pressure monitoring device was removed. Alerting response was defined separately for systolic and diastolic measures as a decrease of > or =8 or > or =6 mmHg, respectively, from first measure to the average of the second and third measures.

MAIN RESULTS

An alerting response was observed in 20.4% of nurse-performed blood pressure measurements and 28.4% of Omron measurements. A large range of variation between first blood pressure and average second and third measures was observed, with changes of up to 30 mmHg systolic and 20 mmHg diastolic. The only demographic factor associated with the alerting response was body mass index, with obese patients more likely to exhibit an alerting response (P=0.004) in nurse-measured blood pressure.

CONCLUSIONS

We found the alerting response with both methods of blood pressure measurement; however, it was not consistently observed in the same individuals. This confirms that hypertensive patients require multiple blood pressure measurements.

Clinical significance and reproducibility of new arterial distensibility index

BACKGROUND

The brachial-ankle pulse wave velocity (baPWV) is used to evaluate the degree of atherosclerosis and arterial distensibility, but its major limitation is that it is affected by changes in blood pressure (BP) during measurement. Recently, a new atherosclerotic index, the cardio-ankle vascular index (CAVI), has been developed by measuring PWV and BP. CAVI is adjusted for BP based on the stiffness parameter beta and should measure arterial stiffness independent of BP. The purpose of this study was to evaluate the validity of CAVI compared with baPWV, the reproducibility of the measurement of CAVI, and the effect of BP changes on CAVI and baPWV.

METHODS AND RESULTS

One thousand and thirty-three consecutive subjects undergoing health checkups were studied. CAVI was automatically calculated from the pulse volume record, BP, and the vascular length from heart to ankle. In this general population, both baPWV and CAVI demonstrated a positive correlation with age and systolic BP (SBP). CAVI showed a weaker correlation with SBP than baPWV. The measurement of CAVI demonstrated good reproducibility and was not affected by the increase in BP during measurement.

CONCLUSIONS

CAVI is a useful index of arterial distensibility and is not influenced by BP changes during measurement.

Initial results of wireless pressure sensing for endovascular aneurysm repair: The APEX Trial—Acute Pressure Measurement to Confirm Aneurysm Sac EXclusion

OBJECTIVE

Complete exclusion and depressurization of the aneurysm sac is the prime goal of endovascular repair (EVAR) of abdominal aortic aneurysms. Thus, any EVAR that results in a type I or III endoleak has been classified as a technical failure. The current method to detect endoleaks uses intraoperative aortography. However, aortography is limited by its subjective nature, inability to quantify the significance of the endoleak, and artifacts such as bowel gas that may mimic an endoleak. In addition, repetitive contrast injection may impair renal function. To increase the efficacy and safety of intraoperative endoleak detection, a wireless pressure-monitoring system has been developed and tested in the clinical setting.

METHODS

The APEX trial (Acute Pressure Measurement to Confirm Aneurysm Sac EXclusion) is a prospective, multicenter/international trial sponsored by CardioMEMS to evaluate the safety and efficacy of the EndoSure wireless pressure sensor for EVAR. The 30 x 5 x 1.5-mm sensor contains no battery and is powered externally with radiofrequency energy. The sensors are extremely stable, operate over the full physiologic range of pressures, and have a resolution of 1 mm Hg. A total of 90 patients were enrolled at 12 sites, 76 of whom were eligible for analysis. The sensor was implanted via the contralateral femoral artery at the time of EVAR. The sac pulse pressure was measured with both an angiographic catheter and the sensor after deployment of the main endograft but before the deployment of the contralateral limb (type I endoleak equivalent). Sac pressure was again measured with the sensor after deployment of the contralateral limb and completion of the EVAR. Data were collected in a prospective manner.

RESULTS

In all of the eligible patients (n = 76), the initial sensor pressure measurement agreed closely with the angiographic catheter pressure measurement of the type I endoleak equivalent. At the completion of the procedure, there was agreement between the sensor measurement and angiography regarding the presence or absence of a type I or III endoleak in 92.1% (n = 70) of the measurements. Overall, the sensitivity was 0.94 and the specificity was 0.80 for detecting type I or III endoleaks. Final pulse pressures decreased significantly compared with baseline measurements.

CONCLUSIONS

Implantation of the wireless pressure sensor is safe, and remote aneurysm sac pressure sensing is feasible. It was a valuable guide in evaluating the completeness of the EVAR procedure. Long-term study will be needed to prove its efficacy for postoperative surveillance.

Blood pressure in non-critically ill preterm and full-term neonates

The neonatal period is a time of extensive hemodynamic changes. It is expected that these changes are most prominent in premature infants during the first week of life. The aim of this study was to examine arterial blood pressure (BP) measured by an oscillometric device in the first month of life in a stable premature population admitted to our neonatal intensive care unit (NICU), and to evaluate the influence of gestational age, postnatal age, birth weight, gender, and sleep state on BP. This prospective study was conducted over 27 months. The study population consisted of 373 hemodynamically stable infants (292 preterm and 81 full-term infants). Overall 12,552 BP measurements were carried out using a non-invasive oscillometric blood pressure monitor. Both systolic and diastolic blood pressure progressively increased during the first month of life. BP increased more rapidly in preterm infants than in full-term infants, and was higher in groups with higher birth weight. Multiple regression analysis showed that mean BP during the first week and on the 30th day increased with gestational age, and also that it was higher in the awake than in the sleep state.

Phenotyping the level of blood pressure by telemetry in mice

1. Using telemetry, arterial blood pressure (BP) can be measured directly over long periods in freely behaving animals without recent anaesthesia or surgery. In the present review, we discuss the strengths and limitations of this method and important considerations in using the method to characterize the BP level in mice. 2. A variety of informative statistics can be used to describe the BP level and we have made available a spreadsheet template for their calculation on a routine basis. The BP level is well summarized using the average value for an entire 24 h period or for the individual light and dark phases of the day. Such long-term averages exhibit less statistical variation than those of short recording periods. In addition, averages of the dark and light phases of the day convey information concerning circadian variations of BP. 3. The frequency distribution of BP samples provides additional information concerning the range of BP values recorded over the course of the day and can be described in terms of percentiles of the distribution that correspond with the minimum and maximum BP values and their span. 4. In mice, BP can be markedly affected by locomotor activity cycles that occur frequently throughout both the light and dark phases of the day. In addition, BP is strongly affected by ambient temperature and food intake, as well as potentially by other determinants of energy balance. Consideration of these factors may help improve accuracy and precision when phenotyping the BP level in mice.

[Prevalence of white-coat hypertension and masked hypertension in the general population, through home blood pressure measurement]

OBJECTIVE

To determine the prevalence of white-coat hypertension (WCH) and masked hypertension (MH) in the general population, by means of home blood pressure measurement (HBPM).

DESIGN

Cross-sectional, descriptive study.

SETTING

Four primary care centres.

PARTICIPANTS

A sample of 1400 individuals over 18 years old, selected from the Municipal Register of Inhabitants (Huelva, Spain) and randomised and stratified by age and gender.

MAIN MEASUREMENTS

Two blood pressure (BP) measurements in clinic (CBP) and 12 measurements in a week of BP by HBPM were performed (OMRON 705-CP). Pressure was seen as normal when CBP means were <140/90 mm Hg and HBPM was <135/85 mm Hg. WCH was defined as when CBP was >140/90 mm Hg and HBPM <135/85 mm Hg, and hypertension when CBP was >140 mm Hg and HBPM >135/85 mm Hg or patients were in treatment for hypertension. MH was when CBP was <140/90 mm Hg and at home was >135 mm Hg and/or 85 mm Hg.

RESULTS

A total of 1153 individuals (82.35% of the sample) with mean age of 45.4 (SD, 16.1) were included: 560 men and 593 women. The prevalence of MH was 8.9% (CI+/-1.6) in the general population and 9.8% (CI+/-3.2) in individuals with hypertension. WCH prevalence was 3.6% (CI+/-1.05) overall and 12.8% (CI+/-3.6) in hypertense patients, with its prevalence increasing steadily as age groups rose (P = .001).

CONCLUSIONS

The prevalence of WCH in the general population is low, whereas the prevalence of MH is high.

Primary-care physicians' views about the use of home/self blood pressure monitoring: nationwide survey in Hungary

OBJECTIVE

To obtain unbiased views of primary-care physicians about home blood pressure monitoring (HBPM).

METHODS

A mail survey was conducted in a random sample (n = 700) of all Hungarian primary-care physicians (n = 5112). Items in the questionnaire related to the extent and indications for use of HBPM, to the significance attributed to its results, to the methods of its use, and to concerns physicians had with HBPM.

RESULTS

Of the 700 questionnaires, 405 (58%) could be analysed. HBPM was popular among the respondents: 60% of them had more then 50 patients on HBPM, 90% of them were recommending its use either 'often' or 'almost all the time', and 75% of them considered the results of HBPM of either 'considerable' or of 'extreme importance'. The most frequent indications for use were white-coat hypertension (97%), assessing 24-h drug effects (87%), improving compliance (82%), suspicion of hypotension (63%), and resistant hypertension (61%). Physicians actively recommended devices with an upper-arm cuff (83%), equipped with a built in memory (63%). Most respondents (67%) had someone in their offices to teach the patient the correct measurement technique. Surprisingly, 65% of the physicians only reviewed the data to obtain a 'general picture' and did not analyse the data. Most of the respondents (78%) encouraged their patients to call their offices, and 90% of them did receive a call. Main concerns with HBPM were the use of non-validated devices (75%), and patient preoccupation with blood pressure (55%). Areas for suggested improvements were the need for patient training facilities (48%), established measurement protocols (44%) and better methods of displaying readings (30%).

CONCLUSIONS

We found an unexpected popularity in the use of HBPM among primary-care physicians. In order to fully exploit the benefits of HBPM, the concerns raised (validated devices, patient preoccupation) and areas to be improved upon (patient training, better methods of displaying results) will have to be addressed by researchers, societies and the industry.

A telemedicine instrument for home monitoring of patients with chronic respiratory diseases

We developed a telemedicine instrument for home monitoring of subjects with respiratory diseases. The instrument directly measures blood oxygen saturation and pulse rate, but the most relevant aspect is that it also acts as digital recorder of parameters coming from several external instruments (spirometer, capnometer, NIBP device, etc.). It also connects to all pulmonary ventilators. The instrument main board includes five slots, which are used to insert the measuring boards (saturation and ventilation boards) and the interface boards (connecting the external instruments). Depending on patient's needs, only the proper measuring/interface boards are mounted, thus allowing maximum flexibility and cost saving. The instrument has several I/O units, and especially an internal modem for direct connection to the Internet through TCP/IP protocol. The instrument was extensively tested, and preliminary trials were performed over fifteen patients with amyotrophic lateral sclerosis.

Arterial blood pressure and baroreflex sensitivity 1-18 years after completing anthracycline therapy

The analysis of short-term blood pressure regulation in children, adolescents and young adults 1 to 18 years after the treatment with anthracyclines known to have cardiotoxic side effects for oncological diseases was the aim of the present study. Thirty-one subjects treated with anthracyclines (PA) and 11 subjects treated with different antitumour drugs (P0) were investigated twice (the interval between two investigations 1-9 years). Three hundred and thirty-nine healthy subjects served as controls (C). Systolic (SBP), diastolic blood pressures (DBP) in the finger arteries and inter-beat interval (IBI) were recorded beat-to-beat (FINAPRES, Ohmeda, metronome controlled breathing, 5 minute recording); the values were corrected by auscultatory blood pressure measurements. Baroreflex sensitivity (BRS, ms/mmHg) was determined by a spectral method. As the investigated subjects were of different ages, the measured values were standardised on the age of 16 years by linear regression, and only standardised values (IBI16, SBP16, DBP16 and BRS16) were further analysed. No differences were found between PA, P0 and C in BRS16 and IBI16. SBP16 and DBP16 were significantly lower in PA (102.1+/-8.3/59.7+/-7.1 versus C: 114.1+/-12.4/69.0+/-9.5 mmHg; p<0.001/p<0.001; mean from two investigations). SBP16 but not DBP16 was also lower in P0 (102.7+/-12.6/64.5+/-9.7 mmHg; p<0.01/no significant) than in C. The correlation coefficient between SBP16 and period after treatment in PA was -0.11 (no significant) and -0.06 in DBP16 (no significant). Thus, there is not seen a trend to normalisation.

CONCLUSION

The anthracycline antitumour therapy in children decreases blood pressure and within 18 years after the treatment there is not observed a trend toward normal values. BRS was not influenced by the anthracycline therapy.