Oscillometric Technique Research Articles

PP.23.08

Objective: Measurement of brachial-ankle pulse wave velocity (baPWV) is recognized as a simple and practical method for assessing arterial stiffness. This study aimed to provide data on the baPWV distribution in Japanese adolescents and to develop a nomogram of the relationship between baPWV and age for males and females. Design and method: The study population consisted of 3215 Japanese adolescents ranging from 12 to 18 years of age (1551 males and 1664 females). They had no history of treatment for hypertension, syndromal obesity, diabetes mellitus, dyslipidemia, or renal disease. The baPWV was measured using a simple automatic oscillometric technique with an appropriate size cuff. Anthropometric measures and blood pressure were evaluated, and fasting blood sample was collected for the measurement of lipid and glucose profiles by standard techniques. Results: The baPWV of the adolescents increased substantially with age and was significantly higher in males than in females (9.74 ± 1.25m/s vs. 9.35 ± 1.08m/s, p < 0.001). The age effect, gender effect, and age × gender interactions effect were significant by two-way ANOVA. Multivariate regression analysis revealed that age, weight, and systolic and diastolic blood pressures were the major determinants of baPWV for both genders. To generate the nomogram of the relation between baPWV and age, the 50th, 75th, 90th, and 97th centile values of baPWV were calculated, and the age-specific centile curves of baPWV were constructed for males and females by regression curve analysis. Among the study samples, the subgroup with elevated blood pressure together with dyslipidemia and/or impaired fasting glycemia was used to compare their baPWV values with the obtained nomograms. In these multiple-risk subjects, the measured baPWV values were significantly higher than the estimated values by interpolating their ages to the 50th centile curve of the nomogram in males (10.54 ± 1.17m/s vs. 9.89 ± 0.47m/s, p = 0.001) and in females (10.31 ± 1.30m/s vs. 9.36 ± 0.29m/s, p = 0.012). Conclusions: The nomograms of baPWV and its derived cutoff values may be useful in precisely identifying individuals who are at risk for developing atherosclerotic diseases in the future and, thereby, who should be subjected to further observation and in whom other measures should be taken to reduce their risk condition.

Differential responses in brachial and ankle blood pressure during blood pressure reactivity tests

Blood pressure (BP) reactivity has been assessed by a variety of stimuli, including physical, psychological, and physiological perturbations, that can be further classified into cardiac or vascular in regard to the effector organs. In many BP reactivity studies, changes in brachial BP are taken as systemic changes and are combined with leg measurements to assess vasoactive states. Currently, it is unknown if leg BP behaves similarly to arm BP.PurposeWe compared BP changes between the brachial and post‐tibial arteries during acute BP perturbations.MethodsThirty apparently healthy subjects (57% males, 46±4 years) were studied. Both brachial and ankle systolic BP (SBP) were measured simultaneously with the oscillometric technique during resting baseline, head‐up tilt (HUT), head‐down tilt (HDT), mental stress (MS), isometric hand‐grip exercise (HG), and a cold pressor test (CPT).ResultsBrachial (bSBP) and ankle (aSBP) SBP at rest were significantly and highly correlated (r=0.81). Changes in bSBP were significantly and positively associated with changes in aSBP in response to HUT (r=0.46), HDT (r=0.53), MS (r=0.70), HG (r=0.63), and CPT (r=0.75). The magnitudes of bSBP and aSBP changes were not different n response to MS, HG, and CPT since all were within 5 mmHG. There were significant differences in the magnitude of changes in bSBP and aSBP in response to HDT (12±1 mmHg) and HUT (40±2 mmHg).ConclusionBoth brachial and ankle BP respond similarly in many vascular reactivity maneuvers. During head‐down and head‐up tilt, however, differences in their responses may be quite large, presumably due to the hydrostatic pressure gradients created during the maneuvers.Supported by Fukuda Denshi.

Comparison of pulse wave velocity assessed by three different techniques: Arteriograph, Complior, and Echo-tracking.

Arterial stiffness estimated by pulse wave velocity (PWV) is an independent predictor of cardiovascular morbidity and mortality. Although recommended by the current guidelines, clinical applicability of this parameter is difficult, due to differences between the various techniques used to measure it and to biological variability. Our aim was to compare PWV assessed by 3 different commercially available systems. 100 subjects (51 ± 16 years, 45 men) were evaluated using the 3 methods: an oscillometric technique (Arteriograph, PWV-A); a piezo-electric method (Complior, PWV-C); and an high-resolution ultrasound technique implemented with an Echo-tracking system (Aloka, PWV-E). Conventional biological markers were measured. Correlations of PWV measured by the 3 methods were poor (r = 0.39, r = 0.39, and r = 0.31 for PWV-A vs. PWV-C, PWV-A vs. PWV-E, and PWV-C vs. PWV-E, respectively, all p < 0.05). By Bland-Altman analysis, mean difference (±SD) of PWV-A vs. PWV-C was -1.9 ± 2.0 m/s, of PWV-A vs. PWV-E -3.6 ± 1.9 m/s, and of PWV-C vs. PWV-E -2.7 ± 1.9 m/s, with a wide coefficient of variation (22.3, 25.7, and 25.7 %, respectively). As expected, PWV-A, PWV-C, and PWV-E correlated with other arterial stiffness parameters, such as intima-media thickness (r = 0.22, r = 0.22, and r = 0.36, respectively), E p (r = 0.37, r = 0.26, and r = 0.94, respectively), and augmentation index measured by Arteriograph method (r = 0.66, r = 0.35, and r = 0.26, respectively); all p < 0.05. Assessment of PWV is markedly dependent on the technique used to measure it, related to various methods for measuring traveled distance of the arterial wave. Our results suggest the urgent need to establish reference values of PWV for each of these techniques, separately, to be used in routine clinical practice.

Blood pressure values in healthy term newborns at a tertiary health facility in Enugu, Nigeria.

Blood pressure (BP) is a reflection of hemodynamic variables. It is an important vital sign and indicator of clinical stability. Accurate measurement of this physiological signal is essential for the optimal management of the ill infant. An increase in the awareness of hypertension among neonates has resulted to increased ability to diagnose neonates with the disease. This study aimed to determine BP values in apparently healthy term newborns in the first 48 h of life and evaluate the factors affecting BP at birth. Three hundred and ten healthy appropriate for gestational age term newborns were consecutively recruited. BP measurements were determined using the oscillometric technique with the neonate supine after an appropriate size cuff was applied on the right arm. The monitor (Dinamap 8100) is switched on while the cuff inflation and deflation is automatically done by the instrument with subsequent display of the BP values on the screen. BP measurements were taken at age 0-24 h and 25-48 h. Their weight was measured with infant's weighing scale, and data analyzed with SPSS version 15. The mean systolic BP (SBP), diastolic and mean arterial BP at 0-24 h were 63.3 ± 5.5 mmHg, 36.8 ± 5.3 mmHg and 46.4 ± 5.2 mmHg respectively. There was a positive correlation between birth weight and SBP at birth. No significant correlation was found between BP and gender, mode of delivery or maternal age. This study provides current normative BP values that can be used in neonatal Intensive Care Unit.

Sex and Race (Black-White) Differences in the Relationship of Childhood Risk Factors to Adulthood Arterial Stiffness: The Bogalusa Heart Study

BackgroundCardiovascular risk factors in childhood are predictive of adulthood arterial stiffness. However, it is unknown whether this relationship varies by race or sex. MethodsSix hundred and eighty adults aged 24 to 43 had been followed for an average of 26.3years, from the Bogalusa Heart Study. Brachial to ankle pulse wave velocity (bapWV) measured by an automatic oscillometric technique was used as the outcome variable for arterial stiffness during adulthood. Body mass index (BMi), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), glucose, and systolic blood pressure (SBP), all measured in childhood, were used as predictors. The average values of childhood measurements at multiple time points were used, standardized to age, race, and sex-specific z-scores. ResultsIn the total sample, childhood SBP was the only significant predictor (P<0.001) for adult baPWV. Significant interactions between sex and BMI (P=0.001), between sex and LDL-C (P=0.035), and between race and HDL-C (P=0.002) on adult baPWV were identified. Childhood predictors of adult baPWV were BMI (30.9cm/s reduction in baPWV per standard deviation increase, 95% confidence interval [CI]: −55.0, −6.9cm/s), LDL-C (30.8cm/s increase, 95% CI: 2.9, 59.5cm/s), and HDL-C (46.8cm/s reduction, 95% CI: −76.2, −17.4cm/s) in white males; SBP (38.2cm/s increase, 95% CI: 11.0, 65.4cm/s) in white females; BMI (71.3cm/s reduction, 95% CI: –119.9, −22.7cm/s) in black males; and none in black females. ConclusionsThe associations of childhood cardiovascular risk factors with adult arterial stiffness varied by race and sex.

Arterial stiffness estimation in healthy subjects: a validation of oscillometric (Arteriograph) and tonometric (SphygmoCor) techniques.

Arterial stiffness is an important cardiovascular risk marker, which can be measured noninvasively with different techniques. To validate such techniques in healthy subjects, we compared the recently introduced oscillometric Arteriograph (AG) technique with the tonometric SphygmoCor (SC) method and their associations with carotid ultrasound measures and traditional risk indicators. Sixty-three healthy subjects aged 20-69 (mean 48 ± 15) years were included. We measured aortic pulse wave velocity (PWVao) and augmentation index (AIx) by AG and SC, and with SC also the PWVao standardized to 80% of the direct distance between carotid and femoral sites (St-PWVaoSC). The carotid strain, stiffness index and intima-media thickness (cIMTmean) were evaluated by ultrasound. PWVaoAG (8.00 ± 2.16 m s(-1)) was higher (P<0.001) than PWVaoSC (6.87 ± 1.47 m s(-1)), but did not differ from St-PWVaoSC (7.68 ± 1.58 m s(-1)), and correlated (P<0.001) with both (r = 0.54 and 0.59). St-PWVaoSC was significantly (P < 0.01) higher than PWVaoAG for values below median (7.4 m s(-1)). PWVao by SC and AG differed significantly in females (P<0.001), but not in males (P=0.40). AIxaoAG (27.5 ± 14.5%) was higher (P < 0.001) than AIxaoSC (20.5 ± 17.4%), but related closely (r=0.97, P<0.001). St-PWVaoSC, PWVao and AIxao by SC, and PWVao and AIxao by AG were all related to serum cholesterol and to cIMTmean (P<0.001). Arterial stiffness indices by AG and SC correlate with vascular risk markers in healthy subjects. AIxao results by AG and SC are closely interrelated, but higher values are obtained by AG. In the lower range, PWVao values by AG and SC are similar, but differ for higher values. Our results imply the necessity to apply one and the same technique for repeated studies.

Three-Year Longitudinal Clinical Trial of Arterial Function Assessed by a Oscillometric Non-Invasive Method in Comparison With Carotid Sclerosis and Transferrin Kidney-Transplanted Patients

Chronic kidney disease remains one of the main risk factors of cardiovascular disease. However, patients with kidney transplantation have better life expectancy and better quality of life compared with patients on dialysis. In patients with a well-functioning graft, the main cause of death is cardiovascular in origin. Metabolic pathways have complex effects on arterial function that can be monitored by conventional ultrasonography and with the assessment of arterial stiffness by oscillometric non-invasive technique. Forty-one primer cadaver kidney–transplanted patient were involved in a 3-year longitudinal clinical trial (21 female, 20 male; average age, 40.16 ± 12.56 years). Arterial stiffness parameters referring to rigidity of the arterial wall (pulse wave velocity [PWV], augmentation index, and pulse pressure) were investigated. Correlation between stiffness, and laboratory parameters (serum creatinine, urea, hemoglobin, albumin, cholesterine, triglycerides, transferrin, uric acid, glomerular filtration rate, and C-reactive protein) were analyzed. A non-invasive oscillometric method—Tensiomed Arteriograph—was applied to assess the arterial stiffness parameters. Statistical analysis was performed with the use of Statistica for Windows, version 8.0. A value of P < .05 was considered statistically significant for all statistical tests. We found a positive correlation between PWV and left ventricular wall thickness and a negative correlation between PWV and ejection fraction. We also found a positive significant correlation between serum level of transferrin and PWV. There was simultaneous significant progression concerning PWV and carotid artery sclerosis in a 3-year follow-up. There was no fatal cardiovascular event during the study period among our patients. All of our patients involved in this study are still alive. Our findings suggest that arterial stiffness monitoring is a reliable method to assess global cardiovascular risk among kidney-transplanted patients. The oscillometric method is convenient, fast, painless technique to monitor arterial function, which, in the case of pathological findings, proposes more frequent cardiovascular control.

AB0969 Reliability of Measuring Aortic Stiffness in A Routine Rheumatology Clinic Setting

BackgroundCardiovascular (CV) disease is a major cause of mortality and morbidity in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) [1]and arterial stiffness (AS) may be an early...

Spectral analysis of femoral artery blood flow waveforms of conscious domestic cats.

The qualitative and quantitative aspects of femoral artery blood flow waveform spectra were evaluated in 15 male and 15 female Persian and mixed breed domestic cats (Felis catus), which were healthy and not sedated, using duplex Doppler ultrasonography (DDU). Spectral Doppler demonstrated a biphasic characteristic in 16 (53.34%) of the animals evaluated, and a triphasic characteristic in the 14 (46.66%) remaining animals. The systolic blood pressure and heart rate values were within the normal range for the species. The quantitative parameters evaluated, based on the spectral Doppler, were as follows: systolic velocity peak (SVP), recent diastolic velocity peak (RDVP), end diastolic velocity peak (EDVP), mean velocity (MV), integral velocity time (ITV), artery diameter (AD), femoral flow volume (FFV), pulsatility index (PI), resistive index (RI), systolic peak acceleration time (AT) and deceleration time (DT). The respective mean values were: 36.41 ± 7.33 cm/s, 4.69 ± 0.90 cm/s, 10.74 ± 2.74 cm/s, 23.06 ± 4.86 cm/s, 3.91 ± 1.05 cm, 0.17 ± 0.04 cm, 0.11 ± 0.08 cm(3), 3.85 ± 0.19, 1.40 ± 0.20, 39.84 ± 7.38 ms, and 114.0 ± 22.15 ms. No significant differences were found between males and females. The analyses carried out on the femoral artery flow spectrum obtained by DDU showed that it is easy to use and highly tolerated in non-sedated, healthy cats. It appears that DDU may be a useful diagnostic technique, but further studies are needed to evaluate how it compares with invasive telemetric methodology or high-definition oscillometric waveform analytic techniques.

Comparison of invasive and oscillometric blood pressure measurement techniques in anesthetized sheep, goats, and cattle

ObjectiveTo determine the level of agreement between an oscillometric (O-NIBP) and an invasive method (IBP) of monitoring arterial blood pressure (ABP) in anesthetized sheep, goats, and cattle. Study designProspective clinical study. AnimalsTwenty sheep and goats, 20 cattle weighing <150 kg body weight, and 20 cattle weighing >150 kg body weight. MethodsAnimals were anesthetized and systolic ABP (SABP), mean ABP (MABP), and diastolic ABP (DABP) were measured using IBP and O-NIBP. Differences between IBP and O-NIBP, and 95% limits of agreement (LOA) between SABP, MABP, and DABP values were assessed by the Bland–Altman method. ResultsMean difference ± standard deviation (range) between SABP, DABP, and MABP measurements in sheep and goats was 0 ± 16 (-57 to 38) mmHg, 13 ± 16 (-37 to 70) mmHg, and 8 ± 13 (-34 to 54) mmHg, respectively. Mean difference between SABP, DABP, and MABP measurements in small cattle was 0 ± 19 (-37 to 37) mmHg, 6 ± 18 (-77 to 48) mmHg, and 4 ± 16 (-73 to 48) mmHg, respectively. Mean difference between SABP, DABP, and MABP measurements in large cattle was -18 ± 32 (-107 to 71) mmHg, 7 ± 29 (-112 to 63) mmHg, and -5 ± 28 (-110 to 60) mmHg, respectively. The 95% LOAs for SABP, DABP, and MABP were -31 to +31, -19 to +44, and -19 to +34 mmHg, respectively in sheep and goats; were -37 to +37, -19 to +44, and -19 to +34 mmHg, respectively in small cattle; and were -81 to +45, -50 to +63, and -59 to +50 mmHg, respectively in large cattle. ConclusionsAgreement was poor between O-NIBP and IBP monitoring techniques. Clinical relevanceArterial BP should be monitored in anesthetized sheep, goats, and cattle using IBP.

On Employing Nonparametric Bootstrap Technique in Oscillometric Blood Pressure Measurement for Confidence Interval Estimation

Blood pressure (BP) is an important vital signal for determining the health of an individual subject. Although estimation of mean arterial blood pressure is possible using oscillometric blood pressure techniques, there are no established techniques in the literature for obtaining confidence interval (CI) for systolic blood pressure (SBP) and diastolic blood pressure (DBP) estimates obtained from such BP measurements. This paper proposes a nonparametric bootstrap technique to obtain CI with a small number of the BP measurements. The proposed algorithm uses pseudo measurements employing nonparametric bootstrap technique to derive the pseudo maximum amplitudes (PMA) and the pseudo envelopes (PE). The SBP and DBP are then derived using the new relationships between PMA and PE and the CIs for such estimates. Application of the proposed method on an experimental dataset of 85 patients with five sets of measurements for each patient has yielded a smaller Cl than the conventional student t-method.

Tidal breathing flow measurement in awake young children by using impedance pneumography

Characteristics of tidal breathing (TB) relate to lung function and may be assessed even in young children. Thus far, the accuracy of impedance pneumography (IP) in recording TB flows in young children with or without bronchial obstruction has not been evaluated. The aim of this study was to evaluate the agreement between IP and direct flow measurement with pneumotachograph (PNT) in assessing TB flow and flow-derived indices relating to airway obstruction in young children. Tidal flow was recorded for 1 min simultaneously with IP and PNT during different phases of a bronchial challenge test with methacholine in 21 wheezy children aged 3 to 7 years. The agreement of IP with PNT was found to be excellent in direct flow signal comparison, the mean deviation from linearity ranging from 2.4 to 3.1% of tidal peak inspiratory flow. Methacholine-induced bronchoconstriction or consecutive bronchodilation induced only minor changes in the agreement. Between IP and PNT, the obstruction-related tidal flow indices were equally repeatable, and agreement was found to be high, with intraclass correlation coefficients for T PTEF/T E, V PTEF/V E, and parameter S being 0.94, 0.91, and 0.68, respectively. Methacholine-induced changes in tidal flow indices showed significant associations with changes in mechanical impedance of the respiratory system assessed by the oscillometric technique, with the highest correlation found in V PTEF/V E (r = -0.54; P < 0.005 and r = -0.55; P < 0.005 by using IP or PNT, respectively). The results indicate that IP can be considered as a valid method for recording tidal airflow profiles in young children with wheezing disorders.

An Optimized Algorithm to Measure Arterial Blood Pressure

Blood pressure is one of the most important indexes for human beings health. This paper presents an optimized algorithm to measure arterial blood pressure based on oscillometric technique. The bilateral filter and Gaussian-fitting method are respectively expressed to apply in noise eliminating, oscillation pulse extracting and curve fitting. The systolic pressure and diastolic pressure are determined by combination of proportional coefficient method, maximum slope method and curvature method. Moreover, a judgment for arrhythmias is employed in heart rate calculation. Experimental results have proved the precision and accuracy of the algorithm.

Comparison of invasive versus noninvasive blood pressure measurements before and after hemorrhage in anesthetized greyhounds using theSurgivetV9203

To determine the agreement between blood pressure obtained with a noninvasive technique and direct technique using the Surgivet V9203 at varying blood pressure levels created using a canine hemorrhage model. Experimental study. University Teaching Hospital. Twenty-nine greyhounds with an average weight of 30 kg. Approval from the Murdoch University Animal Ethics Committee was obtained (R228609). Arterial blood pressure (BP) was measured noninvasively (NIBP) via a cuff placed over the dorsal metatarsal artery and via a catheter in the contralateral dorsal metatarsal artery (IBP). Retrospectively the blood pressure measurements recorded were divided into various BP categories. A total of 84 paired readings were obtained. The data were further analyzed with respect to heart rate [<120/min and >120/min]. Comparison of the measurements was performed using the Bland-Altman method. For all categories, BP measurements were generally lower when recorded using the oscillometric technique [Systolic (Sys) bias 4.20 kPa (31.54 mm Hg), mean bias 0.52 kPa (3.93 mm Hg), and diastolic bias 1.04 kPa (7.83 mm Hg)]. Mean arterial BP had the least bias and greatest precision in the hypotensive group (bias 0.174 kPa (1.3063 mm Hg), precision 0.79 kPa (5.89 mm Hg)), low BP group (bias 0.62 kPa (4.67mm Hg) and precision 0.89 kPa (6.67mm Hg)) and normotensive group [bias 0.76 kPa (5.71 mm Hg) and precision 1.16 kPa (8.73 mmHg)]. The results demonstrate that the agreement between NIBP measurements and IBP, are within the limits of agreement recommended by the American College of Veterinary Internal Medicine Hypertension Consensus Panel for all pressures except Sys BP. This suggests that mean and diastolic NIBP using the Surgivet V9203 are a clinically acceptable alternative of IBP in hypovolemic hypotensive dogs.

Evaluation of the oscillometric technique for intermittent non-invasive arterial blood pressure measurement in the anaesthetized pig

This study was designed to evaluate the oscillometric technique for intermittent non-invasive measurement of arterial pressure (AP) in the anaesthetized pig. In six pigs under sevoflurane anaesthesia, intermittent (every 2 minutes) oscillometric measurements of AP made at a forelimb (FL), a hindlimb (HL) and the tail base were compared with simultaneous direct AP measurements made at the aortic arch (AA) over a wide pressure range (30-140 mmHg of mean AP). All oscillometric measurements strongly correlated (Pearson correlation coefficient >0.837, P < 0.001) with direct AP measurements, with those made at the FL exhibiting the highest correlation. On the basis of consistency of difference between oscillometric and AA pressure readings at graded pressure levels, measurements made at the tail base provided reliable prediction of systolic AP, at the FL of diastolic AP and at both the tail base and the FL of mean AP. In conclusion, oscillometric measurements at the FL and the tail base offer reliable prediction of AP in the anaesthetized pig.

Putting Evidence Into Nursing Practice: Four Traditional Practices Not Supported by the Evidence

Evidence-based nursing practice is essential to the delivery of high-quality care that optimizes patients' outcomes. Studies continue to show improved outcomes when best evidence is used in the delivery of patient care. Despite awareness of the importance of practicing by using best evidence, achieving and sustaining evidence-based practice within practice environments can be challenging, and research suggests that integration of evidence-based practice into daily clinical practice remains inconsistent. This article addresses 4 practice issues that, first, are within the realm of nursing and if changed might improve care of patients and, second, are areas in which the tradition and the evidence do not agree and practice continues to follow tradition. The topics addressed are (1) noninvasive measurement of blood pressure in children, (2) oxygen administration for patients with chronic obstructive pulmonary disease, (3) intravenous catheter size and blood administration, and (4) infection control practices to prevent infections. The related beliefs, current evidence, and recommendations for practice related to each topic are described.

Abstract WP197: Race (Black-White) and Sex Divergences in the Relationship of Childhood Cardiovascular Risk Factors to Arterial Stiffness in Adulthood: The Bogalusa Heart Study

Arterial stiffness is an important risk factor for cardiovascular diseases including stroke. It has been established that childhood cardiovascular (CV) risk factors are predictive of adulthood arterial stiffness as measured by pulse wave velocity. Limited information is available on this relationship such as race- and sex-specific differential effects. This aspect was examined in a black-white, longitudinal cohort of 786 adults (28% blacks, 42% men) aged 23-44 years who were examined as both children (age&lt;18 years) and adults (age≥18 years) for traditional CV risk factors with an average follow-up period of 24.2 years. Multiple childhood measurements were averaged and standardized to age-specific z-scores. Brachial-ankle pulse wave velocity (baPWV) measured by an automatic oscillometric technique was used as an index of arterial stiffness in adults. Systolic blood pressure in childhood was predictive of baPWA in adults (P=0.002) in the total cohort. However, nominally significant (P&lt;0.05) childhood predictors of adult baPWV included body mass index (BMI), low-density lipoprotein cholesterol (LDL-C) and systolic blood pressure in white men; systolic blood pressure in white women; and BMI in black women. For race difference, childhood LDL-C tended to show a stronger effect on baPWA in adults in whites than in blacks (P=0.04). For sex difference, BMI tended to be a stronger predictor and LDL-C a weaker predictor in women than in men (P=0.0002 and P=0.003, respectively). Such differences persisted even after adjustment for adulthood risk factors (P&lt;0.05 in all cases). In conclusion, the predictability of childhood CV risk factors for increased arterial stiffness in adulthood varies by race and sex, and this observation indicates that arterial stiffening is different in blacks vs whites and in men vs women.

Comparison of high definition oscillometric and Doppler ultrasound devices with invasive blood pressure in anaesthetized dogs

ObjectiveTo use the American College of Veterinary Internal Medicine (ACVIM) validation criteria to evaluate the performance of high definition oscillometric (HDO) and Doppler blood pressure measurement techniques against invasive blood pressure measurements in anaesthetized dogs. Study designProspective clinical study. AnimalsTwenty client-owned dogs. Materials and MethodsInvasive blood pressure was measured using a catheter inserted into a pedal artery and an electronic transducer. The sites of cuff placement for the HDO measurements were the mid antebrachium or the proximal tail and, for the Doppler technique, the distal tibia. Agreement between invasive and non-invasive blood pressure measurements was estimated by the Bland–Altman method. ResultsOnly 10% and 34% of Doppler measurements were within 10 and 20 mmHg of invasive blood pressure values, respectively. The Doppler device failed to meet the ACVIM validation criteria for blood pressure measurement devices. The best agreement between HDO and invasive blood pressure measurement technique was observed for mean arterial blood pressure (MAP); 67% and 95% of readings were within 10 and 20 mmHg of invasive blood pressure values respectively. In addition, 52% and 87% of diastolic arterial blood pressure (DAP) measurements were within 10 and 20 mmHg of invasive readings. High definition oscillometric readings did not meet ACVIM recommended limits for SAP. Conclusion and clinical relevanceThe Doppler technique overestimated and the HDO device showed limited agreement with invasive blood pressure measurement in anaesthetized dogs. High definition oscillometry met most of the ACVIM requirements for MAP and DAP while the Doppler technique did not.

Diastolic Ankle-Brachial Indices as a Complementary Measure to Screen for Peripheral Arterial Disease in Diabetic Patients

Introduction Ankle-brachial systolic pressure ratio or Index (ABI or ABI-S) has influenced cardiovascular screening for decades. Total or partial rigidity (i.e. calcification) of tibial arteries has hampered Doppler ABI-S measurements in patients with diabetes. Diastolic pressures are measurable with the oscillometric technique. The authors of a previous study demonstrated that ABI-D (ankle-brachial index based on diastolic pressure ratio) was less sensitive than ABI-S, but partial or total incompressibility of tibial arteries was suspected if ABI-D &lt; ABI-S. This study examined whether ABI-D added information to screen for peripheral arterial disease (PAD) in patients with diabetes. Methods An “eye-to-foot” screening/educational program was performed at the city of Arapiraca, state of Alagoas, northeast of Brazil. A vascular surgeon, an expert on the diabetic foot, selected subjects with decreased pulse and/or older age. Bilateral arm and ankle pressures were performed in 71 diabetic patients: 47 (66%) women and 24 (34%) men, 68 ± 10 years (range, 46–86). ABI-S and ABI-D were calculated on the basis of bilateral brachial and ankle oscillometric pressures. Screening for PAD was compared on the basis of the prevalence of ABI &lt; 0.90. Results ABI-S, ABI-D, or either ABI &lt; 0.90 were detected in 36 (51%), 48 (68%), and 55 (77%) diabetics, respectively. ABI-S and ABI-D, only ABI-S, or only ABI-D were &lt;0.90 in 53% (n = 29), 13% (n = 7), and 35% (n = 19) of the 55 diabetics with ABI &lt; 0.90. The increase in frequency of ABI &lt; 0.90 was significant if ABI-D complemented ABI-S ( p &lt; 0.001 by chi-square). ABI-D and ABI-S were 0.83 ± 0.06 (0.68–0.895) versus 1.01 ± 0.10 (0.92–1.30) in the only ABI-D &lt; 0.90 group. Conclusions Diastolic ankle pressures were estimated successfully by use of the oscillometric technique. Diastolic ABI correlated with expert physician assessment and contributed to quantitative screening for PAD in diabetic patients with apparently falsely elevated systolic ABI caused by partial incompressibility of tibial arteries.

Requirements for professional office blood pressure monitors

For more than half a century measurement of blood pressure in the doctor's office using a mercury sphygmomanometer and the auscultatory method has been the cornerstone for hypertension management. However, due to the environmental and service issues mercury devices will not be available in the near future. As the mercury sphygmomanometer is being progressively eliminated from clinical use, it is being replaced by a variety of devices, which may not have been validated. This change in the practice of measurement may have an unpredictable impact on the threshold levels used for the diagnosis of hypertension and may also influence the management of hypertension. This expert document provides (i) information on the current availability of technologies and devices with potential for professional use (oscillometric, hybrid, aneroid and mercury devices) and the advantages and limitations of each one of them, and (ii) guidance on the requirements and selection of mercury-free blood pressure monitors for professional use. With the increasing use of automated oscillometric devices it is likely that the auscultatory technique will soon become redundant. However, consideration will be given to some of the technical aspects of the oscillometric technique and to the educational aspects of auscultation that may make it premature to abandon the technique altogether.