Auscultatory Blood Pressure Measurement Research Articles

AN EXPLANATION FOR UNDERESTIMATION OF SYSTOLIC PRESSURE IN CUFF-BASED MEASUREMENT

Objective: Auscultatory blood pressure measurement is the gold standard used to calibrate other measurement devices. However, auscultatory tests systematically underestimate systolic blood pressure (SBP) and overestimate diastolic blood pressure (DBP). While there is some literature explaining overestimation, there is no physical understanding of the underestimated SBP. Our objective is to understand why auscultatory measurement results in the underestimation of SBP. The SBP is recorded when the artery first begins to reopen, during cuff deflation. Prior to this, the cuff cuts off the blood supply and the pressure in the distal part of the artery drops to the venous pressure. We propose this low pressure as a cause of underestimation and investigate this through a controlled variation of the downstream pressure in an experimental rig. Design and method: Figure 1 shows a schematic of the rig. The tube representing the artery is compressed under an inflatable cuff. The downstream pressure is varied between tests. The upstream pressure is fixed with a header tank for simplicity. Therefore, the ‘blood pressure’ measured in the rig is constant rather than oscillatory, resulting in only a single opening of the artery as the cuff is deflated, rather than repeated opening and closing. This single opening is equivalent to the first opening of the artery in the body and so represents the systolic measurement. Figure 2 depicts an example test run. The cuff around the artery is gradually deflated, and the reopening of the artery is indicated by the rise of the downstream pressure (point a). The cuff pressure at this timestamp is recorded (point b), representing the measured SBP. Results: Figure 3 shows that the recorded cuff pressure is a function of downstream pressure, with the cuff reading giving greater underestimation of SBP when the downstream pressure is lowered. Conclusions: The delay in artery reopening which results from lowering the downstream pressure provides an explanation for the systematic underestimation of SBP. This information may lead to recommendations for new measurement protocol which avoid a drop in the pressure distal to the cuff, and the resulting underestimation of SBP.

Visual assessment of Korotkoff sounds improves the accuracy of a validated professional automated auscultatory blood pressure monitor KOROT P3 Accurate.

A novel automated auscultatory upper-arm cuff blood pressure (BP) monitor for office use (KOROT P3 Accurate, previously InBody BPBIO480KV), which displays Korotkoff sound curves for each BP reading was recently developed. This study investigated whether the review of Korotkoff sound curves by healthcare professionals further improves the accuracy of the device by identifying unreliable BP readings. Three observers assessed independently the morphology of Korotkoff sound curves of BP measurements obtained during an ISO 81060-2:2018 validation study, and classified them as of good, fair, or poor quality (low amplitude or sound intensity, aberrant morphology, background noise, signal artifact, auscultatory gap, irregular rhythm). The observers were blinded to the study BP measurements. Korotkoff sound curves of 255 BP readings obtained in 85 individuals were analyzed (mean age 57.3 ± 15.0 years, 53 men). Of the SBP readings 80.4/12.2/7.4% were classified as good/fair/poor, and DBP 76.9/12.2/10.9%. Inter-observer agreement in detecting poor-quality curves was 84.7/83.1% (systolic/diastolic). Of poor-quality curves, 10.5/60.7% (systolic/diastolic) clustered in the same individuals. The validation criterion 1 [mean test-reference BP difference ≤5 ± 8 (SD) mmHg] was satisfied for readings with good (0.1 ± 4.9/0.3 ± 3.8 mmHg, systolic/diastolic) and fair-quality curves (-0.4 ± 6.4/0.2 ± 5.0), but not for poor-quality ones (2.7 ± 8.8/3.6 ± 8.1). By excluding poor-quality readings (40 of 255), criterion 1 of the validation study was improved (0.2 ± 4.9/0.2 ± 3.9 versus 0.3 ± 5.5/0.6 ± 4.7 mmHg). The visual assessment of Korotkoff sounds generated during automated auscultatory BP measurement by the KOROT P3 Accurate professional monitor identifies unreliable readings and further improves the device accuracy.

Assessment of Cardiovascular Indices in Obese Women Resident in Rivers State, Nigeria

Cardiovascular diseases (CVDs), which are often thought to be a “man’s” challenge, are now recorded as the primary cause of death for women globally. Consequently, the present study set out to assess the cardiovascular indices in obese women resident in Rivers State, Nigeria. Utilizing the Leslie Fischer's formula; exactly 334 obese and non-obese women within their 18 and 65 years of age with no obvious health condition and resident in Upland and Riverine areas of Rivers State were recruited by the present study. The multistage sampling technique was used, and subjects were drawn across the upland and riverine locations of the State. Consenting subjects were randomly surveyed from the multi-ethnic residents of the state. Anthropometric (body mass index-BMI) data and auscultatory blood pressure measurement were done using Seca weight/height scale and mercury sphygmomanometer and stethoscope respectively. Electrocardiographic (ECG) features were recorded using the standard resting 12 – lead ECG. Numerical data obtained were subjected to statistical analyses using the statistical package for social sciences (SPSS) version 21.0. One-way analysis of variance (ANOVA) and independent t-test with a p< 0.05 considered statistically significant were determined. The BMI values were generally higher in the RVR subjects when compared to their UPL counterparts, but only that of obese class II were significant (P<0.05) of the aforementioned increases. The systolic and diastolic blood pressure (SBP and DBP) of all subjects indicated graded increases from obese class I to obese class III and these increases were seen to be significant (P<0.05) when compared to that of the non-obese and down the successive groups. The ECG features in the non-obese and obese class I subgroups indicated higher prevalence of left ventricular hypertrophy in the UPL residents than the RVR residents. The study thus found that there was a significantly raised prevalence of obesity in younger RVR .......

B3X: a novel efficient algorithm for accurate automated auscultatory blood pressure estimation

Objective. The auscultatory technique is still considered the most accurate method for non-invasive blood pressure (NIBP) measurement, although its reliability depends on operator’s skills. Various methods for automated Korotkoff sounds analysis have been proposed for reliable estimation of systolic (SBP) and diastolic (DBP) blood pressures. To this aim, very complex methodologies have been presented, including some based on artificial intelligence (AI). This study proposes a relatively simple methodology, named B3X, to estimate SBP and DBP by processing Korotkoff sounds recordings acquired during an auscultatory NIBP measurement. Approach. The beat-by-beat change in morphology of adjacent Korotkoff sounds is evaluated via their cross-correlation. The time series of the beat-by-beat cross-correlation and its first derivative are analyzed to locate the timings of SBP and DBP values. Extensive tests were performed on a public database of 350 annotated measurements, and the performance was evaluated according to the BHS, AAMI/ANSI, and International Organization for Standardization (ISO) quality standards. Main results. The proposed approach achieved ‘A’ scores for SBP and DBP in the BHS grading system, and passed the quality tests of AAMI/ANSI and ISO standards. The B3X algorithm outperformed two well-established algorithms for oscillometric NIBP measurement in both SBP and DBP estimation. It also outperformed four AI-based algorithms in DBP estimation, while providing comparable performance for SBP, at the cost of a much lower computational burden. The full code of the B3X algorithm is provided in a public repository. Significance. The very good performances ensured by the proposed B3X algorithm, at a low computational cost and without the need for parameter training, support its direct implementation into clinical blood pressure (BP) monitoring devices. The results of this study pave the way for solving/overcoming the trade-off between the accuracy of the auscultatory technique and the objectivity of oscillatory measurements, by bringing an automated auscultatory BP measurement method in clinical practice.

Correlation between electronic wrist blood pressure with auscultatory blood pressure in children.

The increasing prevalence of obesity in children and adolescents has turned hypertension into an important public health issue. In the current literature, auscultatory blood pressure measurement is recommended for the diagnosis of hypertension. The number of studies comparing electronic blood pressure measurement and auscultatory blood pressure measurement is limited. This study aimed to compare auscultatory blood pressure measurement with electronic blood pressure measurement in the children population group aged 5-15 years. A total of 72 patients aged between 5-15 years without chronic disease were included in the study. Anthropometric measurements (height, weight, body mass index, wrist circumference, mid-upper arm circumference) were performed. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were first measured electronically from the wrist using an Omron Rs7 Intelli It HEM-6232T device, and then auscultatory measurements were performed. Each type of measurement was performed 3 times intermittently. The mean wrist circumference was 14.43±0.22 cm and the mean mid-upper arm circumference was 21.43±0.55 cm. Mean SBP, DBP and MAP measured electronically on the wrist were 104.1±1.5, 65.6±1.3 and 78.1±1.3 mmHg, respectively, and mean SBP, DBP and MAP measured via auscultation were 99.3±1, 61.4±0.7 and 73.6±0.7 mmHg, respectively. Electronically-measured wrist MAP had significantly moderate correlations with mid-upper arm and wrist circumference (r:0.547, r:0.559, p<0.01). Since the differences were less than 4 mmHg in both systolic and diastolic pressures between electronic wrist blood pressure (EWBP) measurement and auscultatory measurement, it appears that electronic measurement may be important in first line of blood pressure screening. Since it is easy and practical to use in the early period, it may be an alternative approach to auscultatory measurement among non-critical pediatric patients.

VISUAL ASSESSMENT OF KOROTKOFF SOUNDS FURTHER IMPROVES THE ACCURACY OF A VALIDATED PROFESSIONAL AUTOMATED AUSCULTATORY BLOOD PRESSURE MONITOR – INBODY BPBIO480KV

Objective: A novel automated auscultatory upper-arm cuff blood pressure (BP) monitor for office use (InBody BPBIO480KV, Seoul, S Korea) has been recently validated, which allows healthcare professionals to visually review the Korotkoff sounds curves generated for each BP reading. This study investigated whether this feature could further improve the accuracy of the device by identifying unreliable BP readings. Design and method: Three observers assessed independently the morphology of Korotkoff sound curves generated during a validation study according to the ISO 81060-2:2018 standard, and classified them as having good, fair, or poor signal quality (low signal amplitude or sound intensity, aberrant signal morphology, interference of background noise or other signal artifact, presence of auscultatory gap, or irregular rhythm), separately for the systolic and diastolic BP area. The observers were blinded to the automated and the reference BP measurement results. Disagreement among observers was resolved by a supervisor. Factors associated with poor quality signal were also investigated. Results: A total of 255 Korotkoff sound curves (test BP readings) by 85 participants (mean age 57.3±15.0 years, 53 men) were analyzed. For systolic BP, 82.0/12.2/7.5% were classified as good/fair/poor quality and for diastolic 76.9/12.2/11.0%. Inter-observer agreement in detecting poor quality curves was 84.7/83.1% (systolic/diastolic). Of poor quality curves 10.5/60.7% (systolic/diastolic) clustered in the same individuals. Young age and female sex increased the odds for poor quality signal. ISO validation Criterion 1 (mean BP difference ±SD) was satisfied for readings with good (0.1±4.9/0.3±3.8 mmHg, systolic/diastolic) and fair (-0.4±6.4/0.2±5.0) quality curves, good/fair quality curves (0.1±5.1/0.2±4.0 mmHg, systolic/diastolic), but not for those with poor quality signal (2.7±8.8/3.6±8.1 mmHg). In the ISO validation study, excluding readings with poor quality signal (systolic and/or diastolic area; 40 of 255) Criterion 1 was improved (0.2±4.9/0.2±3.9 mmHg versus 0.3±5.5/0.6±4.7 mmHg). Conclusions: The visual assessment of Korotkoff sounds generated by automated auscultatory BP measurement using the InBody BPBIO480KV professional office BP monitor is useful in identifying unreliable readings and further improves the device accuracy.

Agreement of Oscillometric and Auscultatory blood pressure measurement methods: An ambulance noise simulation study

ObjectiveAlthough noise is known to negatively affect blood pressure (BP) measurements, its impact on different BP measurement methods remains unclear. The aim of this study is to compare the agreement of oscillometric and auscultatory BP measurement methods under in-ambulance noise levels. MethodsThis method-comparison study was conducted on 50 healthy volunteers in a tertiary emergency department (ED). Participants were divided into two groups of 25, and BP was measured using auscultatory and oscillometric methods in noisy and ambient environments by 2 emergency medicine technicians (EMT). The primary object of the study was to compare the agreement of auscultatory mercury sphygmomanometers and automated auscillometric BP measurements in ambient and noisy environments. ResultsWe examined the agreement between auscultative and oscillometric measurements of BP conducted in an ambient environment (46.75 [IQR (41.2--55.18)] dB) and found that both systolic and diastolic BP were within the level of agreement (LoA) established before the study (systolic BP [−13.96 to 8.48 mmHG], diastolic BP [−7.44 to 8.08 mmHg]); whereas, in noisy environment (92.35 [IQR 88–96.55] dB) both systolic and diastolic BP were outside the range of LoA (systolic BP [−37.77 to 9.94 mmHg], diastolic BP [−21.73 to 16.37 mmHg]). Additionally, we found that in ambient environments, concordance correlation coefficients were higher than in noisy environments (0.943 [0.906–0.966], 0.957 [0.93–0.974]; 0.574 [0.419–0.697], 0.544 [0.326–0.707]; systolic and diastolic BP, respectively). ConclusionThe results of this study demonstrate that noise significantly affects the agreement between oscillometric and auscultatory blood pressure measurement methods.

Assessment of the Uncertainty Associated With Two Consecutive Blood Pressure Measurements Using the Auscultatory Method

Accurate non-invasive blood pressure measurements are vital in preventing and treating many cardiovascular diseases. The “gold standard” for non-invasive procedures is the auscultatory method, which is based on detecting Korotkoff sounds while deflating an arm cuff. Using this method as a “gold standard” requires highly-trained technicians and has an intrinsic uncertainty in its blood pressure predictions. In this paper, we analyze and characterize the origins of this uncertainty. This paper defines an uncertainty model for two consecutive blood pressure measurements. Our research group developed a computer-based simulation of auscultatory blood pressure measurement uncertainty, and these results were compared to a human-subject experiment with a group of 20 diverse-conditioned individuals. Uncertainties were categorized and quantified. The total computer-simulated uncertainty ranged between -8.4 mmHg to 8.4 mmHg in systolic blood pressure and -8.4 mmHg to 8.3 mmHg in diastolic blood pressure at a 95% confidence interval, while the limits in the human-based study ranged from -8.3 mmHg to 8.3 mmHg in systolic blood pressure and -16.7 mmHg to 4.2 mmHg in diastolic blood pressure.

Oscillometric vs. Auscultatory Blood Pressure Measurements and the Impact of Atrial Fibrillation

Oscillometric vs. Auscultatory Blood Pressure Measurements and the Impact of Atrial Fibrillation

Development and validation of a deep learning-based automatic auscultatory blood pressure measurement method

Manual auscultatory is the gold standard for clinical non-invasive blood pressure (BP) measurement, but its usage is decreasing as it requires substantial professional skills and training, and its environmental concerns related to mercury toxicity. As an alternative, automatic oscillometric technique has been used as one of the most common methods for BP measurement, however, it only estimates BPs based on empirical equations. To overcome these problems, this study aimed to develop a deep learning-based automatic auscultatory BP measurement method, and clinically validate its performance. A deep learning-based method that utilized time-frequency characteristics and temporal dependence of segmented Korotkoff sound (KorS) signals and employed convolutional neural network (CNN) and long short-term memory (LSTM) network was developed and trained using KorS and cuff pressure signals recorded from 314 subjects. The BPs determined by the manual auscultatory method was used as the reference for each measurement. The measurement error and BP category classification performance of our proposed method were then validated on a separate dataset of 114 subjects. Its performance in comparison with the oscillometric method was also comprehensively analyzed. The deep learning method achieved measurement errors of 0.2 ± 4.6 mmHg and 0.1 ± 3.2 mmHg for systolic BP and diastolic BP, respectively, and achieved high sensitivity, specificity and accuracy (all > 90 %) in classifying hypertensive subjects, which were better than those of the traditional oscillometric method. This validation study demonstrated that deep learning-based automatic auscultatory BP measurement can be developed to achieve high measurement accuracy and high BP category classification performance.

IS AUSCULTATION ADEQUATE TO ESTIMATE BLOOD PRESSURE RESPONSES RELATED TO BODY POSITION CHANGES?

Abstract Objective: The auscultatory blood pressure (BP) measurement technique, relying on the K1 and K5 Korotkoff sounds, is the current reference to validate new devices in the standard sitting position. There are few data to tell whether it should also be used for device validation in other body positions, since the K1 and K5 sounds can be affected by changes in vascular tone. In this study, we recorded the BP responses to body position changes by the auscultatory method, and we compared them to data from simultaneous recordings by a volume-clamp method. Design and method: Systolic (SBP) and diastolic (DBP) were estimated on the left upper arm by two independent blinded observers, and on the ipsilateral middle finger by a volume-clamp device (Nexfin, BMEYE, The Netherlands) in the supine followed by the standing position, and in the standing followed by the supine position. The auscultatory readings were repeated if readings differed more than 4mmHg between the two observers. A first auscultation was performed before the position change, and a second one 150 s after the position change. Because volume-clamp measurements were not available during upper-arm cuff inflation, the mean of volume-clamp values in a 30 s window prior to auscultation onset were used for the analyses. Results: Sixty-seven participants, between 21 and 65 years old, participated in this study. As illustrated in the figure, volume-clamp reported a consistent mean DBP increase of 9.3 mmHg when moving from supine to sitting, and a consistent mean DBP decrease of 10.4 mmHg when moving from sitting to supine. These results agree with those previously reported using simultaneous invasive and volume-clamp measurements. On the contrary, auscultation detected no consistent body position-related change in the DBP readings. Neither auscultation nor volume-clamp detected consistent body position-related changes in SBP readings. Conclusions: Compared to volume-clamp, auscultation was not able to detect any consistent changes in BP during orthostatic challenge. Our study suggests that the use of Korotkoff sounds to estimate BP in body positions other than sitting and relaxed may not be appropriate.

Validation of the blood pressure measurement technology used in the Novacor Diasys 3 Plus (DIP-0001-00) upper-arm device for ambulatory blood pressure measurement, according to AAMI/ANSI/ISO 81060-2: 2013, ESH-IP 2010 and MEDDEV 2.7/1.

The objective of this study was to determine the accuracy of the auscultatory and oscillometric blood pressure (BP) measurement technologies of the Novacor Diasys 3 Plus (model number DIP-0001-00) BP monitor, intended for ambulatory BP measurement when used with the recommended Standard Plus (ACC-0210-00), Large Plus (ACC-0211-00) and Paediatric Plus (ACC-0212-00) cuffs. The auscultatory measurement technology Novacor Diasys 3 Plus (model number DIP-0001-00) was evaluated according to the requirements of the AAMI/ANSI/ISO 81060-2:2013 standard, including an additional cardiac-stress study, a requirement for ambulatory BP measurement devices. It was also validated according to the requirements of the European Society of Hypertension International Protocol revision 2010. The oscillometric measurement technology was compared to that of the Novacor Diasys 3 (model number DIS-0001-00) according to the equivalence requirements of MEDDEV 2.7/1 rev 4. The protocol requirements for all three studies and the equivalence were followed precisely. The Novacor Diasys 3 Plus (model number DIP-0001-00) fulfilled all of the requirements for a pass in each of the three studies of the auscultatory measurement technology. In the primary AAMI/ANSI/ISO 81060-2:2013 study, the criterion 1 errors were + 3.6 ± 2.7 mmHg for SBP and + 3.0 ± 2.7 mmHg for DBP. It was also proven to be equivalent to the Novacor Diasys 3 (model number DIS-0001-00) with respect to the oscillometric measurement technology CONCLUSION: The Novacor Diasys 3 Plus (model number DIP-0001-00), when used with the recommended cuffs, can be recommended for ambulatory BP measurement in the adult population.

PCA-Based Multi-Wavelength Photoplethysmography Algorithm for Cuffless Blood Pressure Measurement on Elderly Subjects.

The prevalence of hypertension has made blood pressure (BP) measurement one of the most wanted functions in wearable devices for convenient and frequent self-assessment of health conditions. The widely adopted principle for cuffless BP monitoring is based on arterial pulse transit time (PTT), which is measured with electrocardiography and photoplethysmography (PPG). To achieve cuffless BP monitoring with more compact wearable electronics, we have previously conceived a multi-wavelength PPG (MWPPG) strategy to perform BP estimation from arteriolar PTT, requiring only a single sensing node. However, challenges remain in decoding the compounded MWPPG signals consisting of both heterogeneous physiological information and motion artifact (MA). In this work, we proposed an improved MWPPG algorithm based on principal component analysis (PCA) which matches the statistical decomposition results with the arterial pulse and capillary pulse. The arteriolar PTT is calculated accordingly as the phase shift based on the entire waveforms, instead of local peak lag time, to enhance the feature robustness. Meanwhile, the PCA-derived MA component is employed to identify and exclude the MA-contaminated segments. To evaluate the new algorithm, we performed a comparative experiment (N = 22) with a cuffless MWPPG measurement device and used double-tube auscultatory BP measurement as a reference. The results demonstrate the accuracy improvement enabled by the PCA-based operations on MWPPG signals, yielding errors of 1.44 ± 6.89 mmHg for systolic blood pressure and -1.00 ± 6.71 mm Hg for diastolic blood pressure. In conclusion, the proposed PCA-based method can improve the performance of MWPPG in wearable medical devices for cuffless BP measurement.

Recommendations for blood pressure measurement in large arms in research and clinical practice: position paper of the European society of hypertension working group on blood pressure monitoring and cardiovascular variability.

: Blood pressure measurement in obese individuals can be challenging because of the difficulty in properly cuffing large upper arms. Achieving a proper cuff fit can be problematic especially in people with a shorter arm length relative to circumference. This expert statement provides recommendations on blood pressure measurement in large arms for clinical use and research purposes. Tronco-conically shaped cuffs should be used in people with large arms, especially with arm circumferences greater than 42 cm as they better fit on the conical arm shape. Cuffs with frustum of the cone slant angle of 85° should satisfy most conditions. In individuals with short upper-arm that does not allow application of a properly sized cuff, wrist or forearm measurement might be used in clinical practice, but not for validation of automatic devices. Wide-range cuffs coupled to oscillometric devices provided with special software algorithms can also be used as alternatives to standard cuff measurement, provided they are independently validated per AAMI/ISO 81060-2 protocol. For validation studies, the intraarterial measurement is generally considered as the gold standard, yet for possible methodological pitfalls and ethical concerns, it is not recommended as the method of choice. Tronco-conical cuffs with inflatable bladder dimensions of 37-50 × 75-100% arm circumference should be used for reference auscultatory blood pressure measurement wherever the upper arm length allows a proper fit. There is a need for future studies that help identify the optimal shape of cuffs and bladders investigating the influence of sex, age, arm physical properties, and artery characteristics.

Gagné’s 9 Events of Instruction With Active Learning: Teaching Student Pharmacists How to Measure Blood Pressure

As the scope of practice for pharmacists expands to include rendering physical assessment procedures, colleges and schools of pharmacy are increasingly incorporating various assessment skills into the curriculum. Pharmacy practice faculty are increasingly tasked with teaching and assessing learners on professional competency in entrustable professional activities and skills such as manual blood pressure measurement. Manual measurement using a sphygmomanometer and a stethoscope is considered the gold standard with regard to evaluating blood pressure. As pharmacy faculty begin to develop courses on physical assessment, a step-by-step, evidence-based andragogic/pedagogic method for designing, planning, instructing, and assessing learner proficiency is essential. The principles and techniques of active learning are frequently discussed and increasingly incorporated into the curricular and teaching philosophies of colleges and schools of pharmacy. However, the practical application of andragogic/pedagogic principles toward lesson planning and curation of active learning is infrequently discussed. In this article, we aim to illustrate a deliberate approach to designing and operationalizing active learning for auscultatory manual blood pressure measurement within the framework of Gagné’s 9 events of instruction. For each design and instruction step, we propose user-friendly, high-impact operational practices derived empirically from education science, experience, and observations. Schematically, the approach described is intended to also facilitate instructor metacognition and knowledge building of applied andragogy/pedagogy through pre hoc, ad hoc, and post hoc reflection. Pragmatically, the approach accommodates active learning lesson planning, promotes transparency of teaching and learning, and is generalizable and applicable toward the instruction of various physical assessment procedures within the health professions.

Ambulatory Blood Pressure Monitoring: Profiles in Chronic Kidney Disease Patients and Utility in Management.

Optimal control of blood pressure (BP) may reduce the risk of progression of CKD. Misclassification of hypertension (HTN) and status of control may result in suboptimal management. Clinic or home BP may overestimate or underestimate status of control compared with ambulatory BP monitoring (ABPM), which is considered the gold standard. The latter relates not only to the superiority of ABPM concerning outcome prognosis but also to its ability to accurately diagnose white coat and masked HTN, which is critical in assuring adequate BP control. However, ABPM has not gained widespread use in practice because of limited third-party reimbursement and a paucity of high quality randomized controlled intervention studies evaluating its use. Herein, we review HTN phenotypes that have been identified in patients with CKD, and the potential value of ABPM in this high-risk population.

Effects of measurement intervals on the values of repeated auscultatory blood pressure measurements

ABSTRACTObjective: For repeated measurements of blood pressure (BP) using the auscultatory method, current guidelines recommend intervals of 1–2 minutes; however, evidence to support this recommendation is insufficient. In the present study, the effects of intervals among repeated BP measurements using the auscultatory method were evaluated.Methods: Systolic and diastolic BPs were measured using the auscultatory method in 37 participants. The measurements were repeated 5 times each at intervals of 15, 30, 60, 90, and 120 seconds. The changes in the BP along with the increasing the number of repetitions were assessed at each measurement interval using a linear mixed model.Results: With an increasing number of measurements, the systolic and diastolic BPs showed significant progressive decrease and increase (p < 0.05), respectively, when the measurement interval was 15 seconds. However, the precision of BP measurements was not affected by performing the measurements at intervals of 30 seconds or longer.Conclusion: Repeated BP measurements using the auscultatory method need to have an interval of at least 30 seconds, which is shorter than the intervals recommended by the current guidelines.

Renovascular hypertension masquerading as nephrotic proteinuria in an 10-month-old girl — analysis of errors in diagnostic approach

A 10-month-old girl with nephrotic proteinuria, hypercholesterolaemia, hypoalbuminaemia, hyponatraemia, hypokalaemia, hypocalcaemia, metabolic alkalosis, normal auscultatory blood pressure on multiple occasions, and an enlarged left kidney on ultrasound, was referred to hospital. A left-kidney biopsy showed normal glomeruli with mild mesangial proliferation and the thickening of arteriolar walls. Glucocorticoid therapy was started. A further course was complicated by vomiting, irritation, pulsatile fontanel, and an enlarged ventricular system on ultrasound. A ventriculoperitoneal shunt was inserted but, during anaesthesia, repeated automated, oscillometric measurements revealed blood pressure of 220/120 mmHg. Intravenous antihypertensive treatment lowered the blood pressure to 110–120/70 mmHg, with a decrease in proteinuria. A CT abdominal angiography revealed left-renal-artery stenosis, a reduced right kidney and an enlarged left kidney, with foci of a post-infarct area in the lower pole. The patient was referred to a tertiary-care hospital. Renal scintigraphy showed that the right-kidney function had decreased to 6%. A right nephrectomy was performed but, due to persistent arterial hypertension, oral antihypertensive treatment was intensified. Microscopic analysis of the removed right kidney revealed relatively normal glomeruli and fibromuscular dysplasia in the right-renal-artery specimen. Oral antihypertensive therapy based on an angiotensin-converting enzyme inhibitor and a calcium-channel blocker continued after surgery allowed the attaining of normotension, the gradual normalisation of proteinuria and metabolic abnormalities, and an improvement in the left-kidney function. This case shows that auscultatory blood-pressure measurements in small children and incorrect interpretation of the obtained test results can lead to the erroneous misdiagnosis of hypertensive crisis, with dramatic consequences.

AUTOMATED VERSUS AUSCULTATORY OR INTRA-ARTERIAL BLOOD PRESSURE MEASUREMENT IN ATRIAL FIBRILLATION

Objective: The cuff-based measurement of blood pressure (BP) in atrial fibrillation (AF) is considered as difficult and uncertain and the accuracy of automated BP monitors in AF is regarded questionable. Design and method: A systematic PubMed search was conducted for identifying studies comparing automated (oscillometric or automated auscultatory) BP measurements versus manual auscultatory (mercury or aneroid sphygmomanometers) or intra-arterial BP measurements in patients with sustained AF. Results: Fifteen articles including 13 non-invasive studies (N = 877; 5 home, 2 ambulatory, 4 office BP monitors) and 4 invasive studies (N = 179; 2 office, 2 home monitors) were included in meta-analyses. There was a significant heterogeneity in the validation procedure used for comparing BP measurements in different studies. Meta-analysis of non-invasive studies showed pooled correlation coefficients between auscultatory and automated BP measurements to be stronger for systolic (SBP) than diastolic BP (DBP) (r 0.87 versus 0.76, p < 0.05). Automated BP measurements were slightly higher than auscultatory measurements (pooled average SBP difference 0.5 mmHg, 95% confidence intervals [CI] −0.9, 1.9; DBP 1.5 mmHg, 95% CI −0.6, 3.6). Meta-analysis of invasive studies showed automated SBP to be lower than intra-arterial SBP measurements (pooled difference −4.2 mmHg, 95% CI −8.4, −0.02), whereas automated DBP was higher (6.1 mmHg, 95% CI: 3.8, 8.4). Conclusions: There is significant heterogeneity in the non-invasive validation studies of automated BP monitors in AF. The current evidence suggests acceptable agreement of automated with auscultatory BP measurements, which is further supported by limited invasive studies showing similar relationship as in sinus rhythm. There seems to be a consistent trend towards more accurate measurement of systolic BP and overestimation of diastolic BP, which however is less important in AF patients who are usually elderly with systolic hypertension.

Accuracy of Automated Blood Pressure Measurement in Children: Evidence, Issues, and Perspectives.

There is a general consensus in the European1 and American2 guidelines for pediatric hypertension that children from 3 years of age and older who are seen in a medical setting should have their blood pressure (BP) measured. This is because hypertension in children and adolescents has become an emerging public health issue, with increasing prevalence mainly driven by the obesity epidemic in this population.1,2 Because hypertension is almost always asymptomatic until there is severe organ damage or it evolves into a malignant phase, the only method for early detection and intervention aiming to prevent its complications is the measurement of BP. The accurate measurement of BP is a prerequisite in the adults and in children for the reliable diagnosis of hypertension and the avoidance of misdiagnosis and over- or undertreatment.1,2 The main methods for noninvasive measurement of BP are the auscultatory method using conventional mercury or aneroid devices and the automated method using electronic, mostly oscillometric, devices.3 This article aims to discuss the evidence and the issues of automated BP measurement in children (age 3–12 years). Current guidelines for pediatric hypertension in Europe1 and the United States2 recommend the auscultatory BP measurement method for the diagnosis of hypertension in children. If elevated BP in children is detected by an electronic (oscillometric) BP monitor, it should be confirmed by auscultatory BP measurement.1,2 This is mainly because in children, the available reference values for defining the threshold for hypertension diagnosis have been obtained by the auscultatory method and the fact that auscultatory and automated electronic BP measurements are not necessarily interchangeable.1 In children, the auscultatory BP measurement encounters several obstacles, mainly because of anatomic and physiological characteristics of the young individuals. These include small arm dimensions, small …