Oscillometric Blood Pressure Measurement Research Articles

Evaluation of lingual oscillometric blood pressure measurement in anaesthetised pigs.

ObjectiveTo evaluate the agreement between invasive blood pressure measurements (IBP) and oscillometric blood pressure measurements from the tongue (OBPton) using a multiparameter monitor. Study DesignUnblinded prospective experimental study AnimalsA total of 12 female Large White Crossbreed Pigs MethodsPigs undergoing experimental procedures which required arterial cannula placement were recruited. A blood pressure cuff with the closest width to 40% of the circumference of the tongue was placed rostral to the lingual frenulum. Systolic, mean and diastolic IBP and OBPton were measured simultaneously at 5-minute intervals. Agreement between paired measurements was examined using Bland-Altman analysis. Mean bias, precision (standard deviation of mean bias), 95% limits of agreement (LOA), correlation coefficients and percentage of measurements within 10 and 20 mmHg of IBP were calculated. ResultsThe total numbers of paired measurements recorded were of 124, 126 and 124 for systolic, mean and diastolic blood pressures, respectively. The mean bias, precision and 95% limits of agreement for systolic OBPton were 11.5, 11.5 (-11.1 to 34.2), for mean OBPton 5.6, 5.7 (-5.7 to 16.8) and for diastolic OBPton 7.6, 10.1 (-12.1 to 27.4) mmHg. Correlation coefficients were greater than 0.9 for mean OBPton only. More than 50% of measurements were within 10 mmHg of IBP and 80% of measurements were within 20mmHg of IBP for mean and diastolic OBPton only. Conclusions and clinical relevanceThe tongue as a cuff site for oscillometric blood pressure measurement is a useful site for measuring mean arterial, but not systolic or diastolic blood pressure in anaesthetised Large White Crossbreed pigs. This technique fulfils the American College of Veterinary Internal Medicine criteria for measuring mean arterial pressure but not systolic or diastolic arterial pressure.

DIPPING STATUS OF BLOOD PRESSURE AND PROGNOSIS

Objective: Ambulatory blood pressure monitoring (ABPM) plays an important role in monitoring the effectiveness of antihypertensive treatment. It enables to obtain clear information about absolute values and variability of blood pressure in time-defined periods. The aim of our work was to evaluate the clinical benefit not only from the point of view of BP control, but also from the prognostic aspect by determining the diurnal index. Design and method: To control the effectiveness of antihypertensive treatment, we used ABPM - Cardiosoft-Tonoport V, General Electric (USA) with oscillometric blood pressure measurement. We analyzed 206 ABPM records in hospitalized patients. There were 93 men (45%) and 113 women (55%). The monitored group of patients was divided into 4 groups according to age. There were 31 persons in the age group of 18-44 years, 78 persons in the age group of 45-64 years, 52 persons in the age group of 65-74 years and 45 persons in the oldest age group (75 years and over). In 15 patients (7.3%), we did not determine the diurnal sign for night waking. Results: The group of dippers consisted of 79 people (38.3%), there were also 79 people (38.3%) in the group of non-dippers, there were 30 risers (14.6%) and 3 extreme dippers (1.5%). Following the further fate of the investigated persons, we found that 19 persons (9.2%) died within 2 years, of which 14 were from groups with a disturbed diurnal index (9 non-dippers and 5 risers). Conclusions: Our results point to the fact that in addition to the basic parameters of BP used as an indicator of blood pressure control, the analyses of diurnal character disturbances has a importance in prognostic aspect. Identifying these patients may therefore be helpful in the management of hypertension and comorbidities.

Comparison of routine office blood pressure measurement versus standardized attended manually activated oscillometric office blood pressure measurement in patients with chronic kidney disease

ABSTRACT Context: Erroneous blood pressure measurement could lead to improper treatment and hence progression of chronic kidney disease (CKD). In routine clinical practice, there is poor adherence to the various steps to be followed during blood pressure measurement. Automated oscillometric BP measurement is difficult to perform in routine clinical practice due to several practical limitations. Aims: To evaluate the quality of blood pressure measurement and to compare routine office blood pressure measurement with standardized attended manually activated oscillometric blood pressure measurement in patients with CKD attending the nephrology outpatient department (OPD) of a tertiary care referral center. Settings and Design: This cross-sectional study was conducted in patients aged more than 18 years with CKD stage 3–5ND, and previously diagnosed hypertension, in the nephrology OPD of a tertiary care referral center between July 2022 and September 2022. Methods and Material: The quality of blood pressure measurement was evaluated using a questionnaire. The study participants had their blood pressure checked by both methods—routine office blood pressure and standardized attended manually activated oscillometric blood pressure. Results: Standardized attended manually activated oscillometric blood pressure measurement yielded a significantly higher systolic blood pressure (SBP) compared to routine office blood pressure measurement (Mean SBP: 139.53 ± 29.1 vs 132.57 ± 23.59; P < 0.001). However, the diastolic blood pressure did not differ significantly between the two methods of measurement. Conclusions: Standardized attended manually activated oscillometric BP measurement yields a higher systolic BP compared to routine office BP measurement. Further studies are required to compare the standardized attended oscillometric BP measurement used in this study with unattended automated oscillometric BP measurement and ambulatory BP measurement.

One size does not fit all: universal cuff overestimates oscillometric blood pressure in persons with large arm circumference

Objective Some brachial cuffs for oscillometric blood pressure (BP) measurement are claimed to cover a wide range of upper-arm circumferences; however, their validation is rarely conducted. Our aim was to compare oscillometric BP measurements obtained with a universal cuff with those obtained with an appropriately sized cuff. Methods We utilised the Microlife B6 Connect monitor, conducting oscillometric BP measurements in a random sequence with both a universal cuff (recommended for arm circumferences from 22 to 42 cm) and an appropriately sized cuff (medium for circumference 22–32 cm and large for 32–42 cm). We included 91 individuals with an arm circumference of 22–32 cm and 64 individuals with an arm circumference of 32–42 cm. Results For arm circumferences > 32 cm, systolic and diastolic BP measured with the universal cuff was higher than that measured with the large cuff (systolic 6.4 mmHg, 95% confidence interval [CI]). 3.9–8.8, diastolic 2.4 mmHg, 95%CI, 1.2–3.7, p < 0.001 for both). Overestimation of BP with the universal cuff was statistically significant after correcting for the sequence of measurements. No statistical difference was found between the universal cuff and medium cuff for circumferences in the 22–32 cm range. The bladder size in the universal cuff matched the dimensions of the medium-sized cuff; however, the cuff was larger. Conclusion Overestimation of BP measured with a universal cuff in persons with large arm circumferences is clinically important. It poses the risk of unnecessary initiation or intensification of antihypertensive medication in persons using the universal cuff.

Validation of the Mindray VS9 Vital Signs Monitor in a combined adult and pediatric population according to ISO Standard 81060-2:2018.

We aimed to validate the accuracy of the Mindray VS9 Vital Signs Monitor, which features the Mindray TrueBP inflation algorithm for oscillometric blood pressure (BP) measurement, to check if it complies with the International Organization for Standardization Standard (ISO 81060-2:2018) in a combined adult and pediatric population. A total of 86 participants, including both adult and pediatric subjects, were recruited. The distribution of their ages, gender, BPs and limb sizes all complied with the requirement of the ISO standard. The inflation and deflation algorithms were validated independently using the same-arm sequential BP measurement method. For each subject, the BP was first determined by two independent observers using a mercury sphygmomanometer (R1). The BP of the subject was then determined by the third observer using the test equipment (T1). Then, using a mercury sphygmomanometer, two independent observers were asked to determine the subject's BP (R2) again. R1-T1-R2 were considered a valid pair of data. This cycle continued until 3 pairs of valid data were achieved. We collected 258 pairs of valid BP data for the validation of the inflation and deflation algorithms respectively. For validation Criterion 1, the mean ± SD of the differences between the readings obtained from the test device and reference BP was 0.0 ± 6.6/-1.8 ± 7.1 mmHg (systolic/diastolic) when the deflation algorithm was used, and 2.4 ± 6.3/ 0.3 ± 6.9 mmHg (systolic/diastolic) when the inflation algorithm was used. For validation Criterion 2, the SD of the averaged BP differences between the test device and the reference BP per subject was 5.35/6.33 mmHg (systolic/diastolic) when the deflation algorithm was used, and 5.17/5.75 mmHg (systolic/diastolic) when the inflation algorithm was used. The VS9 Vital Signs Monitor fulfilled all the criteria in the ISO Standard. Moreover, the inflation algorithm had a shorter Measure Time (by 7-21 s) and lower maximum inflation pressure (by 9.7-22 mmHg). The VS9 Vital Signs Monitor fulfilled all the requirements of the ISO Standard (ISO 81060-2:2018) in a combined adult and pediatric population and is recommended for clinical use.

Abstract P405: Calibrating Routine Blood Pressures Among Preterm Infants: A Retrospective, Cross-Sectional Analysis

Background: Among preterm infants (&lt; 12 months postnatal age and born &lt; 37 weeks gestation), oscillometric systolic blood pressure (SBP) measurements are error-prone. However, some preterm infants have “gold standard” SBPs measured using an arterial line, in addition to the error-prone oscillometric SBPs. Objective: To compare different statistical methods to calibrate oscillometric SBPs to mimic arterial line SBPs Methods: We sampled participants from an existing pilot study of preterm infants treated with an antihypertensive therapy at the University of Alabama at Birmingham. Participants' data was obtained from the hospital's data warehouse for electronic medical records. Participants for this analysis had at least one arterial line SBP measurement, and for each of these "gold standard" measurements we identified the closest paired oscillometric SBP measurement (&lt;10 minutes apart). We also collected participant factors such as race (white vs. black/African American), gender, gestational age at birth (weeks), postnatal age at arterial line SBP measurement (weeks), and whether the participant had received an antihypertensive medication. We predicted the arterial line SBPs from oscillometric SBPs and covariates using linear regression, linear regression with restricted cubic splines, random forest, and Bayesian additive regression trees (BART). Prediction errors were calculated using 10-fold cross-validation. We used complete case analysis. Results: We identified 822 measurements among 28 participants. Ten of 28 (36%) participants were black and 13 of 28 (46%) were female. The median (Q1, Q3) gestational age at birth was 33 (29, 35) weeks. The root mean squared error for predicting arterial line SBP from oscillometric SBP by itself was 17.1 mmHg. The root mean squared error of the predicted arterial line SPBs from different statistical methods varied little from the most error (linear regression with restricted cubic splines: 13.5 mmHg) to the least error (BART: 12.6 mmHg), meaning that any calibration resulted in at least a 21% reduction in error compared to the oscillometric SBPs. BART tended to underpredict the arterial line SBPs that were above 100 mmHg. Conclusions: Among preterm infants, statistical calibration is a viable strategy for reducing the variability of error-prone oscillometric SBPs. The different statistical models performed similarly in this small pilot study, but a larger sample size using additional important variables (e.g., birth weight) is required to confirm this finding.

Comparison between invasive and oscillometric blood pressure measurements in a controlled hemorrhage model in dorsally-recumbent isoflurane-anesthetized horses

Comparison between invasive and oscillometric blood pressure measurements in a controlled hemorrhage model in dorsally-recumbent isoflurane-anesthetized horses

A comparison of invasive arterial blood pressure measurement with oscillometric non-invasive blood pressure measurement in patients with sepsis.

This study aimed to compare non-invasive oscillometric blood pressure (NIBP) measurement with invasive arterial blood pressure (IBP) measurement in patients with sepsis. We conducted a retrospective study to evaluate the agreement between IBP and NIBP using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Paired blood pressure measurements of mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were compared using Bland-Altman analysis and paired Student's t test. We also focus on the effect of norepinephrine (NE) on the agreement between the two methods and the association between blood pressure and mortality during intensive care unit (ICU) stay. A total of 96,673 paired blood pressure measurements from 6060 unique patients were analyzed in the study. In Bland-Altman analysis, the bias (± SD, 95% limits of agreement) was 6.21mmHg (± 12.05mmHg, -17.41 to 29.83mmHg) for MAP, 0.39mmHg (± 19.25mmHg, -37.34 to 38.12mmHg) for SBP, and 0.80mmHg (± 12.92mmHg, -24.52 to 26.12mmHg) for DBP between the two techniques. Similarly, large limits of agreement were shown in different groups of NE doses. NE doses significantly affected the agreement between IBP and NIBP. SBP between the two methods gave an inconsistent assessment of patients' risk of ICU mortality. IBP and NIBP were not interchangeable in septic patients. Clinicians should be aware that non-invasive MAP was clinically and significantly underestimated invasive MAP.

Comparison of Thames Medical CAT+ Doppler and SunTech Vet 20 oscillometric devices for non-invasive blood pressure measurement in conscious cats.

A comparative assessment of systolic blood pressure (BP) measurement agreement and precision in two commonly used non-invasive BP devices was carried out in conscious cats. Systolic BP measurements were obtained from 50 conscious cats as part of their clinical investigations. All measurements were taken by the same operator and were performed according to the American College of Veterinary Internal Medicine (ACVIM) consensus guidelines. The same cuff location and cuff size were used for paired measurements. The order of device use was randomised, and an arousal score was assigned during each procedure. Precision was assessed using standard deviation and coefficient of variance comparisons. Agreement was assessed using graphical and statistical comparisons of derived 'delta mean' and 'mean of means' data. A total of 50 cats aged between 3 months and 15 years were enrolled (29 domestic shorthair, seven domestic longhair, three British Shorthair, two Ragdoll, two Sphynx, two Persian, one Siamese, one Burmese, one Russian Blue, one Maine Coon and one Oriental) with a body weight in the range of 1.2-6.2 kg. BP measurements were in the range of 95-179 mmHg. Oscillometric measurements were associated with lower arousal scores. The Doppler device demonstrated superior repeatability precision. Body weight, sex, cuff size, cuff location, arousal score and the order in which the devices were used had no significant effect on precision or agreement. Correlation between the two devices was 0.0837 and agreement was considered clinically acceptable (<10 mmHg) in 32/50 (64%) cats. Of the 18 cats with suboptimal agreement, the oscillometric mean BP was higher in 14 (78%) cats. Based on this study sample, suboptimal agreement between paired CAT+ Doppler and SunTech Vet20 oscillometric BP measurements in 36% of conscious cats suggests that these devices should not be used interchangeably. Compared with Doppler, oscillometric measurements were consistently higher, particularly at higher blood pressures. Further studies are required to assess which device has superior accuracy in conscious cats.

Smartphone-Based versus Non-Invasive Automatic Oscillometric Brachial Cuff Blood Pressure Measurements: A Prospective Method Comparison Volunteer Study.

Introduction: Mobile health diagnostics have demonstrated effectiveness in detecting and managing chronic diseases. This method comparison study aims to assess the accuracy and precision of the previously evaluated OptiBP™ technology over a four-week study period. This device uses optical signals recorded by placing a patient's fingertip on a smartphone's camera to estimate blood pressure (BP). Methods: In adult participants without cardiac arrhythmias and minimal interarm blood pressure difference (systolic arterial pressure (SAP) < 15 mmHg or diastolic arterial pressure (DAP) < 10 mmHg), three pairs of 30 s BP measurements with the OptiBP™ (test method) were simultaneously compared using three pairs of measurements with the non-invasive oscillometric brachial cuff (reference method) on the opposite arm over a period of four consecutive weeks at a rate of two measurements per week (one in the morning and one in the afternoon). The agreement of BP values between the two technologies was analyzed using Bland-Altman and error grid analyses. The performance of the smartphone application was investigated using the International Organization for Standardization (ISO) definitions, which require the bias ± standard deviation (SD) between two technologies to be lower than 5 ± 8 mmHg. Results: Among the 65 eligible volunteers, 53 participants had adequate OptiBP™ BP values. In 12 patients, no OptiBP™ BP could be measured due to inadequate signals. Only nine participants had known chronic arterial hypertension and 76% of those patients were treated. The mean bias ± SD between both technologies was -1.4 mmHg ± 10.1 mmHg for systolic arterial pressure (SAP), 0.2 mmHg ± 6.5 mmHg for diastolic arterial pressure (DAP) and -0.5 mmHg ± 6.9 mmHg for mean arterial pressure (MAP). Error grid analyses indicated that 100% of the pairs of BP measurements were located in zones A (no risk) and B (low risk). Conclusions: In a cohort of volunteers, we observed an acceptable agreement between BP values obtained with the OptiBPTM and those obtained with the reference method over a four-week period. The OptiBPTM fulfills the ISO standards for MAP and DAP (but not SAP). The error grid analyses showed that 100% measurements were located in risk zones A and B. Despite the need for some technological improvements, this application may become an important tool to measure BP in the future.

Hybrid Deep Morpho-Temporal Framework for Oscillometric Blood Pressure Measurement.

Oscillometric blood pressure (BP) measurement devices are widely utilized as the primary automated BP measurement tools in non-specialist environments. However, their accuracy and reliability vary under different settings and for different age groups and health conditions. An essential constraint of current oscillometric BP measurement devices is their analysis algorithms' incapacity to capture the BP information encoded in the pattern of recorded oscillometric pulses to its fullest extent. In this paper, we propose a new 2D oscillometric data representation that enables a full characterization of arterial system and empowers the application of deep learning to extract the most informative features correlated with BP. A hybrid convolutional-recurrent neural network was developed to capture the oscillometric pulses morphological information as well as their temporal evolution over the cuff deflation period from the 2D structure, and estimate BP. The performance of the proposed method was verified on three oscillometric databases collected from the wrist and upper arms of 245 individuals. It was found that it achieves a mean error and a standard deviation of error of as low as 0.08 mmHg and 2.4 mmHg in the estimation of systolic BP, and 0.04 mmHg and 2.2 mmHg in the estimation of diastolic BP, respectively. Our proposed method outperformed the state-of-the-art techniques and satisfied the current international standards for BP monitors by a wide margin. The proposed method shows promise toward robust and objective BP estimation in a variety of patients and monitoring situations.

Evaluation of lingual oscillometric blood pressure measurement in anaesthetised pigs

Evaluation of lingual oscillometric blood pressure measurement in anaesthetised pigs

Blood pressure measurement device change in the Healthy Finland health examination survey

Abstract Background Blood pressure (BP) measurements in health examination surveys (HESs) are needed for public health monitoring. In Finland, population-based HESs with BP measurements have been performed with mercury sphygmomanometers since the 1960's. The use of oscillometric devices has rendered sphygmomanometers impractical for health surveys. This study describes the change in BP measurement method and mean BP values in Finnish HESs. Methods 66 000 randomly selected adults living in Finland were invited to the Healthy Finland questionnaire-based health survey in 2022-2023. Of those, 10 000 were asked to participate in a HES including BP, anthropometric, and functional capacity measurements as well as collection of biological samples. Prior to the selection of the new oscillometric BP device, validation studies for devices were evaluated, and the availability was checked. BP measurements were performed using WatchBP Office Vascular (TWIN200 VSR) device. Results Two consecutive BP measurements were obtained from 3424 participants aged 30 years or older (ongoing until 6/2023). The mean (95% CI) systolic blood pressures (SBP) for men and women were 137.1 (136.2-140.0) and 134.7 mmHg (133.7-135.6), respectively. The corresponding values for diastolic blood pressure (DBP) were 82.3 (81.8-82.8) and 79.3 mmHg (78.9-79.8). The mean difference (95% CI) between the 1st and the 2nd SBP measurements were -2.4 (-2.7- -2.0) and -1.8 (-2.1- -1.4) in men and women, while the corresponding values for DBP were -1.1 (-1.4- -0.9) and -1.2 (-1.5- -1.0). Distribution of measurements was Gaussian apat from some values, that were unlikely to be obtained (SBP: 155, 156, 157; DBP: 96, 99). Conclusions Oscillometric BP provide reliable data in HESs. Finnish BP levels may be on the rise. Further reseach is needed to estimate the effects of gaps in the measurement algorithm of TWIN200 VSR and the differences in consecutive measurements. Key messages • In a health examination survey, oscillometric blood pressure measurements led to similar results as with a sphygmomanometer. • Algorithm gaps and smaller difference on successive measurements were seen.

Technical evaluation of a simulator for accurate reproduction of oscillometric blood pressure pulses, providing traceability for automated oscillometric sphygmomanometers

Oscillometric blood pressure measurement devices are not directly traceable to primary standards. Currently, device accuracy is measured by comparison between a sample device and reference measurements in a clinical trial. We researched in this study the potential for an alternative evaluation with a simulator. Our research simulator was studied for repeatability and accuracy in delivering simulated blood pressure pulses. Clinical cuff pressure measurements were obtained, along with simultaneous recordings of oscillometric pulse waveforms, spanning the clinical range of cuff pressures, pulse intervals and pulse shapes. Oscillometric pulse peak amplitudes ranged from 1.1 to 3.6 mmHg. Simulated repeatability results showed an average Standard Deviation (SD) for pulse peaks of 0.018 mmHg; 1.0% of peak amplitudes. Comparing simulated pulse shapes, the average repeat SD was 0.015 mmHg; 0.8% of the normalised pulse shapes. The simulated accuracy results had a mean error of − 0.014 ± 0.042 mmHg with a mean accuracy of 97.8%. For pulse shape the corresponding values were − 0.104 ± 0.071 mmHg with a mean accuracy of 95.4%. The correlation between the reference and simulated pulse shapes ranged from 0.991 to 0.996 (all p < 0.00003), with a mean 0.994. We conclude that oscillometric pulses can be reproduced with high repeatability and high accuracy with our research simulator. The extended uncertainty U(p sim ) = 0.3 mmHg for the simulated pulses is dominated by the uncertainty (64%) of the clinical reference data. These results underpin the potential of the simulator to become a secondary standard for millions of oscillometric sphygmomanometers.

The effect of oscillometric blood pressure measurement on pain response in preterm infants.

Preterm neonates are exposed to many painful procedures in neonatal intensive care units. This study aims to evaluate the effect of oscillometric blood pressure (BP) measurement on pain response in preterm infants. This prospective study was performed over 4 months in a level III neonatal intensive care unit. Premature neonates whose gestational age was <34 weeks and postmenstrual age <36 weeks were included if they had no systemic diseases. BP measurement was performed on the right arm. The Premature Infant Pain Profile-Revised (PIPP-R) scores were evaluated three times before, during, and 10 min after BP measurement. During the 5-month period, 100 preterm neonates (53 male infants) were included in the study. Median birth weight and gestational age of the infants were 1148 (IQR: 1015-1300) g and 28 (IQR: 27-30) weeks, respectively. PIPP-R scores were found to be ≥7 in 34% of neonates. PIPP-R scores increased during BP measurement and decreased after. Our results demonstrated that oscillometric BP measurement which is generally accepted as a non-invasive tool for monitoring can produce mild pain in premature neonates of postmenstrual age <36 weeks.

A prospective comparison of invasive and non-invasive blood pressure in children undergoing cardiac catheterization.

Blood pressure measurement is a standard of monitoring during general anesthesia. Invasive measurement is considered the gold standard but is less commonly used than non-invasive. Automated oscillometric blood pressure devices measure the mean arterial pressure (MAP) and use an algorithm to determine the systolic and diastolic pressures. Few devices have been validated in children, particularly during anesthesia. Few studies have assessed the agreement between invasive and non-invasive blood pressure measurements in children. This was a multi-center prospective observational study of children under 16 years undergoing cardiac catheterization with general anesthesia. Paired invasive and non-invasive blood pressure measurements were recorded for each patient during stable periods of the procedure. Correlation within and between sites was assessed with Pearson's correlation coefficient, and agreement was examined using Bland-Altman methodology to determine bias. Agreement during episodes of hypotension and for age and weight was also determined. Bias greater than 5 mmHg and standard deviation greater than 8 mmHg was considered clinically significant. The primary end point was agreement of MAP measurements. A total of 683 paired blood pressure values were collected from 254 children in three pediatric hospitals. Median [IQR] age and weight were 3 [1-7] years and 13.9 [8-23] Kg. The overall bias (SD) for mean arterial pressure values was 7.2 (11.4) mmHg. During hypotension (190 readings), the bias (SD) was 15 (11.0) mmHg. The non-invasive MAP was frequently higher than invasive MAP during infancy, and lower in older children. Automated oscillometric blood pressure measurement is unreliable in anesthetized children during cardiac catheterization. Invasive pressure measurement should be considered for high-risk cases.

OFFICE BLOOD PRESSURE VARIABILITY: WITHIN SESSION STABILITY ACROSS CONSECUTIVE MEASUREMENTS USING OSCILLOMETRIC DEVICES

Objective: Blood pressure (BP) is routinely monitored by healthcare providers and during drug development. For improvement in accuracy, several oscillometric devices perform multiple sequential inflations, rather than relying on a single inflation, to determine a mean systolic and diastolic blood pressure (SBP, DBP). Blood pressure is known to vary physiologically throughout a day, and over the course of days and weeks, due to intrinsic and extrinsic factors. Little data has been published describing the variability of SBP and DBP recorded minutes apart using oscillometric methods (i.e. within session variability). Design and method: We investigated the stability of within session SBP and DBP across 4 datasets by evaluating differences between 3 consecutive inflations recorded 1-2 minutes apart using a clinically validated oscillometric BP monitor that passed the ANSI/AAMI/ISO 2013, ESH-IP 2002 and BHS 1993 protocols (Table 1). These datasets included patients with controlled or uncontrolled hypertension. Results: Data were available from over 10.000 measurement pairs. The differences between inflation 1 and 2 were within ±10, 20 and 30 mmHg for 78.1, 94.4 and 97.9% of the SBP measurements, respectively. For the DBP, 90.7, 95.5 and 97.3 % of the differences between inflation 1 and 2 were within ±10, 15 and 20 mmHg, respectively. A similar trend was seen between inflation 2 and 3. Table 1: Categorical Analysis of BP changes between consecutive inflations. Conclusions: Our data demonstrate substantial variability between consecutive oscillometric BP measurements performed a few minutes apart. Over 20% of the time, consecutive inflations show an absolute change in SBP of at least 10 mmHg. It is unclear whether this represents true physiologic changes in BP or is partly artefactual due to failure of a device's algorithm to determine BP accurately from the oscillometric waveform. These data suggest that criteria for within session variability for automated oscillometric blood pressure devices should be established, including a threshold for repeating the session after 10 minutes of rest.

Evaluation of the accuracy of oscillometric non-invasive blood pressure measurement at the ankle in children during general anesthesia.

This study aimed to evaluate the accuracy of oscillometric blood pressure measurement at the ankle in children using invasive blood pressure as reference standard. This prospective observational study included children undergoing noncardiac surgery. Paired radial invasive and ankle non-invasive blood pressure measurements were obtained. Delta blood pressure was calculated as the difference between two consecutive readings. The primary outcome was the mean bias and agreement between the two methods using the Bland-Altman analysis. The ISO standard was fulfilled if the mean bias between the two methods was ≤ 5 ± 8 mmHg. Other outcomes included the trending ability of ankle blood pressure using the four-quadrant plot and the accuracy of ankle measurement to detect hypotension using area under receiver operating characteristic curve (AUC) analysis. We analyzed 683 paired readings from 86 children. The mean bias between the two methods for systolic, diastolic, and mean blood pressure (SBP, DBP, MAP) was - 7.2 ± 10.7, 4.5 ± 12.8, and - 1.8 ± 8.2 mmHg, respectively. The concordance rate of ankle blood pressure was 72%, 71%, and 77% for delta SBP, DBP and MAP, respectively. The AUC (95% confidence interval) for ankle MAP ability to detect hypotension was 0.91 (0.89-0.93) with negative predictive value of 100% at cut-off value ≤ 70 mmHg, We concluded that in pediatric population undergoing noncardiac surgery, ankle blood pressure was not interchangeable with the corresponding invasive readings with the ankle MAP having the least bias compared to SBP and DBP. An ankle MAP > 70 mmHg can exclude hypotension with negative predictive value of 100%.

Oscillometric arterial blood pressure in haemodynamically stable neonates in the first 2 weeks of life

BackgroundWe aimed to provide data on the normal blood pressure of haemodynamically stable neonates. Our study uses retrospective, real-life oscillometric blood pressure measurement values to determine the expected blood pressure in different gestational age, chronological age and birth weight groups. We also investigated the effect of antenatal steroid on neonatal blood pressure.MethodsOur retrospective study (2019–2021) was carried out in the Neonatal Intensive Care Unit of the University of Szeged, Hungary. We involved 629 haemodynamically stable patients and analysed 134,938 blood pressure values. Data were collected from electronic hospital records of IntelliSpace Critical Care Anesthesia by Phillips. We used the PDAnalyser program for data handling and the IBM SPSS program for statistical analysis.ResultsWe found a significant difference between the blood pressure of each gestational age group in the first 14 days of life. The systolic, diastolic and mean blood pressure rise are steeper in the preterm group than in the term group in the first 3 days of life. No significant blood pressure differences were found between the group with a complete antenatal steroid course and those who received incomplete steroid prophylaxis or did not receive antenatal steroids.ConclusionWe determined the average blood pressure of stable neonates and obtained normative data by percentiles. Our study provides additional data on how blood pressure varies with gestational age and birth weight.Graphical abstractA higher resolution version of the Graphical abstract is available as Supplementary information

Cardiac output and regional-cerebral-oxygen-saturation in preterm neonates during immediate postnatal transition - an observational study.

To examine potential correlations between cardiac output (CO) with cerebral-regional-oxygen-saturation (crSO2 ) and cerebral-fractional-tissue-oxygen-extraction (cFTOE) during immediate fetal-to-neonatal transition in term and preterm neonates with and without respiratory support. Post-hoc analyses of secondary outcome parameters of prospective observational studies were performed. We included neonates with cerebral near-infrared-spectroscopy (NIRS) monitoring and an oscillometric blood pressure measurement at minute 15 after birth. Heart rate (HR) and arterial oxygen saturation (SpO2 ) were monitored. CO was calculated with Liljestrand and Zander formula and correlated with crSO2 and cFTOE. Seventy-nine preterm neonates and 207 term neonates with NIRS measurements and calculated CO were included. In 59 preterm neonates (mean gestational age (GA): 29.4±3.7 weeks) with respiratory support CO correlated significantly positively with crSO2 and significantly negatively with cFTOE. In 20 preterm neonates (GA 34.9±1.3 weeks) without respiratory support and in 207 term neonates with and without respiratory support CO correlated neither with crSO2 nor with cFTOE. In compromised preterm neonates with lower gestational age and in need of respiratory support CO was associated with crSO2 and cFTOE whereas in stable preterm neonates with higher gestational age as well as in term neonates with and without respiratory support no associations were observed.