Accuracy of oscillometric noninvasive blood pressure at the ankle in the lateral position during general anesthesia.

BACKGROUND: This study aimed to evaluate the accuracy of ankle blood pressure measurements in relation to invasive blood pressure in the lateral position. METHODS: This prospective observational study included adult patients scheduled for elective non-cardiac surgery under general anesthesia in the lateral position. Paired radial artery invasive and ankle noninvasive blood pressure readings were recorded in the lateral position using GE Carescape B650 monitor. The primary outcome was the ability of ankle mean arterial pressure (MAP) to detect hypotension (MAP < 70 mmHg) using area under the receiver operating characteristic curve (AUC) analysis. The secondary outcomes were the ability of ankle systolic blood pressure (SBP) to detect hypertension (SBP > 140 mmHg) as well as bias (invasive measurement - noninvasive measurement), and agreement between the two methods using the Bland-Altman analysis. RESULTS: We analyzed 415 paired readings from 30 patients. The AUC (95% confidence interval [CI]) of ankle MAP for detecting hypotension was 0.88 (0.83-0.93). An ankle MAP of ≤ 86 mmHg had negative and positive predictive values (95% CI) of 99 (97-100)% and 21 (15-29)%, respectively, for detecting hypotension. The AUC (95% CI) of ankle SBP to detect hypertension was 0.83 (0.79-0.86) with negative and positive predictive values (95% CI) of 95 (92-97)% and 36 (26-46)%, respectively, at a cutoff value of > 144 mmHg. The mean bias between the two methods was - 12 ± 17, 3 ± 12, and - 1 ± 11 mmHg for the SBP, diastolic blood pressure, and MAP, respectively. CONCLUSION: In patients under general anesthesia in the lateral position, ankle blood pressure measurements are not interchangeable with the corresponding invasive measurements. However, an ankle MAP > 86 mmHg can exclude hypotension with 99% accuracy, and an ankle SBP < 144 mmHg can exclude hypertension with 95% accuracy.

A smartphone application toward detection of systolic hypertension in underserved populations.

High systolic blood pressure (BP) is the most important modifiable risk factor for cardiovascular disease. Managing systolic hypertension is especially difficult in underserved populations wherein access to cuff BP devices is limited. We showed that ubiquitous smartphones without force sensing can be converted into absolute pulse pressure (PP) monitors. The concept is for the user to perform guided thumb and hand maneuvers with the phone to induce cuff-like actuation and allow built-in sensors to make cuff-like measurements for computing PP. We developed an Android smartphone PP application. The 'app' could be learned by volunteers and yielded PP with total error < 8 mmHg against cuff PP (N = 24). We also analyzed a large population-level database comprising adults less than 65 years old to show that PP plus other basic information can detect systolic hypertension with ROC AUC of 0.9. The smartphone PP app could ultimately help reduce the burden of systolic hypertension in underserved populations and thus health disparities.

Long-Term Visit-to-Visit Blood Pressure Variability and Cognitive Decline Among Patients With Hypertension: A Pooled Analysis of 3 National Prospective Cohorts.

BACKGROUND: A limited number of studies investigated the association between blood pressure variability (BPV) and cognitive impairment in patients with hypertension. This study aimed to identify the longitudinal association between BPV and cognitive decline and the role of blood pressure (BP) control in this association. METHODS AND RESULTS: Participants with hypertension from the HRS (Health and Retirement Study), the ELSA (English Longitudinal Study of Ageing), and the CHARLS (China Health and Retirement Longitudinal Study) were included. Variation independent of the mean (VIM) was adopted to measure BPV. Cognitive function was measured by standard questionnaires, and a standardized Z score was calculated. Linear mixed-model and restricted cubic splines were adopted to explore the association between BPV and cognitive decline. The study included 4853, 1616, and 1432 eligible patients with hypertension from the HRS, ELSA, and CHARLS, respectively. After adjusting for covariates, per-SD increment of VIM of BP was significantly associated with global cognitive function decline in Z scores in both systolic BP (pooled ß, -0.045 [95% CI, -0.065 to -0.029]) and diastolic BP (pooled ß, -0.022 [95% CI, -0.040 to -0.004]) among hypertensive patients. Similar inverse associations were observed in patients with hypertension taking antihypertensive drugs and in patients with hypertension with well-controlled BP. CONCLUSIONS: High BPV was independently associated with a faster cognitive decline among patients with hypertension, even those with antihypertensive medications or well-controlled BP. Further studies are needed to confirm our results and determine whether reducing BPV can prevent or delay cognitive decline.

Implementation of a Cell-Enabled Remote Blood Pressure Monitoring Program During the Postpartum Period at a Safety-Net Hospital.

BACKGROUND: Postpartum hypertension is a risk factor for severe maternal morbidity; however, barriers exist for diagnosis and treatment. Remote blood pressure (BP) monitoring programs are an effective tool for monitoring BP and may mitigate maternal health disparities. We aimed to describe and evaluate engagement in a remote BP monitoring program on BP ascertainment during the first 6-weeks postpartum among a diverse patient population. METHODS AND RESULTS: A postpartum remote BP monitoring program, using cell-enabled technology and delivered in multiple languages, was implemented at a large safety-net hospital. Eligible patients are those with hypertensive disorders before or during pregnancy. We describe characteristics of patients enrolled from January 2021 to May 2022 and examine program engagement by patient characteristics. Linear regression models were used to calculate mean differences and 95% CIs between characteristics and engagement metrics. We describe the prevalence of patients with BP ≥140/or >90 mm Hg. Among 1033 patients, BP measures were taken an average of 15.2 days during the 6-weeks, with the last measurement around 1 month (mean: 30.9 days), and little variability across race or ethnicity. Younger maternal age (≤25 years) was associated with less frequent measures (mean difference, -4.3 days [95% CI: -6.1 to -2.4]), and grandmultiparity (≥4 births) was associated with shorter engagement (mean difference, -3.5 days [95% CI, -6.1 to -1.0]). Prevalence of patients with BP ≥140/or >90 mm Hg was 62.3%, with differences by race or ethnicity (Black: 72.9%; Hispanic: 52.4%; White: 56.0%). CONCLUSIONS: A cell-enabled postpartum remote BP monitoring program was successful in uniformly monitoring BP and capturing hypertension among a diverse, safety-net hospital population.

Blood Pressure Pattern and Prevalence of Hypertension amongst Apparently Healthy Primary School Pupils in Abuja, Nigeria.

OBJECTIVES: The objective of this study was to determine the blood pressure (BP) pattern and prevalence of hypertension amongst apparently healthy primary school pupils in Abuja. METHODOLOGY: This was a descriptive, cross-sectional study carried out on apparently healthy primary school children aged 6-12 years. BP was measured using a standard mercury sphygmomanometer according to standard guidelines. Data were analysed using SPSS version 17.0. Pearson's correlation coefficient (r) and analysis of variance were used to determine the relationship between BP and various variables where applicable. P = 0.05 was considered statistically significant. RESULTS: Out of 1011 pupils recruited for the study, 457 (42.2%) were male. The mean systolic and diastolic BP (SBP and DBP) increased significantly with age from 94.5 mmHg to 101.0 mmHg and from 61.5 mmHg to 65.3 mmHg from 6 to 12 years for SBP and DBP, respectively (P < 0.05). The prevalence of high BP was 9.1%. Age was the only predictor of SBP (ß = -0.629, 95% confidence interval [CI] -1.115, -0.142), while age, height and body mass index (BMI) were the predictors of DBP (ß = -0.686, 95% CI of -1.152, -0.221; ß = 0.490, 95% CI of 0.172, 0.809; ß = 1.753, 95% CI of 0.374, 3.160) for age, height and BMI, respectively, at P < 0.05. CONCLUSION: The predictors of SBP and DBP as shown in this study support the recommendations by various reports for taking body size into consideration in developing reference values for various populations. Age and body size are important determinants of BP in children. Its measurement should be encouraged in schools.

Application of Independent Component Analysis and Nelder-Mead Particle Swarm Optimization Algorithm in Non-Contact Blood Pressure Estimation.

In recent years, hypertension has become one of the leading causes of illness and death worldwide. Changes in lifestyle among the population have led to an increasing prevalence of hypertension. This study proposes a non-contact blood pressure estimation method that allows patients to conveniently monitor their blood pressure values. By utilizing a webcam to track facial features and the region of interest (ROI) for obtaining forehead images, independent component analysis (ICA) is employed to eliminate artifact signals. Subsequently, physiological parameters are calculated using the principle of optical wave reflection. The Nelder-Mead (NM) simplex method is combined with the particle swarm optimization (PSO) algorithm to optimize the empirical parameters, thus enhancing computational efficiency and accurately determining the optimal solution for blood pressure estimation. The influences of light intensity and camera distance on the experimental results are also discussed. Furthermore, the measurement time is only 10 s. The superior accuracy and efficiency of the proposed methodology are demonstrated by comparing them with those in other published literature.

Development of a Personalized Multiclass Classification Model to Detect Blood Pressure Variations Associated with Physical or Cognitive Workload.

Comprehending the regulatory mechanisms influencing blood pressure control is pivotal for continuous monitoring of this parameter. Implementing a personalized machine learning model, utilizing data-driven features, presents an opportunity to facilitate tracking blood pressure fluctuations in various conditions. In this work, data-driven photoplethysmograph features extracted from the brachial and digital arteries of 28 healthy subjects were used to feed a random forest classifier in an attempt to develop a system capable of tracking blood pressure. We evaluated the behavior of this latter classifier according to the different sizes of the training set and degrees of personalization used. Aggregated accuracy, precision, recall, and F1-score were equal to 95.1%, 95.2%, 95%, and 95.4% when 30% of a target subject's pulse waveforms were combined with five randomly selected source subjects available in the dataset. Experimental findings illustrated that incorporating a pre-training stage with data from different subjects made it viable to discern morphological distinctions in beat-to-beat pulse waveforms under conditions of cognitive or physical workload.

Engagement in mHealth-Prompted Self-Measured Blood Pressure Monitoring Among Participants Recruited From a Safety-Net Emergency Department: Secondary Analysis of the Reach Out Trial.

Background: Hypertension, a key modifiable risk factor for cardiovascular disease, is more prevalent among Black and low-income individuals. To address this health disparity, leveraging safety-net emergency departments for scalable mobile health (mHealth) interventions, specifically using text messaging for self-measured blood pressure (SMBP) monitoring, presents a promising strategy. This study investigates patterns of engagement, associated factors, and the impact of engagement on lowering blood pressure (BP) in an underserved population. Objective: We aimed to identify patterns of engagement with prompted SMBP monitoring with feedback, factors associated with engagement, and the association of engagement with lowered BP. Methods: This is a secondary analysis of data from Reach Out, an mHealth, factorial trial among 488 hypertensive patients recruited from a safety-net emergency department in Flint, Michigan. Reach Out participants were randomized to weekly or daily text message prompts to measure their BP and text in their responses. Engagement was defined as a BP response to the prompt. The k-means clustering algorithm and visualization were used to determine the pattern of SMBP engagement by SMBP prompt frequency-weekly or daily. BP was remotely measured at 12 months. For each prompt frequency group, logistic regression models were used to assess the univariate association of demographics, access to care, and comorbidities with high engagement. We then used linear mixed-effects models to explore the association between engagement and systolic BP at 12 months, estimated using average marginal effects. Results: For both SMBP prompt groups, the optimal number of engagement clusters was 2, which we defined as high and low engagement. Of the 241 weekly participants, 189 (78.4%) were low (response rate: mean 20%, SD 23.4) engagers, and 52 (21.6%) were high (response rate: mean 86%, SD 14.7) engagers. Of the 247 daily participants, 221 (89.5%) were low engagers (response rate: mean 9%, SD 12.2), and 26 (10.5%) were high (response rate: mean 67%, SD 8.7) engagers. Among weekly participants, those who were older (>65 years of age), attended some college (vs no college), married or lived with someone, had Medicare (vs Medicaid), were under the care of a primary care doctor, and took antihypertensive medication in the last 6 months had higher odds of high engagement. Participants who lacked transportation to appointments had lower odds of high engagement. In both prompt frequency groups, participants who were high engagers had a greater decline in BP compared to low engagers. Conclusions: Participants randomized to weekly SMBP monitoring prompts responded more frequently overall and were more likely to be classed as high engagers compared to participants who received daily prompts. High engagement was associated with a larger decrease in BP. New strategies to encourage engagement are needed for participants with lower access to care.

Design and validation of dual-point time-differentiated photoplethysmogram (2PPG) wearable for cuffless blood pressure estimation.

BACKGROUND & OBJECTIVES: Measurement of blood pressure (BP) in ambulatory patients is crucial for at high-risk cardiovascular patients. A non-obtrusive, non-occluding device that continuously measures BP via photoplethysmography will enable long-term ambulatory assessment of BP. The aim of this study is to validate the metasense 2PPG cuffless wearable design for continuous BP estimation without ECG. METHODS: A customized high-speed electronic optical sensor architecture with laterally spaced reflectance pulse oximetry was designed into a simple unobtrusive low-power wearable in the form of a watch. 78 volunteers with a mean age of 32.72 ± 7.4 years (21 to 64), 51% male, 49% female were recruited with ECG-2PPG signals acquired. The fiducial features of the 2PPG morphologies were then attributed to the estimator. A 9-1 K-fold cross-validation was applied in the ML. RESULTS: The correlation for PTT-SBP was 0.971 and for PTT-DBP was 0.954. The mean absolute error was 3.167±1.636 mmHg for SBP and 6.4 ± 3.9 mm Hg for DBP. The ambulatory estimate for SBP and DBP for an individual over 3 days with 8-hour recordings was 0.70-0.81 for SBP and 0.42-0.51 for DBP with a ± 2.65 mmHg for SBP and ±2.02 mmHg for DBP. For SBP, 98% of metasense measurements were within 15 mm Hg and for DBP, 91% of metasense measurements were within 10 mmHg CONCLUSIONS: The metasense device provides continuous, non-invasive BP estimations that are comparable to ambulatory BP meters. The portability and unobtrusiveness of this device, as well as the ability to continuously measure BP could one day enable long-term ambulatory BP measurement for precision cardiovascular therapeutic regimens.

Measurement of arterial occlusion pressure using straight and curved blood flow restriction cuffs.

Arterial occlusion pressure (AOP) is influenced by the characteristics of the cuff used to measure AOP. Doppler ultrasound was used to measure AOP of the brachial and superficial femoral arteries using straight and curved blood flow restriction cuffs in 21 males and 21 females. Vessel diameter and blood flow were evaluated as independent predictors of AOP. Overall, there were no significant differences in AOP when using the straight and curved cuffs in the brachial (129 mmHg vs. 128 mmHg) or superficial femoral artery (202 mmHg vs. 200 mmHg), respectively. Overall, AOP was greater (p < 0.05) in males than in females in the arm (135 mmHg, 123 mmHg) and leg (211 mmHg, 191 mmHg). Brachial (0.376 mm, 0.323 mm) and superficial femoral (0.547 mm, 0.486 mm) arteries were larger (p = 0.016) in males than in females, respectively. Systolic blood pressure (SBP) and arm circumference were predictive of brachial artery AOP, whereas SBP, diastolic blood pressure, thigh circumference, and vessel diameter were predictive of superficial femoral artery AOP. Straight and curved cuffs are efficacious in the measurement of AOP in the arm and leg. Differences in vessel size may contribute to sex differences in AOP but this requires further investigation.

[How to manage arterial hypertension in 2024 to optimize cardiorenal protection]. / Comment prendre en charge une hypertension artérielle en 2024 pour optimiser la protection cardio-rénale.

The latest guidelines for the management of arterial hypertension, the silent killer, were published in summer 2023. They particularly emphasize again the quality of blood pressure measurement which ideally should always be automated using oscillometric device and an arm cuff already in the consulting room. They remind you how to manage the blood pressure of a patient whose hypertension has been confirmed, to stimulate drug compliance and to avoid therapeutic inertia. A holistic view of the patient with all his or her risk factors is always required. The general practitioner is the key player in the diagnosis, treatment and monitoring of the hypertensive patient whose therapeutic education has been as complete as possible with practice of self-measurement of blood pressure at home if possible. The goal is to normalize blood pressure within the first three months of treatment initiation and to reduce as much as possible the cardiovascular risk of the treated patient in the frame of preventive medicine.

Les dernières directives de prise en charge de l'hypertension artérielle, le tueur silencieux, ont été publiées à l'été 2023. Elles insistent particulièrement, à nouveau, sur la qualité de la mesure de la pression artérielle qui, idéalement, doit être automatisée toujours à l'aide d'un brassard et ce, déjà au cabinet de consultation. Elles rappellent comment gérer la pression artérielle d'un patient dont l'hypertension a bien été confirmée, comment stimuler l'adhérence au traitement et éviter l'inertie thérapeutique. Une vue globale du patient avec tous ses facteurs de risque est toujours de rigueur. Le médecin généraliste est l'acteur-clé du diagnostic, du traitement et du suivi du patient hypertendu dont l'éducation thérapeutique a été la plus complète possible avec pratique de l'automesure tensionnelle à domicile si possible. Le but est de normaliser la pression artérielle dans les trois premiers mois de la prise en charge et de réduire le plus possible le risque cardiovasculaire et rénal du patient traité dans le cadre d'une médecine préventive.

Comparison of Central and Peripheral Arterial Blood Pressure Gradients in Critically Ill Patients: A Systematic Review and Meta-Analysis.

OBJECTIVES: Measurement of blood pressure taken from different anatomical sites, are often perceived as interchangeable, despite them representing different parts of the systemic circulation. We aimed to perform a systematic review and meta-analysis on blood pressure differences between central and peripheral arterial cannulation in critically ill patients. DATA SOURCES: We searched MEDLINE, Cochrane Central Register of Controlled Trials, and Embase from inception to December 26, 2023, using Medical Subject Headings (MeSH) terms and keywords. STUDY SELECTION: Observation study of adult patients in ICUs and operating rooms who underwent simultaneous central (femoral, axillary, or subclavian artery) and peripheral (radial, brachial, or dorsalis pedis artery) arterial catheter placement in ICUs and operating rooms. DATA EXTRACTION: We screened and extracted studies independently and in duplicate. We assessed risk of bias using the revised Quality Assessment for Studies of Diagnostic Accuracy tool. DATA SYNTHESIS: Twenty-four studies that enrolled 1598 patients in total were included. Central pressures (mean arterial pressure [MAP] and systolic blood pressure [SBP]) were found to be significantly higher than their peripheral counterparts, with mean gradients of 3.5 and 8.0 mm Hg, respectively. However, there was no statistically significant difference in central or peripheral diastolic blood pressure (DBP). Subgroup analysis further highlighted a higher MAP gradient during the on-cardiopulmonary bypass stage of cardiac surgery, reperfusion stage of liver transplant, and in nonsurgical critically ill patients. SBP or DBP gradient did not demonstrate any subgroup specific changes. CONCLUSIONS: SBP and MAP obtained by central arterial cannulation were higher than peripheral arterial cannulation; however, clinical implication of a difference of 8.0 mm Hg in SBP and 3.5 mm Hg in MAP remains unclear. Our current clinical practices preferring peripheral arterial lines need not change.

Impact of seasonal blood pressure changes on visit-to-visit blood pressure variability and related cardiovascular outcomes.

BACKGROUND: Visit-to-visit blood pressure (BP) variability associates with an increased risk of cardiovascular events. We investigated the role of seasonal BP modifications on the magnitude of BP variability and its impact on cardiovascular risk. METHODS: In 25 390 patients included in the ONTARGET and TRANSCEND trials, the on-treatment systolic (S) BP values obtained by five visits during the first two years of the trials were grouped according to the month in which they were obtained. SBP differences between winter and summer months were calculated for BP variability quintiles (Qs), as quantified by the coefficient of variation (CV) of on-treatment mean SBP from the five visits. The relationship of BP variability with the risk of cardiovascular events and mortality was assessed by the Cox regression model. RESULTS: SBP was approximately 4 mmHg lower in summer than in winter regardless of confounders. Winter/summer SBP differences contributed significantly to each SBP-CV quintile. Increase of SBP-CV from Q1 to Q5 was associated with a progressive increase in the adjusted hazard ratio (HR) of the primary endpoint of the trials, i.e. morbid and fatal cardiovascular events. This association was even stronger after removal of the effect of seasonality from the calculation of SBP-CV. A similar trend was observed for secondary endpoints. CONCLUSIONS: Winter/summer SBP differences significantly contribute to visit-to-visit BP variability. However, this contribution does not participate in the adverse prognostic significance of visit-to-visit BP variations, which seems to be more evident after removal of the BP effects of seasonality from visit-to-visit BP variations.

Protocol for Evaluating Remote Patient Blood Pressure Monitoring Adapted to Black Women and Birthing Persons.

Cardiovascular disease is the leading cause of maternal death among Black women in the United States. A large, urban hospital adopted remote patient blood pressure monitoring (RBPM) to increase blood pressure monitoring and improve the management of hypertensive disorders of pregnancy (HDP) by reducing the time to diagnosis of HDP. The digital platform integrates with the electronic health record (EHR), automatically inputting RBPM readings to the patients' chart; communicating elevated blood pressure values to the healthcare team; and offers a partial offset of the cost through insurance plans. It also allows for customization of the blood pressure values that prompt follow-up to the patient's risk category. This paper describes a protocol for evaluating its impact. Objective 1 is to measure the effect of the digitally supported RBPM on the time to diagnosis of HDP. Objective 2 is to test the effect of cultural tailoring to Black participants. The ability to tailor digital content provides the opportunity to test the added value of promoting social identification with the intervention, which may help achieve equity in severe maternal morbidity events related to HDP. Evaluation of this intervention will contribute to the growing literature on digital health interventions to improve maternity care in the United States.

Effect of limb and cuff positioning on measurement of arterial blood pressure with an oscillometry device (PetMAP) in anaesthetized cats.

Arterial blood pressure (ABP) is often measured with oscillometry during anaesthesia. Changing the height of the measuring cuff with respect to the level of the heart is known to affect oscillometry accuracy in some species; however, this effect has not been investigated in cats. The objective of this study was to determine the effects of raising and lowering the measuring cuff from standard position (level of the heart) on ABP, measured with PetMAP, in anaesthetised cats. ABP readings were obtained from 29 cats with the cuff at standard position (baseline), and 5 cm above and below the heart. The end-tidal isoflurane concentrations were maintained constant during data acquisition. There were no differences between baseline values and those measured below the heart, while ABP measured above the heart was consistently lower than baseline for both the thoracic and pelvic limbs (P < 0.001), with absolute differences of 8.2 (2.5 - 14) mmHg and 6.5 (3.0 - 15.0) mmHg, respectively. Systolic ABP readings at the pelvic limb were consistently higher than those at the thoracic limb at standard position (112 ± 26 versus 103 ± 21 mmHg, p = 0.010), above (106 ± 22 versus 95 ± 20 mmHg, p = 0.003), and below the heart (116 ± 26 versus 107 ± 22 mmHg, p = 0.011). This study shows that raising the cuff by 5 cm above the heart, which may become necessary during procedural positioning, results in clinically significant underestimation of ABP measured with PetMAP.