Continuous Non-invasive Blood Pressure Monitoring Research Articles

Maternal haemodynamics during labour epidural analgesia with and without adrenaline.

Labour is one of the most painful experiences in a woman's life. Epidural analgesia using low-concentration local anaesthetics and lipophilic opioids is the gold standard for pain relief during labour. Pregnancy in general, particularly labour, is associated with changes in maternal haemodynamic variables, such as cardiac output and heart rate, which increase and peak during uterine contractions. Adrenaline is added to labour epidural solutions to enhance efficacy by stimulating the α2-adrenoreceptor. The minimal effective concentration of adrenaline was found to be 2μgmL-1 for postoperative analgesia. The addition of adrenaline may also produce vasoconstriction, limiting the absorption of fentanyl into the systemic circulation, thereby reducing foetal exposure. However, adrenaline may influence the haemodynamic fluctuations, possibly adding to the strain on the circulatory system. The aim of this study was to compare the haemodynamic changes after application of labour epidural analgesia with or without adrenaline 2μgmL-1. This was a secondary analysis of a single-centre, randomised double-blind trial. Forty-one nulliparous women in labour requesting epidural analgesia were randomised to receive epidural solution of bupivacaine 1mgmL-1, fentanyl 2μgmL-1 with or without adrenaline 2μgmL-1. The participants were monitored using a Nexfin CC continuous non-invasive blood pressure and cardiac output monitor. The primary outcomes were changes in peak systolic blood pressure and cardiac output during uterine contraction within 30min after epidural activation. The effect of adrenaline was tested statistically using a linear mixed-effects model of the outcome variables' dependency on time, adrenaline, and their interaction. After excluding three patients due to poor data quality and two due to a malfunctioning epidural catheter, 36 patients (18 in each group) were analysed. The addition of adrenaline to the solution had no significant effect on the temporal changes in peak systolic blood pressure (p=0.26), peak cardiac output (0.84), or heart rate (p=0.91). Furthermore, no significant temporal changes in maternal haemodynamics (peak systolic blood pressure, p=0.54, peak cardiac output, p=0.59, or heart rate p=0.55) were associated with epidural analgesia during 30min after epidural activation in both groups despite good analgesia. The addition of 2μgmL-1 adrenaline to the epidural solution is not likely to change maternal haemodynamics during labour.

Evaluation of Cardiovascular Functions during the Practice of Different Types of Yogic Breathing Techniques.

Introduction: Yoga is the science of right living practice to promote health. Many studies have documented the cardiovascular effects of various yogic breathing techniques (YBTs), comparing the cardiovascular changes before and after the practice. However, there is a lack of study reporting the cardiovascular changes during the practice of YBT.Materials and Methods: Twenty healthy individuals performed four different YBTs (Bhastrika, Bhramari, Kapalbhati, and Kumbhaka) in four different orders. Cardiovascular variables such as systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (CO), pulse interval (PI), and total peripheral resistant (TPR) were assessed using a continuous noninvasive blood pressure monitoring system, before, during, and immediately after each YBT. Data were analyzed using repeated measures analysis of variance followed by post hoc analysis with Bonferroni adjustment for multiple comparisons using Statistical Package for the Social Sciences, Version 16.0.Results: Results of this study showed a significant increase in DBP, MAP, HR, and CO along with a reduction in PI during Bhastrika; a significant increase in DBP, MAP, HR, and TPR with a reduction in SV, CO, and PI during Bhramari pranayama; a significant increase in SBP, DBP, MAP, HR, and CO with a reduction in PI during Kapalbhati; and a significant increase in SBP, DBP, MAP, and TPR with a reduction in SV and CO during Kumbhaka practice.Conclusion: In healthy individuals, cardiovascular changes during the practice of Bhastrika and Kapalbhati are more or less similar to each other and are different from those of Bhramari and Kumbhaka in most of the variables.

Cuff-less continuous blood pressure measurement based on multiple types of information fusion

Non-invasive and cuff-less real-time continuous blood pressure monitoring plays an important role in both intensive care unit (ICU) and the management of chronic diseases such as hypertension and cardiovascular disease. Although pulse wave transit time (PTT) and pulse waveform parameters (PWPs) can be extracted from photoplethysmography (PPG) and electrocardiographic (ECG) to estimate blood pressure, the value of blood pressure is also constrained by personal characteristics parameters (PCPs). For example, the blood pressure may vary with height, weight and age. In this paper, we present a cuff-less continuous blood pressure measurement method based on multiple types of information fusion. First, we recruited 186 volunteers and measured their personal data (PPG signal, ECG signal, height, age, weight, gender). Second, extract the PTT and PWPs from the PPG signal and ECG signal. Then, according to the extracted parameters, the blood pressure models of control group and experimental group were established respectively (the experimental group uses the multiple types of information fusion method to model, the control group only considers PTT and PWPs). Experiments show that, comparing with the control group, the experimental group systolic blood pressure (SBP) correlation was increased from 0.9355 to 0.9948, root mean square error (RMSE) was reduced from 5.2 mmHg to 1.5 mmHg, while the diastolic blood pressure (DBP) correlation was improved from 0.9331 to 0.9931, RMSE was reduced from 2.9 mmHg to 0.9 mmHg. Therefore, the modeling method proposed in this paper can get more accurate blood pressure values. Further promotion, to achieve the measurement with the "modeling" method, all "restriction" elements must be taken into account in order to obtain a more accurate and stable model.

Detection of hypotension during spinal anesthesia for caesarean section with continuous non-invasive arterial pressure monitoring and intermittent oscillometric blood pressure monitoring in patients treated with ephedrine or phenylephrine

Introduction/Objective. Despite frequent side effects such as hypotension, spinal anesthesia (SA) is still one of the best anesthetic methods for elective cesarean section (CS). Intermittent, oscillometric, noninvasive blood pressure monitoring (NIBP) frequently leads to missed hypotensive episodes. The objective was to compare continuous non-invasive arterial pressure (CNAP) monitoring with NIBP in the terms of efficiency to detect hypotension. Methods. In this study, we compared CNAP and NIBP monitoring for hypotension detection in 76 patients divided into two groups of 38 patients treated with ephedrine (E) or phenylephrine (P), during threeminute intervals, starting from SA, by the end of the surgery. Results. In E group, significantly lower mean systolic blood pressure (SBP) values with CNAP compared with NIBP (p = 0.008) was detected. By monitoring CNAP, we detected 31 (81.6%) hypotensive patients in E group and significantly lower number, 20 (52.6%), with NIBP (p = 0.001), while in P group CNAP detected 34 patients (89.5%) and NIBP only 18 (47.3%), p = 0.001. By monitoring CNAP, we detected significantly higher number of hypotensive intervals in E and P groups (p < 0.001). Umbilical vein pH was lower within hypotensive compared with normotensive patients in E and P groups, with CNAP and NIBP, respectively (p < 0.001, p = 0.027 in E, and p = 0.009, p < 0.001, in P group). Conclusion. CNAP is more efficient in hypotension detection for CS during SA, which allows faster treatment of hypotension, thus improving fetal and maternal outcome.

An iterative run-to-run learning model to derive continuous brachial pressure estimates from arterial and venous lines during dialysis treatment

Objective:Non-invasive continuous blood pressure monitoring is not yet part of routine practice in renal dialysis units but could be a valuable tool in the detection and prevention of significant variations in patient blood pressure during treatment. Feasibility studies have delivered an initial validation of a method which utilises pressure sensors in the extra-corporeal dialysis circuit, without any direct contact with the person receiving treatment. Our main objective is to further develop this novel methodology from its current early development status to a continuous-time brachial artery pressure estimator. Methods:During an in vivo patient feasibility study with concurrent measurement validation by Finapres Nova experimental physiological measurement device, real-time continuous dialysis line pressures, and intermittent occluding arm cuff pressure data were collected over the entire period of (typically 4-hour) dialysis treatments. There was found to be an underlying quasi-linear relationship between arterial line and brachial pressure measurements which supported the development of a mathematical function to describe the relationship between arterial dialysis line pressure and brachial artery BP. However, unmodelled non-linearities, dynamics and time-varying parameters present challenges to the development of an accurate BP estimation system. In this paper, we start to address the problem of physiological parameter time variance by novel application of an iterative learning run-to-run modelling methodology originally developed for process control engineering applications to a parameterised BP model. Results:The iterative run-to-run learning methodology was applied to the real-time data measured during an observational study in 9 patients, supporting subsequent development of an adaptive real-time BP estimator. Tracking of patient BP is analysed for all the subjects in our patient study, supported only by intermittent updates from BP cuff measurements. Conclusion:The methodology and associated technology is shown to be capable of tracking patient BP non-invasively via arterial line pressure measurement during complete 4-hour treatment sessions. A robust and tractable method is demonstrated, and future refinements to the approach are defined.

Abstract 17298: Validation of Beat-to-Beat Blood Pressure and Left Ventricular Ejection Time by the Caretaker Physiological Monitor Against Invasive Central Aortic Measurement

Objective: There is an unmet need for noninvasive continuous blood pressure (BP) monitoring technologies in various clinical settings. We examined the accuracy of noninvasive Caretaker device against invasively measured central aortic BP. Methods: Beat-to-beat BP by Caretaker was recorded simultaneously with central aortic BP measured in patients undergoing cardiac catheterization. We derived correlations and Bland-Altman comparisons, after calibrating the Caretaker with 20 seconds of the initial catheter readings, as well as trend analyses for both systolic (SBP) and diastolic BP (DBP). We also measured left ventricular ejection time (LVET) from both aortic pressure tracing and Caretaker and compared the two. Results: A total of 47 patients were included in the study. A total of 31,369 beats obtained during the diagnostic portion of coronary angiogram were used for analysis. The correlations for SBP and DBP were 0.89 and 0.78, respectively (p < 0.001 for both). The Bland-Altman comparison yielded overall mean differences of 2.11 mmHg (SD 7.40) for SBP and 1.46 mmHg (SD 6.12) for DBP respectively (p <0.001 for all comparisons). The trend analysis yielded concordances of 86% and 85% for SBP and DBP, respectively. The correlation and Bland-Altman analyses for the LVET comparison yielded 0.89 (p< 0.001) with a mean difference of 13.9 ms (SD 14.4 ms). Conclusion: Beat-to-beat BP by Caretaker showed excellent agreement and high concordance in the direction and the degree of BP change with central aortic BP. This study supports the satisfactory performance of the Caretaker device in continuous tracking of beat-to-beat BP and LVET measurements.

A Feasibility Study of Non-Invasive Continuous Estimation of Brachial Pressure Derived From Arterial and Venous Lines During Dialysis.

Objective: Intradialytic haemodynamic instability is a significant clinical problem, leading to end-organ ischaemia and contributing to morbidity and mortality in haemodialysis patients. Non-invasive continuous blood pressure monitoring is not currently part of routine practice but may aid detection and prevention of significant falls in blood pressure during dialysis. Brachial blood pressure is currently recorded intermittently during haemodialysis via a sphygmomanometer. Current methods of continuous non-invasive blood pressure monitoring tend to restrict movement, can be sensitive to external disturbances and patient movement, and can be uncomfortable for the wearer. Additionally, poor patient blood circulation can lead to unreliable measurements. In this feasibility study we performed an initial validation of a novel method and associated technology to continuously estimate blood pressure using pressure sensors in the extra-corporeal dialysis circuit, which does not require any direct contact with the person receiving dialysis treatment. Method: The paper describes the development of the measurement system and subsequent in vivo patient feasibility study with concurrent measurement validation by Finapres Nova physiological measurement device. Real-time physiological data is collected over the entire period of (typically 4-hour) dialysis treatment. Results: We identify a quasi-linear mathematical function to describe the relationship between arterial line pressure and brachial artery BP, which is confirmed in a patient study. The results from this observational study suggest that it is feasible to derive a continuous measurement of brachial pressure from continuous measurements of arterial and venous line pressures via an empirically based and updated mathematical model. Conclusion: The methodology presented requires no interfacing to proprietary dialysis machine systems, no sensors to be attached to the patient directly, and is robust to patient movement during treatment and also to the effects of the cyclical pressure waveforms induced by the hemodialysis peristaltic blood pump. This represents a key enabling factor to the development of a practical continuous blood pressure monitoring device for dialysis patients.

Non-invasive continuous blood pressure monitoring (ClearSight\u2122 system) during shoulder surgery in the beach chair position: a prospective self-controlled study

BackgroundThe beach chair position that is commonly used in shoulder surgery is associated with relative hypovolemia, which leads to a reduction in arterial blood pressure. The effects of patient positioning on the accuracy of non-invasive continuous blood pressure monitoring with the ClearSight™ system (CS-BP; Edwards Lifesciences, Irvine CA, USA) have not been studied extensively. Our research aim was to assess agreement levels between CS-BP measurements with traditional blood pressure monitoring techniques.MethodsFor this prospective self-controlled study, we included 20 consecutively treated adult patients undergoing elective shoulder surgery in the beach chair position. We performed Bland-Altman analyses to determine agreement levels between blood pressure values from CS-BP and standard non-invasive (NIBP) methods. Perioperative measurements were done in both the supine (as reference) and beach chair surgical positions. Additionally, we compared invasive blood pressure (IBP) measurements with both the non-invasive methods (CS-BP and NIBP) in a sub-group of patients (n = 10) who required arterial blood pressure monitoring.ResultsWe analyzed 229 data points (116 supine, 113 beach chair) from the entire cohort; per patient measurements were based on surgical length (range 3–9 supine, 2–10 beach chair). The mean difference (±SD; 95% limits of agreement) in the mean arterial pressure (MAP) between CS-BP and NIBP was − 0.9 (±11.0; − 24.0–22.2) in the beach chair position and − 4.9 mmHg (±11.8; − 28.0–18.2) when supine. In the sub-group, the difference between CS-BP and IBP in the beach chair position was − 1.6 mmHg (±16.0; − 32.9–29.7) and − 2.8 mmHg (±15.3; − 32.8–27.1) in the supine position. Between NIBP and IBP, we detected a difference of 3.0 mmHg (±9.1; − 20.8–14.7) in the beach chair position, and 4.6 mmHg (±13.3; − 21.4–30.6) in the supine position.ConclusionsWe found clinically acceptable mean differences in MAP measurements between the ClearSight™ and non-invasive oscillometric blood pressure systems when patients were in either the supine or beach chair position. For all comparisons of the monitoring systems and surgical positions, the standard deviations and limits of agreement were wide.Trial registrationThis study was prospectively registered at the German Clinical Trial Register (www.DRKS.de; DRKS00013773). Registered 26/01/2018.

Simulations of blood pressure and identification of atrial fibrillation and arterial stiffness using an extended Kalman filter with oscillometric pulsation measurements

Background and ObjectiveThe accuracy of systolic and diastolic blood pressure levels from oscillometric devices is difficult to assess for patients with atrial fibrillation and arterial stiffness; in such cases, changes in these levels from heartbeat to heartbeat can only be known if the actual total waveform during a test can be observed. Variation in these levels affects the accuracy of the algorithms in oscillometric devices where precision is of paramount importance according to the American College of Cardiology and the American Heart Association. Recently issued guidelines lowered the definition of high blood pressure; approximately three-quarters of men over 65 years of age meet the criterion and are diagnosed as hypertensive. A review in 2019 reported that atrial fibrillation affects approximately 3% of the general population in the U.S. and is twice as common in hypertensive patients. The actual shape and details of the arterial blood pressure waveform not only reveal variations in rhythm and in systolic and diastolic levels but has also proven to be valuable in the diagnosis of arterial stiffness and atrial fibrillation which are vital to determining the physiological status of a patient's cardiovascular system. This research pertains to the identification of a patient's total arterial blood pressure waveform using only the measured pulsations in the cuff of an oscillometric device. MethodEmpirically formulated hypothetical arterial blood pressure waveforms were simulated and assumed to be unknown. Oscillometric pulsations corresponding to these simulated unknown waveforms were used as input to a new model-based extended Kalman filter algorithm for identifying the levels, shape and features of the unknown waveforms. ResultsSimulations with hypothetical waveforms with varying systolic and diastolic levels and with variations in heartbeat rhythm associated arterial fibrillation and stiff arteries, demonstrate potential arterial pressure estimate accuracies of 1.5 mmHg with standard deviations on the order of 0.1 mmHg; in addition, variations in heartbeat rhythm were observed and degrees of arterial stiffness identified and quantified. ConclusionsComputational analysis of the oscillometric cuff pulsations with the extended Kalman filter can be used to detect variations in heartbeat rhythm and blood pressure levels associated atrial fibrillation, quantify arterial stiffness, and provide noninvasive continuous blood pressure monitoring without the need for electrocardiogram or photoplethysmography sensors.

Association of transient orthostatic hypotension with falls and syncope in patients with Parkinson disease.

To assess the frequency of transient orthostatic hypotension (tOH) and its clinical impact in Parkinson disease (PD), we retrospectively studied 173 patients with PD and 173 age- and sex-matched controls with orthostatic intolerance, who underwent cardiovascular autonomic function testing under continuous noninvasive blood pressure (BP) monitoring. We screened for tOH (systolic BP fall ≥20 mm Hg or diastolic ≥10 mm Hg resolving within the first minute upon standing) and classic OH (cOH, sustained systolic BP fall ≥20 mm Hg or diastolic ≥10 mm Hg within 3 minutes upon standing). In patients with PD, we reviewed the medical records of the 6 months preceding and following autonomic testing for history of falls, syncope, and orthostatic intolerance. tOH occurred in 24% of patients with PD and 21% of controls, cOH in 19% of patients with PD and in none of the controls, independently of any clinical-demographic or PD-specific characteristic. Forty percent of patients with PD had a history of falls, in 29% of cases due to syncope. Patients with PD with history of orthostatic intolerance and syncope had a more severe systolic BP fall and lower diastolic BP rise upon standing, most pronounced in the first 30-60 seconds. tOH is an age-dependent phenomenon, which is at least as common as cOH in PD. Transient BP falls when changing to the upright position may be overlooked with bedside BP measurements, but contribute to orthostatic intolerance and syncope in PD. Continuous noninvasive BP monitoring upon standing may help identify a modifiable risk factor for syncope-related falls in parkinsonian patients.

Blood pressure monitoring in sleep: time to wake up.

Hypertension is a highly common condition with well-established adverse consequences. Ambulatory blood pressure monitoring has repeatedly been shown to better predict cardiovascular outcomes and mortality, compared to single office visit blood pressure. Non-dipping of sleep-time blood pressure is an independent marker for increased cardiovascular risk. We review blood pressure variability and the challenges of blood pressure monitoring during sleep. Although pathological sleep such as obstructive sleep apnea has been associated with non-dipping of sleep-time blood pressure, blood pressure is not routinely measured during sleep due to lack of unobtrusive blood pressure monitoring technology. Second, we review existing noninvasive continuous blood pressure monitoring technologies. Lastly, we propose including sleep-time blood pressure monitoring during sleep studies and including sleep studies in patients undergoing ambulatory blood pressure monitoring.

Continuous Non-Invasive Blood Pressure Monitoring: A Methodological Review on Measurement Techniques

Continuous measurement of blood pressure is crucial to the assessment of many medical conditions. However, the current clinical gold standard involving an arterial catheter, occluding cuff, and other invasive procedures are performed in hospital settings while home-based devices can provide only intermittent measurement and are not as reliable. Therefore, there is a significant need for continuous non-invasive blood pressure (cNIBP) monitoring in the daily life. Pulse transit time (PTT)/pulse arrival time (PAT) - based blood pressure measurement has proven its potential to address this need. In this article, we present state-of-the-art devices and recent literature related to measurement technologies used in PTT/PAT - based methods for cNIBP monitoring. Various physiological signals which could be used to enable cNIBP in the home setting are categorized into two groups (i.e., proximal waveforms and distal waveforms) and are thoroughly discussed and compared. Given insightful analysis of these waveforms, we highlight their combinations to derive PTT/PAT values for BP measurement then discuss challenges presented from the cuffless and PTT/PAT - based nature of these devices. Finally, we conclude with future directions needed for home-based cNIBP adaptation and present societal broader impacts.

Comparison of a noninvasive 3D force sensor-based method and the invasive arterial cannula in postsurgery intensive care patients: a pilot study

Improvement in sensing technologies is leading to new, accurate noninvasive monitoring devices. However, noninvasive continuous blood pressure (BP) monitoring still faces many challenges, such as: patient's movement, device accuracy and consistency. In this study, the accuracy of a novel noninvasive BP measuring system based on a three-axis force sensor is compared with the invasive arterial cannula taking 21 simultaneous measurements mostly on elderly, postsurgical participants. For the simultaneously recorded invasive and noninvasive signals, the similarity was high, the average correlation was 0.9001 ± 0.0588. The average differences (±SD) for simultaneously recorded systolic, diastolic and mean arterial pressures were: -9.53 ± 4.69, -0.26 ± 3.06 and 1.25 ± 2.26 mmHg, respectively. The results of diastolic and mean arterial pressure satisfy the criteria set by the Association for the Advancement of Medical Instrumentation. These results suggest that this noninvasive system could be a useful tool in continuous noninvasive BP monitoring, but still requires development.

Anesthetic management of modified electroconvulsive therapy for a patient with coronary aneurysms: a case report

BackgroundModified electroconvulsive therapy (m-ECT) is utilized worldwide as an effective treatment for drug-resistant psychiatric disorders. However, during m-ECT, treatment of hypotension and hypertension in response to rapid hemodynamic changes is required. We used noninvasive continuous blood pressure monitoring system for continuous hemodynamic measurement during m-ECT.Case presentationThe patient was a 77-year-old man with depression complicated by coronary artery aneurysms (CAAs). We managed general anesthesia during m-ECT by using the ClearSight™ system (Edwards Lifesciences Corp, Irvine, CA, USA) for hemodynamic measurement. As a result, we performed a total of 10 m-ECTs. No rupture of CAAs or myocardial ischemia occurred and depressive symptoms improved.ConclusionWe successfully managed the anesthesia in m-ECT for a depressed patient with CAAs without complications by using the ClearSight™ system, which was used for the effective management of circulatory fluctuations.

Non-invasive continuous blood pressure monitoring systems: current and proposed technology issues and challenges.

High blood pressure (BP) or hypertension is the single most crucial adjustable risk factor for cardiovascular diseases (CVDs) and monitoring the arterial blood pressure (ABP) is an efficient way to detect and control the prevalence of the cardiovascular health of patients. Therefore, monitoring the regulation of BP during patients' daily life plays a critical role in the ambulatory setting and the latest mobile health technology. In recent years, many studies have been conducted to explore the feasibility and performance of such techniques in the health care system. The ultimate aim of these studies is to find and develop an alternative to conventional BP monitoring by using cuff-less, easy-to-use, fast, and cost-effective devices for controlling and lowering the physical harm of CVDs to the human body. However, most of the current studies are at the prototype phase and face a range of issues and challenges to meet clinical standards. This review focuses on the description and analysis of the latest continuous and cuff-less methods along with their key challenges and barriers. Particularly, most advanced and standard technologies including pulse transit time (PTT), ultrasound, pulse arrival time (PAT), and machine learning are investigated. The accuracy, portability, and comfort of use of these technologies, and the ability to integrate to the wearable healthcare system are discussed. Finally, the future directions for further study are suggested.

Analysis of Pulse Arrival Time as an Indicator of Blood Pressure in a Large Surgical Biosignal Database: Recommendations for Developing Ubiquitous Blood Pressure Monitoring Methods.

As non-invasive continuous blood pressure monitoring (NCBPM) has gained wide attraction in the recent decades, many pulse arrival time (PAT) or pulse transit time (PTT) based blood pressure (BP) estimation studies have been conducted. However, most of the studies have used small homogeneous subject pools to generate models of BP based on particular interventions for induced hemodynamic change. In this study, a large open biosignal database from a diverse group of 2309 surgical patients was analyzed to assess the efficacy of PAT, PTT, and confounding factors on the estimation of BP. After pre-processing the dataset, a total of 6,777,308 data pairs of BP and temporal features between electrocardiogram (ECG) and photoplethysmogram (PPG) were extracted and analyzed. Correlation analysis revealed that PAT or PTT extracted from the intersecting-tangent (IT) point of PPG showed the highest mean correlation to BP. The mean correlation between PAT and systolic blood pressure (SBP) was −0.37 and the mean correlation between PAT and diastolic blood pressure (DBP) was −0.30, outperforming the correlation between BP and PTT at −0.12 for SBP and −0.11 for DBP. A linear model of BP with a simple calibration method using PAT as a predictor was developed which satisfied international standards for automatic oscillometric BP monitors in the case of DBP, however, SBP could not be predicted to a satisfactory level due to higher errors. Furthermore, multivariate regression analyses showed that many confounding factors considered in previous studies had inconsistent effects on the degree of correlation between PAT and BP.

Closed-loop Vasopressor Infusion Using Continuous Noninvasive Blood Pressure Monitoring

Closed-loop Vasopressor Infusion Using Continuous Noninvasive Blood Pressure Monitoring

Systematic review: does continuous noninvasive blood pressure monitoring improve patient outcomes?

Systematic review: does continuous noninvasive blood pressure monitoring improve patient outcomes?

Effectiveness and accuracy of a domestic continuous non-invasive blood pressure device in monitoring intraoperative blood pressure

Objective To evaluate the effectiveness and accuracy of a domestic continuous non-invasive blood pressure (NIBP) device in monitoring intraoperative blood pressure. Methods Sixty patients of both sexes, aged 18-64 yr, with body mass index of 18-30 kg/m2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, undergoing elective surgery under general anesthesia, were included in the study.The invasive blood pressure (IBP) and NIBP were simultaneously measured in the radial artery.Systolic and diastolic blood pressure (SBP, DBP) was continuously recorded, and the paired data and data of waveform were collected.For paired data, the agreement was evaluated using Bland-Altman analyses between the two monitoring methods.For waveform data, Pearson linear correlate analysis was performed between the two monitoring methods. Results For paired data, the bias of NIBP value from IBP value were (-2.1±5.4)mmHg(95% CI -3.5-0.7 mmHg) and (2.6±6.4)mmHg (95% CI 1.0-4.3 mmHg) for SBP and DBP, respectively.The 95% limit of agreement of bias between the two methods was -12.6-8.5 mmHg for SBP and -10.0-15.3 mmHg for DBP.For waveform data, the bias of NIBP value from IBP value were (-2.1±6.5) mmHg(95% CI -3.7-0.4 mmHg) and (3.1±6.8) mmHg (95% CI 1.3-4.8 mmHg) for SBP and DBP, respectively.The correlation coefficient between the two methods was 0.82 for SBP and 0.88 for DBP, P<0.01. Conclusion The effectiveness and accuracy of this domestic continuous NIBP monitoring device in monitoring intraoperative blood pressure is clinically acceptable. Key words: Blood pressure determination; Monitoring, intraoperative

Efficacy of a continuous non-invasive arterial blood pressure monitor system for bronchoscope diagnosis and treatment under general anesthesia

Objective To compare continuous non-invasive arterial blood pressure (CNAP) monitoring with non-invasive blood pressure (NIBP) monitoring in anesthesia monitoring application value of bronchoscope diagnosis and treatment, and to find whether the CNAP can improve the detection rate of hypotension and detect low blood pressure earlier so that improve the safety of patients. Methods Twenty patients undergoing bronchoscope diagnosis and treatment under general anesthesia from outpatient were included in this study. The NIBP monitoring was put on one side of the upper limb and the CNAP monitoring was connected to the other side upper limb before inducement of general anesthesia. Both connections were kept until the end of operation. The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) of the CNAP were recorded one time per minute whereas the SBP, DBP and MAP of NIBP were recorded one time every 3 min. The low blood pressure (SBP<80 mmHg, 1 mmHg=0.133 kPa) frequency of CNAP and NIBP were respectively counted. The low blood pressure detection rate and the hypotension checkout time of NIBP and CNAP were calculated respectively. The consistency and correlation between the two blood pressure measurements were compared. At the same time, the complications of the two methods of monitoring were recorded and compared. Results The low blood pressure detection rate of CNAP and NIBP was 17.2% and 14.7% (P<0.05). The hypotension checkout time of CNAP and NIBP were (1.2±0.4) min and (3.0±0.0) min respectively (P<0.05). The SBP, DBP and MAP bias of CNAP and NIBP measurement were (1.5±8.8), (1.1±8.2) mmHg and (1.3±7.1) mmHg respectively. Consistency limits were -18.70-15.70 mmHg, -17.20-14.90 mmHg and -15.30-12.70 mmHg respectively. The proportion within the scope of the consistency of its corresponding boundary were 96.70%, 97.10% and 97.10% respectively. The correlation coefficients of SBP, DBP and MAP measured by CNAP and NIBP were 0.910, 0.861 and 0.941 respectively (P<0.05). None of the patients had complications. Conclusions CNAP is more sensitive and timely in detecting hypotension. It has higher consistency and more correlation than NIBP. Thus, CNAP can improve the safety of anesthesia monitoring for bronchoscope diagnosis and treatment. Key words: Continuous non-invasive arterial blood pressure monitoring; Bronchoscope diagnosis and treatment; Anesthesia, general