Hemodynamic Monitoring Technologies Research Articles

IMPACT OF ADVANCED HEMODYNAMIC MONITORING ON MYOCARDIAL REVASCULARIZATION SURGERY IN HIGH-RISK PATIENTS

Coronary artery bypass grafting is a critical procedure for patients with advanced coronary disease, especially those classified as high risk due to comorbidities such as heart failure, hypertension and diabetes. Advanced hemodynamic monitoring has proved essential in this context, allowing continuous and accurate surveillance of cardiac and vascular parameters, which can reduce intra- and post-operative complications. This abstract aims to assess the impact of advanced hemodynamic monitoring during coronary artery bypass graft surgery in high-risk patients. The aim is to explore the advantages of this type of monitoring, the technologies used and the benefits in terms of clinical outcomes and reduction of complications. This is a literature review with a qualitative approach, carried out in the PubMed, SciELO, LILACS, BVS and Google Scholar databases. In order to optimize the search, descriptors such as Hemodynamic Monitoring, Cardiac Surgery, High Risk Patients and Fluid Management were used. For time delimitation, the research considered publications between the years 2019 and 2022, a period that reflects the latest advances in hemodynamic monitoring technologies in high-risk cardiac surgeries. Advanced hemodynamic monitoring includes the use of devices such as the pulmonary artery catheter and non-invasive bioimpedance systems, which provide real-time data on cardiac output, blood pressure, oxygen saturation and systemic vascular resistance. In high-risk patients, these devices allow for precise adjustments in the administration of fluids and vasoactive drugs, promoting better hemodynamic stability. Studies indicate that this approach reduces the incidence of serious complications, such as cardiogenic shock and arrhythmias, optimizing post-operative recovery. Therefore, advanced hemodynamic monitoring is a crucial tool in CABG surgeries, especially for high-risk patients. Its implementation improves intraoperative management, reducing the risk of complications and promoting better clinical outcomes. Therefore, its use should be considered an integral part of strategies for complex cardiac surgeries.

The pressure field model: a challenge to the conventional Starling and Guyton model of hemodynamic management

IntroductionEnsuring hemodynamic stability with adequate perfusion to vital organs is critical to the safe conduct of anesthesia. Recent advances in hemodynamic monitoring technologies allow pressure, flow, and resistance to be measured continuously; however, there is limited evidence to suggest that these technologies alter clinical management or improve patient outcomes significantly. This may be because the fundamental hemodynamic model, established by Starling and Guyton, fails to offer the granular level of insight needed to guide clinical management.MethodsWe collected hemodynamic data from 950 patients who underwent major surgery with advanced hemodynamic monitoring (AHM) that provided continuously derived cardiac output and vascular resistance measurements. These measurements were based on the hemodynamic model of Starling and Guyton. Additionally, investigational monitoring software was developed to visualize a different hemodynamic model, termed the “pressure field” model. This model expresses the pulsatile, beat-to-beat relationship between ventricular performance (measured by stroke volume) and vascular tone (indicated by systemic elastance).ResultsWithin this dataset were several patients who experienced major hemorrhage. Case studies of these patients demonstrate that abnormal pressure and flow regulation patterns are observed through the lens of the pressure field model, but these patterns are typically not visible through the lens of the traditional Starling and Guyton model (cardiac output and systemic vascular resistance, which involve averaging hemodynamic performance over successive cardiac cycles). Furthermore, “before and after” case studies using our investigational pressure field monitoring software suggest that the traditional Starling and Guyton hemodynamic model has limited utility in managing hemorrhage.DiscussionWe propose that the pressure field model may allow hemorrhage to be managed more effectively via improved monitoring granularity [the beat-by-beat visualization of the stroke volume-systemic elastance relationship, rather than the use of the composite metrics of cardiac output (heart rate × stroke volume) and systemic vascular resistance]. Further research into the utility of the pressure field model is warranted.

Non-Invasive Hemodynamic Monitoring System Integrating Spectrometry, Photoplethysmography, and Arterial Pressure Measurement Capabilities.

Minimally invasive and non-invasive hemodynamic monitoring technologies have recently gained more attention, driven by technological advances and the inherent risk of complications in invasive techniques. In this article, an experimental non-invasive system is presented that effectively combines the capabilities of spectrometry, photoplethysmography (PPG), and arterial pressure measurement. Both time- and wavelength-resolved optical signals from the fingertip are measured under external pressure, which gradually increased above the level of systolic blood pressure. The optical channels measured at 434-731 nm divided into three groups separated by a group of channels with wavelengths approximately between 590 and 630 nm. This group of channels, labeled transition band, is characterized by abrupt changes resulting from a decrease in the absorption coefficient of whole blood. External pressure levels of maximum pulsation showed that shorter wavelengths (<590 nm) probe superficial low-pressure blood vessels, whereas longer wavelengths (>630 nm) probe high-pressure arteries. The results on perfusion indices and DC component level changes showed clear differences between the optical channels, further highlighting the importance of wavelength selection in optical hemodynamic monitoring systems. Altogether, the results demonstrated that the integrated system presented has the potential to extract new hemodynamic information simultaneously from macrocirculation tomicrocirculation.

Continuous Blood Pressure Monitoring in Patients Having Surgery: A Narrative Review.

Hypotension can occur before, during, and after surgery and is associated with postoperative complications. Anesthesiologists should thus avoid profound and prolonged hypotension. A crucial part of avoiding hypotension is accurate and tight blood pressure monitoring. In this narrative review, we briefly describe methods for continuous blood pressure monitoring, discuss current evidence for continuous blood pressure monitoring in patients having surgery to reduce perioperative hypotension, and expand on future directions and innovations in this field. In summary, continuous blood pressure monitoring with arterial catheters or noninvasive sensors enables clinicians to detect and treat hypotension immediately. Furthermore, advanced hemodynamic monitoring technologies and artificial intelligence-in combination with continuous blood pressure monitoring-may help clinicians identify underlying causes of hypotension or even predict hypotension before it occurs.

New Hemodynamic Parameters in Peri-Operative and Critical Care-Challenges in Translation.

Hemodynamic monitoring technologies are evolving continuously-a large number of bedside monitoring options are becoming available in the clinic. Methods such as echocardiography, electrical bioimpedance, and calibrated/uncalibrated analysis of pulse contours are becoming increasingly common. This is leading to a decline in the use of highly invasive monitoring and allowing for safer, more accurate, and continuous measurements. The new devices mainly aim to monitor the well-known hemodynamic variables (e.g., novel pulse contour, bioreactance methods are aimed at measuring widely-used variables such as blood pressure, cardiac output). Even though hemodynamic monitoring is now safer and more accurate, a number of issues remain due to the limited amount of information available for diagnosis and treatment. Extensive work is being carried out in order to allow for more hemodynamic parameters to be measured in the clinic. In this review, we identify and discuss the main sensing strategies aimed at obtaining a more complete picture of the hemodynamic status of a patient, namely: (i) measurement of the circulatory system response to a defined stimulus; (ii) measurement of the microcirculation; (iii) technologies for assessing dynamic vascular mechanisms; and (iv) machine learning methods. By analyzing these four main research strategies, we aim to convey the key aspects, challenges, and clinical value of measuring novel hemodynamic parameters in critical care.

A Physiologic Approach to Hemodynamic Monitoring and Optimizing Oxygen Delivery in Shock Resuscitation.

The approach to shock resuscitation focuses on all components of oxygen delivery, including preload, afterload, contractility, hemoglobin, and oxygen saturation. Resuscitation focused solely on preload and fluid responsiveness minimizes other key elements, resulting in suboptimal patient care. This review will provide a physiologic and practical approach for the optimization of oxygen delivery utilizing available hemodynamic monitoring technologies. Venous oxygen saturation (SvO2) and lactate will be discussed as indicators of shock states and endpoints of resuscitation within the framework of resolving oxygen deficit and oxygen debt.

Meta-analyses on measurement precision of non-invasive hemodynamic monitoring technologies in adults

An ideal non-invasive monitoring system should provide accurate and reproducible measurements of clinically relevant variables that enables clinicians to guide therapy accordingly. The monitor should be rapid, easy to use, readily available at the bedside, operator-independent, cost-effective and should have a minimal risk and side effect profile for patients. An example is the introduction of pulse oximetry, which has become established for non-invasive monitoring of oxygenation worldwide. A corresponding non-invasive monitoring of hemodynamics and perfusion could optimize the anesthesiological treatment to the needs in individual cases. In recent years several non-invasive technologies to monitor hemodynamics in the perioperative setting have been introduced: suprasternal Doppler ultrasound, modified windkessel function, pulse wave transit time, radial artery tonometry, thoracic bioimpedance, endotracheal bioimpedance, bioreactance, and partial CO2 rebreathing have been tested for monitoring cardiac output or stroke volume. The photoelectric finger blood volume clamp technique and respiratory variation of the plethysmography curve have been assessed for monitoring fluid responsiveness. In this manuscript meta-analyses of non-invasive monitoring technologies were performed when non-invasive monitoring technology and reference technology were comparable. The primary evaluation criterion for all studies screened was aBland-Altman analysis. Experimental and pediatric studies were excluded, as were all studies without anon-invasive monitoring technique or studies without evaluation of cardiac output/stroke volume or fluid responsiveness. Most studies found an acceptable bias with wide limits of agreement. Thus, most non-invasive hemodynamic monitoring technologies cannot be considered to be equivalent to the respective reference method. Studies testing the impact of non-invasive hemodynamic monitoring technologies as atrend evaluation on outcome, as well as studies evaluating alternatives to the finger for capturing the raw signals for hemodynamic assessment, and, finally, studies evaluating technologies based on aflow time measurement are current topics of clinical research.

Journal of Clinical Monitoring and Computing 2017 end of year summary: cardiovascular and hemodynamic monitoring.

Hemodynamic monitoring provides the basis for the optimization of cardiovascular dynamics in intensive care medicine and anesthesiology. The Journal of Clinical Monitoring and Computing (JCMC) is an ideal platform to publish research related to hemodynamic monitoring technologies, cardiovascular (patho)physiology, and hemodynamic treatment strategies. In this review, we discuss selected papers published on cardiovascular and hemodynamic monitoring in the JCMC in 2017.

Current use of the pulmonary artery catheter in cardiac surgery: a survey study.

Because of its invasive nature, debated effect on patient outcome, and the development of alternative hemodynamic monitoring technologies, the intraoperative use of the pulmonary artery catheter (PAC) has significantly decreased. The authors conducted a survey of the members of the Society of Cardiovascular Anesthesiologists (SCA) to assess current use of the PAC and alternative hemodynamic monitoring technologies in patients undergoing cardiac surgery. A survey study. Hospitals in North America, Europe, Asia, Australia, New Zealand, and South America. SCA members in North America, Europe, Asia, Australia, New Zealand, and South America. The survey was e-mailed by the SCA to roughly 6,000 of its members. The survey was left open for 30 days. Respondents accessed the survey via a secured web-based database. A total of 854 questionnaires were completed. A total of 705 (82.6%) were from North American members. Four hundred twelve of the respondents (48.1%) worked in a private practice setting, while 350 (40.9%) were from an academic practice. A majority of the respondents (57.9%) were from hospitals that performed more than 400 cardiac surgeries a year, a subset of which (29.6%) did more than 800 cases annually. For cases using cardiopulmonary bypass, 583 (68.2%) of the respondents used a PAC more than 75% of the time, while 30 (3.5%) did not use the PAC at all. Ninety-four percent of respondents used transesophageal echocardiography (TEE) as part of the intraoperative monitoring. When not using a PAC, FloTrac/Vigileo was the alternative cardiac monitoring modality in 15.2% of the responses. Similar trends in monitor preferences were seen in off-pump coronary artery bypass grafting and minimally invasive/robotic heart surgery. The results of this study suggested that a majority of the respondents still prefer to use the PAC for most cardiac surgeries. Subgroup analysis of the data revealed that geographical location, type of practice, and surgeon support played a significant role in the decision to use a PAC. Although most respondents prefer to use TEE as a complimentary tool, TEE also remains the most popular supplemental/alternative hemodynamic monitoring technology.

Guiding Goal-Directed Therapy

Several studies have demonstrated that perioperative hemodynamic optimization (or “goal directed therapy”) using minimally invasive hemodynamic monitoring technologies has the ability to improve postoperative patients’ outcome with lower complication rates, shorter hospital lengths of stay, and lower cost of surgery. This specific concept of goal-directed therapy (GDT) uses perioperative cardiac output monitoring and manipulation of physiologic parameters (dynamic parameters of fluid responsiveness) to guide intravenous fluids and inotropic therapy with the goal of ensuring adequate tissue perfusion. Recently, the evidence related to the implementation of GDT strategies has been considered strong enough to allow for the creation of national recommendations in the UK, in France, and by the European Society of Anaesthesiology. The aims of the programs are to apply best practices to high-risk surgical patients and requires the participation of all clinicians involved in patients’ care. Considering the potential clinical and economic benefits of GDT protocols and the positive recommendations from influential scientific societies, more and more hospitals around the world have become interested in implementing hemodynamic optimization in their departments. This review provides the information about the evolution of hemodynamic monitoring from invasive to the more recent noninvasive devices, and how these devices can be used in the operating rooms through well-defined algorithms of GDT.

Two Methods of Hemodynamic and Volume Status Assessment in Critically Ill Patients: A Study of Disagreement.

The invasive nature and potential complications associated with pulmonary artery (PA) catheters (PACs) have prompted the pursuit of less invasive monitoring options. Before implementing new hemodynamic monitoring technologies, it is important to determine the interchangeability of these modalities. This study examines monitoring concordance between the PAC and the arterial waveform analysis (AWA) hemodynamic monitoring system. Critically ill patients undergoing hemodynamic monitoring with PAC were simultaneously equipped with the FloTrac AWA system (both from Edwards Lifesciences, Irvine, California). Data were concomitantly obtained for hemodynamic variables. Bland-Altman methodology was used to assess CO measurement bias and κ coefficent to show discrepancies in intravascular volume. Significant measurement bias was observed in both CO and intravascular volume status between the 2 techniques (mean bias, -1.055 ± 0.263 liter/min, r = 0.481). There was near-complete lack of agreement regarding the need for intravenous volume administration (κ = 0.019) or the need for vasoactive agent administration (κ = 0.015). The lack of concordance between PAC and AWA in critically ill surgical patients undergoing active resuscitation raises doubts regarding the interchangeability and relative accuracy of these modalities in clinical use. Lack of awareness of these limitations can lead to errors in clinical decision making when managing critically ill patients.

Update on minimally invasive hemodynamic monitoring in thoracic anesthesia

Advanced hemodynamic monitoring is indispensable for adequate management of patients undergoing major surgery. This article will summarize minimally invasive hemodynamic monitoring technologies and their potential use in thoracic anesthesia. According to their inherent principle, currently available technologies can be classified into four groups: bioimpedance and bioreactance, applied Fick's principle, pulse wave analysis and Doppler. All devices measure stroke volume and cardiac output. Functional hemodynamic variables and volumetric parameters have been integrated in some devices. Two major indications can be identified: the 'hemodynamically unstable' patient and the patient 'at risk' for hemodynamic instability. Although there is evidence for the first indication, pre-emptive hemodynamic therapy or perioperative hemodynamic optimization for the patient 'at risk' is still an issue of ongoing debate. There is a growing body of evidence that this approach can positively influence patients' outcome with less postoperative complications in selected patient groups. Many different minimally invasive hemodynamic monitoring devices have been developed and clinically introduced in the last years. They offer the advantage of being less invasive and easier to use. However, these techniques have several limitations and data are scarce in patients undergoing thoracic anesthesia, preventing their widespread use so far.

Advanced Hemodynamic Monitoring in Critically Ill Children

Circulatory shock is an important cause of pediatric morbidity and mortality and requires early recognition and prompt institution of adequate treatment protocols. Unfortunately, the hemodynamic status of the critically ill child is poorly reflected by physical examination, heart rate, blood pressure, or laboratory blood tests. Advanced hemodynamic monitoring consists, among others, of measuring cardiac output, predicting fluid responsiveness, calculating systemic oxygen delivery in relation to oxygen demand, and quantifying (pulmonary) edema. We discuss here the potential value of these hemodynamic monitoring technologies in relation to pediatric physiology.