Hemodynamic Bedside Monitoring Instrument with Pressure and Optical Sensors: Validation and Modality Comparison.

Results from two independent clinical validation studies for measuring hemodynamics at the patient's bedside using a compact finger probe are reported. Technology comprises a barometric pressure sensor, and in one implementation, additionally, an optical sensor for photoplethysmography (PPG) is developed, which can be used to measure blood pressure and analyze rhythm, including the continuous detection of atrial fibrillation. The capabilities of the technology are shown in several form factors, including a miniaturized version resembling a common pulse oximeter to which the technology could be integrated in. Several main results are presented: i) the miniature finger probe meets the accuracy requirements of non-invasive blood pressure instrument validation standard, ii) atrial fibrillation can be detected during the blood pressure measurement and in a continuous recording, iii) a unique comparison between optical and pressure sensing mechanisms is provided, which shows that the origin of both modalities can be explained using a pressure-volume model and that recordings are close to identical between the sensors. The benefits and limitations of both modalities in hemodynamic monitoring are further discussed.

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 to microcirculation.

Eficacia y seguridad del equipo de monitoreo hemodinámico no invasivo por biorreactancia en pacientes con sepsis o shock séptico atendidos en el área de emergencias / Eficácia e segurança de equipamentos de monitorização hemodinâmica não invasiva por biorreatância em pacientes com sepse ou choque séptico atendidos na área de emergência

ANTECEDENTES: En el marco de la metodología ad hoc para evaluar solicitudes de tecnologías sanitarias, aprobada mediante Resolución de Instituto de Evaluación de Tecnologías en Salud e Investigación N°111-IETSI-ESSALUD-2021, se ha elaborado el presente dictamen, el cual expone la evaluación de la eficacia y seguridad del equipo de monitoreo hemodinámico no invasivo por biorreactancia (EMHB) en pacientes con sepsis o shock séptico que son atendidos en área de emergencias. De este modo, la Dra. Guiliana Patricia Matos Ibérico, jefa del departamento de emergencia del Hospital Nacional Edgardo Rebagliati Martins (HNERM), siguiendo la Directiva N° 001-IETSI-ESSALUD-2018, envía al Instituto de Evaluación de Tecnologías en Salud e Investigación (IETSI) la solicitud de inclusión del equipo biomédico EMHB en el Petitorio de Dispositivos Médicos de EsSalud. ASPECTOS GENERALES: De acuerdo con el tercer consenso internacional para sepsis y shock séptico, la sepsis se define como una disfunción orgánica potencialmente mortal causada por una respuesta desregulada del ser humano ante la infección (Singer et al. 2016). Así, un estudio de datos provenientes de 195 países reportó que la mortalidad asociada a sepsis representa 19.7 % de las muertes globales (Rudd et al. 2020). Muchos pacientes que llegan a los servicios de emergencias presentan signos y síntomas compatibles con sepsis (McNevin et al. 2016) y una proporción variable evoluciona a sepsis severa o shock séptico (McNevin et al. 2018). De estos últimos, alrededor del 34 % son admitidos a las unidades de cuidados intensivos (UCI), lo que indica que la mayoría de pacientes con sepsis son tratados en emergencias (Rezende et al. 2008). La rápida administración de fluidoterapia (fluidos endovenosos) es clave para el paciente con sepsis a fin de evitar desenlaces graves (L. Evans et al. 2021). Sin embargo, se ha documentado que el exceso de fluidos se encuentra asociado a complicaciones clínicas, duración de la estancia hospitalaria y mortalidad (Boyd et al. 2011; Jones et al. 2008), por lo que resulta necesario optimizar cuidadosamente las cantidades de fluidos administrados. METODOLOGÍA: Se llevó a cabo una búsqueda bibliográfica exhaustiva con el objetivo de identificar la mejor evidencia sobre la eficacia y seguridad del EMHB. La búsqueda bibliográfica se realizó en las bases de datos PubMed, The Cochrane Library y LILACS. Asimismo, se realizó una búsqueda manual dentro de las páginas web pertenecientes a grupos que realizan evaluación de tecnologías sanitarias (ETS) y guías de práctica clínica (GPC) incluyendo el National Institute for Health and Care Excellence (NICE), Canadian Agency for Drugs and Technologies in Health (CADTH), Scottish Medicines Consortium (SMC), Scottish Intercollegiate Guidelines Network (SIGN), Institute for Clinical and Economic Review (ICER), el Instituto de Calidad y Eficiencia en la Atención de la Salud (IQWiG, por sus siglas en alemán), la Base Regional de Informes de Evaluación de Tecnologías en Salud de las Américas (BRISA), la OMS, el Ministerio de Salud del Perú (MINSA) y el Instituto de Evaluación de Tecnologías en Salud e Investigación (IETSI). RESULTADOS: Luego de la búsqueda bibliográfica (febrero del 2022) y la selección de la evidencia, se identificaron dos GPC (L. Evans et al. 2021; Instituto de Evaluación de Tecnologías en Salud e Investigación 2018) y un ECA (Kuan et al. 2016) los cuales fueron considerados para inclusión en el presente documento. CONCLUSIÓN: Por lo expuesto, el IETSI no aprueba el uso del equipo de monitoreo hemodinámico no invasivo por biorreactancia (EMHB) para pacientes con sepsis o shock séptico atendidos en el área de emergencias.

Quantification of stroke volume in a simulated healthy volunteer model of traumatic haemorrhage; a comparison of two non-invasive monitoring devices using error grid analysis alongside traditional measures of agreement.

INTRODUCTION: Haemorrhage is a leading cause of death following traumatic injury and the early detection of hypovolaemia is critical to effective management. However, accurate assessment of circulating blood volume is challenging when using traditional vital signs such as blood pressure. We conducted a study to compare the stroke volume (SV) recorded using two devices, trans-thoracic electrical bioimpedance (TEB) and supra-sternal Doppler (SSD), against a reference standard using trans- thoracic echocardiography (TTE). METHODS: A lower body negative pressure (LBNP) model was used to simulate hypovolaemia and in half of the study sessions lower limb tourniquets were applied as these are common in military practice and can potentially affect some haemodynamic monitoring systems. In order to provide a clinically relevant comparison we constructed an error grid alongside more traditional measures of agreement. RESULTS: 21 healthy volunteers aged 18-40 were enrolled and underwent 2 sessions of LBNP, with and without lower limb tourniquets. With respect to absolute SV values Bland Altman analysis showed significant bias in both non-tourniquet and tourniquet strands for TEB (-42.5 / -49.6 ml), rendering further analysis impossible. For SSD bias was minimal but percentage error was unacceptably high (35% / 48%). Degree of agreement for dynamic change in SV, assessed using 4 quadrant plots showed a seemingly acceptable concordance rate for both TEB (86% / 93%) and SSD (90% / 91%). However, when results were plotted on an error grid, constructed based on expert clinical opinion, a significant minority of measurement errors were identified that had potential to lead to moderate or severe patient harm. CONCLUSION: Thoracic bioimpedance and suprasternal Doppler both demonstrated measurement errors that had the potential to lead to clinical harm and caution should be applied in interpreting the results in the detection of early hypovolaemia following traumatic injury.

Soft fibers with magnetoelasticity for wearable electronics.

Magnetoelastic effect characterizes the change of materials' magnetic properties under mechanical deformation, which is conventionally observed in some rigid metals or metal alloys. Here we show magnetoelastic effect can also exist in 1D soft fibers with stronger magnetomechanical coupling than that in traditional rigid counterparts. This effect is explained by a wavy chain model based on the magnetic dipole-dipole interaction and demagnetizing factor. To facilitate practical applications, we further invented a textile magnetoelastic generator (MEG), weaving the 1D soft fibers with conductive yarns to couple the observed magnetoelastic effect with magnetic induction, which paves a new way for biomechanical-to-electrical energy conversion with short-circuit current density of 0.63 mA cm-2, internal impedance of 180 Ω, and intrinsic waterproofness. Textile MEG was demonstrated to convert the arterial pulse into electrical signals with a low detection limit of 0.05 kPa,  even with heavy perspiration or in underwater situations without encapsulations.

Implantable devices for heart failure monitoring.

Heart failure (HF) is associated with considerable morbidity and mortality. The increasing prevalence of HF and inpatient HF hospitalization has a considerable burden on healthcare cost and utilization. The recognition that hemodynamic changes in pulmonary artery pressure (PAP) and left atrial pressure precede the signs and symptoms of HF has led to interest in hemodynamic guided HF therapy as an approach to allow earlier intervention during a heart failure decompensation. Remote patient monitoring (RPM) utilizing telecommunication, cardiac implantable electronic device parameters and implantable hemodynamic monitors (IHM) have largely failed to demonstrate favorable outcomes in multicenter trials. However, one positive randomized clinical trial testing the CardioMEMS device (followed by Food and Drug Administration approval) has generated renewed interest in PAP monitoring in the HF population to decrease hospitalization and improve quality of life. The COVID-19 pandemic has also stirred a resurgence in the utilization of telehealth to which RPM using IHM may be complementary. The cost effectiveness of these monitors continues to be a matter of debate. Future iterations of devices aim to be smaller, less burdensome for the patient, less dependent on patient compliance, and less cumbersome for health care providers with the integration of artificial intelligence coupled with sophisticated data management and interpretation tools. Currently, use of IHM may be considered in advanced heart failure patients with the support of structured programs.

A multi-point heart rate monitoring using a soft wearable system based on fiber optic technology.

Early diagnosis can be crucial to limit both the mortality and economic burden of cardiovascular diseases. Recent developments have focused on the continuous monitoring of cardiac activity for a prompt diagnosis. Nowadays, wearable devices are gaining broad interest for a continuous monitoring of the heart rate (HR). One of the most promising methods to estimate HR is the seismocardiography (SCG) which allows to record the thoracic vibrations with high non-invasiveness in out-of-laboratory settings. Despite significant progress on SCG, the current state-of-the-art lacks both information on standardized sensor positioning and optimization of wearables design. Here, we introduce a soft wearable system (SWS), whose novel design, based on a soft polymer matrix embedding an array of fiber Bragg gratings, provides a good adhesion to the body and enables the simultaneous recording of SCG signals from multiple measuring sites. The feasibility assessment on healthy volunteers revealed that the SWS is a suitable wearable solution for HR monitoring and its performance in HR estimation is strongly influenced by sensor positioning and improved by a multi-sensor configuration. These promising characteristics open the possibility of using the SWS in monitoring patients with cardiac pathologies in clinical (e.g., during cardiac magnetic resonance procedures) and everyday life settings.

Perioperative Continuous Noninvasive Arterial Pressure Monitoring for Neuroendovascular Interventions: Prospective Study for Evaluation of the Vascular Unloading Technique.

BACKGROUND: Blood pressure monitoring is crucial during neuroendovascular procedures. Intraoperative hemodynamic instability is associated with complications, which underscores the importance of continuous monitoring. Although direct measurement with an intra-arterial catheter is the gold standard for determining arterial pressure, it is costly, time-consuming, and associated with complications. The novel ClearSight system offers a noninvasive technique for monitoring arterial pressure via a finger cuff. This study compared noninvasive arterial pressure measurements with the gold standard method. METHODS: Simultaneous recording of noninvasive and invasive arterial pressure was performed in patients undergoing neuroendovascular interventions. Both techniques were compared employing linear regression, Lin's correlation coefficient, Bland-Altman, and error grid analysis. RESULTS: The study enrolled 24 consecutive patients. The concordance correlation coefficient between both methods was 0.3526 (95% confidence interval [0.3134, 0.3906]) for mean arterial pressure and 0.4680 (95% confidence interval [0.4353, 0.4995]) and for systolic arterial pressure. The mean (SD) of the differences was 0.81 (17.86) mm Hg (95% limits of agreement [-52.52, 54.14]) for mean arterial pressure and 5.38 (14.64) mm Hg (95% limits of agreement [-45.12, 56.08]) for systolic arterial pressure. Error grid analysis demonstrated that the majority of measurements lie in regions with no or low risk for patients (mean arterial pressure, 71.0% and 24.4%; systolic arterial pressure, 59.2% and 25.8%). CONCLUSIONS: The ClearSight system provided accurate measurements of arterial blood pressure compared with invasive methods and within safe clinical parameters. This method may serve as a safe and reliable alternative for invasive blood pressure monitoring during neuroendovascular procedures.

Feasibility of non-invasive measurement of central blood pressure and arterial stiffness in shock.

BACKGROUND: Patients in haemodynamic shock are in need for an intensive care treatment. Invasive haemodynamic monitoring is state of the art for these patients. However, evolved, non-invasive blood pressure monitoring devices offer advanced functions like the assessment of central blood pressure and arterial stiffness. We analysed the feasibility of two oscillometric blood pressure devices in patients with shock. METHODS: We performed a monocentre prospective study, enrolling 57 patients admitted to the intensive care unit (ICU), due to septic and/or cardiogenic shock. We assessed invasive and non-invasive peripheral and central blood pressure <24 hours and 48 hours after admission on the ICU. Additional haemodynamic parameters such as pulse wave velocity (PWV), augmentation pressure and augmentation index were obtained through Mobil-o-Graph PWA (IEM) and SphygmoCor XCEL (AtCor Medical). RESULTS: A complete haemodynamic assessment was successful in all patients (48) with the Mobil-o-Graph 24 hours PWA and in 29 patients with the SphygmoCor XCEL (P = .001), when cases of death or device malfunction were excluded. Reasons for failure were severe peripheral artery disease, haemodynamic instability, oedema and agitation. Invasive blood pressure showed a sufficient correlation with both devices; however, large differences between invasive and non-invasive techniques were recorded in Bland-Altmann analysis (P < .05 for all parameters). PWV differed between the two devices. CONCLUSION: Non-invasive peripheral blood pressure measurement remains a rescue technique. However, non-invasive assessment of arterial stiffness and central blood pressure is possible in patients with septic or cardiogenic shock. Further studies are required to assess their clinical significance for patients in shock.

Wireless Hemodynamic Monitoring in Patients with Heart Failure.

PURPOSE OF REVIEW: Wireless hemodynamic monitoring in heart failure patients allows for volume assessment without the need for physical exam. Data obtained from these devices is used to assist patient management and avoid heart failure hospitalizations. In this review, we outline the various devices, mechanisms they utilize, and effects on heart failure patients. RECENT FINDINGS: New applications of these devices to specific populations may expand the pool of patients that may benefit. In the COVID-19 pandemic with a growing emphasis on virtual visits, remote monitoring can add vital ancillary data. Wireless hemodynamic monitoring with a pulmonary artery pressure sensor is a highly effective and safe method to assess for worsening intracardiac pressures that may predict heart failure events, giving lead time that is valuable to keep patients optimized. Implantation of this device has been found to improve outcomes in heart failure patients regardless of preserved or reduced ejection fraction.

Point-of-Care Echocardiography and Hemodynamic Monitoring in Cirrhosis and Acute-on-Chronic Liver Failure in the COVID-19 Era.

Point-of-Care (POC) transthoracic echocardiography (TTE) is transforming the management of patients with cirrhosis presenting with septic shock, acute kidney injury, hepatorenal syndrome and acute-on-chronic liver failure (ACLF) by correctly assessing the hemodynamic and volume status at the bedside using combined echocardiography and POC ultrasound (POCUS). When POC TTE is performed by the hepatologist or intensivist in the intensive care unit (ICU), and interpreted remotely by a cardiologist, it can rule out cardiovascular conditions that may be contributing to undifferentiated shock, such as diastolic dysfunction, myocardial infarction, myocarditis, regional wall motion abnormalities and pulmonary embolism. The COVID-19 pandemic has led to a delay in seeking medical treatment, reduced invasive interventions and deferment in referrals leading to "collateral damage" in critically ill patients with liver disease. Thus, the use of telemedicine in the ICU (Tele-ICU) has integrated cardiology, intensive care, and hepatology practices across the spectrum of ICU, operating room, and transplant healthcare. Telecardiology tools have improved bedside diagnosis when introduced as part of COVID-19 care by remote supervision and interpretation of POCUS and echocardiographic data. In this review, we present the contemporary approach of using POC echocardiography and offer a practical guide for primary care hepatologists and gastroenterologists for cardiac assessment in critically ill patients with cirrhosis and ACLF. Evidenced based use of Tele-ICU can prevent delay in cardiac diagnosis, optimize safe use of expert resources and ensure timely care in the setting of critically ill cirrhosis, ACLF and liver transplantation in the COVID-19 era.

A wireless, skin-interfaced biosensor for cerebral hemodynamic monitoring in pediatric care.

The standard of clinical care in many pediatric and neonatal neurocritical care units involves continuous monitoring of cerebral hemodynamics using hard-wired devices that physically adhere to the skin and connect to base stations that commonly mount on an adjacent wall or stand. Risks of iatrogenic skin injuries associated with adhesives that bond such systems to the skin and entanglements of the patients and/or the healthcare professionals with the wires can impede clinical procedures and natural movements that are critical to the care, development, and recovery of pediatric patients. This paper presents a wireless, miniaturized, and mechanically soft, flexible device that supports measurements quantitatively comparable to existing clinical standards. The system features a multiphotodiode array and pair of light-emitting diodes for simultaneous monitoring of systemic and cerebral hemodynamics, with ability to measure cerebral oxygenation, heart rate, peripheral oxygenation, and potentially cerebral pulse pressure and vascular tone, through the utilization of multiwavelength reflectance-mode photoplethysmography and functional near-infrared spectroscopy. Monte Carlo optical simulations define the tissue-probing depths for source-detector distances and operating wavelengths of these systems using magnetic resonance images of the head of a representative pediatric patient to define the relevant geometries. Clinical studies on pediatric subjects with and without congenital central hypoventilation syndrome validate the feasibility for using this system in operating hospitals and define its advantages relative to established technologies. This platform has the potential to substantially enhance the quality of pediatric care across a wide range of conditions and use scenarios, not only in advanced hospital settings but also in clinics of lower- and middle-income countries.

Accuracy and Reliability of a Disposable Vascular Pressure Device for Arterial Pressure Monitoring in Critical Care Transport.

OBJECTIVE: Arterial catheterization is a commonly performed procedure in intensive care units to guide the management of critically ill patients who require precise hemodynamic monitoring; however, this technology is not always available in the transport setting because of cumbersome and expensive equipment requirements. We compared the accuracy and reliability of a disposable vascular pressure device (DVPD) with the gold standard (ie, the transducer pressure bag invasive arterial monitoring system) used in intensive care units to determine if the DVPD can be reliably used in place of the traditional pressure transducer setup. METHODS: This study was a single-center, prospective, observational study performed in the adult intensive care unit of a large academic university hospital. A convenience cohort of hemodynamically stable, adult critically ill patients with femoral, brachial, or radial arterial catheters was recruited for this study. The Compass pressure device (Centurion Medical Products, Williamston, MI) is a disposable vascular pressure-sensing device used to assure venous access versus inadvertent arterial access during central line placement. The DVPD was attached to an in situ arterial catheter and measures the mean intravascular pressure via an embedded sensor and displays the pressure via the integrated LCD screen. Using a 3-way stopcock, the DVPD was compared with the standard arterial setup. We compared the mean arterial pressure (MAP) in the standard setup with the DVPD using Bland-Altman plots and methods that accounted for repeated measures in the same subject. RESULTS: Data were collected on 14 of the 15 subjects enrolled. Five measurements were obtained on each patient comparing the DVPD with the standard arterial setup at 1-minute intervals over the course of 5 minutes. A total of 70 observations were made. Among the 15 subjects, most (10 [67%]) were radial or brachial sites. The average MAP scores and standard deviation values obtained by the standard setup were 83.5 mm Hg (14.8) and 81.1 mm Hg (19.3) using the DVPD. Just over half (51.4%) of the measurements were within a ± 5-mm Hg difference. Using Bland-Altman plotting methods, standard arterial measurements were 2.4 mm Hg higher (95% confidence interval, 0.60-4.1) than with the DVPD. Differences between the 2 devices varied significantly across MAP values. The standard arterial line measurements were significantly higher than the DVPD at low MAP values, whereas the DVPD measurements were significantly higher than the standard arterial line at high MAP values. CONCLUSION: The DVPD provides a reasonable estimate of MAP and may be suitable for arterial pressure monitoring in settings where standard monitoring setups are not available. The DVPD appears to provide "worst-case" values because it underestimates low arterial blood pressure and overestimates high arterial blood pressure. Future trials should investigate the DVPD under different physiological conditions (eg, hypotensive patients, patients with ventricular assist devices, and patients on extracorporeal membrane oxygenation), different patient populations (such as pediatric patients), and in different environments (prehospital, air medical transport, and austere locations).

Evaluation of hemodynamics in healthy term neonates using ultrasonic cardiac output monitor.

BACKGROUND: Transition from intrauterine to extrauterine life is a critical phase during which several changes occur in cardiovascular system. In clinical practice, it is important to have a method that allows an easy, rapid and precise evaluation of hemodynamic status of a newborn for clinical management. We here propose a rapid, broadly applicable method to monitor cardiovascular function using ultrasonic cardiac output monitoring (USCOM). METHODS: We here present data obtained from a cohort of healthy term newborns (n = 43) born by programmed cesarean section at Fondazione MBBM, Ospedale San Gerardo. Measurements were performed during the first hour of life, then at 6 + 2, at 12-24, and 48 h of life. We performed a screening echocardiography to identify a patent duct at 24 h and, if patent, it was repeated at 48 h of life. RESULTS: We show that physiologically, during the first 48 h of life, blood pressure and systemic vascular resistance gradually increase, while there is a concomitant reduction in stroke volume, cardiac output, and cardiac index. The presence of patent ductus arteriosus significantly reduces cardiac output (p = 0.006) and stroke volume (p = 0.023). Furthermore, newborns born at 37 weeks of gestational age display significantly lower cardiac output (p < 0.001), cardiac index (p = 0.045) and stroke volume (p < 0.001) compared to newborns born at 38 and ≥ 39 weeks. Finally, birth-weight (whether adequate, small or large for gestational age) significantly affects blood pressure (p = 0.0349), stroke volume (p < 0.0001), cardiac output (p < 0.0001) and cardiac index (p = 0.0004). In particular, LGA infants display a transient increase in cardiac index, cardiac output and stroke volume up to 24 h of life; showing a different behavior from AGA and SGA infants. CONCLUSIONS: Compared to previous studies, we expanded measurements to longer time-points and we analyzed the impact of commonly used clinical variables on hemodynamics during transition phase thus making our data clinically applicable in daily routine. We calculate reference values for each population, which can be of clinical relevance for quick bedside evaluation in neonatal intensive care unit.

Análisis de la repercusión hemodinámica de dispositivos de protección embólica de red en un modelo in vitro / Hemodynamic impact analysis of mesh-type embolic protection devices in an in vitro model

INTRODUCCIÓN: los dispositivos de protección embólica tipo red para procedimientos endovasculares carotídeos (DPEr) son de uso habitual. Su objetivo es disminuir el riesgo de embolia cerebral secundaria a la manipulación y rotura de placa. Sus diferentes características hacen sospechar un distinto comportamiento que puede afectar a su eficacia. OBJETIVO: valorar la repercusión hemodinámica provocada por los DPEr analizando su resistencia al flujo en un modelo hemodinámico in vitro y comparar los resultados entre distintos dispositivos. MATERIALES Y MÉTODOS: se construyó un modelo de flujo pulsátil con suero salino fisiológico (SSF) y se estudiaron 4 DPEr distintos con 5 mediciones por dispositivo para conocer el gradiente de presión en mmHg y resistencia en unidades de resistencia periférica (URP) antes y después de su despliegue. Se utilizó la prueba de los rangos con signo de Wilcoxon para datos pareados y el análisis de dos vías de Friedman de varianza por rangos de muestras. Se consideraron significativos los resultados con una p < 0,05. RESULTADOS: se realizaron 60 mediciones: 10 basales, 10 con catéter portador y 40 con filtro desplegado. El DPEr1 presentó la mayor resistencia (0,88 ± 0,04 URP), significativamente mayor al resto (p = 0,041). El DPEr4 tuvo una resistencia mayor a DPEr2 y DPEr3 (0,70 ± 0,02 frente a 0,57 ± 0,08 y 0,57 ± 0,02 URP, respectivamente), aunque no significativa (p = 0,78). No se observaron diferencias entre los DPEr2 y DPEr3. La forma de cono simétrica se asoció con mayor resistencia (p = 0,002). No se observaron diferencias de los parámetros medidos en función del material de fabricación. CONCLUSIONES: existen diferencias en los DPEr en cuanto a resistencia al flujo que dependen de su diseño y porosidad. Los DPEr con mayor resistencia son el DPEr1 y DPEr4, mientras que el DPEr2 ofrece la menor resistencia al flujo en detrimento de su eficacia

INTRODUCTION: mesh-type embolic protection devices for carotid endovascular procedures (DPEr) are commonly used, their objective is to reduce the risk of cerebral embolism secondary to plaque manipulation and rupture. Their different characteristics make suspect a different behavior that can affect its effectiveness. Objective: to assess the hemodynamic impact caused by DPEr by analyzing their resistance to flow in an in vitro hemodynamic flow model and compare the results between different devices. MATERIALS AND METHODS: an in vitro pulsatile flow model with physiological saline serum (SSF) was constructed. Four different DPEr were studied with 5 measurements per device to know the pressure gradient in mmHg and resistance in peripheral resistance units (URP) before and after its deployment. The Wilcoxon signed ranges test and Friedman’s two-way analysis of variance by sample ranges were used. Significant results were considered with a p < 0.05 RESULTS: 60 measurements were made: 10 baselines, 10 with carrier catheter and 40 with unfolded filter. The DPEr1 presented the highest resistance (0.88 ± 0.04 URP) significantly higher than the rest (p = 0.041). DPEr4 had a greater resistance to DPEr2 and DPEr3 (0.70 ± 0.02 vs. 0.57 ± 0.08 and 0.57 ± 0.02 URP) although not significant (p = 0.70). No differences were observed between DPEr2 and DPEr3. The symmetrical cone shape was associated with greater resistance (p = 0.002). No differences in the measured parameters were observed depending on the manufacturing material. CONCLUSIONS: there are differences in DPEr in terms of resistance to flow that depend on their design and porosity. The DPEr with the highest resistance are the DPEr1 and DPEr4 while the DPEr2 offers the least resistance to flow at the expense of its effectiveness

Non-invasive cerebral perfusion monitoring in cardiac arrest patients: a prospective cohort study.

OBJECTIVES: To determine if non-invasive cerebral perfusion estimation provided by a new acousto-optic technology can be used as a reliable predictor of neurological outcome. PATIENTS AND METHODS: We performed a prospective, observational cohort study of consecutive comatose patients successfully resuscitated from out-of-hospital cardiac arrest. Patients were monitored using c-FLOW (Ornim Medical) from critical care unit admission up to 72 h, full awakening, or death. Primary outcome was favourable neurological outcome at hospital discharge, defined as a Cerebral Performance Category score of 1 or 2. RESULTS: A total of 21 patients were enrolled, without any loss to follow-up. Mean perfusion index over the monitoring period was not associated with functional outcome at hospital discharge (OR 1.03 [0.93, 1.17]). Adjustment for initial rhythm, time to return of spontaneous circulation and Glasgow coma scale motor score did not significantly alter the results (OR 1.06 [0.99, 1.12]). Mean perfusion index showed a poor discriminative value with an area under the curve of 0.60 for functional outcome (0.64 for survival). Correlation between the probes was weak (Pearson coefficient 0.35). CONCLUSION: Cerebral perfusion monitoring using a c-FLOW device in survivors of cardiac arrest is feasible, but reliability of the information provided has yet to be demonstrated. In our cohort, we were unable to identify any association between the perfusion index and clinical outcomes at discharge. As such, clinical management of cardiac arrest patients based on non-invasive perfusion index is not supported and should be limited to research protocols. The trial was registered with ClinicalTrials.gov, number NCT02575196.

Usefulness of Hemodynamic Device-Based Optimization in Heterogeneous Patients Implanted with Cardiac Resynchronization Therapy Defibrillator.

Optimization of the atrioventricular (AV) and interventricular (VV) timings of the CRT is the most supposed correctable variable to improve the rate of CRT responder. The aim of the present study has been to evaluate if there is a specific subgroup of patients who can actually benefit the most from a hemodynamic optimization of AV. This is a prospective, observational single-center study that enrolled consecutive patients with clinical indication for CRT; all patients were implanted with CRT-D devices with SonR technology, able to automatically adjust AV and VV delay on a weekly basis. Among 57 patients, 39 (69%) showed a LVESV reduction > 15%. The SonR was able to modify the pacing parameters, but an increase of left atrial diameter was associated to a reduced AV variability, suggesting that an impaired left atrial function could potentially reduce the ability of the SonR algorithm to adjust the correct timing of pacing. Graphical abstract Patients with respectively a high (A) and low (B) AV timing variability, among several parameters that could potentially influence the AV timing, only left atrial dimensions demonstrated a significant impact. In fact an increase of left atrial diameter was associated to a reduced AV variability, suggesting that an impaired left atrial function could potentially reduce the ability of the SonR algorithm to adjust the correct timing of pacing.

Exercise is feasible in patients receiving vasoactive medication in a cardiac surgical intensive care unit: A prospective observational study.

BACKGROUND: Patients may require vasoactive medication after cardiac surgery. The effect and safety profile of exercise on haemodynamic parameters in these patients is unclear. OBJECTIVES: The objective of this study was to measure the effect of upright positioning and low-level exercise on haemodynamic parameters in patients after cardiac surgery who were receiving vasoactive therapy and to determine the incidence of adverse events. METHODS: This was a prospective, single-centre, observational study conducted in an adult intensive care unit of a tertiary, cardiothoracic university-affiliated hospital in Australia. The Flotrac-Vigileo™ system was used to measure haemodynamic changes, including cardiac output, cardiac index, and stroke volume. Normally distributed variables are presented as n (%) and mean (standard deviation), and non-normally distributed variables are presented as median [interquartile range]. RESULTS: There were a total of 20 participants: 16 (80%) male, with a mean age of 65.9 (10.6) years. Upright positioning caused significant increases (p = 0.018) in the mean arterial pressure (MAP), with MAP readings increasing from baseline (supine), from 72.31 (11.91) mmHg to 77.44 (9.55) mmHg when back in supine. There were no clinically significant changes in cardiac output, heart rate, stroke volume, or cardiac index with upright positioning. The incidence of adverse events was low (5%). The adverse event was transient hypotension of low severity. CONCLUSIONS: Low-level exercise in patients after cardiac surgery receiving vasoactive medication was well tolerated with a low incidence of adverse events and led to significant increases in MAP. Upright positioning and low-level exercise appeared safe and feasible in this patient cohort.

Comparison the accuracy and trending ability of cardiac index measured by the fourth- generation of FloTrac with the PiCCO device in septic shock patients

Background/aim: FloTrac/Vigileo is a noncalibrated arterial pressure waveform analysis for cardiac index (CI) monitoring. The aim of our study was to compare the CI measured by the 4th generation of FloTrac with PiCCO in septic shock patients. Materials and methods: We simultaneously measured the CI using FloTrac (CIv) and compared it with the CI derived from transpulmonary thermodilution (CItd) as well as the pulse contour-derived CI using PiCCO (CIp). Results: Thirty-one septic shock patients were included. The CIv correlated with CItd (r = 0.62, P < 0.0001). The Bland-Altman analysis showed a bias of 0.14, and the limits of agreement were ­1.62­1.91 L/min/m2 with a percentage error of 47.4%. However, the concordance rate between CIv and CItd was 93.6%. The comparison of CIv with CIp (n = 352 paired measurements) revealed a bias of -0.16, and the limits of agreement were ­1.45­1.79 L/min/m2 with a percentage error of 44.8%. The overall correlation coefficient between CIv and CIp was 0.63 (P < 0.0001), and the concordance rate was 85.4%. Conclusion: The 4th generation of FloTrac has not acceptable agreement to assess CI; however, it has the ability to tracked changes of CI, when compared with the transpulmonary thermodilution method by PiCCO.