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PloS One 2024Even with the powerful statistical parameters derived from the Extreme Gradient Boost (XGB) algorithm, it would be advantageous to define the predicted accuracy to the...
Even with the powerful statistical parameters derived from the Extreme Gradient Boost (XGB) algorithm, it would be advantageous to define the predicted accuracy to the level of a specific case, particularly when the model output is used to guide clinical decision-making. The probability density function (PDF) of the derived intracranial pressure predictions enables the computation of a definite integral around a point estimate, representing the event's probability within a range of values. Seven hold-out test cases used for the external validation of an XGB model underwent retinal vascular pulse and intracranial pressure measurement using modified photoplethysmography and lumbar puncture, respectively. The definite integral ±1 cm water from the median (DIICP) demonstrated a negative and highly significant correlation (-0.5213±0.17, p< 0.004) with the absolute difference between the measured and predicted median intracranial pressure (DiffICPmd). The concordance between the arterial and venous probability density functions was estimated using the two-sample Kolmogorov-Smirnov statistic, extending the distribution agreement across all data points. This parameter showed a statistically significant and positive correlation (0.4942±0.18, p< 0.001) with DiffICPmd. Two cautionary subset cases (Case 8 and Case 9), where disagreement was observed between measured and predicted intracranial pressure, were compared to the seven hold-out test cases. Arterial predictions from both cautionary subset cases converged on a uniform distribution in contrast to all other cases where distributions converged on either log-normal or closely related skewed distributions (gamma, logistic, beta). The mean±standard error of the arterial DIICP from cases 8 and 9 (3.83±0.56%) was lower compared to that of the hold-out test cases (14.14±1.07%) the between group difference was statistically significant (p<0.03). Although the sample size in this analysis was limited, these results support a dual and complementary analysis approach from independently derived retinal arterial and venous non-invasive intracranial pressure predictions. Results suggest that plotting the PDF and calculating the lower order moments, arterial DIICP, and the two sample Kolmogorov-Smirnov statistic may provide individualized predictive accuracy parameters.
Topics: Humans; Intracranial Pressure; Machine Learning; Probability; Female; Male; Algorithms; Adult; Middle Aged
PubMed: 38950055
DOI: 10.1371/journal.pone.0306028 -
IEEE Transactions on Bio-medical... Jul 2024Total artificial heart (TAH) using dual rotary blood pumps (RBPs) is a potential treatment for end-stage heart failure. A well-noted challenge with RBPs is their low...
OBJECTIVE
Total artificial heart (TAH) using dual rotary blood pumps (RBPs) is a potential treatment for end-stage heart failure. A well-noted challenge with RBPs is their low sensitivity to preload, which can lead to venous congestion and ventricular suction. To address this issue, we have developed an innovative closed-loop control system of dual RBPs in TAH. This system emulates the Frank-Starling law of the heart in controlling RBPs while monitoring stressed blood volume (V) based on the circulatory equilibrium framework. We validated the system in in-vivo experiments.
METHODS
In 9 anesthetized dogs, we prepared a TAH circuit using 2 centrifugal-type RBPs. We first investigated whether the flow and inlet atrial pressure in each RBP adhered to a logarithmic Frank-Starling curve. We then examined whether the RBP flows and atrial pressures were maintained stably during aortic occlusion (AO) and pulmonary cannula stenosis (PS), whether averaged flow of dual RBPs and bilateral atrial pressures were controlled to their predefined target values for a specific V, and whether this system could maintain the atrial pressures within predefined control ranges under significant changes in V.
RESULTS
This system effectively emulated the logarithmic Frank-Starling curve. It robustly stabilized the flow and atrial pressures during AO and PS without venous congestion or ventricular suction, accurately achieved target values in averaged flow and atrial pressures, and efficaciously maintained these pressures within the control ranges.
CONCLUSION
This system controls dual RBPs in TAH accurately and stably.
SIGNIFICANCE
This system may accelerate clinical application of TAH with dual RBPs.
PubMed: 38949936
DOI: 10.1109/TBME.2024.3420907 -
Clinical Science (London, England :... Jul 2024We reported that salt-sensitive hypertension (SSHTN) is associated with increased pro-inflammatory immune cells, inflammation, and inflammation-associated...
We reported that salt-sensitive hypertension (SSHTN) is associated with increased pro-inflammatory immune cells, inflammation, and inflammation-associated lymphangiogenesis in the kidneys and gonads of male and female mice. However, it is unknown whether these adverse end organ effects result from increased blood pressure (BP), elevated levels of salt, or both. We hypothesized that pharmaceutically lowering BP would not fully alleviate the renal and gonadal immune cell accumulation, inflammation, and lymphangiogenesis associated with SSHTN. SSHTN was induced in male and female C57BL6/J mice by administering nitro-L-arginine methyl ester hydrochloride (L-NAME; 0.5 mg/mL) in their drinking water for 2 weeks, followed by a 2-week washout period. Subsequently, the mice received a 3-week 4% high salt diet (SSHTN). The treatment group underwent the same SSHTN induction protocol but received hydralazine (HYD; 250 mg/L) in their drinking water during the diet phase (SSHTN+HYD). Control mice received tap water and a standard diet for 7 weeks. In addition to decreasing systolic BP, HYD treatment generally decreased pro-inflammatory immune cells and inflammation in the kidneys and gonads of SSHTN mice. Furthermore, the decrease in BP partially alleviated elevated renal and gonadal lymphatics and improved renal and gonadal function in mice with SSHTN. These data demonstrate that high systemic pressure and salt differentially act on end organ immune cells, contributing to the broader understanding of how BP and salt intake collectively shape immune responses and highlight implications for targeted therapeutic interventions.
PubMed: 38949825
DOI: 10.1042/CS20240698 -
Blood Pressure Dec 2024In 2022 hypertensive disease was the second cause of death in Croatia. The crude prevalence of hypertension is increasing and still majority of hypertensive patients did...
PURPOSE
In 2022 hypertensive disease was the second cause of death in Croatia. The crude prevalence of hypertension is increasing and still majority of hypertensive patients did not reach blood pressure and cholesterol goals Low awareness, and small number of treated and controlled patients point on poor adherence and even worse clinical inertia.
MATERIALS AND METHODS
Croatian Hypertension League (CHL) has started the permanent public health action aiming to increase health literacy. In 2023 we decided to intensify program with two missions - ' and aiming to achieve target values in 70% and in 50% of patients treated for hypertension and dyslipidaemia, respectively, by 2026. For the health care workers, the program will primarily involve digital education, and In the second arm of the program, we will advise patients and general population to visit our educational website with important and useful information on how to improve bad lifestyle, how to proper measure blood pressure, why is it important to sustain in taking drugs etc. In 2026, the CHL will organise field research to assess the success of programs using the same methodology as we used in previous EH-UH studies.
CONCLUSION
We will monitor and analyse trends in the management and control of patients treated for hypertension and dyslipidaemia. This will enable us to make an evidence-based conclusion how successful we were in increasing health literacy.
Topics: Humans; Croatia; Dyslipidemias; Hypertension; Health Literacy; Blood Pressure; Male; Female
PubMed: 38949789
DOI: 10.1080/08037051.2024.2371863 -
ASAIO Journal (American Society For... Jul 2024Extracorporeal carbon dioxide removal (ECCO2R) devices are increasingly used in treating acute-on-chronic respiratory failure caused by chronic lung diseases. There are...
Extracorporeal carbon dioxide removal (ECCO2R) devices are increasingly used in treating acute-on-chronic respiratory failure caused by chronic lung diseases. There are no large studies that investigated safety, efficacy, and the independent association of prognostic variables to survival that could define the role of ECCO2R devices in such patients. This multicenter, multinational, retrospective study investigated the efficacy, safety of a single ECCO2R device (Hemolung) in patients with acute on chronic respiratory failure and identified variables independently associated with intensive care unit (ICU) survival. The primary outcome was improvement in blood gasses with the use of Hemolung. Secondary outcomes included reduction in tidal volume, respiratory rate, minute ventilation, survival to ICU discharge, and complication profile. Multivariable regression analysis was used to identify variables that are independently associated with ICU survival. A total of 62 patients were included. There was a significant improvement in pH and partial pressure of carbon dioxide in arterial blood (PaCO2) along with a reduction in respiratory rate, tidal volume, and minute ventilation with Hemolung therapy. The complication profile did not differ between survivors and nonsurvivors. Multivariable analysis identified the duration of Hemolung therapy to be independently associated with survival to ICU discharge (adjusted odds ratio = 1.21; 95% confidence interval [CI] = 1.040-1.518; p = 0.01).
Topics: Humans; Retrospective Studies; Male; Female; Middle Aged; Respiratory Insufficiency; Carbon Dioxide; Aged; Extracorporeal Membrane Oxygenation; Intensive Care Units; Treatment Outcome; Adult; Tidal Volume
PubMed: 38949772
DOI: 10.1097/MAT.0000000000002155 -
Annals of Biomedical Engineering Jun 2024Through their contractile and synthetic capacity, vascular smooth muscle cells (VSMCs) can regulate the stiffness and resistance of the circulation. To model the...
PURPOSE
Through their contractile and synthetic capacity, vascular smooth muscle cells (VSMCs) can regulate the stiffness and resistance of the circulation. To model the contraction of blood vessels, an active stress component can be added to the (passive) Cauchy stress tensor. Different constitutive formulations have been proposed to describe this active stress component. Notably, however, measuring biomechanical behaviour of contracted blood vessels ex vivo presents several experimental challenges, which complicate the acquisition of comprehensive datasets to inform complex active stress models. In this work, we examine formulations for use with limited experimental contraction data as well as those developed to capture more comprehensive datasets.
METHODS
First, we prove analytically that a subset of constitutive active stress formulations exhibits unstable behaviours (i.e., a non-unique diameter solution for a given pressure) in certain parameter ranges, particularly for large contractile deformations. Second, using experimental literature data, we present two case studies where these formulations are used to capture the contractile response of VSMCs in the presence of (1) limited and (2) extensive contraction data.
RESULTS
We show how limited contraction data complicates selecting an appropriate active stress model for vascular applications, potentially resulting in unrealistic modelled behaviours.
CONCLUSION
Our data provide a useful reference for selecting an active stress model which balances the trade-off between accuracy and available biomechanical information. Whilst complex physiologically motivated models' superior accuracy is recommended whenever active biomechanics can be extensively characterised experimentally, a constant 2nd Piola-Kirchhoff active stress model balances well accuracy and applicability with sparse contractile data.
PubMed: 38949730
DOI: 10.1007/s10439-024-03532-x -
Obstetrics and Gynecology Jul 2024To evaluate maternal and neonatal outcomes by type of antihypertensive used in participants of the CHAP (Chronic Hypertension in Pregnancy) trial. (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
OBJECTIVE
To evaluate maternal and neonatal outcomes by type of antihypertensive used in participants of the CHAP (Chronic Hypertension in Pregnancy) trial.
METHODS
We conducted a planned secondary analysis of CHAP, an open-label, multicenter, randomized trial of antihypertensive treatment compared with standard care (no treatment unless severe hypertension developed) in pregnant patients with mild chronic hypertension (blood pressure 140-159/90-104 mm Hg before 20 weeks of gestation) and singleton pregnancies. We performed three comparisons based on medications prescribed at enrollment: labetalol compared with standard care, nifedipine compared with standard care, and labetalol compared with nifedipine. Although active compared with standard care groups were randomized, medication assignment within the active treatment group was not random but based on clinician or patient preference. The primary outcome was the occurrence of superimposed preeclampsia with severe features, preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The key secondary outcome was small for gestational age (SGA) neonates. We also compared medication adverse effects between groups. Relative risks (RRs) and 95% CIs were estimated with log binomial regression to adjust for confounding.
RESULTS
Of 2,292 participants analyzed, 720 (31.4%) received labetalol, 417 (18.2%) received nifedipine, and 1,155 (50.4%) received no treatment. The mean gestational age at enrollment was 10.5±3.7 weeks; nearly half of participants (47.5%) identified as non-Hispanic Black; and 44.5% used aspirin. The primary outcome occurred in 217 (30.1%), 130 (31.2%), and 427 (37.0%) in the labetalol, nifedipine, and standard care groups, respectively. Risk of the primary outcome was lower among those receiving treatment (labetalol use vs standard adjusted RR 0.82, 95% CI, 0.72-0.94; nifedipine use vs standard adjusted RR 0.84, 95% CI, 0.71-0.99), but there was no significant difference in risk when labetalol was compared with nifedipine (adjusted RR 0.98, 95% CI, 0.82-1.18). There were no significant differences in SGA or serious adverse events between participants receiving labetalol and those receiving nifedipine.
CONCLUSION
No significant differences in predetermined maternal or neonatal outcomes were detected on the basis of the use of labetalol or nifedipine for treatment of chronic hypertension in pregnancy.
CLINICAL TRIAL REGISTRATION
ClinicalTrials.gov, NCT02299414.
Topics: Humans; Pregnancy; Female; Labetalol; Nifedipine; Antihypertensive Agents; Adult; Pregnancy Outcome; Hypertension; Infant, Newborn; Pregnancy Complications, Cardiovascular; Hypertension, Pregnancy-Induced; Administration, Oral; Infant, Small for Gestational Age; Pre-Eclampsia; Chronic Disease
PubMed: 38949541
DOI: 10.1097/AOG.0000000000005613 -
Minerva Anestesiologica Jul 2024Brain dysfunction is a frequent complication of sepsis. Most likely, sepsis-associated brain dysfunction (SABD) results from the interaction between multiple factors:...
Brain dysfunction is a frequent complication of sepsis. Most likely, sepsis-associated brain dysfunction (SABD) results from the interaction between multiple factors: neurodegeneration due to microglial activation, altered neurotransmission, neuroinflammation and impairment of cerebral macro- and microcirculation. Altered brain perfusion might results from several mechanism: global or regional alterations in cerebral blood flow (CBF); reduced cerebral perfusion pressure - which is the driving force propelling blood through cerebral blood vessels - due to systemic hypotension; global or regional vasoconstriction; dysfunction of the intrinsic regulatory mechanisms of CBF, such as cerebral autoregulation and cerebrovascular reactivity; endothelial and blood-brain barrier dysfunction; autonomic nervous system dysfunction and metabolic uncoupling. Disorders of brain perfusion and CBF regulation are frequently observed in humans with sepsis, and intracranial hemodynamics monitoring can potentially be useful in clinical management of septic patients. The aim of this review is to provide an update of the current knowledge on alterations in brain hemodynamics associated with sepsis, along with physiological and methodological considerations intended to help the reader navigate the diverse results from published literature and a practical guide to apply non-invasive intracranial hemodynamics monitoring to septic patients in clinical practice.
PubMed: 38949458
DOI: 10.23736/S0375-9393.24.17978-3 -
Journal of Visualized Experiments : JoVE Jun 2024Lung transplantation is hampered by the lack of suitable donors. Previously, donors that were thought to be marginal or inadequate were discarded. However, new and...
Lung transplantation is hampered by the lack of suitable donors. Previously, donors that were thought to be marginal or inadequate were discarded. However, new and exciting technology, such as ex vivo lung perfusion (EVLP), offers lung transplant providers extended assessment for marginal donor allografts. This dynamic assessment platform has led to an increase in lung transplantation and has allowed providers to use donors that were previously discarded, thus expanding the donor pool. Current perfusion techniques use cellular or acellular perfusates, and both have distinct advantages and disadvantages. Perfusion composition is critical to maintaining a homeostatic environment, providing adequate metabolic support, decreasing inflammation and cellular death, and ultimately improving organ function. Perfusion solutions must contain sufficient protein concentration to maintain appropriate oncotic pressure. However, current perfusion solutions often lead to fluid extravasation through the pulmonary endothelium, resulting in inadvertent pulmonary edema and damage. Thus, it is necessary to develop novel perfusion solutions that prevent excessive damage while maintaining proper cellular homeostasis. Here, we describe the application of a polymerized human hemoglobin (PolyhHb)-based oxygen carrier as a perfusate and the protocol in which this perfusion solution can be tested in a model of rat EVLP. The goal of this study is to provide the lung transplant community with key information in designing and developing novel perfusion solutions, as well as the proper protocols to test them in clinically relevant translational transplant models.
Topics: Animals; Rats; Lung Transplantation; Hemoglobins; Perfusion; Lung; Humans; Oxygen; Blood Substitutes; Male; Organ Preservation Solutions
PubMed: 38949382
DOI: 10.3791/66702 -
Frontiers in Neuroscience 2024The nucleus tractus solitarii (NTS) plays a critical role in the homeostatic regulation of respiration, blood pressure, sodium consumption and metabolic processes....
The nucleus tractus solitarii (NTS) plays a critical role in the homeostatic regulation of respiration, blood pressure, sodium consumption and metabolic processes. Despite their significance, the circuitry mechanisms facilitating these diverse physiological functions remain incompletely understood. In this study, we present a whole-brain mapping of both the afferent and efferent connections of Phox2b-expressing and GABAergic neurons within the NTS. Our findings reveal that these neuronal populations not only receive monosynaptic inputs primarily from the medulla oblongata, pons, midbrain, supra-midbrain and cortical areas, but also mutually project their axons to these same locales. Moreover, intense monosynaptic inputs are received from the central amygdala, the paraventricular nucleus of the hypothalamus, the parasubthalamic nucleus and the intermediate reticular nucleus, along with brainstem nuclei explicitly engaged in respiratory regulation. In contrast, both neuronal groups extensively innervate brainstem nuclei associated with respiratory functions, although their projections to regions above the midbrain are comparatively limited. These anatomical findings provide a foundational platform for delineating an anatomical framework essential for dissecting the specific functional mechanisms of these circuits.
PubMed: 38948926
DOI: 10.3389/fnins.2024.1427384