Aortic calcification and femoral bone density are independently associated with left ventricular mass in patients with chronic kidney disease

Background Vascular calcification and reduced bone density are prevalent in chronic kidney disease and linked to increased cardiovascular risk. The mechanism is unknown. We assessed the relationship between vascular calcification, femoral bone density and left ventricular mass in patients with stage 3 non-diabetic chronic kidney disease in a cross-sectional observational study. Methodology and Principal Findings A total of 120 patients were recruited (54% male, mean age 55±14 years, mean glomerular filtration rate 50±13 ml/min/1.73 m2). Abdominal aortic calcification was assessed using lateral lumbar spine radiography and was present in 48%. Mean femoral Z-score measured using dual energy x-ray absorptiometry was 0.60±1.06. Cardiovascular magnetic resonance imaging was used to determine left ventricular mass. One patient had left ventricular hypertrophy. Subjects with aortic calcification had higher left ventricular mass compared to those without (56±16 vs. 48±12 g/m2, P = 0.002), as did patients with femoral Z-scores below zero (56±15 vs. 49±13 g/m2, P = 0.01). In univariate analysis presence of aortic calcification correlated with left ventricular mass (r = 0.32, P = 0.001); mean femoral Z-score inversely correlated with left ventricular mass (r = −0.28, P = 0.004). In a multivariate regression model that included presence of aortic calcification, mean femoral Z-score, gender and 24-hour systolic blood pressure, 46% of the variability in left ventricular mass was explained (P<0.001). Conclusions In patients with stage 3 non-diabetic chronic kidney disease, lower mean femoral Z-score and presence of aortic calcification are independently associated with increased left ventricular mass. Further research exploring the pathophysiology that underlies these relationships is warranted

The Toowoomba adult trauma triage tool

Since the introduction of the Australasian Triage Scale (ATS) there has been considerable variation in its application. Improved uniformity in the application of the ATS by triage nurses is required. A reproducible, reliable and valid method to classify the illness acuity of Emergency Department patients so that a triage category 3 by one nurse means the same as a triage category 3 by another, not only in the same ED but also in another institution would be of considerable value to emergency nurses. This has been the driving motivation behind developing the Toowoomba Adult Trauma Triage Tool (TATTT). It is hoped the TATTT will support emergency nurses working in this challenging area by promoting standardisation and decreasing subjectivity in the triage decision process

Late systolic central hypertension as a predictor of incident heart failure : the Multi-Ethnic Study of Atherosclerosis

Background: Experimental studies demonstrate that high aortic pressure in late systole relative to early systole causes greater myocardial remodeling and dysfunction, for any given absolute peak systolic pressure. Methods and Results: We tested the hypothesis that late systolic hypertension, defined as the ratio of late (last one third of systole) to early (first two thirds of systole) pressure-time integrals (PTI) of the aortic pressure waveform, independently predicts incident heart failure (HF) in the general population. Aortic pressure waveforms were derived from a generalized transfer function applied to the radial pressure waveform recorded noninvasively from 6124 adults. The late/early systolic PTI ratio (L/ESPTI) was assessed as a predictor of incident HF during median 8.5 years of follow-up. The L/ESPTI was predictive of incident HF (hazard ratio per 1% increase= 1.22; 95% CI= 1.15 to 1.29; P58.38%) was more predictive of HF than the presence of hypertension. After adjustment for each other and various predictors of HF, the HR associated with hypertension was 1.39 (95% CI= 0.86 to 2.23; P=0.18), whereas the HR associated with a high L/E was 2.31 (95% CI=1.52 to 3.49; P<0.0001). Conclusions: Independently of the absolute level of peak pressure, late systolic hypertension is strongly associated with incident HF in the general population

Blood Pressure, Internal Carotid Artery Flow Parameters, and Age-Related White Matter Hyperintensities

White matter hyperintensities (WMH) are associated with hypertension. We examined interactions between blood pressure (BP), internal carotid artery (ICA) flow velocity parameters and WMH. We obtained BP measurements from 694 community-dwelling subjects at mean ages 69.6 (±0.8) and again at 72.6 (±0.7) years, plus brain MRI and ICA ultrasound at age 73±1 years. Diastolic and mean BP decreased and pulse pressure increased but systolic BP did not change between 70 and 73 years. Multiple linear regression, corrected for vascular disease and risk factors, showed that WMH at age 73 were associated with history of hypertension (β=0.13, p<0.001) and with BP at age 70 (systolic β=0.08, mean β=0.09, diastolic β=0.08, all p<0.05); similar but attenuated associations were seen for BP at age 73. Lower diastolic BP and higher pulse pressure were associated with higher ICA pulsatility index at age 73 (diastolic BP: standardized β, age 70=−0.24, p<0.001; pulse pressure age 70 β=0.19, p<0.001). WMH were associated with higher ICA pulsatility index (β=0.13, p=0.002) after adjusting for BP and correction for multiple testing. Therefore falling diastolic BP and increased pulse pressure are associated with increased ICA pulsatility index, which in turn is associated with WMH. This suggests that hypertension and WMH may either associate indirectly because hypertension increases arterial stiffness which leads to WMH over time, or co-associate through advancing age and stiffer vessels, or both. Reducing vascular stiffness may reduce WMH progression and should be tested in randomised trials, in addition to testing antihypertensive therapy

Pulmonary Artery Acceleration Time Provides a Reliable Estimate of Invasive Pulmonary Hemodynamics in Children

Background Pulmonary artery acceleration time (PAAT) is a non-invasive method to assess pulmonary hemodynamics, but lacks validity in children. This study sought to evaluate the accuracy of Doppler echocardiography (DE) derived PAAT in predicting right heart catheterization (RHC) derived pulmonary arterial pressure (PAP), pulmonary vascular resistance (PVR) and compliance in children. Methods Prospectively acquired and retrospectively measured DE derived PAAT and RHC derived systolic PAP (sPAP), mean PAP (mPAP), index PVR (PVRi) and compliance were compared by regression analysis in a derivation cohort of 75 children (median age, 5.3 years; 1.3–12.6) with wide ranges of pulmonary hemodynamics. To account for heart rate variability, PAAT was adjusted for right ventricle ejection time (RVET) and corrected by the RR interval. Regression equations incorporating PAAT and PAAT:RVET from the derivation cohort were then evaluated for the accuracy of its predictive values for invasive pulmonary hemodynamics in a validation cohort of 50 age- and weight- matched children with elevated PAP and PVR. Results There were significant inverse correlations between PAAT and RHC derived mPAP (r = −0.82) and PVRi (r= −0.78) and direct correlation (r= 0.78) between PAAT and pulmonary compliance in the derivation cohort. For detection of pulmonary hypertension (PRVi > 3 WU x m2 and mPAP > 25 mmHg), PAAT < 90 msec and PAAT:RVET < 0.31 resulted in a sensitivity of 97% and a specificity of 95%. In the derivation cohort, the regression equations relating PAAT with mPAP and PVRi were: mPAP = 48 – 0.28 x PAAT and PVRi = 9 –0.07 x PAAT. These PAAT integrated equations predicted RHC measured pulmonary hemodynamics in the validation cohort with good correlations (r = 0.88, 0.83 respectively), small biases (<10%), and minimal coefficient of variation (<8%). Conclusions PAAT inversely correlates with RHC measured pulmonary hemodynamics and directly correlates with pulmonary arterial compliance in children. The study established PAAT based regression equations in children to accurately predict RHC derived PAP and PVR

Aortic Calcification and Femoral Bone Density Are Independently Associated with Left Ventricular Mass in Patients with Chronic Kidney Disease

Background Vascular calcification and reduced bone density are prevalent in chronic kidney disease and linked to increased cardiovascular risk. The mechanism is unknown. We assessed the relationship between vascular calcification, femoral bone density and left ventricular mass in patients with stage 3 non-diabetic chronic kidney disease in a cross-sectional observational study. Methodology and Principal Findings A total of 120 patients were recruited (54% male, mean age 55±14 years, mean glomerular filtration rate 50±13 ml/min/1.73 m2). Abdominal aortic calcification was assessed using lateral lumbar spine radiography and was present in 48%. Mean femoral Z-score measured using dual energy x-ray absorptiometry was 0.60±1.06. Cardiovascular magnetic resonance imaging was used to determine left ventricular mass. One patient had left ventricular hypertrophy. Subjects with aortic calcification had higher left ventricular mass compared to those without (56±16 vs. 48±12 g/m2, P = 0.002), as did patients with femoral Z-scores below zero (56±15 vs. 49±13 g/m2, P = 0.01). In univariate analysis presence of aortic calcification correlated with left ventricular mass (r = 0.32, P = 0.001); mean femoral Z-score inversely correlated with left ventricular mass (r = −0.28, P = 0.004). In a multivariate regression model that included presence of aortic calcification, mean femoral Z-score, gender and 24-hour systolic blood pressure, 46% of the variability in left ventricular mass was explained (P<0.001). Conclusions In patients with stage 3 non-diabetic chronic kidney disease, lower mean femoral Z-score and presence of aortic calcification are independently associated with increased left ventricular mass. Further research exploring the pathophysiology that underlies these relationships is warranted

A Reinforcement Learning Approach to Weaning of Mechanical Ventilation in Intensive Care Units

The management of invasive mechanical ventilation, and the regulation of sedation and analgesia during ventilation, constitutes a major part of the care of patients admitted to intensive care units. Both prolonged dependence on mechanical ventilation and premature extubation are associated with increased risk of complications and higher hospital costs, but clinical opinion on the best protocol for weaning patients off of a ventilator varies. This work aims to develop a decision support tool that uses available patient information to predict time-to-extubation readiness and to recommend a personalized regime of sedation dosage and ventilator support. To this end, we use off-policy reinforcement learning algorithms to determine the best action at a given patient state from sub-optimal historical ICU data. We compare treatment policies from fitted Q-iteration with extremely randomized trees and with feedforward neural networks, and demonstrate that the policies learnt show promise in recommending weaning protocols with improved outcomes, in terms of minimizing rates of reintubation and regulating physiological stability

Comparison of lung ultrasound with transpulmonary thermodilution in assessing extra-vascular lung water

Background: Increased extra-vascular lung water (EVLW) is common in critical care and correlates with the severity of acute lung injury, length of intensive care unit stay and mortality. Lung ultrasound (LUS) can assess EVLW by determining the amount of ‘B-lines’: artefacts signifying alveolar-interstitial oedema. This study’s aim was to determine whether EVLW estimation with the help of LUS correlates with the more accurate PiCCO2® cardiac output system utilising transpulmonary thermodilution.Methods: This prospective observational study was undertaken at Universitas Academic Hospital, Bloemfontein. Patients were scanned according to a fixed protocol, followed by transpulmonary thermodilution. The cumulative B-line count was compared with the EVLW index generated by the PiCCO2® system.Results: Four males and six females were enrolled. The mean EVLW index was 9.1 ml/kg/m2 (standard deviation 1.45), and the median cumulative B-line count was 14 (interquartile range 6–25). A positive, but not statistically significant, correlation was found (r = 0.40, p = 0.25) between the B-line count and EVLW index.Conclusion: This study investigated a possible correlation between LUS interpretation and transpulmonary thermodilution in assessing EVLW. Results seem promising, but the small sample could indicate only that LUS might be of use for the assessment of EVLW. Further studies are needed.Keywords: B-lines,critical care, extra-vascular lung water, lung ultrasound, thermodilutio

Systems and methods for physiological signal enhancement and biometric extraction using non-invasive optical sensors

A system and method for signal processing to remove unwanted noise components including: (i) wavelength-independent motion artifacts such as tissue, bone and skin effects, and (ii) wavelength-dependent motion artifact/noise components such as venous blood pulsation and movement due to various sources including muscle pump, respiratory pump and physical perturbation. Disclosed are methods, analytics, and their uses for reliable perfusion monitoring, arterial oxygen saturation monitoring, heart rate monitoring during daily activities and in hospital settings and for extraction of physiological parameters such as respiration information, hemodynamic parameters, venous capacity, and fluid responsiveness. The system and methods disclosed are extendable to include monitoring platforms for perfusion, hypoxia, arrhythmia detection, airway obstruction detection and sleep disorders including apnea.Board of Regents, University of Texas Syste