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This study aimed to determine whether caffeine gum influenced perceptual-cognitive and physical performance during the extra-time period of simulated soccer match-play. Semiprofessional male soccer players (n = 12, age: 22 ± 3 years, stature: 1.78 ± 0.06 m, mass: 75 ± 9 kg) performed 120-min soccer-specific exercise on two occasions. In a triple-blind, randomized, crossover design, players chewed caffeinated (200 mg; caffeine) or control (0 mg; placebo) gum for 5 min following 90 min of soccer-specific exercise. Perceptual-cognitive skills (i.e., passing accuracy, reaction time, composure, and adaptability) were assessed using a soccer-specific virtual reality simulator, collected pre- and posttrial. Neuromuscular performance (reactive-strength index, vertical jump height, absolute and relative peak power output, and negative vertical displacement) and sprint performance (15 and 30 m) were measured at pretrial, half-time, 90 min, and posttrial. Caffeine gum attenuated declines in reaction time (pre: 90.8 ± 0.8 AU to post: 90.7 ± 0.8 AU) by a further 4.2% than placebo (pre: 92.1 ± 0.8 AU to post: 88.2 ± 0.8 AU; p <.01). Caffeine gum reduced composure by 4.7% (pre: 69.1 ± 0.8 AU to post: 65.9 ± 0.8 AU) versus placebo (pre: 68.8 ± 0.8 AU to post: 68.3 ± 0.8 AU; p <.01). Caffeine gum did not influence any other variables (p >.05). Where caffeine gum is consumed by players prior to extra-time, reaction time increases but composure may be compromised, and neuromuscular and sprint performance remain unchanged. Future work should assess caffeine gum mixes with substances like L-theanine that promote a relaxed state under stressful conditions. [ABSTRACT FROM AUTHOR]

Background: Accurate volume status assessment and dry weight achievement are the most challenging goals for a nephrologist. We aimed to evaluate the role of ultrasonographic parameters including lung ultrasound and inferior vena cava (IVC) measurements as practical methods of volume status assessment in children on hemodialysis by comparing them with established techniques, such as clinical evaluation and bioimpedance spectroscopy. Methods: A prospective cross-sectional study compared pre- and post-dialysis volume status using bioimpedance spectroscopy (BIS) parameters and clinical data with ultrasonographic lung B-lines and IVC parameters in children on regular hemodialysis. Results: A total 60 children (mean age 9.4 ± 2.8 years) were enrolled. Twenty patients (33.3%) were clinically overloaded to varying degrees (17 patients had mild to moderate signs of fluid overload and 3 patients had moderate to severe signs of fluid overload). All other patients (66.7%) were clinically euvolemic. Sonographic parameters were significantly lower post-dialysis than pre-dialysis, including lung B-line count and IVC diameter. IVC collapsibility index mean was significantly higher post-dialysis than pre-dialysis. There was a significant correlation between the lung B-line count, IVC parameters, and BIS-measured overhydration both before and after hemodialysis. Nine patients had ≥ 8 B-lines post-dialysis, only three of them were hypertensive. Conclusions: Clinical criteria alone are not specific for determining accurate fluid status in pediatric hemodialysis patients. Lung B-line score, IVC parameters, and BIS may be complementary to each other and to clinical data. Lung B-lines outperform IVC measurements and BIS in subclinical volume overload detection in pediatric hemodialysis patients. [ABSTRACT FROM AUTHOR]

Background: Conventional MRI has no distinction between high- and low-grade meningiomas, which has a crucial for choice of therapeutic plan, especially skull base meningiomas which need more meticulous endoscopy-approached surgery. The aim of our study was to evaluate role of perfusion by arterial spin labeling and dynamic susceptibility perfusion in grading of skull base meningiomas. Results: The relative arterial spin labeling (ASL), tumor blood flow (TBF), and tumor blood volume (TBV) ratios showed significant differences between low- and high-grade meningiomas. Conclusions: MRI perfusion is a useful in differentiation between low- and high-grade meningiomas. There is significant correlation between ASL and DSC perfusion supporting possibility of using ASL in clinical practice as an alternative technique to DSC perfusion, particularly for patients with renal impairment where no contrast injection needed. [ABSTRACT FROM AUTHOR]

Venoarterial extracorporeal membrane oxygenation (VA ECMO) has become a standard of care for severe cardiogenic shock, refractory cardiac arrest and related impending multiorgan failure. The widespread clinical use of this complex temporary circulatory support modality is still contrasted by a lack of formal scientific evidence in the current literature. This might at least in part be attributable to VA ECMO related complications, which may significantly impact on clinical outcome. In order to limit adverse effects of VA ECMO as much as possible an indepth understanding of the complex physiology during extracorporeally supported cardiogenic shock states is critically important. This review covers all relevant physiological aspects of VA ECMO interacting with the human body in detail. This, to provide a solid basis for health care professionals involved in the daily management of patients supported with VA ECMO and suffering from cardiogenic shock or cardiac arrest and impending multiorgan failure for the best possible care. [ABSTRACT FROM AUTHOR]

The monitoring of physiological parameters is a crucial topic in promoting human health and an indispensable approach for assessing physiological status and diagnosing diseases. Particularly, it holds significant value for patients who require long-term monitoring or with underlying cardiovascular disease. To this end, Visual Contactless Physiological Monitoring (VCPM) is capable of using videos recorded by a consumer camera to monitor blood volume pulse (BVP) signal, heart rate (HR), respiratory rate (RR), oxygen saturation (SpO2) and blood pressure (BP). Recently, deep learning-based pipelines have attracted numerous scholars and achieved unprecedented development. Although VCPM is still an emerging digital medical technology and presents many challenges and opportunities, it has the potential to revolutionize clinical medicine, digital health, telemedicine as well as other areas. The VCPM technology presents a viable solution that can be integrated into these systems for measuring vital parameters during video consultation, owing to its merits of contactless measurement, cost-effectiveness, user-friendly passive monitoring and the sole requirement of an off-the-shelf camera. In fact, the studies of VCPM technologies have been rocketing recently, particularly AI-based approaches, but few are employed in clinical settings. Here we provide a comprehensive overview of the applications, challenges, and prospects of VCPM from the perspective of clinical settings and AI technologies for the first time. The thorough exploration and analysis of clinical scenarios will provide profound guidance for the research and development of VCPM technologies in clinical settings. [ABSTRACT FROM AUTHOR]

The article offers information on the use of umbilical venous catheters (UVC) in neonatal care, highlighting their importance in providing central venous access for fluids, medications, and blood products. Topics include the risks and complications associated with UVC placement, such as malpositioning leading to thrombosis, infection, cardiac dysrhythmias, and cardiac tamponade.

Background: Sodium (Na) balance is unexplored in dialyzed children. We assessed a simplified sodium balance (sNaB) and its correlates in pediatric patients receiving maintenance dialysis. Methods: Patients < 18 years old on hemodialysis (HD) or peritoneal dialysis (PD) in six European Pediatric Dialysis Working Group centers were recruited. sNaB was calculated from enteral Na, obtained by a 3-day diet diary, Na intake from medications, and 24-h urinary Na (uNa). Primary outcomes were systolic blood pressure and diastolic blood pressure standard deviation scores (SBP and DBP SDS), obtained by 24-h ambulatory blood pressure monitoring or office BP according to age, and interdialytic weight gain (IDWG). Results: Forty-one patients (31 HD), with a median age of 13.3 (IQR 5.2) years, were enrolled. Twelve patients (29.3%) received Na-containing drugs, accounting for 0.6 (0.7) mEq/kg/day. Median total Na intake was 1.5 (1.1) mEq/kg/day, corresponding to 60.6% of the maximum recommended daily intake for healthy children. Median uNa and sNaB were 0.6 (1.8) mEq/kg/day and 0.9 (1.7) mEq/kg/day, respectively. The strongest independent predictor of sNaB in the cohort was urine output. In patients receiving HD, sNaB correlated with IDWG, pre-HD DBP, and first-hour refill index, a volume index based on blood volume monitoring. sNaB was the strongest predictor of IDWG in multiple regression analysis (β = 0.63; p = 0.005). Neither SBP SDS nor DBP SDS correlated with sNaB. Conclusions: Na intake is higher than uNa in children on dialysis, and medications may be an important source of Na. sNaB is best predicted by urine output in the population, and it is a significant independent predictor of IDWG in children on HD. [ABSTRACT FROM AUTHOR]

Hemodynamic and intravascular volume monitoring has been utilized and significantly improved thanks to the technology revolution. Goal-Directed Therapy (GDT) derived from this advanced monitoring is beneficial for complex surgeries, and it shifted the medical approaches from static therapy to more personalized functional treatments. Conventional monitoring methods such as blood pressure, heart rate, urinary output, and central venous pressure are commonly used. However, studies have shown these routine parameters often cannot precisely estimate the quality of tissue perfusion. Tissue hypoperfusion and hypoxia play a crucial role in initiating a systemic inflammatory response after prolonged surgeries, resulting in unstable hemodynamic condition of the patients. Several studies reported the importance of GDT in non-cardiac surgeries and there are few reports on cardiac surgeries. However, tissue perfusion and fluid management are more critical in complex and prolonged cardiovascular surgeries to avoid complications such as low cardiac output syndrome and renal or pulmonary dysfunction. Different advanced hemodynamic monitorings have been utilized perioperatively in cardiac surgery to help decision-making on inotrope and fluid management. In this article we present 5 cases of usefulness hemodynamic monitoring in patients who underwent cardiovascular surgeries. [ABSTRACT FROM AUTHOR]

Objective: The aim of this pilot study was to explore if internal jugular vein (IJV) ultrasound studies on agricultural workers in a field-based research setting could assess volume status during a hydration intervention. Methods: We performed pre- and post-work shift IJV ultrasound images on 30 agricultural workers. The IJV collapsibility index values were <39% (euvolemic) or =39% (hypovolemic). Results: Of the water group, 13% (2/15) had an IJV collapsibility index =39%, and this increased to 19% (3/16) by the end of the work shifts. The electrolyte group did not have any workers start the work shift with an IJV collapsibility index =39%; however, at the postshift assessment, 15% (2/13) were hypovolemic. Conclusion: Internal jugular vein ultrasounds may have the potential to be a useful tool to determine volume status in field-based research settings. Further investigation is needed to confirm these findings. [ABSTRACT FROM AUTHOR]

Changes between pre- and postpartum hemoglobin might be useful for optimizing the postpartum diagnosis of postpartum hemorrhage (PPH), defined as a blood loss exceeding 500 mL. This study's principal objective was to estimate the mean change in hemoglobin (between pre/post-delivery hemoglobin) among women with vaginal deliveries and PPH. The secondary objectives were to analyze: hemoglobin changes according to blood volume loss, the appropriateness of standard thresholds for assessing hemoglobin loss, and the intrinsic and extrinsic performances of these threshold values for identifying PPH. French maternity units (n = 182) participated in the prospective HERA cohort study. Women with a vaginal delivery at or after a gestation of 22 weeks with a PPH (n = 2964) were eligible. The principal outcome was hemoglobin loss in g/L. The mean hemoglobin change was 30 ± 14 g/L among women with a PPH. Overall, hemoglobin decreased by at least 10% in 90.4% of women with PPH. Decreases ≥ 20 g/L and ≥40 g/L were found, respectively, in 73.9% and 23.7% of cases. Sensitivity and specificity values for identifying PPH were always <65%, the positive predictive values were between 35% and 94%, and the negative predictive values were between 14% and 84%. Hemoglobin decrease from before to after delivery should not be used as a PPH diagnostic screening test for PPH diagnosis for all vaginal deliveries. [ABSTRACT FROM AUTHOR]

Introduction: This paper seeks to identify which of three published formulas used for estimating the blood volume of normal human subjects correlates most closely with blood volumes measured in a published study where erythrocyte volume was determined by a method using 51Cr and a nonradioactive dye was used to determine the plasma volume. Methods: Blood volumes predicted by three published algorithms were compared with blood volume estimates from a study by Retzlaff et al. using the two-tailed Wilcoxon signed rank test and a robust version of the Bland–Altman test. Results: When applied to a sample of normal subjects selected from Mayo Clinic personnel and patients, the Nadler formula correlated more closely with blood volume measured using a radio nucleotide technique than did the Allen formula or one based on a saline haemodilution technique. Conclusions: The Nadler formula correlated more closely with blood volume measurements derived from Retzlaff's study than the other formulas for estimating blood volume in a population with height and weight distribution more consistent with that seen in North America. It should be used in preference to the Allen formula for estimating blood volume in adult patients currently undergoing cardiac surgical procedures. Saline haemodilution techniques used to measure blood volume require validation against more recently developed nuclear medicine techniques using statistical methods other than regression analysis. Until validated, they should be used with caution for estimating blood volume in adult patients currently undergoing cardiac surgical procedures. If a formula using height, weight and sex is used to estimate blood volume in the context of cardiac surgery, then it must be derived using a much more comprehensive sample of the population to which it is applied than has occurred to date. In particular, it should include broader distributions of height, weight and the presence or absence and type of significant valvular disease. [ABSTRACT FROM AUTHOR]

Introduction: Prescribing the ultrafiltration in hemodialysis patients remains challenging and might benefit from the information on absolute blood volume, estimated by intradialytic dialysate bolus administration. Here, we aimed at determining the relationship between absolute blood volume, normalized for body mass (specific blood volume, Vs), and ultrafiltration‐induced decrease in relative blood volume (∆RBV) as well as clinical parameters including body mass index (BMI). Methods: This retrospective analysis comprised 77 patients who had their dialysate bolus‐based absolute blood volume extracted routinely with an automated method. Patient‐specific characteristics and ∆RBV were analyzed as a function of Vs, dichotomizing the data above or below a previously proposed threshold of 65 ml/kg for Vs. Statistical methodology comprised descriptive analyses, two‐group comparisons, and correlation analyses. Findings: Median Vs was 68.6 ml/kg (54.9 ml/kg [Quartile 1], 83.4 ml/kg [Quartile 3]). Relative blood volume decreased by 6.3% (2.6%, 12.2%) over the entire hemodialysis session. Vs correlated inversely with BMI (rs = −0.688, p < 0.001). ∆RBV was 9.8% in the group of patients with Vs <65 ml/kg versus 6.0% in the group of patients with Vs ≥65 ml/kg (p = 0.024). The two groups did not differ significantly regarding their specific ultrafiltration volume, normalized for body mass, which amounted to 34.1 ml/kg and 36.0 ml/kg in both groups, respectively (p = 0.630). ∆RBV correlated inversely with Vs (rs = −0.299, p = 0.008). Discussion: The present study suggests that patients with higher BMI and lower Vs experience larger blood volume changes, despite similar ultrafiltration requirements. These results underline the clinical plausibility and importance of dialysate bolus‐based absolute blood volume determination in the assessment of target weight, especially in view of a previous study where intradialytic morbid events could be decreased when the target weight was adjusted, based on Vs. [ABSTRACT FROM AUTHOR]

The development of clinical congestion resulting from volume overload, either by renal fluid retention or redistribution of blood volume from venous reservoirs, is a recurrent scenario in patients with chronic heart failure (HF). As a result, the treatment of congestion, most commonly by initiating aggressive diuretic therapy, is a front-line issue in the management of patients with HF. However, the association of clinical congestion and volume overload with physical signs and symptoms, as well as other surrogates of volume assessment, has limitations in accuracy and, therefore, reliability to direct appropriate interventions. The ability to quantitate intravascular volume and identify the variability in volume profiles among patients with HF can uniquely inform individualized volume management and aid in risk stratification. This tool is provided by contemporary nuclear medicine-based BVA-100 methodology, which uses the well-established indicator-dilution principle and is a requested topic for discussion in this review. [ABSTRACT FROM AUTHOR]

Determining blood loss [100% -- RBV (%)] is challenging in the management of haemorrhagic shock. We derived an equation estimating RBV (%) via serial haematocrits (Hct1, Hct2) by fixing infused crystalloid fluid volume (N) as [0.015 x body weight (g)]. Then, we validated it in vivo. Mathematically, the following estimation equation was derived: RBV (%) = 24k / [(Hct1 / Hct2) - 1]. For validation, non-ongoing haemorrhagic shock was induced in Sprague--Dawley rats by withdrawing 20.0%-60.0% of their total blood volume (TBV) in 5.0% intervals (n = 9). Hct1 was checked after 10 min and normal saline N cc was infused over 10 min. Hct2 was checked five minutes later. We applied a linear equation to explain RBV (%) with 1 / [(Hct1 / Hct2) - 1]. Seven rats losing 30.0%-60.0% of their TBV suffered shock persistently. For them, RBV (%) was updated as 5.67 / [(Hct1 / Hct2) - 1] + 32.8 (95% confidence interval [CI] of the slope: 3.14-8.21, p = 0.002, R² = 0.87). On a Bland-Altman plot, the difference between the estimated and actual RBV was 0.00 ± 4.03%; the 95% CIs of the limits of agreements were included within the pre-determined criterion of validation (< 20%). For rats suffering from persistent, non-ongoing haemorrhagic shock, we derived and validated a simple equation estimating RBV (%). This enables the calculation of blood loss via information on serial haematocrits under a fixed N. Clinical validation is required before utilisation for emergency care of haemorrhagic shock. [ABSTRACT FROM AUTHOR]

PurposeTo evaluate a leakage correction algorithm for T1 and T2* artifacts arising from contrast agent extravasation in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) that accounts for bidirectional contrast agent flux and compare relative cerebral blood volume (CBV) estimates and overall survival (OS) stratification from this model to those made with the unidirectional and uncorrected models in patients with recurrent glioblastoma (GBM).Materials and methodsWe determined median rCBV within contrast-enhancing tumor before and after bevacizumab treatment in patients (75 scans on 1.5T, 19 scans on 3.0T) with recurrent GBM without leakage correction and with application of the unidirectional and bidirectional leakage correction algorithms to determine whether rCBV stratifies OS.ResultsDecreased post-bevacizumab rCBV from baseline using the bidirectional leakage correction algorithm significantly correlated with longer OS (Cox, P = 0.01), whereas rCBV change using the unidirectional model (P = 0.43) or the uncorrected rCBV values (P = 0.28) did not. Estimates of rCBV computed with the two leakage correction algorithms differed on average by 14.9%.ConclusionAccounting for T1 and T2* leakage contamination in DSC-MRI using a two-compartment, bidirectional rather than unidirectional exchange model might improve post-bevacizumab survival stratification in patients with recurrent GBM. J. Magn. Reson. Imaging 2016;44:1229-1237.

Arterial compliance is an important cardiovascular parameter characterizing mechanical and structural properties of arteries and significantly influencing ventricular-arterial coupling. Decreased arterial compliance is associated with several physiological states and pathological processes. Furthermore, arterial compliance is influenced by other cardiovascular parameters even at short time scales. Today, there are numerous noninvasive methods of estimation arterial compliance in vivo introducing some level of confusion about selection of the best method for particular application and measurement setting. In this review, the most common noninvasive methods of arterial compliance estimation are summarized, discussed and categorized. Finally, interpretation of estimated arterial compliance in the context of other possible confounders is discussed. [ABSTRACT FROM AUTHOR]

Background: Increased pulmonary blood volume (PBV) is a measure of congestion and is associated with an increased risk of cardiovascular events. PBV can be quantified using cardiovascular magnetic resonance (CMR) imaging as the product of cardiac output and pulmonary transit time (PTT), the latter measured from the contrast time-intensity curves in the right and left side of the heart from first-pass perfusion (FPP). Several methods of estimating PTT exist, including pulmonary transit beats (PTB), peak-to-peak, and center of gravity (CoG). The aim of this study was to determine the accuracy and precision for these methods of quantifying the PBV, taking the left atrium volume (LAV) into consideration. Methods: Fifty-eight participants (64 ± 11 years, 24 women) underwent 1.5 T CMR. PTT was quantified from (1) a basal left ventricular short-axis image (FPP), and (2) the reference method with a separate contrast administration using an image intersecting the pulmonary artery (PA) and the LA (CoG(PA-LA)). Results: Compared to the reference, PBV for (a) PTB(FPP) was 14 ± 17% larger, (b) peak-peak(FPP) was 17 ± 16% larger, and (c) CoG(FPP) was 18 ± 10% larger. Subtraction of the LAV (available for n = 50) decreased overall differences to − 1 ± 19%, 2 ± 18%, and 3 ± 12% for PTB(FPP), peak-peak(FPP), and CoG(FPP), respectively. Lowest interobserver variability was seen for CoG(FPP) (− 2 ± 7%). Conclusions: CoG(PA-LA) and FPP methods measured the same PBV only when adjusting for the LAV, since FPP inherently quantifies a volume consisting of PBV + LAV. CoG(FPP) had the best precision and lowest interobserver variability among the FPP methods of measuring PBV. [ABSTRACT FROM AUTHOR]

Objective  This study was aimed to determine if confirmation bias affects diagnoses in obstetrics, specifically estimation of blood loss and amniotic fluid volume. Study Design  We performed a randomized simulation-based trial. Participants went through the following three consecutive scenarios: (1) the first involved estimating the volume of blood (actually a blood-like substance) in a container at the simulation model's perineum. The actual volume was either 500 or 1,500 mL. Participants were told it was blood seen after a vaginal delivery. One group was told that the "patient" was normotensive, the other was told that the "patient" was hypotensive. (2) The second scenario involved estimation of amniotic fluid from an ultrasound picture of four quadrants, with one group told that the patient was normotensive and the other group told that the patient had chronic hypertension. (3) The third scenario was a "negative image" of the first (i.e., if they had been randomized to the 500 mL/normotensive in scenario one, then they would be presented with the 1,500 mL/hypotensive). They also filled a survey including demographics and tolerance of ambiguity and confirmation bias scales. Results  From April 2018 through May 2018, a convenience sample of 85 providers was recruited. Participants were more likely to overestimate blood loss when they were told that the patient was hypotensive (p  = 0.024), in comparison to when they were told the patient had normal blood pressure. They were also less likely to estimate the amniotic fluid as normal when they were told that the patient was hypertensive (p  = 0.032). Conclusion  Confirmation bias affects estimates of blood loss and amniotic fluid. [ABSTRACT FROM AUTHOR]

The aim of the study was to derive and compare metabolic parameters relating to benign and malignant pulmonary nodules using dynamic 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) PET/CT, and nodule perfusion parameters derived through perfusion computed tomography (CT). Twenty patients with 21 pulmonary nodules incidentally detected on CT underwent a dynamic 18F-FDG PET/CT and a perfusion CT. The maximum standardized uptake value (SUVmax) was measured on conventional 18F-FDG PET/CT images. The influx constant (Ki) was calculated from the dynamic 18F-FDG PET/CT data using Patlak model. Arterial flow (AF) using the maximum slope model and blood volume (BV) using the Patlak plot method for each nodule were calculated from the perfusion CT data. All nodules were characterized as malignant or benign based on histopathology or 2 year follow up CT. All parameters were statistically compared between the two groups using the nonparametric Mann-Whitney test. Twelve malignant and 9 benign lung nodules were analysed (median size 20.1 mm, 9–29 mm) in 21 patients (male/female = 11/9; mean age ± SD: 65.3 ± 7.4; age range: 50–76 years). The average SUVmax values ± SD of the benign and malignant nodules were 2.2 ± 1.7 vs. 7.0 ± 4.5, respectively (p = 0.0148). Average Ki values in benign and malignant nodules were 0.0057 ± 0.0071 and 0.0230 ± 0.0155 min-1, respectively (p = 0.0311). Average BV for the benign and malignant nodules were 11.6857 ± 6.7347 and 28.3400 ± 15.9672 ml/100 ml, respectively (p = 0.0250). Average AF for the benign and malignant nodules were 74.4571 ± 89.0321 and 89.200 ± 49.8883 ml/100g/min, respectively (p = 0.1613). Dynamic 18F-FDG PET/CT and perfusion CT derived blood volume had similar capability to differentiate benign from malignant lung nodules. [ABSTRACT FROM AUTHOR]

Cardiovascular disease, commonly known as heart disease, is one of the leading causes of death in the United States and worldwide. Early detection of the disease can save thousands of lives and billions of dollars in healthcare costs. A statistical model with the ability to accurately predict heart disease could be of immense help to the patients, their families, the medical community, and the healthcare system. Hospitals and providers collect many patient health metrics during screening and routine lab tests, which could be used to build such a statistical model. A robust heart disease prediction model is built using a sample dataset from the University of California, Irvine Machine Learning repository. Initial Hypotheses are formulated, and the most significant predictor variables are identified using the Wald test. The statistical significance of the proposed model is tested using the Likelihood-Ratio test. A repeated 10-fold cross-validation technique is used to evaluate the model's prediction power on previously unseen data. Keeping in mind the simplicity, usability, and explainability of results to the medical community, a Logistic Regression model that predicts the heart disease class with a high degree of accuracy is presented in this paper. [ABSTRACT FROM AUTHOR]

The f-cell ratio of 0.91 is a conversion factor between the hematocrit measured in peripheral blood and the hematocrit obtained by separate measurements of the red blood cell mass and plasma volume. The physiological background of the f-cell ratio is unclear. Data were retrieved from 155 intravenous infusion experiments where 15–25 mL/kg of crystalloid fluid diluted the blood hemoglobin and plasma albumin concentrations. The hemodilution was converted to plasma dilution using the peripheral hematocrit, and the volume of distribution of exogenous albumin was calculated in 41 volunteers who received 20 % or 5 % albumin by intravenous infusion. Finally, the kinetics of plasma albumin was studied during 98 infusion experiments with 20 % albumin. Plasma dilution based on hemoglobin and albumin showed a median difference of −0.001 and a mean difference of 0.000 (N = 2184), which demonstrates that these biomarkers indicate the same expandable vascular space. In contrast, exogenous albumin occupied a volume that was 10 % larger than the plasma volume indicated by the anthropometric equations of Nadler et al. and Retzlaff et al. The kinetic analysis identified a secondary compartment that was 450 mL in size and rapidly exchanged albumin with the circulating plasma. The results suggest that the f-cell ratio is due to rapid exchange of albumin between the plasma and a non-expandable compartment located outside the circulating blood (possibly the liver sinusoids). This means that the hematocrit measured in peripheral blood correctly represents the ratio between the red cell volume and the circulating plasma volume. • The f-cell ratio of 0.91 converts the peripheral hematocrit to the whole-body hematocrit. • This ratio is applied when measuring the blood volume, but its origin is unclear. • Plasma dilution data (N 2184) ruled out maldistribution in the circulation as the cause. • Infused albumin distributed over a 10 % larger space than the expected plasma volume. • Infused albumin distributed within the plasma but also to a fast-exchange smaller space. [ABSTRACT FROM AUTHOR]

BackgroundDynamic susceptibility contrast (DSC)-MRI is a well-established perfusion MR imaging technique for estimating relative cerebral blood volume (CBV) in primary brain tumors; however, tumors localized to regions with naturally elevated perfusion, including cortical tissue and common vascular territories, make evaluation of tumor vascularity difficult to assess. In the current study, we have constructed a large-scale radiographic atlas of CBV to assess treatment response to bevacizumab in individual patients with recurrent glioblastoma.MethodsZ-score normalized CBV maps were registered to stereotactic atlas space in 450 patients with brain tumors. A CBV atlas was created by calculating the voxel-wise mean and variability in CBV. MRI and CBV maps from 32 recurrent glioblastoma patients were then obtained prior to and following treatment with bevacizumab, registered to and compared with the CBV atlas. The volume of tumor tissue with elevated CBV, percentage of enhancing tumor with elevated CBV, and the mean and maximum change in normalized CBV intensity relative to the atlas were computed.ResultsVoxel-wise comparison of individual patient CBV maps to the atlas allowed delineation of elevated tumor perfusion from artery and normal cortical tissue. An atlas-defined hypervascular tumor blood volume greater than 2.35 cc prior to treatment, 0.14 cc after treatment, and a decrease in atlas-defined hypervascular tumor volume less than 80% following treatment were characteristic of a shorter PFS and OS. Traditional measures of CBV were not predictive of PFS or OS.ConclusionsThis study highlights the advantages of large-scale population maps to identify abnormal biological tissues.

The objective of the current study was to evaluate the regional and voxel-wise correlation between dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) measurement of cerebral blood flow (CBF) in patients with brain tumors. Thirty patients with histologically verified brain tumors were evaluated in the current study. DSC-MRI was performed by first using a preload dose of gadolinium contrast, then collecting a dynamic image acquisition during a bolus of contrast, followed by posthoc contrast agent leakage correction. Pseudocontinuous ASL was collected using 30 pairs of tag and control acquisition using a 3-dimensional gradient-echo spin-echo (GRASE) acquisition. All images were registered to a high-resolution anatomical atlas. Average CBF measurements within regions of contrast-enhancement and T2 hyperintensity were evaluated between the two modalities. Additionally, voxel-wise correlation between CBF measurements obtained with DSC and ASL were assessed. Results demonstrated a positive linear correlation between DSC and ASL measurements of CBF when regional average values were compared; however, a statistically significant voxel-wise correlation was only observed in around 30-40% of patients. These results suggest DSC and ASL may provide regionally similar, but spatially different measurements of CBF.

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Blood loss continues to be a common surgical risk in total hip (THR) and knee replacements (TKR). Accurate prediction of blood loss permits appropriate counselling of risks to patients, target optimisation and forecasting future transfusion requirements. We compared blood volume formulae of Moore and Nadler, and blood loss formulae of Liu, Mercuriali, Bourke, Ward, Gross, Lisander and Meunier, to assess associations between calculated values with length of stay and transfusion requirements and determine which are useful in contemporary practice. We retrospectively studied patients undergoing primary THR and TKR. We collected data on patient demographics, surgical interventions, pre- and postoperative haemoglobin and haematocrit values, length of stay and blood transfusion requirements. Spearman correlation tests and least squares multiple linear regression were performed. 149 THRs and 90 TKRs in 239 patients were analysed over four months. There was a very strong correlation between blood volume formulae. There were multiple very strong and strong associations between blood loss formulae. Bourke correlated significantly to length of stay, and Liu, Mercuriali, Lisander and Meunier correlated for incidence of transfusion. Accurate estimation of perioperative blood loss is increasingly important as demand for joint replacement surgery increases in an ageing population. If the primary interest is the association of blood loss and length of stay, Bourke's formula should be preferred. If the primary interest is calculating risk of transfusion, the formulae of Liu or Meunier should be preferred. The formulae of Mercuriali and Lisander are becoming redundant in contemporary practice. [ABSTRACT FROM AUTHOR]

The article discusses about remote blood sampling. Topics include that it is a patient-centric approach driven by the need for social distancing precautions to avoid unnecessary personal contact and potential exposure to the virus; and it has accelerated telemedicine and at-home testing, bypassing the inconvenience of travel and time away from family, work, and school.

PurposeTo compare "standardization," "Gaussian normalization," and "Z-score normalization" intensity transformation techniques in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) estimates of cerebral blood volume (CBV) in human gliomas. DSC-MRI is a well-established biomarker for CBV in brain tumors; however, DSC-MRI estimates of CBV are semiquantitative. The use of image intensity transformation algorithms provides a mechanism for obtaining quantitatively similar CBV maps with the same intensity scaling.Materials and methodsThe coefficient of variance (CV) in normal-appearing white matter and relative contrast between tumor regions and normal tissue was compared between the three CBV transformations across five different MR scanners in 96 patients with gliomas.ResultsThe results suggest all normalization techniques improved variability and relative tumor contrast of CBV measurements compared with nonnormalized CBV maps. The results suggest Gaussian normalization of CBV maps provided slightly lower CV in normal white matter and provided slightly higher tumor contrast for glioblastomas (WHO grade IV) compared with other techniques.ConclusionThe results suggest Gaussian normalization of leakage-corrected CBV maps may be the best choice for image intensity correction for use in large-scale, multicenter clinical trials where MR scanners and protocols vary widely due to ease of implementation, lowest variability, and highest tumor to normal tissue contrast.

Abstract Background Methods to guide fluid therapy in spontaneously breathing patients are scarce. No studies have reported the accuracy of end-tidal CO2 (ET-CO2) to predict volume responsiveness in these patients. We sought to evaluate the ET-CO2 gradient (ΔET-CO2) after a passive leg rise (PLR) maneuver to predict volume responsiveness in spontaneously breathing healthy adults. Methods We conducted a prospective study in healthy adult human volunteers. A PLR maneuver was performed and cardiac output (CO) was measured by transthoracic echocardiography. ET-CO2 was measured with non-invasive capnographs. Volume responsiveness was defined as an increase in cardiac output (CO) > 12% at 90 s after PLR. Results Of the 50 volunteers, 32% were classified as volume responders. In this group, the left ventricle outflow tract velocity time integral (VTILVOT) increased from 17.9 ± 3.0 to 20.4 ± 3.4 (p = 0.0004), CO increased from 4.4 ± 1.5 to 5.5 ± 1.6 (p = 0.0), and ET-CO2 rose from 32 ± 4.84 to 33 ± 5.07 (p = 0.135). Within the entire population, PLR-induced percentage ∆CO was not correlated with percentage ∆ET-CO2 (R 2 = 0.13; p = 0.36). The area under the receiver operating curve for the ability of ET-CO2 to discriminate responders from non-responders was of 0.67 ± 0.09 (95% CI 0.498–0.853). A ΔET-CO2 ≥ 2 mmHg had a sensitivity of 50%, specificity of 97.06%, positive likelihood ratio of 17.00, negative likelihood ratio of 0.51, positive predictive value of 88.9%, and negative predictive value of 80.5% for the prediction of fluid responsiveness. Conclusions ΔET-CO2 after a PLR has limited utility to discriminate responders from non-responders among healthy spontaneously breathing adults.

An original method for determining the volume of early hypotonic hemorrhage is presented. The method is based on clinical application of 3D modeling of results obtained by ultrasound investigations of the uterine cavity and gravimetric assessment of the volume of external blood loss. A scheme for computation is described, a method for 3D modeling of the postpartum uterus is created, and the effectiveness of using this method for determining the volume of hemorrhage is assessed. [ABSTRACT FROM AUTHOR]

Minimally invasive extracorporeal circulation systems are developed to decrease the deleterious effects of cardiopulmonary bypass. For instance, prime volume and foreign surface area are decreased in these systems. However, because of the lack of a venous reservoir in minimized systems, air handling properties of these minimally invasive extracorporeal circulation systems may be decreased as compared to conventional cardiopulmonary bypass systems. The aim of this in vitro study is to compare the air handling properties of two complete minimized cardiopulmonary bypass systems of two manufacturers, of which one system is provided with the air purge control. In an in vitro study, two minimally invasive extracorporeal circulation systems, Inspire Min.I manufactured by Sorin Group Italia, Mirandola, Italy (LivaNova, London, United Kingdom) and minimized extracorporeal circulation manufactured by Maquet, Rastatt, Germany (Getinge, Germany), were challenged with two types of air challenges; a bolus air challenge and a gaseous microemboli challenge. The air removal characteristics of the venous bubble traps and of the complete minimally invasive extracorporeal circulation systems were assessed by measuring the gaseous microemboli volume and number downstream of the venous bubble traps in the arterial line with a bubble counter. No significant differences were observed in air reduction between the venous bubble traps of Getinge (venous bubble traps) and LivaNova (Inspire venous bubble traps 8 in conjunction with the air purge control). Similarly, no significant differences were observed in volume and number of gaseous microemboli in the arterial line of both complete minimally invasive extracorporeal circulation systems. However, the gaseous microemboli load of the Inspire Min.I system was marginally lower after both the bolus air and the gaseous microemboli challenges. Both minimally invasive extracorporeal circulation systems assessed in this study, the LivaNova Inspire Min.I and the Getinge minimized extracorporeal circulation, showed comparable air removal properties, after both bolus and gaseous microemboli air challenges. Besides, air purge control automatic air removal system provided with the LivaNova Inspire Min.I. system may enhance patient's safety with the use of a minimally invasive extracorporeal circulation system. We consider both systems equally safe for clinical use. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether intraprocedural C-arm cone-beam CT (CBCT) parenchymal blood volume (PBV) can predict the response of colorectal cancer liver metastases (CRCLM) 2 months after irinotecan drug-eluting bead (DEBIRI) chemoembolization.Materials and Methods: This single-center observational study was compliant with the Helsinki Declaration and approved by our institutional review board. Thirty-four consecutive CRCLM patients referred for DEBIRI chemoembolization were enrolled between March 2015 and December 2016. Tumor size was assessed at baseline and 2 months after DEBIRI chemoembolization by multidetector CT (Response Evaluation Criteria in Solid Tumors RECIST 1.0), and PBV was measured before and after DEBIRI chemoembolization. Two independent readers reviewed all data. We determined the potential correlation (Spearman's rank correlation) between intraprocedural PBV values and tumor response at 2 months. The relationship between tumor response and PBV was studied using a mixed model. A logistic regression model was applied to study the relationship between patient "Responder/Non-responder" and PBV.Results: There was a strong correlation between baseline PBV or the percent change of PBV and the 2-month tumor response (rho = - 0.8587 (p = 0.00001) and rho = 0.8027 (p = 0.00001), respectively). The mixed model showed that an increase of 1 ml/1000 ml in PBV of a tumor before DEBIRI chemoembolization led to a 0.54 mm decrease in diameter (p < 0.005). A 1% decrease in PBV after DEBIRI chemoembolization resulted in tumor shrinkage of 0.75 mm (p < 0.005). The logistic regression model showed that patients with a 1% smaller mean decrease of PBV after DEBIRI chemoembolization had a 10% lower likelihood of achieving disease control (OR = 0.9, 95% confidence interval (CI) = 0.81-1; p = 0.0493).Conclusion: Intraprocedural PBV may predict tumor response to DEBIRI chemoembolization.Key Points: • There is a strong relationship between the parenchymal blood volume (PBV) of colorectal liver metastases before DEBIRI chemoembolization and tumor response at 2 months. • Higher PBV values before DEBIRI chemoembolization correlate with greater tumor shrinkage, but only if the PBV decreases by more than 70% after DEBIRI chemoembolization. • Each increase of 1% in the mean decrease of PBV after DEBIRI chemoembolization resulted in a 10% lower likelihood of achieving disease control (OR = 0.9, 95% confidence interval (CI) = 0.81-1; p = 0.0493). [ABSTRACT FROM AUTHOR]

Type 2 diabetes is associated with reduced left ventricular reserve. It is unclear whether exercise training improves left ventricular function in people with type 2 diabetes. Purpose: This study aimed to determine whether 3 months of high-intensity interval training (HIIT) improves left ventricular function during exercise in adults with type 2 diabetes. Methods: Participants performed a V˙O2peak test and received a DXA scan and total blood volume measurement at baseline. Left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and left ventricular stroke volume (LVSV) were then measured at rest and during low- and moderate-intensity semirecumbent exercise in adults with type 2 diabetes before and after 3 months of HIIT (n = 11) or no training (control) (n = 5). The effects of HIIT were determined using repeated-measures ANOVA. Results: HIIT increased V˙O2peak by approximately 15% (P < 0.002) but did not change body composition or total blood volume. LVESV decreased and LVEDV and LVSV increased from rest to moderate-intensity exercise in both groups at baseline (all P < 0.01). Three months of HIIT increased LVEDV (P = 0.008) and LVSV (P = 0.02) at all conditions, but there was no difference in controls (all P > 0.05). HIIT augmented the reduction in LVESV from rest to moderate-intensity exercise (P < 0.04), but LVESV was unchanged in controls. Increased LVEDV explained 51% of the change in LVSV after HIIT intervention. Mitral inflow parameters and mitral annular velocities were unaffected by HIIT (all P > 0.05). Conclusions: HIIT training increased the LVSV response to exercise in adults with type 2 diabetes. These data suggest that HIIT can improve LV filling and emptying during exercise and reverse early cardiac consequences of type 2 diabetes. [ABSTRACT FROM AUTHOR]

Measurement of relative cerebral blood volume (rCBV) with dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) is used extensively for brain tumour diagnosis and follow-up. The aim of this pilot study was to assess the robustness of rCBV measurement in patients with enhancing recurrent glioma in a European multicentre trial setting. We included pre-treatment postcontrast T1 weighted (T1w) and DSC scans of 20 patients with recurrent glioma from 2 European Organisation for Research and Treatment of Cancer trials (26101 and 26091). Three reviewers independently placed a fixed circular region of interest of 70 mm2 in the tumour area of highest rCBV (rCBV max). To calculate the normalised rCBV max (nrCBV max), three ROIs were placed in the anterior, middle and posterior centrum semiovale normal-appearing white matter of the contralateral hemisphere. After several months, each observer repeated the assessments blinded for initial findings. Repeatability and reproducibility were estimated with a mixed model. Each measurement was also classified according to 4 clinically meaningful categories. Three patients were post hoc excluded from analysis because of lack of enhancing tumour. The mean nrCBV max repeatability was 49.5%, and reproducibility was 5.5%. In 14 of 17 patients, at least 2 reviewers classified the patient into the same category. Our results indicate that a well-established review process needs to be applied upfront to assess perfusion in a multicentre trial setting. While awaiting further validation, we propose as a strategy to measure rCBV in the context of recurrent glioma trials to use two central reviewers and an adjudicator in case of disagreement. • Glioma perfusion measurement is only modestly repeatable and reproducible. • Most tumours were classified in the same perfusion category by 2 reviewers. • Relative cerebral blood volume reference values should be used with great care. • In clinical trials, categorisation should be performed by at least two readers. [ABSTRACT FROM AUTHOR]

Hemoglobin mass (Hbmass) and total blood volume (BV) determine the oxygen content in the blood. Varying anthropometric values are used to standardize blood volume and Hbmass. The aim of this study was to create normal values and to evaluate an anthropometric reference for Hbmass and BV. One hundred healthy young subjects participated in this study (50 women: 20.9±2.0 yr; 50 men: 23.2±2.9 yr). The Hbmass was measured twice by using a CO rebreathing method. The BV was calculated from the Hbmass, Hb concentration and hematocrit values. The lean body mass (LBM) was measured by a bio-impedance analysis. Women had a significant lower Hbmass per kg LBM compared with that of men (13.6±1.3 g vs. 16.1±1.7 g; p<0.0001). The BV per kg LBM tended to be lower in women than in men (105.3±8.4 ml vs. 108.7±9.0 ml; p=0.0548). LBM had the best correlation with Hbmass (r=0.9274) and BV (0.9233) when considering the entire study group. Normal values of Hbmass and BV could be potentially useful for fluid management and contribute to the diagnosis of blood disorders. For normalization and assessment of measured BV and Hbmass, lean body mass should be prioritized in future studies instead of body weight or body surface area. [ABSTRACT FROM AUTHOR]

Background: Idarucizumab is a humanized Fab fragment that specifically reverses dabigatran anticoagulation. In trauma, volume expanders are used for resuscitation to compensate for blood loss and hemorrhagic shock, but it is unknown whether volume expanders influence the binding of dabigatran to its antidote. Using a porcine dilutional coagulopathy model, this study investigated whether volume replacement strategies affect binding of dabigatran to idarucizumab. Methods: Twenty-five male pigs were treated orally with dabigatran etexilate (30 mg/kg bid) for 3 days. The following day, animals were anesthetized, infused with dabigatran (total dose 0.645 mg/kg) to achieve supratherapeutic concentrations, and randomized 1:1:1:1:1 (n = 5 per group) to control (no hemodilution) or hemodilution where ~50% of blood volume was substituted with Ringer’s solution, 6% hydroxyethyl starch 130/0.4, 6% hydroxyethyl starch 200/0.5 or 4% gelatin. Idarucizumab was then administered intravenously (30 mg/kg) and serial blood samples were taken for up to 24 hours to measure diluted thrombin time (corresponding with dabigatran activity), total dabigatran (bound to antidote and free drug) and a panel of coagulation parameters. Results: Mean plasma dabigatran levels were 617 ± 16 ng/mL after infusion and 600 ± 114 ng/mL after ~50% hemodilution with no significant differences between groups. Following treatment with idarucizumab, plasma concentrations of unbound dabigatran decreased markedly, with similar reductions in all groups. Dabigatran-induced prolongation of coagulation parameters was rapidly reversed in all groups. Conclusion: This study indicates that several volume expanders used for resuscitation in trauma do not interfere with the binding of idarucizumab to dabigatran. [ABSTRACT FROM AUTHOR]

Introduction: Determination of blood volume, red cell volume, and plasma volume contributes to the understanding of the pathophysiology in heart failure, especially concerning anemia and volume load. The optimized carbon monoxide (CO)-rebreathing method (oCORM) is used to determine these parameters and hemoglobin mass (Hbmass) in exercise physiology. The applicability of oCORM to determine the intravascular volumes and Hbmass in heart failure patients is currently undetermined because assumptions concerning CO kinetics with oCORM rely on healthy subjects with a normal ejection fraction. Therefore, the aim of the present study is to determine the applicability and the systematic error of oCORM arising from a reduced EF when oCORM is used for measurement of intravascular volumes and Hbmass in heart failure patients.Methods: oCORM was performed in 21 patients with heart failure and a reduced ejection fraction (EF) of < 30% (EFsev) and 25 controls (CONT). CO kinetics in capillary blood was studied 3–15 min after commencement of CO rebreathing. Differences in CO kinetics between the groups were assessed using a generalized linear model. The systematic error for determination of Hbmass with oCORM arising from differences in CO kinetics was assessed using the Monte Carlo method.Results: The CO kinetics was significantly different between EFsev and CONT. In both groups, exposure to CO led to a COHb increase to 6.0 ± 1.0% 3 min after CO rebreathing. There were no CO related side effects or any clinical symptoms. Monte Carlo simulation quantifies the systematic error for determination of Hbmass arising from an impaired ejection fraction to be −0.88%.Conclusion: Our results indicate an impaired vascular mixing of CO when EF is severely reduced. When Hbmass is determined using the original oCORM protocol in heart failure patients with a reduced EF, the systematic underestimation of about 1% should be considered. However, the error arising from this impaired vascular mixing appears small and clinically negligible. Furthermore, application of oCORM was safe and not related to any side effects resulting from CO exposure. In conclusion, oCORM can be used for assessing intravascular volumes and Hbmass in patients with a reduced EF.

Introduction: Determination of blood volume, red cell volume, and plasma volume contributes to the understanding of the pathophysiology in heart failure, especially concerning anemia and volume load. The optimized carbon monoxide (CO)-rebreathing method (oCORM) is used to determine these parameters and hemoglobin mass (Hbmass) in exercise physiology. The applicability of oCORM to determine the intravascular volumes and Hbmass in heart failure patients is currently undetermined because assumptions concerning CO kinetics with oCORM rely on healthy subjects with a normal ejection fraction. Therefore, the aim of the present study is to determine the applicability and the systematic error of oCORM arising from a reduced EF when oCORM is used for measurement of intravascular volumes and Hbmass in heart failure patients. Methods: oCORM was performed in 21 patients with heart failure and a reduced ejection fraction (EF) of < 30% (EFsev) and 25 controls (CONT). CO kinetics in capillary blood was studied 3–15 min after commencement of CO rebreathing. Differences in CO kinetics between the groups were assessed using a generalized linear model. The systematic error for determination of Hbmass with oCORM arising from differences in CO kinetics was assessed using the Monte Carlo method. Results: The CO kinetics was significantly different between EFsev and CONT. In both groups, exposure to CO led to a COHb increase to 6.0 ± 1.0% 3 min after CO rebreathing. There were no CO related side effects or any clinical symptoms. Monte Carlo simulation quantifies the systematic error for determination of Hbmass arising from an impaired ejection fraction to be −0.88%. Conclusion: Our results indicate an impaired vascular mixing of CO when EF is severely reduced. When Hbmass is determined using the original oCORM protocol in heart failure patients with a reduced EF, the systematic underestimation of about 1% should be considered. However, the error arising from this impaired vascular mixing appears small and clinically negligible. Furthermore, application of oCORM was safe and not related to any side effects resulting from CO exposure. In conclusion, oCORM can be used for assessing intravascular volumes and Hbmass in patients with a reduced EF. [ABSTRACT FROM AUTHOR]

Purpose: This study was performed to assess the effectiveness of the combined intravenous and intra-articular tranexamic acid (TXA) regimen in total knee arthroplasty (TKA).Methods: The perioperative blood loss in 75 consecutive patients undergoing unilateral TKA that received both 1000 mg of TXA intravenously and 1000 mg of intra-articular TXA (combined TXA group) was compared with a consecutive series of 77 patients that received 1000 mg of TXA intravenously (intravenous TXA group). An additional 1000 mg of intravenous TXA was administered 6 h after the initial administration in both groups. Neither a pneumatic tourniquet nor drain was used. The primary outcome was the perioperative blood loss at 3 days after TKA calculated using the blood volume and change in haemoglobin from the preoperative value.Results: The perioperative blood loss was significantly lower in the combined TXA group at 3 days after TKA than the intravenous TXA group (686 ± 303 vs. 830 ± 317 mL; 95% CI 44-244 mL; p = 0.0049). The perioperative blood loss was also lower in the combined TXA group at 1 and 7 days after TKA (374 ± 265 vs. 459 ± 226 mL; 95% CI 7-165 mL; p = 0.034 and 751 ± 320 vs. 871 ± 327 mL; 95% CI 16-224 mL; p = 0.024, respectively). No thrombotic events were observed during the study periods.Conclusions: Combined intra-articular and intravenous TXA regimen significantly reduced perioperative blood loss compared with only intravenous TXA until 7 days after TKA. [ABSTRACT FROM AUTHOR]

Background: Dry weight is the lowest weight patients on hemodialysis can tolerate; correct dry weight estimation is necessary to minimize morbi-mortality, but is difficult to achieve. Here, we used artificial intelligence to improve the accuracy of dry weight assessment in hemodialysis patients.Methods/Results: We designed a neural network which used bio-impedancemetry, blood volume monitoring, and blood pressure values as inputs; output was artificial intelligence dry weight. Fourteen pediatric patients were switched from nephrologist to artificial intelligence dry weight. Artificial intelligence dry weight was higher (28.6%), lower (50%), or identical to nephrologist dry weight. Mean difference between artificial intelligence and nephrologist dry weights was 0.497 kg (− 1.33 to + 1.29 kg). In patients for whom artificial intelligence dry weight was lower than nephrologist dry weight, systolic blood pressure significantly decreased after dry weight decrease to artificial intelligence dry weight (77th to 60th percentile, p = 0.022); anti-hypertensive treatments were successfully decreased or discontinued in 28.7% of cases. In patients for whom artificial intelligence dry weight was higher than nephrologist dry weight, no hypertension was observed after dry weight increase to artificial intelligence dry weight; when present, symptoms of dry weight underestimation receded.Conclusions: Neural network predictions outperformed those of experienced nephrologists in most cases, proving artificial intelligence is a powerful tool for predicting dry weight in hemodialysis patients. [ABSTRACT FROM AUTHOR]

ABSTRACT: Aim: Cardiovascular disease is associated with morbidity and mortality in peritoneal dialysis patients but the relationship between left ventricular ejection fraction (LVEF) and outcomes is unclear. This study aimed to explore the association between LVEF and mortality in incident continuous ambulatory peritoneal dialysis (CAPD) patients. Methods: The patients were divided into three groups according to LVEF levels (>0.6, 0.5 to 0.6, and <0.5). Kaplan–Meier analysis and the Cox proportional hazards models were used to evaluate association of LVEF with mortality. Results: Among the 594 patients, LVEF levels of >0.6, 0.5 to 0.6, and <0.5 were detected in 428 (72.0%), 127 (21.4%) and 39 (6.6%) patients, respectively. During a median follow‐up of 39.6 months, 127 (21.4%) patients died, of the deaths, 57.5% were attributable to cardiovascular causes. Patients with LVEF <0.5 had worst overall rates of survival and cardiovascular death‐free survival among groups. Compared with LVEF >0.6, adjusted all‐cause mortality hazard ratio (HR) and 95% confidence interval (CI) for patients with LVEF 0.5 to 0.6 and <0.5 were 1.62 (1.09–2.43) and 1.93 (1.06–3.52), respectively. The corresponding adjusted cardiovascular mortality HR were 1.60 (0.94–2.47) and 2.16 (1.04–4.74), respectively. Conclusion: Reduced LVEF is significantly associated with increased all‐cause and cardiovascular mortality in incident CAPD patients. [ABSTRACT FROM AUTHOR]

Myocardial infarction is one of the most common human cerebrovascular conditions and frequently leads to ischemic stroke. Evidence has indicated that magnetic resonance imaging (MRI) is a potential method for the diagnosis of patients with cardiovascular injury. However, the efficacy of MRI in diagnosing patients with myocardial infarction requires to be improved. In the present study, a novel nano-size contrast agent, a chitosan/Fe3O4-enclosed albumin (CFEA), was introduced that was used to quantify blood volume and permeability in the infarcted myocardium. A total of 68 patients with suspected myocardial infarction were recruited to analyze the efficacy of MRI combined with CFEA (MRI-CFEA). All patients received diagnosis by MRI and MRI-CFEA. It was revealed that MRI-CFEA provided a higher signal intensity than MRI in the same patients. It was demonstrated that the diagnostic efficacy of MRI-CFEA for patients with myocardial infarction was higher than that of MRI (P<0.05). By MRI-CFEA, 50/68 of cases with myocardial infarction were diagnosed, providing a significantly higher diagnostic rate compared with the 38/68 of cases diagnosed by contrast-enhanced MRI (P<0.01). MRI-CFEA successfully discriminated the infarcted regions based on a decreased fractional blood volume and increased permeability-surface (PS) area product in the infarcted myocardium. A pharmacodynamics analysis indicated that CFEA was eliminated within 24 h in all individuals. In conclusion, the present study provided a novel method to diagnose infarcted myocardium for patients with myocardial infarction, providing an imaging biomarker for the assessment of endothelial dysfunction in the clinic. [ABSTRACT FROM AUTHOR]

Background  Microsurgical free tissue transfer is a popular technique nowadays. Because of its considerably exquisite procedure, various risk factors can affect surgical outcome. However, current key practices, especially those in blood transfusion, are in contention due to the lack of enough evidence. Therefore, the objective of this study was to investigate the impact of perioperative blood transfusion on microsurgical complication. Methods  Data of a total of 168 patients who underwent microvascular free tissue transfer from 2013 through 2016 were retrospectively reviewed. Age, comorbidity, anatomical surgical site, preoperative and postoperative lowest hemoglobin (Hb) level, estimated blood volume loss, and final clinical flap outcome were compared between patients with and without transfusion treatment. Factors with a significance of p  < 0.05 in univariate analysis were included in the multivariate logistic regression model to identify independent risk factors. Results  Of 168 patients, 72 (43%) were in the transfusion group. Cross analysis statistics showed that flap failure in the transfusion group was 3.6 times higher (p  = 0.018) than that in the control group. Multivariable analysis revealed that age (p  = 0.083) and perioperative lowest Hb level (p  = 0.021) remained as significant predictors of flap failure. Receiver-operating characteristic curve analysis showed that the appropriate lower limit of transfusion commencement of Hb was 8.75 g/dL (area under the curve: 0.721). Conclusion  A transfusion during perioperative period of free flap did not increase its failure rate. Rather than appropriate transfusion strategy, perioperative lowest Hb level, and age were significant predictors of flap failure. Therefore, transfusion can be confidently used in patients who undergo free flap without any hesitation. Results of this study provide practical evidence of performing perioperative transfusion for free tissue transfer patients. [ABSTRACT FROM AUTHOR]

Background Chronic subdural hematoma (CSDH) often occurs in association with cerebrospinal fluid (CSF) hypovolemia. Many cases with CSDH due to CSF hypovolemia and treated by burr hole surgery have been reported to present with paradoxical deterioration. However, the mechanisms and pathology of deterioration after surgery for CSDH due to CSF hypovolemia remain obscure. Case Description We report herein a 62-year-old man with gait disturbance due to subdural fluid collection (SDFC) who underwent burr hole irrigation and additional craniotomy, in which postoperative deterioration resulted from rapidly progressing central herniation with a large amount of air accumulation. Epidural blood patch with saline infusion in the thoracic spine finally resolved central herniation. Conclusion SDFC deteriorating after surgery has never been reported. SDFC has communication with CSF differing from mature CSDH composed of closed cavity surrounded by neomembrane. Under situations of CSF hypovolemia due to spinal dural tear, opening the cranium can prompt air replacement in the CSF space, which might represent a substantial risk for central herniation caused by a rapid loss of buoyancy force. [ABSTRACT FROM AUTHOR]

Interrelationships between physiological changes (Δ) in erythropoietin (EPO), plasma volume (PV), haemoglobin concentration ([Hb]), and total haemoglobin mass (tHb-mass) were examined in cyclists who trained in different altitudes. Regardless of differences in pattern of changes observed in three training locations, ΔEPO was correlated positively with ΔPV, negatively with Δ[Hb], and trivially with ΔtHb-mass. Δ[Hb] was negatively correlated with ΔPV. In the pooled data the Spearman’s rank correlation coefficients were as follows: r = 0.783, P < 0.001; r = −0.704, P < 0.001; r = 0.136, P > 0.05; r = −0.813, P < 0.001, respectively. The obtained results have shown that EPO does not only regulate [Hb] by erythropoiesis stimulation but also by PV modulation, which probably aims at keeping proper level of arterial oxygen content for oxygen delivery to tissues. [ABSTRACT FROM AUTHOR]

Background: Volume overload is a known risk factor for cardiovascular complications in children on hemodialysis (HD), but a measurable index of volume overload is still lacking.Methods: We propose a novel index of pre-HD volume overload based on blood volume (BV) monitoring, the first hour refill index (RI), calculated as the ratio between the ultrafiltration rate indexed for body weight during the first HD hour and the percent BV change at the first hour of the treatment. This parameter was retrospectively calculated in 121 sessions in 11 oligoanuric children and young adults on chronic HD, with median age 14.3 years (range 5.4-22.4), and its association with left-ventricular mass index, pre-HD blood pressure, and number of antihypertensive medications was evaluated.Results: The median RI was 2.07 ml/kg/h/%. There was a significant correlation between RI and median LVMI (r 0.66, p = 0.028), which was 53.4 g/m2.7 (45.7-64) in patients with a median RI > 2, and 36.6 g/m2.7 (24.9-47) in those with a median RI < 2 ml/kg/h/% (p = 0.01). The number of antihypertensive drugs per patient was significantly higher in patients with a RI > 2 than in those with a RI < 2 ml/kg/h/% (three vs one per patient; p = 0.02) while blood pressure was not significantly different between the two groups.Conclusions: The ratio between the ultrafiltration rate per body weight and the BV change during the first hour of a HD session could be a promising index of refill capacity and pre-HD volume overload in children and young adults on chronic HD. [ABSTRACT FROM AUTHOR]

Background: A review of the literature shows that the role of laboratory diagnostics in the multidisciplinary concept of patient blood management (PBM) is underrepresented, so the contribution that laboratory diagnostics can make needs to be elucidated. Methods: The central objective of this study was to decrease the volume of blood drawn for laboratory diagnostics as part of a hospital quality management project focussed on increasing efficiency and reducing the turnaround time (TAT) of laboratory results. Optimization potential within the complete preanalytical process was reviewed to obtain potential improvement measures. These measures fell into two groups: training to reduce preanalytical errors in the entire hospital and using blood collection tubes with lower nominal fill volumes. Results: A validation of the success of these measures was performed after 1 year. The occurrence of several blood collection non-compliances had decreased substantially. By changing the blood collection tube volume, approximately 177 L less patient blood was drawn for diagnostic purposes in the 384-bed hospital per year. For geriatric and intensive care unit (ICU) patients, there was a very significant reduction in diagnostic blood loss (−27.2% ICU, −42.5% geriatric patients). The number of tubes used per patient per day decreased by 13%. Conclusions: In conclusion, this approach represents an important lab-side contribution to PBM concepts. [ABSTRACT FROM AUTHOR]