scholarly journals P1091DYNAMICS OF VASCULAR REFILLING IN EXTENDED NOCTURNAL HAEMODIALYSIS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Susanne Kron ◽  
Daniel Schneditz ◽  
Til Leimbach ◽  
Joachim Kron

Abstract Background and Aims Refilling volume had not been a measurable parameter in clinical practice so far, because the knowledge of absolute blood volume (BV) is necessary. Recently, we developed a simple method to determine absolute BV, thus enabling quantification of the refilling volume. The overnight dialysis is particularly suitable for studying the refilling process due to negligible external influences and the extended treatment time. Method At the beginning of the dialysis (t=0), before starting the ultrafiltration (UF), a defined online bolus of 240 ml dialysate was infused by pressing the emergency button on the haemodiafiltration (HDF) machine (5008, FMC). The subsequent increase in relative BV (RBVpost-RBVpre) was measured with the integrated BV monitor, and absolute BV at t=0 was calculated: absolute BV in ml = bolus volume 240 ml x 100% / increase in relative BV in%. Absolute BV at any other time t was calculated as: Vt = V0 x RBVt (in %) / 100 At constant UF rate refilling volume (Vref) is given for every hour (h) as: Vref h = UFV h – drop in absolute BVh (beginning – end) The refilling fraction is expressed as refilling/UF ratio: Ref% = Vref/UFV x 100, in % Before treatment, volume overload was evaluated by bioimpedance spectroscopy (BIS) using the body composition monitor (FMC). Results Refilling volume and refilling fraction were studied in 10 stable chronic haemodialysis (HD) patients during an extended (7 hour) nocturnal HD session. Specific BV at treatment start was 74.9 ± 11.8 mL/kg and dropped to 68.6 mL/kg at dialysis end. The constant UF rate was set to 406 ± 120 mL/h (specific UF rate 4.81 ± 1.83 mL/kg/h). In the first hour refilling volume amounted only to 23% of UF volume. Refilling fraction reached its maximum in the 2nd, 3 rd and 4th hour at about mean 90% (91.5%, 88.7%, and 91.1% respectively) of UF volume. From the 5th hour on, refilling volume and refilling fraction decreased (5th hour 81.3%, 6th hour 72.5%, and 7th hour 70.0% of UF volume). In the 5th hour, cumulative UF volume exceeded volume overload (1.1 ± 1.0 L) measured by BIS in 9 of 10 patients. Refilling fraction cumulatively increased up to the 4th hour. Thereafter, cumulative ratio remained constant at 70 – 75% due to the decrease in refilling volume. This did not change during the further course of dialysis. Cumulative refilling volume showed a strong correlation (r2 = 0.88; p<0.001) with UF volume. Conclusion After the first hour, when sufficient refilling takes place, refilling volume is in a stable ratio of approximately 90 % of UF volume. Refilling is low in the first hour, and, therefore, refilling volume amounted cumulatively only about 70 to 75% of UF volume during usual dialysis duration. Thereby, absolute BV will be reduced by approximately 250 to 300 ml per liter UF. This must be taken into account in volume management in order to avoid intradialytic complications. As expected, refilling decreases when volume overload in the interstitial space is removed. Due to the reduced refilling, there will be an additional gap in BV.

2015 ◽  
Vol 86 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Marco Taddei ◽  
Giovanni D'Alessandro ◽  
Franco Amunni ◽  
Gabriela Piana

ABSTRACT Objective:  To analyze any differences in the orthodontic treatment between children belonging to a particular subgroup of subjects with special health care needs (SHCN), children with craniofacial anomalies (CFA), and children not diagnosed with SHCN (NO SHCN). Materials and Methods:  The study sample consisted of 50 children with SHCN and a confirmed diagnosis of CFA (SHCN/CFA); the control group consisted of 50 NO SHCN children fully matched for age, gender, and type of appliance used. The differences between the two groups were analyzed retrospectively: pre-, posttreatment scores, and score reduction of the Peer Assessment Rating Index (PAR), dental health component (DHC), and aesthetic component (AC) of Orthodontic Treatment Need Index (IOTN), number of appointments, number of simple or complex chair-time appointments, overall treatment time, and age at treatment start and end. Results:  There were no statistically significant differences between the SHCN/CFA and NO SHCN groups for number of appointments, overall treatment time, age at treatment start, and age at treatment end (P  =  .682, .458, .535, and .675, respectively). There were statistically significant differences between groups in PAR, DHC, AC pre- and posttreatment, and number of simple and complex chair-time appointments (P  =  .030 and .000; .020 and .023; .000 and .000; .043; and .037; respectively). The reduction of PAR, DHC, and AC scores was not significantly different between groups (P  =  .060, .765, and .825, respectively). Conclusion:  The treatment of children with SHCN, in general, and with CFA, in particular, on the one hand involves a higher rate of using complex chair time appointments and an inferior treatment outcome, by the other side implies an overall treatment time and a reduction of PAR, DHC or AC scores similar to the treatment of children not diagnosed with SHCN.


2021 ◽  
Author(s):  
Belén Fernández ◽  
Ainhoa Sarasua Miranda ◽  
Isabel Lorente Blázquez ◽  
Ignacio Diez López

Childhood obesity is a problem of growing importance globally. It is associated with significant health problems. Knowing how to treat it effectively would improve the quality of life of these children. The aim of this chapter is to study how basal metabolism influences the somatometric evolution of the child and adolescent population with obesity in a pediatric endocrinology clinic. Study childhood obesity in a tertiary hospital by means of a multichannel impedanceometry study. All the patients had a basal metabolism lower than the calculated theoretical ideal. In overall terms, weight reduction is not achieved in this pediatric population. However, it is observed a decrease in fat content in the medium term (1-3 years). Bioelectrical impedanceometry measurement is a simple method in clinical practice to evaluate the energy consumption and the body composition. Knowing the body composition of these children would help to intervene more effectively to help control obesity and its health consequences.


2011 ◽  
Vol 9 (2) ◽  
pp. 63
Author(s):  
Wookyung Chung ◽  
Shung Han Choi ◽  
Jiyoon Sung ◽  
Eul Sik Jung ◽  
Dong Su Shin ◽  
...  

2015 ◽  
Vol 49 (4) ◽  
pp. 347-356 ◽  
Author(s):  
Safoora Nikzad ◽  
Bijan Hashemi ◽  
Golshan Mahmoudi ◽  
Milad Baradaran-Ghahfarokhi

Abstract Background. The aim of this study was to use various theoretical methods derived from the Linear Quadratic (LQ) model to calculate the effects of number of subfractions, time intervals between subfractions, dose per subfraction, and overall fraction time on the cells’ survival. Comparison of the results with experimental outcomes of melanoma and breast adenocarcinoma cells was also performed. Finally, the best matched method with experimental outcomes is introduced as the most accurate method in predicting the cell response. Materials and methods. The most widely used theoretical methods in the literature, presented by Keall et al., Brenner, and Mu et al., were used to calculate the cells’ survival following radiotherapy with different treatment schemes. The overall treatment times were ranged from 15 to 240 minutes. To investigate the effects of number of subfractions and dose per subfraction, the cells’ survival after different treatment delivery scenarios were calculated through fixed overall treatment times of 30, 60 and 240 minutes. The experimental tests were done for dose of 4 Gy. The results were compared with those of the theoretical outcomes. Results. The most affective parameter on the cells’ survival was the overall treatment time. However, the number of subfractions per fractions was another effecting parameter in the theoretical models. This parameter showed no significant effect on the cells’ survival in experimental schemes. The variations in number of subfractions per each fraction showed different results on the cells’ survival, calculated by Keall et al. and Brenner methods (P<0.05). Conclusions. Mu et al. method can predict the cells’ survival following fractionation radiotherapy more accurately than the other models. Using Mu et al. method, as an accurate and simple method to predict the cell response after fractionation radiotherapy, is suggested for clinical applications.


Author(s):  
Danica Gordon ◽  
Chandrasekhar Thamire

Thermal ablation in the context of this study refers to destroying cancer cells by heating them to supraphysiological temperatures for appropriate times. Once the tumor cells and a small layer of surrounding tissue cells are killed, they are absorbed by the body over time. Compared to open surgery, radiation, and chemotherapy, thermal therapy can be less expensive and pose less risk of harmful post-procedural complications, while possessing the potential to be effective [1]. Currently microwave and radiofrequency ablation are in use for local hyperthermia; however, they lack the ability to focus heat into the target zones effectively or treat larger tumors without affecting the surrounding healthy tissue. In the current study, high frequency ultrasound (US) ablation is examined as a treatment modality because of its ability to focus and control heat effectively. Objectives of this study are to 1) develop thermal-damage correlations for US thermal therapy and 2) design delivery devices and associated treatment planning protocols. To achieve these goals, thermal damage information is first evaluated for a variety of cells and tissues from published data or pilot experiments. Required US dose levels are determined next through numerical experiments, followed by device design and estimation of thermal coagulation contours by comparing the temperature-history data against the thermal-damage data. Based on the analysis of the results for a range of parameters, namely, the applicator power, geometry, frequency, coolant parameters, treatment time, and tissue perfusion, treatment protocols are developed. Intraluminal, external, and interstitial modes of delivery are considered for focal sites in a variety of target areas. In the following sections, methods followed and sample results obtained are presented.


2016 ◽  
Vol 31 (suppl_1) ◽  
pp. i231-i231
Author(s):  
Shin Fukunaga ◽  
Kazuhiro Yamada ◽  
Akiko Baba ◽  
Yuji Sato ◽  
Shouichi Fujimoto

2020 ◽  
Vol 223 (16) ◽  
pp. jeb221010
Author(s):  
Ritwika Mukherjee ◽  
Daniel P. Caron ◽  
Timothy Edson ◽  
Barry A. Trimmer

ABSTRACTIn response to a noxious stimulus on the abdomen, caterpillars lunge their head towards the site of stimulation. This nocifensive ‘strike’ behavior is fast (∼0.5 s duration), targeted and usually unilateral. It is not clear how the fast strike movement is generated and controlled, because caterpillar muscle develops peak force relatively slowly (∼1 s) and the baseline hemolymph pressure is low (<2 kPa). Here, we show that strike movements are largely driven by ipsilateral muscle activation that propagates from anterior to posterior segments. There is no sustained pre-strike muscle activation that would be expected for movements powered by the rapid release of stored elastic energy. Although muscle activation on the ipsilateral side is correlated with segment shortening, activity on the contralateral side consists of two phases of muscle stimulation and a marked decline between them. This decrease in motor activity precedes rapid expansion of the segment on the contralateral side, presumably allowing the body wall to stretch more easily. The subsequent increase in contralateral motor activation may slow or stabilize movements as the head reaches its target. Strike behavior is therefore a controlled fast movement involving the coordination of muscle activity on each side and along the length of the body.


2014 ◽  
Vol 85 (3) ◽  
pp. 510-517 ◽  
Author(s):  
Hibernon Lopes Filho ◽  
Lúcio H. Maia ◽  
Thiago C. L. Lau ◽  
Margareth M. G. de Souza ◽  
Lucianne Cople Maia

ABSTRACT Objective:  To investigate the body of evidence in the literature about the most favorable time for initiating orthodontic treatment in patients with severe crowding caused by tooth size arch length deficiency (TSALD). Materials and Methods:  Electronic databases (PubMed, Ovid Medline, Scopus, Virtual Health Library, and The Cochrane Library) were searched for articles published between 1900 and April 2014. Studies were included that evaluated treatment of patients with severe crowding caused TSALD, who were treated with first premolar extraction. The association between the stage of development of occlusion at which treatment was started, and the primary and/or secondary outcomes of early and late treatment were investigated. Results:  After application of the eligibility criteria and reading of the full texts, six articles were included in the final review. Of these six articles, all of which were retrospective, four showed that the primary outcome (correction of severe crowding) of the early and late groups was improved, but without statistically significant differences after treatment. Therefore, the findings of secondary outcomes in the literature (postretention crowding relapse, duration of total and active treatment [treatment with appliances], external apical root resorption, and soft tissue profile) were the target of this study. These studies presented low or moderate methodological quality and control of bias. Conclusions:  Both early and late extraction had a similar effect on correction of crowding. Early treatment had two favorable secondary outcomes (less relapse and reduced active treatment time) vs late treatment. However, the levels of evidence were not sufficient to assert which protocol was superior. (Angle Orthod. 2015;85:510–517.)


Author(s):  
Annelies Van Eyck ◽  
Sofie Eerens ◽  
Dominique Trouet ◽  
Eline Lauwers ◽  
Kristien Wouters ◽  
...  

AbstractThere is an increasing need for suitable tools to evaluate body composition in paediatrics. The Body Composition Monitor (BCM) shows promise as a method, but reference values in children are lacking. Twenty children were included and measured twice by 4 different raters to asses inter- and intra-rater reproducibility of the BCM. Reliability was assessed using the Bland-Altman method and by calculating intraclass correlation coefficients (ICCs). The intra-rater ICCs were high (≥ 0.97) for all parameters measured by BCM as were the inter-rater ICCs for all parameters (≥ 0.98) except for overhydration (0.76). Consequently, a study was set up in which BCM measurements were performed in 2058 healthy children aged 3–18.5 years. The age- and gender-specific percentile values and reference curves for body composition (BMI, waist circumference, fat mass and lean tissue mass) and fluid status (extracellular and intracellular water and total body water) relative to age were produced using the GAMLSS method for growth curves.Conclusion: A high reproducibility of BCM measurements was found for fat mass, lean tissue mass, extracellular water and total body water. Reference values for these BCM parameters were calculated in over 2000 children and adolescents aged 3 to 18 years. What is Known• The 4-compartment model is regarded as the ‘gold standard’ of body composition methods, but is inappropriate for regular follow-up or screening of large groups, because of associated limitations. • Body Composition Monitor® is an inexpensive field method that has the potential to be an adequate monitoring tool.What is New• Good reproducibility of BCM measurements in children provides evidence to use the device in longitudinal follow-up, multicentre and comparative studies.• Paediatric reference values relative to age and sex for the various compartments of the body are provided.


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