Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Blood dialysis, modeling

To understand the affinity of chlorinated compounds for dialysis fluid and blood as a model for the transfer of a lipophilic organic contaminant to the blood compartment, it is possible to calculate the blood/dialysis water partition coefficient (A b/dw) under static conditions (see Figure 29.2) ... [Pg.639]

Mix 0.1ml of the sample (model solution, blood serum, dialysis liquid) with 0.9 ml of 0.9% NaCl. [Pg.1214]

Once the structure of the PBPK model is formulated, the next step is specifying the model parameters. These can be classified into a chemical-independent set of parameters (such as physiological characteristics, tissue volumes, and blood flow rates) and a chemical-specific set (such as blood/tissue partition coefficients, and metabolic biotransformation parameters). Values for the chemical-independent parameters are usually obtained from the scientific literature and databases of physiological parameters. Specification of chemical-specific parameter values is generally more challenging. Values for one or more chemical-specific parameters may also be available in the literature and databases of biochemical and metabolic data. Values for parameters that are not expected to have substantial interspecies differences (e.g., tissue/blood partition coefficients) can be imputed based on parameter values in animals. Parameter values can also be estimated by conducting in vitro experiments with human tissue. Partitioning of a chemical between tissues can be obtained by vial equilibration or equilibrium dialysis studies, and metabolic parameters can be estimated from in vitro metabolic systems such as microsomal and isolated hepatocyte syterns. Parameters not available from the aforementioned sources can be estimated directly from in vivo data, as discussed in Section 43.4.5. [Pg.1074]

As an example, let us consider a simple one-compartment model for the prescription of treatment protocols for dialysis by an artificial kidney device (Fig. 1.1). While fire blood irrea concentration (BUN) in the normal individual is usually 15 mg% (mg% = milligrams of the substance per 100 mL of blood), the BUN in irremic patients could teach SO mg%. The purpose of the dialysis is to bring the BUN level closer to the normal. In the artificial kidney, blood flows on one side of the dialyzer membrane and dialysate fluid flows on the other side. Mass transfer across the dialyzer membrane occurs by diffusion due to concentration difference across the membrane. Dilysate fluid is a makeup solution consisting of saline, ions, and the essential nutrients that maintains zero concentration difference for these essential materials across the membrane. However, during the dialysis, some hormones also diffuse out of the dialyzer membrane along with the urea molecule. Too-rapid dialysis often leads to depression in the individual because of the rapid loss of hormones. On the other hand, too-slow dialysis may lead to unreasonable time required at the hospital. [Pg.24]

Blood flow to the dialyzer (Q) is zero when the patient is not on the dialysis machine. Babb et al. (1967) simulated the two-compartmental model and the model results were in agreement with the experimental data (Fig. 1.3). However, the two compartmental model may not be sufficient if one wants to find the concentration of urea in the txain tissue. A multicompartment model involving... [Pg.26]

Obviously, there is a need for so many different dialysis filters. The cohorts of dialysis patients vary in age, gender, body weight, blood volume, comorbid conditions, drug administration, predisposition to allergies and other physiological bystander conditions. Dialysis as a therapy for chronically ill patients tends to become more and more a practical model for personalized dialysis treatment regimen with respect to all patients. Thus, such a diversity of medical devices that is unprecedented in other realms of medical device technology, is needed. [Pg.376]

Fig. 13.8 Sheep model on hemodialysis given that a negatively charged dialysis membrane, such as AN69, is used together with ACE-inhibitors (Enalapiil), a dose dependent blood pressure drop is observed (modified from [46])... Fig. 13.8 Sheep model on hemodialysis given that a negatively charged dialysis membrane, such as AN69, is used together with ACE-inhibitors (Enalapiil), a dose dependent blood pressure drop is observed (modified from [46])...
Shown in Figure 8.10 are data for creatinine in a test dialyzer. The needed parameters are obtained to fit data for the first of the five dialyses shown. It may be seen from this and the four subsequent dialyses that the model fit is excellent. Clearly, the model is greatly simplified neither the body tissue nor the blood is a simple mixing tank. Moreover, the rate of metabolite formation is far from constant. Rather the goodness of fit is due to excellent time constant separation metabolite formation (day), dialysis (hour), organ residence time (minutes), and blood circulation (1 min). [Pg.172]

Vonesh EF, Lysaght MJ, Moran J, Farrell P. 1991. Kinetic modeling as a prescription aid in peritoneal dialysis. Blood Purifi 9 246-270. [Pg.1633]


See other pages where Blood dialysis, modeling is mentioned: [Pg.222]    [Pg.154]    [Pg.457]    [Pg.368]    [Pg.150]    [Pg.606]    [Pg.60]    [Pg.62]    [Pg.511]    [Pg.1721]    [Pg.538]    [Pg.19]    [Pg.366]    [Pg.240]    [Pg.24]    [Pg.498]    [Pg.99]   
See also in sourсe #XX -- [ Pg.460 ]




SEARCH



Blood dialysis

Dialysis

Dialysis model

© 2024 chempedia.info