Document Detail


Mathematical model of renal elimination of fluid and small ions during hyper- and hypovolemic conditions.
MedLine Citation:
PMID:  12631040     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study is concerned with the formulation of a 'kidney module' linked to the plasma compartment of a larger mathematical model previously developed. Combined, these models can be used to predict, amongst other things, fluid and small ion excretion rates by the kidney; information that should prove useful in evaluating values and trends related to whole-body fluid balance for different clinical conditions to establish fluid administration protocols and for educational purposes. The renal module assumes first-order, negative-feedback responses of the kidney to changes in plasma volume and/or plasma sodium content from their normal physiological set points. Direct hormonal influences are not explicitly formulated in this empiric model. The model also considers that the renal excretion rates of small ions other than sodium are proportional to the excretion rate of sodium. As part of the model development two aspects are emphasized (1): the estimation of parameters related to the renal elimination of fluid and small ions, and (2) model validation via comparisons between the model predictions and selected experimental data. For validation, model predictions of the renal dynamics are compared with new experimental data for two cases: plasma overload resulting from external fluid infusion (e.g. infusions of iso-osmolar solutions and/or hypertonic/hyperoncotic saline solutions), and untreated hypo volemic conditions that result from the external loss of blood. The present study demonstrates that the empiric kidney module presented above can provide good short-term predictions with respect to all renal outputs considered here. Physiological implications of the model are also presented.
Authors:
Christina C Gyenge; Bruce D Bowen; Rolf K Reed; Joel L Bert
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Acta anaesthesiologica Scandinavica     Volume:  47     ISSN:  0001-5172     ISO Abbreviation:  Acta Anaesthesiol Scand     Publication Date:  2003 Feb 
Date Detail:
Created Date:  2003-03-12     Completed Date:  2003-07-28     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370270     Medline TA:  Acta Anaesthesiol Scand     Country:  Denmark    
Other Details:
Languages:  eng     Pagination:  122-37     Citation Subset:  IM    
Copyright Information:
Copyright Acta Anaesthesiologica Scandinavica 47 (2003)
Affiliation:
Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, Canada.
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MeSH Terms
Descriptor/Qualifier:
Algorithms
Animals
Blood Volume / physiology*
Chlorides / urine
Hemorrhage / physiopathology
Hypovolemia / physiopathology*
Ions / urine
Kidney / metabolism,  physiology*
Least-Squares Analysis
Models, Biological
Models, Statistical
Osmolar Concentration
Potassium / urine
Reproducibility of Results
Saline Solution, Hypertonic
Sodium / urine
Swine
Urodynamics / physiology
Chemical
Reg. No./Substance:
0/Chlorides; 0/Ions; 0/Saline Solution, Hypertonic; 7440-09-7/Potassium; 7440-23-5/Sodium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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