Modelling of peripheral fluid accumulation after a crystalloid bolus in female volunteers - a mathematical study
Artikel i vetenskaplig tidskrift, 2010

Objective. To simultaneously model plasma dilution and urinary output in female volunteers. Methods. Ten healthy female non-pregnant volunteers, aged 21-39 years (mean 29), with a bodyweight of 58-67kg (mean 62.5kg) participated. No oral fluid or food was allowed between midnight and completion of the experiment. The protocol included an infusion of acetated Ringer's solution, 25ml/kg over 30min. Blood samples (4ml) were taken every 5min during the first 120min, and thereafter the sampling rate was every 10min until the end of the experiment at 240min. A standard bladder catheter connected to a drip counter to monitor urine excretion continuously was used. The data were analysed by empirical calculations as well as by a mathematical model. Results. Maximum urinary output rate was found to be 19 (13-31) ml/min. The subjects were likely to accumulate three times as much of the infused fluid peripherally as centrally; 1/=2.7 (2.0-5.7). Elimination efficacy, Eeff, was 24 (5-35), and the basal elimination kb was 1.11 (0.28-2.90). The total time delay Ttot of urinary output was estimated as 17 (11-31) min. Conclusion. The experimental results showed a large variability in spite of a homogenous volunteer group. It was possible to compute the infusion amount, plasma dilution and simultaneous urinary output for each consecutive time point and thereby the empirical peripheral fluid accumulation. The variability between individuals may be explained by differences in tissue and hormonal responses to fluid boluses, which needs to be further explored.

kinetics

modelling

fluids

peripheral space

anaesthesia

Författare

P. Rodhe

D. Drobin

Universitetssjukhuset i Linkoping

R.G. Hahn

Linköpings universitet

Bernt Wennberg

Chalmers, Matematiska vetenskaper, Matematik

Göteborgs universitet

C. Lindahl

Karolinska universitetssjukhuset

F. Sjöstrand

C.H. Svensen

Karolinska Institutet

Computational and Mathematical Methods in Medicine

1748-670X (ISSN) 1748-6718 (eISSN)

Vol. 11 4 341-351

Ämneskategorier

Annan matematik

DOI

10.1080/1748670X.2010.494605