Plasma Volume Expansion by Rapid Infusion of a Low Molecular Weight Dextran

Abstract

Large infusions of a 10% solution of dextran of molecular weight 40,000 were given to dogs during 3 min using a specially designed apparatus. The initial expansion of plasma volume was about twice the volume of solution injected. Plasma volume then fell rapidly (with a half life of about 2 hr), more rapidly than the fall in dextran concentration (half‐life of about 4.5 hr). Fluctuations in plasma volume and protein concentration were repeatedly observed during the return towards normal values. At 5 to 6 hr renal excretion accounted for 40% of the infused dextran, about 20% was intravascular and the remaining 40% was presumably extra vascular. No dextran was found in the cerebrospinal fluid.

Dynamics of Plasma-Interstitial Fluid Distribution following Intravenous Infusions in Dogs

“…The present analysis suggests a similar kind of autoregulation during the hypervolemic response to infusions. not accounted for by the model, other investigators (30,(39)(40)(41) have reported similar changes of the same magnitude for infusion of both dextran and saline. Moore et al (40) have suggested that it is unlikely that thoracic duct lymph proteins can account for the largest increases that they observed.…”

A New Solution for Initial Perfusion of Transplant Kidneys

“…Our experiments provided no new evidence concerning the mode of action of dextran 40, but a simple colloid osmotic action seems an adequate explanation. The osmotic pressure of a 5 % solution is 77 cm H,O (Hint, 1964), which draws additional fluid into the capillaries, thus diluting their contents and improving fluidity (Davies, Ricketts & Williams, 1963) while dilating the capillaries and reducing vascular resistance (Pegg, 1970(Pegg, , 1971). Whether or not dextran 40 has any specific red-cell disaggregating action, as originally proposed by Thorsen & Hint (1950) is now in considerable doubt (Bygdeman & Wells, 1969;Meiselman, Merrill, Salzman, Gilliland & Pelletier, 1967).…”

Blood volume and haemodilution in extracorporeal circulation: changes during perfusion.

“…Almost identical observations were made in another small patient with tetralogy of Fallot before the present studies were started, and the findings were then regarded as chance, being then isolated. 10% Rheomacrodex has initially a water-binding capacity of approximately its own volume on rapid infusion (Davies, Ricketts, and Williams, 1963 Erythrocyte volume determinations using the semi-automatic method' are based on sample haematocrit and do not usually take account of variations due for trapped plasma and for peripheral:whole body haematocrit ratio. The latter appears to change during perfusion in an upward direction (Table VII), though not significantly.…”

“…Almost identical observations were made in another small patient with tetralogy of Fallot before the present studies were started, and the findings were then regarded as chance, being then isolated. 10% Rheomacrodex has initially a water-binding capacity of approximately its own volume on rapid infusion (Davies, Ricketts, and Williams, 1963). The plasma volume expansion from the patient on perfusion may be considerably less than twice the volume of LMWD used, if there is available water in the perfusate, whether or not this contains readily diffusible solutes, since the LMWD effect is on the oncotic rather than merely on the total osmotic characteristics of blood.…”