Plasma volume expansion and transcapillary fluid exchange in skeletal muscle of albumin, dextran, gelatin, hydroxyethyl starch, and saline after trauma in the cat.

OBJECTIVE

To compare 5% albumin, 6% dextran 70, 3.5% gelatin, 6% hydroxyethyl starch 130/0.4, and saline regarding their plasma volume expanding effect after a surgical skeletal muscle trauma and their simultaneous effects on transvascular fluid exchange in skeletal muscle.

DESIGN

Controlled, prospective, randomized laboratory study.

SETTING

University research laboratory.

SUBJECTS: Thirty-six adult cats.

INTERVENTIONS: Systemic arterial pressure and tissue volume variations of and blood flow to a surgically isolated and autoperfused calf muscle placed in a plethysmograph were recorded. Arterial and venous pressures to the muscle were kept constant. After preparation, plasma volumes were determined by a I albumin tracer technique just before and 3 hrs after a bolus infusion of the plasma expander (25 mL/kg).

MEASUREMENTS AND MAIN

RESULTS

Plasma volume was 20.9 +/- 2.9 mL/kg (n = 36) just before infusion of the plasma expander (normal plasma volume for the cat is 34-37 mL/kg). The remaining volume expansion of the infusion after 3 hrs was 6.8 mL/kg for albumin, 11.2 mL/kg for dextran, 1.8 mL/kg for gelatin, 2.2 mL/kg for hydroxyethyl starch, and 0.9 mL/kg for saline. Plasma volume decreased by 1.1 mL/kg when no solution was given (n = 6 per group). Colloid osmotic pressure was better preserved with dextran and albumin than with the other solutions. Albumin and dextran reduced muscle volume by absorption after 3 hrs, whereas the initial absorption turned to net filtration in the gelatin and hydroxyethyl starch groups. Saline infusion increased muscle volume by filtration for about 20 mins, followed by an approximately constant volume.

CONCLUSION

The relatively poor plasma expansion for all solutions analyzed can most likely be explained by increased transcapillary leakage due to increased microvascular permeability following trauma. Under such circumstances, for equal volumes, plasma expansion was better preserved with 6% dextran 70 than with 5% albumin, which was better than 3.5% gelatin, 6% hydroxyethyl starch 130/0.4, and saline.