Plasma volume expansion of 5% albumin, 4% gelatin, 6% HES 130/0.4, and normal saline under increased microvascular permeability in the rat.

OBJECTIVE

To compare the colloids 5% albumin, 4% gelatin, and 6% HES 130/0.4 with one another and with normal saline regarding their plasma expanding effects at increased permeability and to compare the results with those from a previous study at normal permeability.

DESIGN AND

SETTING

Prospective controlled randomized laboratory study in a university research laboratory.

SUBJECTS: 48 adult male Sprague-Dawley rats.

INTERVENTIONS: Permeability was increased by an injection of 0.5 ml dextran 70 using the fact that dextran causes anaphylactic reaction in the rat. Plasma volume was determined ((125)I albumin tracer technique) after anesthesia, 1 h after dextran injection (before infusion for 10-15 min of 20 ml/kg bw of each of the colloids or 80 ml/kg saline), and 3 h later. Blood pressure, hematocrit, blood gases, and electrolytes were measured. CVP was measured in four rats.

MEASUREMENTS AND

RESULTS

Plasma volume was 41.1+/-1.9 ml/kg at baseline (n=9), and 29.1+/-4.1 ml/kg (n=35) 1 h after the dextran injection. Three hours after infusion of the plasma expander plasma volume had increased by 17.1+/-3.4 ml/kg in the albumin group, 7.9+/-3.6 ml/kg in the gelatin group, 7.4+/-4.4 ml/kg in the HES group, and 12.2+/-3.1 ml/kg in the saline group. It was unchanged in a control group given no solution (n=7 for all groups).

CONCLUSION

Albumin was a more effective plasma volume expander than gelatin or HES or saline (saline in 4 times larger volume). Gelatin and HES were equally effective. All solutions showed a smaller plasma expanding effect than observed in a previous study with normal permeability.