Objective: To determine if a new hydroxyethyl starch, pentafraction, will cause better capillary retention of fluid in thermally burned and nonburned tissues when compared with some currently used volume expanders.
Design: Randomized, controlled, experimental study.
Setting: University research laboratory.
Subjects: Twenty-one healthy adult range ewes.
Interventions: Sheep, surgically prepared for chronic study, were randomly assigned to one of three colloid groups for the resuscitation of thermal injuries: a) ovine fresh-frozen plasma group; b) pentastarch group; and c) pentafraction group. Twenty-one sheep were subjected to a 40% total body surface, third-degree flame burn under anesthesia (1.5% to 2% halothane). When awakened, the sheep received 15 mL/kg of one of the above colloids, and then lactated Ringer's solution (2 mL/hr/kg). All animals survived and were killed at 48 hrs after burn injury.
Measurements and main results: We found that cardiac index decreased and systemic vascular resistance increased in the pentastarch and plasma groups. However, cardiac index increased in the pentafraction group, while systemic vascular resistance increased by only half as much as in the other two groups. Cardiac index in the plasma group decreased significantly for the first 8 hrs, and did not return to the baseline value for 48 hrs. Systemic vascular resistance increased significantly for the first 8 hrs in both the plasma and pentastarch groups. Prefemoral lymph flow was significantly more increased in the pentastarch group, while the lung lymph/plasma oncotic gradient was maintained only by the pentafraction group.
Conclusions: Pentafraction is as good, or even superior, for volume resuscitation in the burn patients, when compared with pentastarch and plasma. This conclusion is made most evident by the attenuated changes in systemic vascular resistance and cardiac index. Pentafraction decreases the fluid flux and potential subsequent edema significantly in burned tissues and effectively maintains the pulmonary microvascular integrity.