Thermal skin injury: II. Effects on edema formation and albumin extravasation of fluid resuscitation with lactated Ringer's, plasma, and hypertonic saline (2,400 mosmol/l) in the rat.

Pentobarbital anesthetized rats were subjected to a 40% body surface area full-thickness scald burn. Intravenous fluid therapy was given as lactated Ringer's (5 ml/hr), plasma (2.5 ml/hr), or very hypertonic saline (2,400 mosmol/l) (0.75 ml/hr) and compared to unburned or burned, untreated controls. At 3 hr postburn, skin water and albumin content and extravasation of radiolabelled albumin were determined. Water content in injured skin increased by 35-78% (least in the untreated group, most in the plasma group) compared to unburned controls (P less than 0.05). After lactated Ringer's therapy water content increased even in unburned skin and in muscle (P less than 0.05). Tissue albumin mass increased generally slightly more than the increase in water content, from 37% (lactated Ringer's group) to 126% (plasma group) in burned areas. Extravasation rate of radiolabelled albumin increased 5-80 times in burned areas, most following plasma treatment (equivalent to 0.6-1.0 ml plasma/g dry weight/180 min). A major part of the estimated total fluid loss following therapy by lactated Ringer's took place in noninjured tissue. Plasma therapy gave less fluid accumulation in unburned tissues but more edema in the injured areas than lactated Ringer's.