ON THE PATHOGENESIS OF BURN SHOCK: CHANGES IN SERUM SURFACE TENSION IN THE ACUTE PERIOD OF SEVERE BURN INJURY

Introduction. The surface tension of serum (STS), reflecting the content of surface-active agents, plays an important role in microcirculation and lymph circulation. Stable surface tension of blood serum in humans and warm-blooded animals, as well as some fish (about 67×10-3 N/m), indicates the physiological importance of this physicochemical phenomenon, and requires further research. In addition, an increased content of surface-active compounds with a detergent effect can negatively affect the integrity of cell membranes and the permeability of microvessels. Aim of the research. Study of the dynamics of surface tension of blood serum and the severity of capillary leakage in patients in a state of burn shock. Materials and methods. Changes in the surface tension of serum and the severity of capillary leakage were studied in 36 patients with severe burn injury during the period of burn shock (48 h). Inclusion criteria: time of admission to the intensive care unit in the first 2 h after injury, age 15-69 years, thermal injury of III-IV degree with an area of more than 40%. Results. In the group of patients with a negative outcome (group 2), a significant decrease in STS was noted compared to the group of surviving patients (group 1). Similar changes were noted when assessing the capillary leakage index (CLI): in the group with fatal outcomes, the CLI parameters were significantly lower than the values in the group of survivors throughout the observation period. A positive correlation was noted between STS and CLI in both groups, indicating the role of surfactants in the development of capillary leakage and, consequently, in the pathogenesis of hypovolemia in burn shock (BS). The use of a methylene blue solution in vitro restored STS to almost normal values at doses tens of times lower than those recommended for clinical use. Conclusion. STS reduction in burn shock affects the severity and outcome of BS, including due to its effect on microvascular permeability. Accumulation of endogenous surfactants of the detergent type should be considered as one of the mechanisms of burn shock development. Methylene blue solution can be considered as an antidote to endogenous surfactants in burn shock.