[Transvascular fluid exchange in the burn area and systemic hemodynamic changes in goats with second degree burn]

Local transvascular fluid exchange and generalized hemodynamic alterations in second degree burned goats were studied. Prefemoral and lung lymph fistulas were prepared in 6 goats under local and pentobarbital anesthesia. The catheters were externalized and secured to the skin for collecting lymph to record the volume and determine the mediators in it. Recovering for 2-3 days after surgery, aortic, central venous and Swan-Ganz catheters were placed through a neck incision under local anesthesia. After baseline measurement of physiological parameters and samples, the goats were given a 30% partial thickness scald burn (85 degrees C water 10-15 sec.) on the hide of bilateral flanks, posterior chest and thighs under ketamine anesthesia. The burned area was reddened. Vascular pressures, cardiac output, hematocrit (Hct), lymph flow, protein concentration and thromboxane B2 (TxB2) were measured prior to burn and hourly after injury for the 7 hr period.

Blood pressure and cardiac output decreased rapidly after burn. Pulmonary arterial pressure (Ppa) elevated for 2 hours. Hct increased significantly, indicating that 30% second degree burn produced both systemic and pulmonary hemodynamic changes. Burn lymph increased two-fold over baseline, lymph to plasma ratio (L/P) elevated, lymph protein clearance (lymph flow x L/P) increased, suggesting vascular permeability in burn area increased. Burn lymph TxB2 elevated, corresponded in time to lymph protein clearance, however, the cause-result relationship could not be defined. TxB2 in lung lymph and arterial plasma elevated 1 hr postburn, it may be the cause of increased Ppa. Lung lymph flow and L/P postburn unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)