Water and sodium balance: the effect of the air-fluidized bed on burned patients

Five patients with burned areas from 20 to 40 per cent BSA were studied in the air-fluidized bed during the first 2-week period post burn. Patients with abnormal renal and intestinal functions and with previous pathological history were not incorporated in the study. The patients were treated by the exposure method, and no surgical procedure was carried out during the study. The water and sodium balances were calculated from intravenous and oral intakes, urine-outflow, urinary sodium excretion and weight changes. In addition measurements of the sodium space were performed in two patients, using Sodium. Evaporative water loss was calculated during the first week, the sodium loss during the first and second weeks. As a result of the study the average daily evaporative water loss could be defined as: 0.81 ml/cm2 burned area +/- 0.07 ml. We compared the actual evaporative water loss with two classical formulas: --Davies, Lamke, Liljedahl (1974) (D.L.L.) min: 0.3 ml X cm2 burned area = ml/day = D.L.L. (0.3) Max: 0.45 ml X cm2 burned area = ml/day = D.L.L. (0.45) --Scott, McDougall, Slade, Pruitt (1978) (S.M.S.P.) (25 + %) X BSA = ml/h = S.M.S.P. --Scott, McDougall, Slade, Pruitt (1978) (S.M.S.P.) (25 + %) X BSA = ml/h = S.M.S.P. The average calculated daily evaporative water was: D.L.L. (0.3) + 5 litre/m2 burned area D.L.L. (0.45) + 3.5 l/m2 burned area S.M.S.P. + 4 litre/m2 burned area. This 'extra' evaporative water loss was closely related to the body burned surface. Correlation coefficient: D.L.L. (0.3) = 0.99 D.L.L. (0.45) = 0.98 S.M.S.P. = 0.97. Day 2 and day 3 showed the most important water loss per cm2 burned area. On the other hand, the sodium loss was found to be as expected: daily average: 0.02 mmol/cm2 burned area.