DETERMINATION OF K42, Na24, Br32 AND TRITIATED WATER CONCENTRATION IN MAN*

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.

A comparison of methods of assessment of body composition including neutron activation analysis of total body nitrogen

Fourteen healthy men underwent determinations of total body nitrogen (TBN) by prompt gamma neutron activation analysis and total body potassium (TBK) by whole body counting to estimate the muscle and nonmuscle components of the fat-free body mass (FFBM) and their protein contents. Comparison of FFBM estimated from TBN and TBK (60.6 +/- 6.9 kg, mean +/- SD), densitometry (62.3 +/- 7.1 kg), TBK alone (62.2 +/- 8.0 kg) and TBW (63.9 +/- 7.8 kg) showed no differences among the techniques. Similarly, there were neither differences in fat mass nor percent body fat among the methods. Analysis of the chemical composition of FFBM of this group showed TBK/FFBM = 62.6 +/- 2.3 mEq/kg, TBW/FFBM = 74.6 +/- 0.2%, TBN/FFBM = 32.74 +/- 1.09 g/kg, protein/FFBM = 20.5+/- 0.7%. The calculated mineral content of the FFBM was 6.4%. These values are strikingly similar to the values calculated by direct chemical analysis. It was concluded that the combined TBN-TBK method is a valid technique for estimating body composition in man.

Variations in body water during recovery from depression

Reports of significant changes in water and electrolytes during recovery from depression may provide insight into important physiological factors in depressive illnesses. Brownet al.(1963) demonstrated an increase in the extracellular fluid volume in 22 of 28 patients suffering from primary depressive disorders treated with E.C.T. or imipramine. The findings of these authors, which were discussed in relation to previous work on sodium metabolism and water balance in depressive disorders, were thought to support the idea of a shift of fluid from intracellular to extracellular spaces during the response to treatment. Coppen and Shaw (1963) found an increase in total body water, extracellular fluid and a decrease in the residual sodium space on recovery from depression.