Weight changes and sodium balances during deterioration and recovery in patients in congestive heart failure

1. ( 1) Change in body sodium has been followed in patients in congestive heart failure during improvement or recovery, during deterioration and for periods of little or no clinical change. 2. ( 2) Sodium balances have been drawn up in 40 patients and measurements made of the exchangeable mass of sodium on at least 2 occasions in 10 patients. 3. ( 3) Calculations have been made of the changes in body sodium that would be caused by observed changes in body weight if these were exclusively caused by gain or loss of extracellular fluid. 4. ( 4) These predictions have been compared with the observed change in body sodium in 47 periods of improvement or recovery, 20 periods of deterioration and 10 steady periods. 5. ( 5) Difficulties of interpretation are discussed. 6. ( 6) It is concluded that the data are consistent with a wholly extracellular location of dropsical fluid in some patients and with additional excess of intracellular water in others. It seems likely too that in some patients not all of the excess sodium in the body is extracellular.