Figure 1

Flow diagram of patients invited to participate. For practical reasons it was necessary to randomize patients before eligibility was confirmed. Study fluid was often started while awaiting the results of the baseline [Na]-- which was used to determine eligibility. It was not always possible to predict which patients would require at least 8 hours of study fluid. Eight medical patients were withdrawn from the study (no exit [Na] obtained) when IV fluids were discontinued prior to completion of 8 hours of study fluid.