WHILE treating patients with large fluid imbalances, we have been impressed with the sometimes misleading nature of central venous pressure determinations in assessing the relationship between blood volume and cardiac competence. In addition to the standard parameters of hourly urine output, central venous pressure, heart rate, hematocrit, arterial blood pressure, and skin perfusion, we have found blood volume determinations to be highly useful in certain patients with difficult fluid management problems. Such problems are hypervolemia without a rising venous pressure, and hypovolemia with a rising venous pressure.
Methods and Materials
Twenty patients with difficult fluid management problems were studied (July to December 1966). The hemodynamic state was evaluated by hourly urine output, hematocrit, heart rate, arterial blood pressure, skin perfusion, and response to subsequent therapy. Central venous pressure and blood volume determinations were performed on each patient and were correlated with the hemodynamic state (Table).Central venous pressure was recorded