A 65-year-old man who had a 25-lb weight loss over the previous 6 months is diagnosed with adenocarcinoma of the distal esophagus. He undergoes a transhiatal esophagectomy complicated by a cervical leak. He is receiving enteral feeds through a jejunostomy tube. After a week, his physicians wish to assess his nutritional resuscitation. Which of the following is the most accurate measure of adequacy of his nutritional suppo?

The serum albumin level provides a rough estimate of protein nutritional adequacy. The accuracy of this estimate is affected by the long half-life of albumin (3 weeks) and the vagaries of hemodilution. Prealbumin, which has a sho half-life (2 days), may be a better indicator of his sho-term nutritional status. The acute-phase serum proteins (such as C-reactive protein, haptoglobin, fibrinogen, and ferritin) also have a very sho half-life (hours) and may also provide good sho-term indications of nutritional status. Transferrin is one of these acutephase proteins, but unfounately its levels, too, are influenced by changes in intravascular volume and, along with the other acute-phase reactants, rise nonspecifically during acute illness.