Screening for colorectal cancer.

n engl j med 362;1 nejm.org january 7, 2010 84 bowel syndrome and subsequent cholestasis who are dependent on parenteral nutrition. In critically ill adults, adequately powered, double-blind, randomized clinical trials evaluating the efficacy of intravenous fish oil infusions given as a component of parenteral nutrition are few, and the results to date are mixed.3 Detailed commentary on this issue was beyond the scope of my article. I agree with Dotson and Tennenberg that substantial intravenous calories may accrue from propofol and clevidipine, which are commonly used in the ICU. Thus, the estimated daily caloric load from these agents (as well as the administered calories from dextrose-containing intravenous fluids) needs to be monitored and the dextrose and lipid calories from parenteral nutrition appropriately adjusted on a day-to-day basis to avoid overfeeding. Peris et al. show data suggesting that real-time ultrasonography-guided placement of a central venous catheter is associated with significantly reduced adverse effects, as compared with “blind” methods, as recommended in recent European clinical practice guidelines.4 In response to Ferrie: European clinical practice guidelines suggesting that protein intake need not be restricted in patients with encephalopathy are based on a grade C recommendation (i.e., expert opinion or clinical experience) and on an unblinded study of enteral diet in patients who were not in the ICU.5 Clinical practice guidelines are not written as absolute requirements but rather offer recommendations on the basis of available published data and expert opinion. Thus, it is inevitable that recommendations for specific aspects of nutritional support differ between recent American guidelines and European guidelines. We have adopted the conservative approach of limiting the dose of protein or amino acids, at least for several days, in such patients to diminish the effect of this potential contributor during diagnostic evaluation. Thomas Ziegler, M.D.