Nutrition Support Blog: Divining Fluids in the ICU
January 11, 2013
When I first started to work in the ICU I quickly found that I was completely unprepared to negotiate the intricacies of fluid management of critically ill patients. My dietetics education had done an admirable job of preparing me to understand hydration issues of athletes, those in a nursing home, or even folks with GI losses. However, in the ICU I was alarmed to see patients with labs suggesting volume contraction receiving substantial doses of diuretics, and others who appeared fluid overloaded receiving very large volumes of normal saline.
I had been trained to provide recommendations for calories, protein and hydration, but it was clear that I needed more information. I was fortunate to have an intensivist graciously clue me in before I had penned too many notes that cast aspersions on the field of dietetics. Naturally, I was a bit miffed that the basic concepts of shock, resuscitation and fluid balance in the ICU had not been adequately covered during my education …before I was out there writing notes. This is not to suggest that I think that nutrition consultants should be directing resuscitation or diuresis in the ICU, but I felt as though I should have learned enough to realize when NOT to be making recommendations. To be completely fair, the field of critical care medicine was still sorting out the specifics of fluid management in the ICU at that time, and the first large randomized study of conservative vs liberal fluid management during ventilator weaning was not published until 2006.1 Nevertheless, it is important for the medical nutrition experts to understand that divining and relocating fluid from one compartment to another is a major part of the day job for critical care physicians, and that the usual rules for hydration generally don’t apply.
Over the years I have talked to many clinicians that had similar experiences as I did, and had the same rough learning curve. We strive to educate our dietetic interns and peers about the basics of fluids in the ICU, and where the role of the nutrition consultant begins and ends. Our experience with interns and our training programs suggests that the core education for dietitians about critically ill patients remains an area that still needs to be improved. It is my fervent desire (another of my brazen and audacious goals for dietetics) that our formal education will evolve to provide enough pathophysiology, pharmacology and endocrinology so that the next generation of professionals does not need to go through the same on the job “learning curve” that I did.
If you are interested in learning more about fluid issues in the ICU patient check out the June 2012 issue of NCP2, the discussion section of the article by Cordemans et al.3 (available full text via Pubmed) and the ARDSnet trial of conservative fluid management.1
- Wiedemann HP, et al. Comparison of two fluid-management
strategies in acute lung injury. N Engl J Med. 2006;354(24):
- Muller JC, Kennard JW, Browne JS, Fecher AM, Hayward TZ. Hemodynamic monitoring in the intensive care unit. Nutr Clin Pract. 2012 Jun;27(3):340-51.
- Cordemans C, De Laet I, Van Regenmortel N, Schoonheydt K, Dits H, Huber W, Malbrain ML. Fluid management in critically ill patients: the role of extravascular lung water, abdominal hypertension, capillary leak, and fluid balance. Ann Intensive Care. 2012 Jul 5;2 Suppl 1:S1.
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