Nutrition Support Blog: ICU Studies, Babies, and Bathwater
November 21, 2012
I was honored to be part of a point-counterpoint presentation at our recent Virginia ASPEN chapter meeting (VASPEN). Our goal was to provide the full spectrum of information about ARDS-specific enteral formulas.
One of the excellent points raised during the “Pro” presentation was the possibility that certain types of critically patients may be helped by ARDS-specific feedings, but others may not – and that average outcomes from studies of mixed critically ill patients may not tell the whole story. Unfortunately the limited number of patients enrolled in most of these studies does not allow you to make firm conclusions about the overall outcomes, so there is certainly no way to extract meaningful data from subgroups. Intensivists have learned the hard way that studies with subgroups of 200-300 patients may suggest a benefit of a medication or intervention, only to find that studies with over 1600 patients revealed net harm.1, 2
However, (as I mentioned in my August blog) the reality is that nutrition and nutrition support studies can rarely secure the funding necessary to conduct studies with sufficient number of patients to make firm conclusions about outcome in the ICU. To add insult to injury, nutrition studies have complexities that medication studies rarely face. Enteral feeding studies are severely compromised when many patients do not receive sufficient amounts of the product (i.e., “the dose”) that are tested because of slow feeding advancement or perceived feeding intolerance. Additionally, some nutrients (antioxidant micronutrients, for example) may not improve outcomes when supplemented in isolation, because they function as part of a chain with other nutrients in a metabolic pathway. However, if we only test nutritional factors as part of a “shotgun” approach with mixed micronutrients, amino acids and/or lipids – then we have no way to know if all of the components are necessary, the doses are correct, or if certain doses of certain components may benefit some patients, but hurt others. It appears to require more studies (and thus more $) to properly investigate and understand nutrition components in the ICU, than it does to study medications.
The exasperating part is that the available data continues to suggest that there are nutrients and nutrient combinations with the potential to improve outcomes of sick people in the ICU. It seems to me that just because we do not yet have adequate evidence to know ‘the who, how and when’ to best employ nutrition and pharmaconutrients, that we should be careful not to discard the whole idea of nutrition manipulation to improve outcomes in the ICU.
One of the items on my long list of brazen and audacious goals for Dietetics and the field of Nutrition Support is that our professional societies will successfully champion the need for proper studies of nutritional factors with the NIH. One would think that it would be obvious that evidence based nutrition interventions are a very cost-effective way to improve patient outcomes and it is in the best interest of our healthcare system in the long run to fund adequate studies. I suspect it is obvious to those of us that work with nutrition support, and perhaps with the right encouragement, the ‘Powers that Be’ will see it as well.
1) Parrillo JE. Severe sepsis and therapy with activated protein C. N Engl J Med. 2005;353(13):1398-1400.
2) Ranieri VM, et al. Drotrecogin alfa (activated) in adults with septic shock. N Engl J Med. 2012; 366(22):2055-2064.
“You may say that I’m a dreamer, but I’m not the only one.”
- John Lennon