July is a time of change and new teaching opportunities at UVA because our dietetic interns have moved on to new adventures and we welcome new Resident and Fellow physicians to the hospital. Our journal club article this month focused on the potential effects of calorie and protein deficits in critically ill surgical ICU patients.
Yeh DD, Fuentes E, Quraishi SA, et al. Adequate Nutrition May Get You Home: Effect of Caloric/Protein Deficits on the Discharge Destination of Critically Ill Surgical Patients. JPEN J Parenter Enteral Nutr. 2015 Apr 29. [Epub ahead of print]
This was a single center, prospective observational study of adult surgical ICU patients which investigated potential relationships between feeding delays and nutrition deficits with clinical outcomes and discharge destinations. Nutrition information collected included hours from ICU admission to EN initiation, prescribed Vs received calories, prescribed vs received protein, cumulative ICU calorie deficit and cumulative protein deficit. Nutrition targets were 25-30 kcals/kg and 1.5-2.0 gm protein//kg using actual body weight for patients with a BMI < 30 and ideal weight for BMI > 30. PN was not started until after 10 days of inadequate EN. Cumulative calorie deficit was defined as low (< 6000 kcals) or high (≥ 6000 kcals) and protein deficit as low (< 300 gm) or high (≥ 300 gm).
The primary outcome was discharge destination (home vs non-home).
Secondary outcomes included complication rates, ICU LOS, hospital LOS, 28-day ventilator-free days (VFD), in-hospital mortality and 30-day mortality.
Logistic regression analysis controlling for BMI and APACHE II score were used to investigate associations between nutrition deficit and discharge destination.
Inclusion and Exclusion Criteria were:
Surgical ICU patients aged ≥ 18 years, started EN during the current ICU admission and received at least 72 hours of EN in the ICU.
ICU admission < 72 hours, previous ICU stay within the same admission, received EN prior to ICU admission, or had a diagnosis of ileus or bowel obstruction.
A total of 213 patients were identified who met inclusion/exclusion criteria over the 2 year, 3 month study period. There were 141 patients with a low deficit in calories and protein, 42 with a high deficit of calories and protein, 19 with a high deficit of just protein, and 11 with only a high calorie deficit. There were no significant differences in age, BMI, time to initiate EN, APACHE II score or Deyo-Charlson comorbidity index between the groups.
High-deficit patients were prescribed significantly greater amounts of calories (and kcals/kg) and protein, and received tube feeding for a significantly longer period of time (7 days low-deficit, 14 days high deficit). High-deficit patients were more commonly male, and a high macronutrient deficit was associated with fewer VFDs, more complications, longer ICU LOS, and prolonged hospital LOS.
Only 15% of all patients (n=33) were discharged to home, and 30 of these were from the low-calorie deficit group. After adjusting for BMI and APACHE II score in the bivariate model, a higher calorie deficit was associated with a lower likelihood of home discharge (OR, 0.28; 95% CI, 0.08–0.96; P = .04) while a high protein deficit was associated with a lower likelihood of home discharge (OR, 0.29; 95% CI, 0.10–0.89; P = .03).
The authors concluded that their results demonstrate that:
“inadequate macronutrient delivery was associated with lower rates of discharge to home. As such, improved nutrition delivery may lead to more favorable clinical outcomes after critical illness and underscores the need for well-designed randomized controlled trials to determine whether nutrition therapy affects the ability of ICU patients to safely go home instead of rehabilitation or nursing facilities.”
This was a single-center, single-ICU observational study with a limited number of patients. The inherent limitation of all observational studies is that they can only document associations, and it is not possible to ascribe cause and effect from this data, because it is not possible to know, or control for, all of the factors that influence patient outcome in an observational study. While it is certainly possible that cumulative calorie and protein deficits can negatively impact surgical ICU patients, it would require large randomized studies to fully appreciate the impact of nutrition deficits on patient outcome.
There are a number of observational studies that have reported the association between ICU outcomes and nutrition delivery1,2: however, randomized data have established that modest differences in calorie provision, in a variety of populations, does not seem to significantly impact patient outcome.3-5 Additionally, studies of some intensive EN protocols to increase the provision of calories and protein may actually have adetrimental effect in some adult ICU populations6,7 (see our June and November, 2014 e-journal entries).
In an observational study, the same factor(s) (such as a difficult ICU course) that impair nutrition delivery can also influence complications or disposition, and it is not necessarily the nutrition that directly influences disposition.
Our Take Home Message (s)
1. Observational data suggests there is an association between patient outcomes and the amount of EN delivery.
2. The best available randomized data suggest that modest calorie deficits do not influence ICU outcomes.
3. Observational data should not be used to imply cause and effect.
4. There is a need for large randomized studies in surgical patients to determine if increased calorie/protein delivery can improve patient outcome.
1. Alberda C, Gramlich L, Jones N, et al. The relationship between nutritional intake and clinical outcomes in critically ill patients: results of an international multicenter observational study. Intensive Care Med. 2009;35:1728–1737.
2. Villet S, Chiolero RL, Bollmann MD, et al. Negative impact of hypocaloric feeding and energy balance on clinical outcome in ICU patients. Clinical Nutrition 2005; 24(4):502-509.
3. Charles EJ, Petroze RT, Metzger R, et al. Hypocaloric compared with eucaloric nutritional support and its effect on infection rates in a surgical intensive care unit: a randomized controlled trial. Am J Clin Nutr. 2014; 100(5):1337-1343.
4. Arabi YM, Aldawood AS, Haddad SH, et al. Permissive underfeeding or standard enteral feeding in critically ill adults. N Engl J 2015; 372(25):2398–2408.
5. Rice TW, Mogan S, Hays MA, et al. Randomized trial of initial trophic versus full-energy enteral nutrition in mechanically ventilated patients with acute respiratory failure. Crit Care Med. 2011; 39:967–974.
6. Taylor B, Brody, Denmark R, Southard R, Byham-Gray L. Improving Enteral Delivery Through the Adoption of the “Feed Early Enteral Diet Adequately for Maximum Effect (FEED ME)” Protocol in a Surgical Trauma ICU: A Quality Improvement Review. Nutr Clin Pract. 2014 Aug 25. [Epub ahead of print.
7. Braunschweig CA, Sheean PM, Peterson SJ, et al. Intensive Nutrition in Acute Lung Injury: A Clinical Trial (INTACT). JPEN J Parenter Enteral Nutr 2014 Apr 9 [Epub ahead of print]
Other News on the UVAHS GI Nutrition Website: (www.ginutrition.virginia.edu):
Upcoming Webinars 2015:
–Tuesday, September 22: Practical Implementation of a Malnutrition Documentation and Coding System in an Acute Care Hospital–Wendy Phillips, MS, RD, CNSC, CLE, FAND
–Wednesday, October 14: Refeeding Syndrome–Carol Parrish, MS, RD
–Tuesday, November 17: Hyperglycemia in the Acute Care Setting–Joe Krenitsky, MS, RD
Latest Practical Gastroenterology article:
Shah ND, Limketkai BN. Low Residue vs. Low Fiber Diets in Inflammatory Bowel Disease: Evidence to Support vs. Habit? Practical Gastroenterology 2015;XXXIX(7):48.
Joe Krenitsky MS, RD
Carol Rees Parrish MS, RD
PS – Please feel free to forward on to friends and colleagues.