January 2016 E-Journal Club

February 4, 2016 by sf8n@virginia.edu

Snowy woods

Greetings,
We do not host training programs in January, in part due to the unpredictable nature of the winter weather. This January is a great example because we are still digging out from the recent snowy maelstrom that engulfed the east coast of the US. Our journal club this month dealt with the topic of enhanced enteral feeding protocols aimed at improving nutrition delivery in the ICU.

January Citation:
Haskins IN, Baginsky M, Gamsky N, et al. A Volume-Based Enteral Nutrition Support Regimen Improves Caloric Delivery but May Not Affect Clinical Outcomes in Critically Ill Patients. JPEN J Parenter Enteral Nutr. 2015 Nov 12. [Epub ahead of print]

Summary:
This was a single center, unblinded, before-after cohort study that investigated the effectiveness of volume-based feedings (VB) to increase nutrition delivery in the adult ICU and the effect on patient outcomes, compared to the usual rate-based feeding (RB). Consecutive adult ICU patients who received continuous feedings from April to July (2013) received the usual rate-based feedings, while patients admitted from December 2013 to February 2014 received volume-based feedings. Whenever the EN was interrupted, an undisclosed algorithm was used to adjust the hourly feeding rate to provide the goal volume of feeding. Initial trophic feedings and prokinetic agents were used during the RB feeding period at the discretion of the individual MD, but were not utilized during the VB period. VB feedings were started at goal flow rate, and utilized a maximum “make-up” rate of 150 ml/hr. The EN formula and nutrition goals were determined by the dietitian during both study periods.

The primary outcomes included percent goal calories delivered, ventilator days, length of ICU stay, hospital stay, and mortality. Secondary outcomes included nosocomial infections, ventilator-associated pneumonia (VAP) and urinary tract infection (UTI). Multivariate regression was used to identify independent predictors of clinical outcomes while controlling for known relevant covariates.

Inclusion and Exclusion Criteria:
Inclusion criteria:
Adult patients who received continuous EN for at least 24 hours at any point during their stay in the ICU.

Exclusion criteria:
Patients younger than 18 years, not admitted to the ICU, and those who received any parenteral nutrition.

Major Results:
A total of 77 patients were enrolled, with 38 patients in the RB group and 39 patients in the VB group. Most baseline demographic and clinical characteristics were similar between the groups, except the VB group had a significantly higher APACHE II score than the RB group (17 VB vs 10 RB, P < .01).

Patients in the VB group received a significantly greater percentage of prescribed calories than those in the RB group (74% VB vs 57% RB, P < .001). Additionally, patients in the VB protocol arm had a significantly longer length of ICU stay (14 vs 9, P = .05) as well as days on the ventilator (9 vs 7, P = .04). However, after controlling for the admission APACHE II score, the differences in clinical outcomes were not statistically significant. There was no significant difference in the hospital LOS, mortality or infections between the 2 groups.

Author’s Conclusions:
“…a VB protocol is one method to improve the delivery of prescribed calories. Considering the consequences of underfeeding in the ICU, we recommend the employment of a VB strategy. Future studies with a larger sample size are needed to further investigate the effect of such a protocol on clinical outcomes.”

Evaluation:
This was a single-center cohort study with a small number of mixed ICU patients. This study enrolled far too few patients to be able to investigate outcomes in the ICU, as evidenced by the fact that the groups had significantly different APACHE II scores at baseline.

Our group was very surprised that in a nutrition support journal this article provided so little nutrition information: e.g. no information was provided regarding the total calories or calories/kg actually received or the amount of protein received. There were no details provided about how feeding rates were adjusted to meet goals in the volume-based group. Additionally, there was no information about the breakdown of patients by diagnosis or medical vs surgical vs trauma. The methods section mentioned that calorie goals were determined by following the 2009 ASPEN/SCCM guidelines, but the discussion section reported that calorie goals were determined using non-protein calories, which is not a recommendation of ASPEN or SCCM.

The discussion section mentions several observational studies that reported an association between patients who have poor outcomes and receiving decreased nutrition, but do not elaborate on the fact that observational studies cannot control for all factors that influence outcome, and should never be used as evidence to imply cause and effect.1 (see our October 2015 ejournal club for a detailed evaluation of one study). The conclusion statement seems to imply (“…the consequences of underfeeding in the ICU”) cause and effect, despite the randomized data that has not demonstrated evidence of harm from reduced calorie provision in the early part of an ICU admission.2-3]

Considering that several other studies have reported potential negative clinical outcomes from volume-based feeding protocols,4-6 and no study has reported improved outcomes from volume-based feeding protocols, there is a need for larger studies, with adequate numbers of patients to study outcome in the ICU before these protocols are adopted in clinical practice.

Our Take Home Message(s)
1. This study enrolled too few patients to reliably study outcomes in the ICU.
2. There is a need for further study of volume-based feeding protocols before they are routinely used in clinical practice.

References:
1. Wei X, Day AG, Ouellette-Kuntz H, et al. The Association Between Nutritional Adequacy and Long-Term Outcomes in Critically Ill Patients Requiring Prolonged Mechanical Ventilation: A Multicenter Cohort Study. Crit Care Med. 2015; 43(8):1569-1579.
2. Arabi YM, Aldawood AS, Haddad SH, et al. Permissive Underfeeding or Standard Enteral Feeding in Critically Ill Adults. N Engl J Med. 2015;372(25):2398-2408.
3. The National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network. Initial Trophic vs. Full Enteral Feeding in Patients with Acute Lung Injury: The EDEN Randomized Trial. 2012;307(8):795-803.
4. Braunschweig CA, Sheean PM, Peterson SJ, et al. Intensive Nutrition in Acute Lung Injury: A Clinical Trial (INTACT). JPEN J Parenter Enteral Nutr. 2015; 39(1):13-20
5. Sheean PM, Peterson SJ, Zhao W, et al. Intensive medical nutrition therapy: methods to improve nutrition provision in the critical care setting. J Acad Nutr Diet. 2012; 112(7):1073-1079.
6. Taylor B, Brody R, 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; 29(5):639-648.

Other News on the UVAHS GI Nutrition Website: (www.ginutrition.virginia.edu):

Having trouble seeing any of the resources on our page?  Our website has recently moved, so you may need to retype www.GInutrition.virginia.edu into your browser to reach our newly updated page

Upcoming Webinars 2015:

February 9: The Malabsorption Work-Up
March 8: Peri-Operative Nutrition
Upcoming Topics include: Gastric Bypass and Calories in the ICU

Latest Practical Gastroenterology article:
Chatterjee S. Nutritional Implications of GI-Related Scleroderma. Practical Gastroenterology 2016;XXXX(1):48.

Joe Krenitsky MS, RDN

PS – Please feel free to forward on to friends and colleagues.