February 2017 E-Journal Club
Greetings,
February was a fickle vortex of shifting weather, with freezing winds immediately followed by teases of springlike warmth, then back to winter the next day. Our journal club article for February was a good warmup for CNW in Orlando, because both the 2016 critical care guidelines and CNW brought a good bit of attention to the NUTRIC score.
February Citation:
Compher C, Chittams J, Sammarco T, et al. Greater Protein and Energy Intake May Be Associated With Improved Mortality in Higher Risk Critically Ill Patients: A Multicenter, Multinational Observational Study. Crit Care Med. 2017;45(2):156-163.
Summary:
This was an analysis of data extracted from the International Nutrition Survey 2013 database, a web-based multinational survey of patients admitted to 202 ICUs. Data was utilized from consecutive patients who stayed in the ICU > 4 days and information recorded regarding mortality, ICU, and hospital length of stay (LOS) for 60 days. Data regarding nutrition goals and actual delivery of calories and protein from all sources was collected for 12 consecutive days. A modified NUTRIC score (Nutritional Risk in Critically Ill) was calculated from age, APACHE II, SOFA score, number of comorbidities, days from admission to ICU admit, because IL-6 data was not available. The purpose of this study was to determine if the amount of protein or energy received interacts with high versus low NUTRIC score to impact 60-day mortality or time to discharge alive (TDA) in the International Nutrition Survey 2013 database
Patients with NUTRIC scores greater than or equal to 5 were considered to be of high risk and those with less than 5 to be of low risk. Logistic regression was used to evaluate the interaction between NUTRIC category and protein (or energy) intake on patient mortality. The interaction between TDA, protein or energy intake, and NUTRIC group was evaluated by Cox proportional hazards while adjusting at the ICU unit level.
Inclusion and Exclusion Criteria:
Inclusion criteria:
Patients from the International Nutrition Survey 2013 database.
Exclusion criteria:
Patients discharged before day 4 (n = 1,097) and those who died (n = 116) were excluded.
Major Results:
The 2,853 patients had a mean age of 61.2 years and the majority were admitted to an ICU for medical (65%) or emergency surgery (27%) care. Overall mortality was 30%. Patients achieved only 59% of goal protein and 62% of goal energy intake (65% and 69%, respectively, for the 12-d subsample).
Enteral nutrition (EN) was used in 75.5%, parenteral nutrition (PN) in 8.7%, both EN and PN in 13.8%, and neither in 2% of patients in the 4-day sample (76.9%, 6.5%, 16.1%, and 0.5%, respectively, in the 12-d sample). The mean NUTRIC score was 4.8.
The authors reported no significant interaction between NUTRIC category, protein intake, and mortality in the 4-day sample (p = 0.560). When the data was adjusted for high-risk patients in the 4-day sample, the odds of death decreased significantly by 6.6% (p = 0.003) with each 10% increase in protein received relative to goal. In the adjusted analysis in low-risk patients, mortality was not significantly different by the level of protein intake.
There was a significant interaction in the 12-day sample between NUTRIC category, protein intake, and mortality (p = 0.02). In the adjusted analysis for high-risk patients in the 12-day sample, the odds of death decreased significantly by 10.1% (p = 0.003) with each 10% increase in protein intake relative to goal but not significantly in the low-risk patients.
There was no significant interaction between NUTRIC category, protein intake, and TDA in the 4-day sample (p = 0.155). In the adjusted model, TDA was significantly shorter by 5.1% (p = 0.01) for each 10% increase in protein intake relative to goal in high-risk patients but not in low-risk patients. Median LOS among survivors was 35.71 (19.75–61.00) days.
There was a significant interaction between NUTRIC category, protein intake, and TDA in the 12-day sample (p = 0.039). In the adjusted analysis in high-risk patients, TDA was significantly shorter by 9.2% (p = 0.002) for each 10% increase in protein intake relative to goal but not significantly in the low-risk patients. Median LOS among survivors was 51.81 (28.53–61.00) days.
There was no significant interaction between NUTRIC category, energy intake, and mortality in the 4-day sample (p = 0.341). In the adjusted analysis of patients in the 4-day sample, for high-risk patients, the odds of death significantly decreased 7.1% (p < 0.001) with each 10% increase in energy intake relative to goal, but not in the low risk patients.
There was a significant interaction between NUTRIC category, energy intake, and mortality in the 12-day sample (p = 0.010). In the adjusted analysis for high-risk patients, the odds of death significantly decreased by 11.6% (p < 0.001) with each 10% increase in delivery of goal energy intake but not in the low-risk patients.
There was no significant interaction between NUTRIC category, energy intake, and TDA in the 4-day sample (p = 0.843). In the adjusted model, TDA was significantly shorter by 4.5% (p = 0.019) for each 10% increase in energy intake relative to goal in high-risk patients but not in low-risk patients.
There was a significant interaction between NUTRIC category, energy intake, and TDA in the 12-day sample (p = 0.01). In the adjusted model, TDA was significantly shorter by 9.1% (p = 0.002) for each 10% increase in energy intake relative to goal in high-risk patients but not significantly in the low-risk patients.
Author’s Conclusions:
“…patients who have higher NUTRIC scores at ICU admission may benefit most significantly from greater protein and energy intake, especially during longer ICU stays, whereas those with lower NUTRIC scores do not have worse mortality or TDA with greater intake. Since it is not possible to predict which patients will remain in the ICU longer, the best policy may be to attempt to feed all patients optimally with an understanding that low-risk and short-stay patients are less likely to benefit significantly from near-goal protein or energy intake. Future clinical trials should determine the most optimal levels of protein and energy intake in high- versus low-risk ICU patients.”
Evaluation:
This is an observational study, which, regardless of what it controls for with statistics, can only document associations. Observational studies have demonstrated repeatedly for the past 35 years1, that ICU patients who have compromised outcomes, end up receiving less nutrition. The NUTRIC score adds a slight twist because it combines existing 2 validated illness/injury severity scores to identify sicker patients. The current study did not assign patients to a different amount of nutrition – so naturally there is an association between decreased nutrition and poor outcome, especially among those patients with a higher level of acuity – because patients that are doing worse (need more lines, CT scans, have slower motility, etc) receive less nutrition.
A recent study published an analysis of patients according to NUTRIC score that were randomized to 2 different calorie intakes2. When patients were randomly assigned to a full versus hypocaloric intake, there was no differences in patient outcomes in either the high or low NUTRIC score patients. See our October 2016 E-journal club for a synopsis of that analysis. https://med.virginia.edu/ginutrition/october-2016-e-journal-club/
Our Take Home Message(s)
- Observational data demonstrates an association between poor ICU outcomes and receiving less nutrition, that is more apparent in sicker patients with a longer ICU stay.
- There is need for randomized data to explore the optimal timing and amount of nutrients to provide adult patients in the ICU.
- There is a need for randomized data to validate the use of NUTRIC score before its use can be recommended for clinical decision making.
References:
- Bartlett RH, Dechert RE, Mault JR, et al. Measurement of metabolism in multiple organ failure. Surgery. 1982;92(4):771-779.
- Arabi YM, Aldawood AS, Al-Dorzi HM, et al. Permissive Underfeeding or Standard Enteral Feeding in High and Low Nutritional Risk Critically Ill Adults: Post-hoc Analysis of the PermiT trial. Am J Respir Crit Care Med. 2017 Mar 1;195(5):652-662.
Other News on the UVAHS GI Nutrition Website: (www.ginutrition.virginia.edu):
Upcoming Webinars 2017:
April 19th—Nutrition Support Cases by Carol Rees Parrish, MS, RD
May 10th—Blenderized Enteral Feeding—Lisa Epp, RD, LD, CNSC
June (Date TBA)—Review of the ASPEN Critical Care Nutrition Support Guidelines—Joe Krenitsky, MS, RD
Latest Practical Gastroenterology article: The Use of Medium-Chain Triglycerides in Gastrointestinal Disorders
Joe Krenitsky MS, RDN
PS – Please feel free to forward on to friends and colleagues.