early trophic enteral feeding in icu is beneficial

This patient is early in her critical illness and still experiencing multisystem organ dysfunction with cardiovascular failure, respiratory failure, and renal failure. Observational data suggest that starting enteral feeding within the first 48 h is associated with reduced mortality. However, these data are prone to indication bias as patients who are sicker are less likely to tolerate enteral feeding and more likely to experience poor outcomes. In addition, the observational data do not inform as to the volume of enteral feeding needed to confer benefit. The NUTRIREA-2 study demonstrated similar outcomes with nutrition delivered via the enteral and parenteral routes in patients who were critically ill and being treated with mechanical ventilation and vasopressors. However, the enteral nutrition route resulted in more mesenteric ischemia and colonic pseudo-obstruction, albeit with low rates of both complications in both arms, and the enteral feedings were full-volume enteral feedings and not trophic rates. The ARDS Network EDEN study demonstrated that trophic feeding rates for the first 6 days resulted in similar clinical outcomes as advancing enteral feeds to goal rates as soon as safely possible, with lower incidence of gastrointestinal complications. Recently, the NUTRIREA-3 study compared lower calorie (6 kcal/kg/day) and lower protein administration (0.2 g/kg/day) for the first 7 days of enteral feeding in patients who were receiving mechanical ventilation and vasopressors with advancing to goal calorie and protein rates as soon as possible. NUTRIREA-3 found similar 90-day mortality rates between the two arms but faster time to readiness for ICU discharge in the lower calorie and protein group and fewer gastrointestinal complications.

Measuring resting energy expenditure (REE) via indirect calorimetry is becoming easier with new indirect calorimeters and advancing technology. Numerous studies have tried to demonstrate benefit in measuring REE intermittently and trying to administer the amount of calories to match the patient’s REE. In general, these studies have not demonstrated benefit to patient outcomes. The EAT-ICU study randomly assigned patients to delivery of calories determined with indirect calorimetry and protein determined with urine nitrogen measures vs standard 25 kcal/kg/day and standard protein administration. Despite delivering more calories and protein in the indirect calorimetry arm, the study demonstrated no difference in any clinical outcome, including quality-of-life measures.

The EFFORT Protein study evaluated the effect of delivering high-dose protein in patients who were critically ill. The study randomly assigned patients who were critically ill, at high nutritional risk, and receiving mechanical ventilation to receive 1.2 or 2.2 g/kg/day of protein. Delivery was accomplished in a pragmatic way through the bedside dietitian and protein supplementation, resulting in the two arms receiving an average of 0.9 and 1.6 g/kg/day, respectively. Overall, there was no difference in clinical outcomes between the two groups. However, in patients with acute renal failure not receiving dialysis, like the patient in this question, higher protein administration resulted in higher mortality and longer time to alive discharge from the hospital. This detrimental effect appears to be attenuated in patients who are receiving renal replacement therapy.1234567

Footnotes

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  2. Allingstrup MJ, Kondrup J, Wiis J, et al. Early goal-directed nutrition versus standard of care in adult intensive care patients: the single-centre, randomised, outcome assessor-blinded EAT-ICU trial. Intensive Care Med. 2017;43(11):1637-1647. PubMed ↩

  3. Heyland DK, Patel J, Compher C, et al; EFFORT Protein Trial team. The effect of higher protein dosing in critically ill patients with high nutritional risk (EFFORT Protein): an international, multicentre, pragmatic, registry-based randomised trial. Lancet. 2023;401(10376):568-576. PubMed ↩

  4. National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network, Rice TW, Wheeler AP, et al. Initial trophic vs full enteral feeding in patients with acute lung injury: the EDEN randomized trial. JAMA. 2012;307(8):795-803. PubMed ↩

  5. Reignier J, Boisramé-Helms J, Brisard L, et al; NUTRIREA-2 Trial Investigators; Clinical Research in Intensive Care and Sepsis (CRICS) group. Enteral versus parenteral early nutrition in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2). Lancet. 2018;391(10116):133-143. PubMed ↩

  6. Reignier J, Plantefeve G, Mira JP, et al; NUTRIREA-3 Trial Investigators; Clinical Research in Intensive Care; Sepsis (CRICS-TRIGGERSEP)Group. Low versus standard calorie and protein feeding in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group trial (NUTRIREA-3). Lancet Respir Med. 2023;11(7):602-612. PubMed ↩

  7. Stoppe C, Patel JJ, Zarbock A, et al. The impact of higher protein dosing on outcomes in critically ill patients with acute kidney injury: a post hoc analysis of the EFFORT protein trial. Crit Care. 2023;27(1):399. PubMed ↩