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Table 1 Guide to EN—summary table

From: A guide to enteral nutrition in intensive care units: 10 expert tips for the daily practice

  Question Suggested answer ASPEN/SCCM guidelines [6] ESPEN guidelines [7]
1 When to start? Start within 24–48 h of ICU admission Recommendation: start early EN within 24–48 h (quality of evidence: very low) Start early EN (within 48 h) rather than delaying EN (grade of recommendation: B strong consensus)
Start early EN (within 48 h) rather than early PN (grade of recommendation: a strong consensus)
2 What to do in case of vasopressor agents? Start low-dose enteral nutrition
Hold EN for patients who are being actively resuscitated or unstable
Suggestion: in the setting of hemodynamic instability, hold EN until the patient is fully resuscitated and/or stable
Consider initiation/reinitiation of EN with caution in patients undergoing withdrawal of vasopressor support (expert consensus)
EN should be delayed if shock is uncontrolled. Low-dose EN can be started as soon as shock is controlled, while remaining vigilant for signs of bowel ischemia [grade of recommendation: Good practice point (GPP)]
3 How to achieve enteral access? Short-term (expected duration < 4 weeks): use nasogastric tube or postpyloric in case of delayed gastric emptying)
Long-term (> 4 weeks): place percutaneous enteral access (gastrostomy or jejunostomy)
Suggestion: in most critically ill patients initiate EN in the stomach {Expert consensus}
Recommendation: Infuse EN lower in the GI tract in patients who are at high risk for aspiration or with intolerance to gastric EN (quality of evidence: moderate to high)
Use gastric access as the standard approach to initiate EN (grade of recommendation: GPP strong consensus)
Use postpyloric feeding in patients with gastric feeding intolerance not solved with prokinetic agents (grade of recommendation: B strong consensus)
Consider postpyloric, mainly jejunal feeding in patients at high risk for aspiration (grade of recommendation: GPP strong consensus)
4 How much energy? Accept below energy expenditure during the early phase and increase energy to match energy expenditure later (4–7 days) Suggestion: patients at low nutrition risk with normal baseline nutrition status and low disease severity (e.g., NRS 2002 ≤ 3 or NUTRIC score ≤ 5) do not require specialized nutrition therapy over the first week of hospitalization in the ICU (expert consensus)
Recommendation: Start either trophic or full nutrition by EN for patients with acute respiratory distress syndrome (ARDS)/acute lung injury (ALI) and those expected to have a duration of mechanical ventilation ≥ 72 h (quality of evidence: high)
Suggestion: advance EN toward goal over 24–48 h while monitoring for refeeding syndrome in patients who are at high nutrition risk (e.g., NRS 2002 ≥ 5 or NUTRIC score ≥ 5, without interleukin 6) or severely malnourished (expert consensus)
Administer hypocaloric EN (not exceeding 70% of EE) in the early phase of acute illness (grade of recommendation: B strong consensus)
Increase caloric delivery can be increased up to 80–100% of measured EE after day 3 (grade of recommendation: 0 strong consensus)
5 When should energy-dense formulas be used? Use energy-dense formulas in patients with GI intolerance of full-volume isocaloric enteral nutrition, patients needing fluid restriction or during transitioning to oral nutrition (intermittent-feeding schedule) No specific recommendation No specific recommendation
6 How much proteins? Low dose (e.g., 0.8 g/kg/day) during the early phase—to be increased to > 1.2 g/kg/day later Suggestion: Administer sufficient (high-dose) protein in the range of 1.2–2.0 g/kg actual body weight per day and may likely be even higher in burn or multitrauma patients (quality of evidence: very low) During critical illness, 1.3 g/kg protein equivalents per day can be delivered progressively (grade of recommendation: 0: strong consensus)
7 When should hyperprotein formulas be considered? During the late stable phase—monitoring of renal function/acid–base status   
8 How and when to start micronutrient supplementation? Thiamin upon admission—others when insufficient amounts by enteral nutrition We suggest that a combination of antioxidant vitamins [including vitamins E and C (ascorbic acid)] and trace minerals (including selenium, zinc, and copper) in doses reported to be safe in critically ill patients be provided to those patients who require specialized nutrition therapy (quality of evidence: low) No specific recommendation
9 How to screen and manage patients for refeeding syndrome? Plasma phosphate levels at least once a day when starting enteral nutrition
Low-dose enteral nutrition, supplemental thiamin and phosphate
Monitor closely serum phosphate concentrations and replace phosphate appropriately when needed suggestion: (expert consensus) Electrolytes (potassium, magnesium, phosphate) should be measured at least once daily for the first week [grade recommendation: GPP strong consensus (92% agreement)]
In patients with refeeding hypophosphatemia (< 0.65 mmol/ l or a drop of > 0.16 mmol/l), electrolytes should be measured 23 times a day and supplemented if needed [grade recommendation: GPP strong consensus (100% agreement)]
In patients with refeeding hypophosphatemia energy supply should be restricted for 48 h and then gradually increased [grade recommendation: B strong consensus (100% agreement)]
10 How to assess gastrointestinal tolerance? At the start of low-dose EN: high gastric residual volume (optional—threshold 500 ml/6 h), vomiting, pain, distension, elevated/increasing intra-abdominal pressure, absent bowel sounds—dynamic ileus Suggestion: Do not use GRVs as part of routine care to monitor ICU patients receiving EN
Suggestion: for those ICUs where GRVs are still utilized, avoid holding EN for GRVs < 500 mL in the absence of other signs of intolerance (quality of evidence: low)
No specific recommendation statement