Table 2 Proposal to achieve a high-protein intake without overfeeding

Step 1: Calculate the caloric need by your preferred equation and target 70% (first week) or measure energy expenditure by indirect calorimetry (after day 3) and set this as the 100% target.

Equations are inaccurate, and overfeeding is associated with increased morbidity and mortality. Early endogenous energy production cannot be inhibited by feeding.

[8, 11, 17]

Step 2: Subtract the amount of non-nutritional calories provided from propofol, glucose, or citrate.

Non-nutritional calories add to the total daily amount of calories and may lead to overfeeding when combined with full-dose feeding.

[46, 47]

Step 3: Calculate the daily limit for overfeeding (maximum calories allowed for feeding).

A step-wise build-up is recommended, for example, after ICU admission, go to target in steps of 25% to reach the target on day 4.

[11]

Step 4: Select a very high-protein-to-energy ratio enteral feed or the highest protein-energy ratio feed available and calculate the maximum acceptable dose based on step 3 without overfeeding.

Concentrated high-energy feeds increase the risk of overfeeding, while not meeting the protein target. When the protein ratio of total calories is higher than 30–32% in most patients, no additional protein supplements are needed.

[28, 48]

Step 5: Monitor the actual intake during the day and progress to higher than calculated infusion rates for limited time in case of previous interruptions of administration (stoppages), and use volume-based strategies.

There are many interruptions while feeding the critically ill; therefore, increasing the administration for short periods of time to compensate for the lost hours is a good strategy to meet the daily targets.

[49]

Step 6: Add enteral protein supplements in case more enteral feeding will lead to overfeeding when increasing the administration dose. Use no protein supplements during the very early phase (day 1–day 3).

In obese or overweight patients, the protein needs are very high while the caloric targets are not; then, even when using very-high-protein feeds, supplemental enteral protein supplements should be considered.

[11, 49]

Step 7: Add parenteral amino acid supplementation in case of contraindications to enteral feeding or inadequate enteral feeding/enteral protein supplementation at 4–7 day post-ICU admission (likely sooner in malnourished patients)

Whenever the enteral route is no option, consider the parenteral route.

[11, 49,50,51]