Nutritional Support: Monitoring (Which Tests and How Often?) (UPDATE IN PROCESS)

Level 1

1. No recommendations

Level 2

1. In head-injured patients, serum pre-albumin levels appear to correlate well with nitrogen balance. Albumin and transferin levels correlate poorly with nitrogen balance. Retinol binding protein also correlates well with nitrogen balance but lags behind pre-albumin.
2. In multi-trauma patients, serum pre-albumin levels appear to correlate well with nitrogen balance. Albumin levels correlate poorly with nitrogen balance.
3. In burn patients, there are insufficient data to make any recommendations regarding the correlation between serum levels of pre-albumin, retinol binding protein, or transferrin and nitrogen balance. However, serum levels of these proteins must be interpreted with caution as they are affected not only by nutritional state but also by other factors (age, burn wound size, post-burn day and nitrogen intake). Albumin levels correlate poorly with nitrogen balance.
4. Nitrogen balance calculation in burn patients may not be accurate due to inability to account for nitrogen losses via the burn wound.
5. When calculating nitrogen balance in burn patients, use of urinary urea nitrogen instead of total urinary nitrogen may result in overestimation of nitrogen balance.

Level 3

1. Nitrogen balance is the gold standard for monitoring the appropriateness of a trauma patient’s nutritional prescription.
2. Serial determinations of serum levels of acute phase reactants (C-reactive protein, fibrinogen, alpha-1-glycoprotein, etc.), along with constituent proteins (pre-albumin, retinol binding protein, transferrin) may improve the latter’s value as a nutritional monitoring tool.