The grades of evidence (I-III) and levels of recommendations (I-III) are defined at the end of the "Major Recommendations" field.
Level I
There are insufficient data to support a Level I recommendation for this topic.
Level II
Patients should be fed to attain full caloric replacement by day 7 post-injury.
Summary
Data show that starved traumatic brain injury (TBI) patients lose sufficient nitrogen to reduce weight by 15% per week; 100 to 140% replacement of Resting Metabolism Expenditure with 15 to 20% nitrogen calories reduces nitrogen loss. Data in non-TBI injured patients show that a 30% weight loss increased mortality rate. The data support feeding at least by the end of the first week. It has not been established that any method of feeding is better than another or that early feeding prior to 7 days improves outcome. Based on the level of nitrogen wasting documented in TBI patients and the nitrogen sparing effect of feeding, it is a Level II recommendation that full nutritional replacement be instituted by day 7 post-injury.
Definitions:
Grades of Evidence
Class I - Good quality randomized controlled trial (RCT)
Class II - Moderate quality RCT, good quality cohort, or good quality case-control
Class III - Poor quality RCT; moderate or poor quality cohort; moderate or poor case-control; or case series, databases, or registries
Levels of Recommendation
Levels of recommendation are Level I, II, and III, derived from Class I, II, and III evidence, respectively.
Level I - Recommendations are based on the strongest evidence for effectiveness, and represent principles of patient management that reflect a high degree of clinical certainty.
Level II - Recommendations reflect a moderate degree of clinical certainty.
Level III - Recommendations for which the degree of clinical certainty is not established.
