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
Treatment should be initiated with intracranial pressure (ICP) thresholds above 20 mm Hg.
Level III
A combination of ICP values and clinical and brain CT findings should be used to determine the need for treatment.
Summary
Current data support 20 to 25 mm Hg as an upper threshold above which treatment to lower ICP should generally be initiated.
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.