The levels of recommendation (I-III) and classes of evidence (I-III) are defined at the end of the "Major Recommendations" field.
Recommendations Regarding Stratifying Physiologic Derangement
Level I
- Standard hemodynamic parameters do not adequately quantify the degree of physiologic derangement in trauma patients. The initial base deficit, lactate level, or gastric intramucosal pH (pHi) can be used to stratify patients with regard to the need for ongoing fluid resuscitation, including packed red blood cells and other blood products, and the risks of multiple organ dysfunction syndrome (MODS) and death.
- The ability of a patient to attain supranormal oxygen delivery parameters correlates with an improved chance for survival.
Level II
- The time to normalization of base deficit, lactate, and pHi is predictive of survival.
- Persistently high base deficit or low pHi (or worsening of these parameters) may be an early indicator of complications (e.g., ongoing hemorrhage or abdominal compartment syndrome).
- The predictive value of the base deficit may be limited by ethanol intoxication or a hyperchloremic metabolic acidosis, as well as administration of sodium bicarbonate.
Level III
- Right ventricular end diastolic volume index (RVEDVI) measurement may be a better indicator of adequate volume resuscitation (preload) than central venous pressure or pulmonary capillary wedge pressure (PCWP).
- Measurements of tissue (subcutaneous or muscle) oxygen and/or carbon dioxide levels may identify patients who require additional resuscitation and are at risk for multiple organ dysfunction syndrome and death.
- Serum bicarbonate levels may be substituted for base deficit levels.
Recommendations Regarding Improved Patient Outcomes
Level I
- There is insufficient data to formulate a level 1 recommendation.
Level II
- During resuscitation, attempts should be made to increase oxygen delivery to normalize base deficit, lactate, or pHi during the first 24 hours. The optimal algorithms for fluid resuscitation, blood product replacement, and the use of inotropes and/or vasopressors have not been determined.
Definitions:
Strength of the Recommendation Scheme
Level I
The recommendation is convincingly justifiable based on the available scientific information alone. This recommendation is usually based on Class I data; however, strong Class II evidence may form the basis for a Level I recommendation, especially if the issue does not lend itself to testing in a randomized format. Conversely, low quality or contradictory Class I data may not be able to support a Level I recommendation.
Level II
The recommendation is reasonably justifiable by available scientific evidence and strongly supported by expert opinion. This recommendation is usually supported by Class II data or a preponderance of Class III evidence.
Level III
The recommendation is supported by available data but adequate scientific evidence is lacking. This recommendation is generally supported by Class III data. This type of recommendation is useful for educational purposes and in guiding future clinical research.
Evidence Classification Scheme
Class I
Prospective randomized controlled trials (PRCTs) - the gold standard of clinical trials. Some may be poorly designed, have inadequate numbers, or suffer from other methodological inadequacies.
Class II
Clinical studies in which the data were collected prospectively, and retrospective analyses which were based on clearly reliable data. These types of studies include observational studies, cohort studies, prevalence studies, and case control studies.
Class III
Most studies based on retrospectively collected data. Evidence used in this class includes clinical series, databases or registries, case reviews, case reports, and expert opinion.
