Base Excess in Critical Care

Clinical Applications

Changes in base excess over time provide valuable information about the effectiveness of resuscitation efforts in critically ill patients 1
Base excess is particularly useful in trauma, shock, and sepsis to quantify metabolic acidosis and guide fluid resuscitation 2
For patients with baseline hypercapnia, base excess helps distinguish chronic respiratory acidosis from acute-on-chronic respiratory failure 1

First evaluate pH to determine if acidemia or alkalemia is present, then examine PCO2 to identify respiratory component, and finally evaluate base excess to identify metabolic component 1
In primary respiratory disorders, base excess should remain normal initially, and in chronic respiratory disorders, base excess will change to compensate 1
The degree of compensation can help determine if the acid-base disorder is acute, chronic, or mixed 1

Base excess is useful in trauma and shock assessment to guide fluid resuscitation 2
Monitoring patients with diabetic ketoacidosis during treatment can be guided by base excess 2
Evaluating patients with suspected toxic ingestions can be informed by base excess 1
Assessing patients with renal failure and metabolic acidosis can be aided by base excess 2
Monitoring patients receiving long-term oxygen therapy to detect respiratory acidosis can be done using base excess 3, 4