Adult Critical Care Specialty (ACCS) Practice Exam

What is the significance of a VBG reading showing a high carbon dioxide level?

1. Indicator of alkalosis

2. Indicator of hypoxemia

3. Indicator of normal ventilation

4. Indicator of respiratory acidosis

The correct answer is: Indicator of respiratory acidosis

A high carbon dioxide (CO2) level in a venous blood gas (VBG) reading is significant as it indicates respiratory acidosis. When the body produces excessive carbon dioxide or fails to eliminate it effectively through respiration, the result is an accumulation of CO2, leading to increased acidity in the blood. This condition often occurs when there is impaired ventilation, such as in situations of airway obstruction, respiratory muscle weakness, or certain pulmonary conditions. Understanding this connection is vital in critical care, as it guides clinicians toward appropriate interventions, such as improving ventilation or addressing the underlying cause of the respiratory failure. The other options do not accurately reflect the implications of high carbon dioxide levels in a VBG. Alkalosis is associated with increased pH levels, hypoxemia refers to low oxygen levels, and normal ventilation would typically not present with high CO2 levels, thus these do not apply in this context.