Anesthesia Technologist Practice Exam

What is a common complication associated with low fresh gas flows during anesthesia?

1. Increased anesthesia depth

2. Hypoxemia

3. Rebreathing of CO2

4. Decreased heart rate

The correct answer is: Rebreathing of CO2

Low fresh gas flows during anesthesia can lead to the rebreathing of carbon dioxide (CO2), making it a common complication in this scenario. When the fresh gas flow is reduced, the rate at which fresh oxygen and anesthetic gases are introduced into the circuit decreases. Consequently, the expired gases, which contain CO2, can accumulate in the breathing circuit. The design of the anesthesia machine typically includes a unidirectional valve and a carbon dioxide absorber to manage exhaled gases, but when the fresh gas flow is low, the effectiveness of these components may diminish, leading to a situation where the patient inhales CO2 they have just exhaled. This rebreathing can cause an increase in CO2 levels in the blood, resulting in respiratory acidosis and other complications. While the other options may pose relevant concerns in specific situations, they are not as directly associated with low fresh gas flows as the rebreathing of CO2. Increased anesthesia depth, hypoxemia, and decreased heart rate can all occur due to various factors, but they are less of an immediate consequence of reduced fresh gas flows compared to the risk of CO2 rebreathing.