Final answer:
Factors that decrease mixed venous O2 sat: decreased cardiac output and increased O2 consumption.
Step-by-step explanation:
The factors that decrease mixed venous O2 saturation are decreased cardiac output and increased O2 consumption.
For example, when cardiac output is decreased, less blood is pumped out of the heart and circulates through the body, resulting in decreased O2 supply to tissues. Increased O2 consumption refers to the increased utilization of oxygen by the tissues, which can lead to a decrease in mixed venous O2 saturation.