Final answer:
Increased carbon dioxide levels in the blood can indicate the need to wean from a mechanical ventilator.
Step-by-step explanation:
The lab result that would indicate a need to wean settings from a mechanical ventilator is increased carbon dioxide levels (Option C).
Elevated carbon dioxide levels in the blood, also known as hypercapnia, can indicate a decreased ability to exchange gases effectively, which may necessitate adjustments to the ventilator settings.
This lab result reflects poor ventilation and can indicate the need to wean from the ventilator.