Quadriplegia means paralysis from the shoulders down. Which cervical levels are typically involved, and what respiratory intervention might be needed?

• A. C1-C4; Ventilation may be required due to diaphragm loss
• B. C5-C7; No ventilation needed
• C. C3-C5; Oxygen only
• D. C6-C8; BiPAP only

Answer: (A)

High cervical injuries can take away the nerves that control the diaphragm, since the diaphragm is primarily innervated by the phrenic nerves from C3 to C5. When the injury extends to C1 through C4, the diaphragm often loses its function, leading to respiratory failure unless the person is supported with ventilation. That’s why the scenario describing involvement of C1–C4 and the need for ventilation because the diaphragm may be lost is the best fit for quadriplegia from the shoulders down.

If the injury were lower, such as C5–C7, the diaphragm is typically still functional, so automatic ventilation isn’t usually required. Oxygen therapy alone wouldn’t address the lost ability to ventilate if the diaphragm isn’t working, and a noninvasive option like BiPAP would depend on the individual’s overall respiratory function rather than being a given for quadriplegia.