For a patient who has achieved return of spontaneous circulation (ROSC) but is not able to follow commands, the immediate post-cardiac arrest care intervention to choose is:

• Initiate targeted temperature management (TTM).

The steps involved in TTM are:

1. Cool the patient to a target temperature of 32-36°C (89.6-96.8°F) as soon as possible.
2. Maintain the target temperature for at least 24 hours.
3. Gradual rewarming after the maintenance period.

TTM is indicated to improve neurological outcomes in comatose patients after cardiac arrest. In addition to TTM, the following interventions should also be considered as part of comprehensive post-cardiac arrest care:

• Optimize hemodynamic and ventilation parameters to maintain adequate organ perfusion (e.g., target a mean arterial pressure (MAP) of 65 mmHg or greater).
• Monitor and manage blood glucose levels to avoid hypoglycemia and hyperglycemia.
• Perform a thorough neurological assessment and consider further neuroprognostication after 72 hours of normothermia.
• Treat and prevent seizures if necessary.
• Evaluate and treat underlying causes of the cardiac arrest to prevent recurrence.

However, initiating TTM is the primary intervention for a patient who is not following commands post-ROSC.