Final answer:
In dire medical emergencies for cardiac tamponade, the technique used is pericardiocentesis, which involves draining excess fluid from the pericardial cavity to relieve pressure on the heart.
Step-by-step explanation:
Cardiac tamponade is a dire medical emergency characterized by excess fluid accumulation in the pericardial space, which puts pressure on the heart and prevents it from fully relaxing and filling with blood. In such critical situations, the technique used is pericardiocentesis, which involves inserting a needle or catheter into the pericardial cavity to drain the excess fluid and relieve the pressure on the heart. Pericardiocentesis is typically performed by a trained healthcare professional and is considered an essential intervention to save a patient's life in cases of cardiac tamponade.