Which intervention is necessary if a patient shows signs of a cardiac arrest?

Starting chest compressions immediately is the correct intervention when a patient shows signs of cardiac arrest. In cardiac arrest, the heart is unable to pump blood effectively to the rest of the body, leading to an absence of circulation and the potential for irreversible organ damage within minutes. Chest compressions are crucial as they help maintain blood flow to vital organs, particularly the brain and heart, thereby increasing the chances of survival until advanced medical care can be initiated.

Chest compressions should be initiated without delay, ideally within the first few seconds of recognizing that the patient is unresponsive and not breathing normally. The recommended compression rate is 100 to 120 compressions per minute, with a depth of about 2 inches for adults, ensuring that compressions allow for full chest recoil between compressions. This intervention is part of the foundational skills taught in CPR and is critical for improving the odds of patient survival in cardiac arrest scenarios.

Other interventions, such as calling for backup, checking the airway, or administering water, do not provide immediate support for the underlying issue of cardiac arrest and may delay necessary actions that could save the patient's life. Thus, swift and effective chest compressions are the priority in this life-threatening situation.