What is the primary immediate response in cases of suspected cardiac arrest?

The primary immediate response in cases of suspected cardiac arrest is to start chest compressions. This action is critical because chest compressions help maintain blood circulation to the brain and vital organs during cardiac arrest when the heart is unable to pump blood effectively. Immediate high-quality compressions can significantly improve the chances of survival and favorable neurological outcomes for the patient.

Starting chest compressions quickly is essential, as every second counts in a cardiac situation. The emphasis is on the continuous rhythm and adequate depth of compressions, which can help sustain life until advanced medical personnel can take over or until a defibrillator is available.

Other responses, such as defibrillation, checking for bleeding, or administering oxygen, may be important in the broader context of resuscitation or injury management but are not the first step in the immediate management of cardiac arrest. Defibrillation is only effective if there's a shockable rhythm; checking for bleeding may distract from urgent life-saving measures, and administering oxygen does not address the immediate need for circulation provided by chest compressions.