What is the most common cause of cardiac arrest in drowning cases?

In drowning cases, the most common cause of cardiac arrest is hypoxia. Hypoxia refers to the lack of sufficient oxygen reaching the tissues, which is critical for cellular function. When an individual is submerged in water, they cannot breathe air, leading to a rapid depletion of oxygen in the bloodstream. This lack of oxygen ultimately causes the heart to stop beating effectively, resulting in cardiac arrest.

When a person is submerged, they experience a drop in their blood oxygen levels, which can lead to unconsciousness and subsequently cardiac arrest if not quickly addressed. Even if a person manages to get some air, if they have been underwater long enough, the lack of oxygen will still lead to hypoxic injury to vital organs, including the heart.

In contrast, while conditions like trauma, arrhythmias, or electrocution can contribute to cardiac arrest in various scenarios, they are not the primary cause in drowning cases. Instead, it is the significant and immediate impact of hypoxia that underscores the urgency of performing rescue breaths and chest compressions to restore oxygenation and circulation in drowning victims.