Final answer:
A drop in sodium level below 110 can cause severe complications inclusive of seizures, coma, cardiac arrest, and respiratory failure due to cell swelling, particularly in the brain.
Step-by-step explanation:
When a patient's sodium level drops below 110, several critical complications can result. Hyponatremia, which is a lower-than-normal concentration of sodium, often leads to an imbalance of fluids in the body and can cause excess water to enter cells through osmosis. This increase in water within the cells leads to swelling, which, when it occurs in neurons within the brain, can indeed result in severe outcomes such as seizures, coma, cardiac arrest, and respiratory failure. Due to the importance of sodium in maintaining proper cellular function and fluid balance, significant drops in sodium levels are life-threatening and require immediate medical attention.