What complication can arise due to hypokalemia and hypomagnesemia in patients with refeeding syndrome?

Hypokalemia and hypomagnesemia are significant electrolyte imbalances that can occur during refeeding syndrome, a serious condition that can affect patients who are malnourished and then receive nutritional replenishment too rapidly. When the body begins to process nutrients after a period of starvation, insulin secretion increases, driving electrolytes such as potassium and magnesium into the cells. This can lead to critically low levels of these electrolytes in the blood.

Low potassium levels (hypokalemia) can lead to various cardiac complications, notably cardiac arrhythmias. Potassium is essential for maintaining normal electrical activity in the heart. Inadequate potassium can disrupt the heart's rhythm, leading to potentially life-threatening arrhythmias. Similarly, magnesium plays a crucial role in cardiac function and is vital for maintaining normal heart rhythm.

While other serious complications can also arise in the context of refeeding syndrome, such as cerebral edema, seizures, and respiratory failure, these are not as directly linked to hypokalemia and hypomagnesemia as the risk of cardiac arrhythmias. Therefore, the most relevant complication associated with these electrolyte imbalances in the context of refeeding syndrome is indeed cardiac arrhythmias.