In a patient with a blood glucose level of 700 mg/dL receiving continuous insulin infusion, what is the critical complication to monitor for?

In a patient receiving continuous insulin infusion, particularly when blood glucose levels are significantly elevated, monitoring for hypokalemia is crucial. Insulin drives potassium into the cells, which can lead to a decrease in serum potassium levels. In this context, even though the patient's blood glucose is very high, the administration of insulin stimulates the Na+/K+ ATPase pump, causing potassium to shift from the extracellular space into the intracellular compartment.

Hypokalemia can result in serious complications, including muscle weakness, cardiac dysrhythmias, and potentially life-threatening conditions like cardiac arrest. Given this mechanism, it is essential to monitor electrolyte levels, specifically potassium, closely during continuous insulin therapy, especially in the setting of severe hyperglycemia.

While hyperglycemia is already being addressed with insulin infusion and is not a complication to monitor for in this context, the other conditions such as hyponatremia and hyperkalemia, while they can occur, are not as directly related to the immediate effects of insulin therapy as hypokalemia is. Therefore, hypokalemia stands out as the critical complication to watch for in this scenario.