Diabetic coma results from excessive accumulation of?

NHM UP Staff Nurse - 2016

Medical Surgical Nursing

Medium

Appeared in: NHM UP Staff Nurse - 2016

Explanation

Diabetic coma in the context of Diabetic Ketoacidosis (DKA) is caused by the buildup of acidic ketone bodies.
A severe lack of insulin forces the body to break down fat for energy, a process called lipolysis.
This fat metabolism produces ketones (acetoacetate and β-hydroxybutyrate) as byproducts.
When ketone production exceeds the body's ability to clear them, they accumulate in the blood, leading to metabolic acidosis.
This severe acidosis, combined with dehydration and electrolyte imbalances, impairs central nervous system function, resulting in coma.

Option A: Excessive accumulation of nitrogenous waste products (azotemia) is characteristic of kidney failure, not diabetic coma. While kidney function can be affected in DKA due to dehydration, nitrogen is not the primary substance that accumulates to cause the coma.
Option C: While severe hyperglycemia (high glucose) is the initial trigger for DKA, the coma is more directly caused by the resulting ketoacidosis. In another type of diabetic coma, Hyperosmolar Hyperglycemic State (HHS), extreme glucose levels are the main cause of coma through severe dehydration and hyperosmolarity, but ketones are minimal.
Option D: Sodium bicarbonate is an alkaline buffer that the body uses to neutralize acids. In DKA, its levels are depleted (low) because it is consumed in an attempt to buffer the high levels of acidic ketones. Therefore, it does not accumulate.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of Diabetic Ketoacidosis (DKA) as background academic context rather than a clinical decision trigger.
Recognizing the signs of impending diabetic coma (e.g., Kussmaul breathing, fruity breath odor, altered mental status) is a critical nursing skill for early intervention.
Priority nursing actions for a patient in DKA include securing the airway, administering IV fluids for rehydration, starting an insulin infusion to stop ketone production, and closely monitoring electrolytes, especially potassium.
Patient education is key to preventing DKA. Nurses must teach patients about sick day management, the importance of not omitting insulin, and how to monitor blood glucose and ketones.

How to Approach the Question

First, identify the core concept of the question, which is the cause of 'diabetic coma'.
Recall that diabetic coma is a severe complication of diabetes, most commonly associated with Diabetic Ketoacidosis (DKA).
Analyze the pathophysiology of DKA: lack of insulin leads to the breakdown of fat, which produces ketones.
Evaluate the options based on this pathophysiology. Ketones are acidic and their accumulation leads to metabolic acidosis, which is the direct cause of the coma.
Consider the other options. High glucose is a trigger but not the direct cause of the acidotic coma. Nitrogen is related to kidney function. Sodium bicarbonate is a buffer that gets used up, so its levels would be low.
Conclude that the excessive accumulation of ketones is the most accurate answer for a coma resulting from DKA.

Concept Tested & Keywords

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