What is the correct code for a patient diagnosed with type 1 diabetes mellitus, coma, and ketoacidosis?

The correct code for a patient diagnosed with type 1 diabetes mellitus, coma, and ketoacidosis is E10.11. This code specifically refers to type 1 diabetes mellitus with ketoacidosis and coma, which matches the clinical scenario provided in the question.

In this coding context, type 1 diabetes is categorized under ICD-10 code E10, which is dedicated to type 1 diabetes mellitus. The additional ".11" extension is crucial as it indicates the presence of diabetic ketoacidosis with coma, making it the most precise choice for documentation of this situation.

The other codes do not accurately reflect the diagnosis of type 1 diabetes with the specified complications. For instance, E11.649 pertains to type 2 diabetes mellitus with ketoacidosis without a coma, while E03.5 relates to hypothyroidism and E24.1 is for Cushing's disease. Hence, they do not align with the conditions involved in the patient's diagnosis. The specificity of E10.11 in relation to type 1 diabetes and the associated complications makes it the correct choice.