Final answer:
The principal diagnosis code for the patient with type 1 diabetes and a blood glucose reading of 350 is E10.65, which indicates type 1 diabetes with hyperglycemia. The secondary diagnosis code is N18.4, reflecting chronic kidney disease, stage 4.
Step-by-step explanation:
The patient with type 1 diabetes and acute on chronic stage 4 renal failure with a blood glucose reading of 350 is treated with Lantus insulin for hyperglycemia. In this scenario, we must identify the correct principal and secondary diagnostic codes. The principal diagnosis code is the condition chiefly responsible for the patient's admission to the hospital, while secondary codes represent additional conditions that are also affecting the patient's health status.
The principal diagnosis is likely E10.65, which pertains to type 1 diabetes with hyperglycemia, as this is the immediate concern leading to the insulin treatment. For the secondary diagnosis, N18.4 reflects chronic kidney disease, stage 4, which is part of the patient's ongoing health issues. Code B.Z79.4 indicates long-term current use of insulin, and while this is pertinent information, it is not a condition but a treatment status and therefore not a diagnosis. N17.9 and N17.4 pertain to acute kidney failure, which may be less accurate given the chronic nature of the renal failure described in the question.
Consequently, the principal diagnosis code is E10.65 and the secondary diagnosis code is N18.4. These codes will help ensure that the patient's medical records accurately reflect their health conditions and the corresponding medical care they receive.