Orthopedic Coding Alert

Question: When should I use a diagnosis of malignant hypertension? One of our hip-replacement patients has hypertension, which I'd like to report as a secondary diagnosis. Should I report 401.0 or 401.1? What sort of language (other than the word "malignant") should I look for in the dictation for a patient with hypertension to determine if the condition qualifies as malignant?

California Subscriber

Answer: Although 401.x (Essential hypertension) contains three fourth-digit subclassification options, many orthopedic coders use the same code: 401.1 (... benign). Because 401.0 (... malignant) describes a life-deteriorating disease, you will rarely use that code.
 
With malignant hypertension, the patient's blood pressure rapidly and severely elevates. The high blood pressure causes severe damage that can result in organ failure and/or death if untreated. A patient in such debilitation would require hospitalization. Therefore, 401.0 normally applies to patients who are in an intensive care unit or an emergency room rather than an inpatient recovery room, where your hip-replacement patient is probably recovering.
 
You should avoid using the third option, 401.9 (...  unspecified), whenever possible. Insurers may not cover unspecified diagnoses as readily as they cover specific codes.