A forty-six year old patient arrives in the emergency room with chief complaint of confusion as described by patient’s spouse. A thorough work up is undertaken including blood work, radiological testing and a neurology consult. No etiology for the confusion is identified.
The attending physician documents the final diagnosis as “acute confusional state, cause unknown”. Using the encoder, the coder assigns the code of 293.0 (Delirium due to conditions classified elsewhere), but receives an edit to code the physical or neurological condition first.
How did the coder handle this?
- The coder checked the alphabetic index under the terms state, confusional and confusion. Each has a sub-term for acute directing the coder to code 293.0. The code is verified in the Tabular List.
- The coder sent a follow-up query to the attending physician verifying there was no known or suspected condition causing the patient’s acute confusion. The physician confirmed that the etiology of the confusion was unknown.
- Next, the coding convention related to this situation was verified with the ICD-9-CM Official Guidelines for Coding and Reporting. The code title for code 293.0 has in its title “due to conditions classified elsewhere” and an instructional note under the code title stating “Code first the associated physical or neurological condition”. Both terms indicate the code is a manifestation and according to coding conventions, these codes are never permitted to be used as first listed or principal diagnosis codes.
- Given the MD response and the official coding convention, the coder was still stuck with code 293.0 which was producing an edit. Or was she stuck with this code? Read further! Upon further review of ICD-9-CM official conventions there are exceptions to this sequencing rule. Not all codes with a “Code first underlying disease” instructional note are part of the etiology/manifestation convention. If the title of the manifestation code and the instructional note are not in italics, then it may be coded alone or as the Principal Diagnosis.
Other Subtle Differences to Know
In addition to the title and the note not being italicized, there is a subtle difference in the terminology used. The code title for 293.0 states “due to conditions classified elsewhere” while the official convention is referencing codes “in diseases classified elsewhere”. The instructional note for the official convention indicates “code first underlying disease” whereas for 293.0 it states “code first the associated physical or neurological condition”.
Another hint regarding this situation is the alphabetic index has a specific entry structure with both conditions listed together. The etiology code is listed first followed by the manifestation code in brackets. The code in brackets is always sequenced second. There is no such directive under state, confusional, acute or confusion, acute in the alphabetic index.
It appears that code 293.0 is appropriate as Principal Diagnosis in this case scenario.
What are your thoughts?