Home Health ICD-9/ICD-10 Alert

Question: Our patient was difficult to rouse and was extremely drowsy due to an unintentional overdose of Ambien. How should we code for him?

New York Subscriber

Answer:  Your first step in coding for this patient is to figure out whether he has experienced a poisoning or the adverse effects of a drug or other chemical.

Phrases such as “wrong substance” or “wrong dose” taken, “wrong person” taking the substance, “overdose” or “intoxication,” in the medical record indicate that a poisoning has occurred. While statements such as “allergic,” “idiosyncratic” or “paradoxical” reactions, “cumulative effect” or “toxicity,” in the medical record, indicate an adverse effect of therapeutic-use. Since your patient had an “unintentional overdose,” you know you’re dealing with a poisoning.

When your patient has suffered a poisoning, you’ll list the poisoning code first. Follow this with a code to describe what happened to the patient because he was poisoned, and then report an E code to describe the circumstances of the poisoning.

To code for this patient, report the following codes:

• 967.8 (Poisoning by other sedatives and hypnotics);
• 780.09 (Alteration in consciousness, other); and
• E852.8 (Accidental poisoning by other specified sedatives and hypnotics; other specified sedative or hypnotic).

Code 967.8 describes the poisoning by a hypnotic, NEC. Next, 780.09 explains that the patient experienced excessive drowsiness because of the poisoning. Finally, E code E852.8 shows that this was an accidental poisoning.

Although you know which sleeping pill the patient overdosed on, there is no specific entry for Ambien in ICD-9-CM. If you can’t find the specific drug name or generic, you must code for the category — a hypnotic in this case.

In ICD-10, you’ll sequence the poisoning code first, but you’ll report only two codes:

• T42.6x1D (Poisoning by other antiepileptic and sedative-hypnotic drugs, accidental [unintentional]; subsequent encounter) and
• R40.0 (Somnolence).

Sequencing tip: When a patient experiences an adverse event after taking properly administered medication, your sequencing will be reversed. With adverse effects, you’ll first report a code to indicate what happened to the patient (the adverse effect). Then you’ll follow this with a code that indicates which drug or drugs were responsible for that adverse effect.