Wiki external cause codes

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Code: Y92
Place of occurrence of the external cause
The following category is for use, when relevant, to identify the place of occurrence of the external cause. Use in conjunction with an activity code.
Place of occurrence should be recorded only at the initial encounter for treatment

Category Notes
Supplementary factors related to causes of morbidity classified elsewhere (Y90-Y99)
Note: These categories may be used to provide supplementary information concerning causes of morbidity. They are not to be used for single-condition coding.

Coding Guidelines
External causes of morbidity (V00-Y99)
Note: This chapter permits the classification of environmental events and circumstances as the cause of injury, and other adverse effects. Where a code from this section is applicable, it is intended that it shall be used secondary to a code from another chapter of the Classification indicating the nature of the condition. Most often, the condition will be classifiable to Chapter 19 , Injury, poisoning and certain other consequences of external causes (S00-T88). Other conditions that may be stated to be due to external causes are classified in Chapters I to XVIII. For these conditions, codes from Chapter 20 should be used to provide additional information as to the cause of the condition.


Yakima, WA
Best answers
I am little confused about the use of external cause codes, Y92. Y93, and Y99 with poisonings. Here is what the guidelines say, but my answer key for my text book is assigning the Y codes for place of occurrence, activity, and status. The text book even has a note that says "recall that external cause, place, activity, and status codes are not applicable to poisoning, adverse effects, misadventures, or late effects" so I am confused as to why the answer key includes them as part of the correct answer.

From the guidelines:

Codes in categories T36-T65 are combination codes that include the substance that was taken as well as the intent. No additional external cause code is required for poisonings, toxic effects, adverse effects and underdosing codes.

No external cause code needed in certain circumstances
No external cause code from Chapter 20 is needed if the external cause and intent are included in a code from another chapter (e.g. T36.0X1- Poisoning by penicillins, accidental (unintentional)).

Best answers
The basic idea is to use the Y codes if they're relevant. It's not necessary, but additional information that could be helpful should be reported if it's not already included in the T code.

I guess an example might be someone who is repairing the inside of their garage and gets carbon monoxide poisoning because the car is running. (I know, but it's the best I could come up with right off hand)

So you'd get Poisoning, Accidental to Motor exhaust gas (T58.01 - toxic effect of carbon monoxide from motor vehicle exhaust). To get a better picture of what happened, you could add Y92.015 (private garage of single-family house...) and Y93.H9 (activity, other activity involving property and land maintenance, building and construction).

Adding that extra information about where and what activity was occurring makes it specific as to explain exactly how the patient ended up with the poisoning.

I better example might be a person underdosing on something, who lived in a nursing home and was eating lunch there..... you get where that's going?