Poisn by unsp agents prim act on the resp sys, undet, subs

This code signifies a poisoning event involving an unknown substance that primarily affects the respiratory system, where the intent (accidental, intentional self-harm, assault) cannot be determined. The patient is in the recovery phase or receiving follow-up care for the sequelae of the initial poisoning.

Apply this code for follow-up encounters when a patient presents with ongoing respiratory symptoms or complications from a poisoning by an unidentified agent. This is appropriate when the initial encounter for the poisoning has already been coded, and the intent remains unclear.

• Requires an external cause code (X-code) to fully describe the circumstances of the poisoning.
• The 7th character "D" indicates a subsequent encounter for care after the active treatment phase.
• Only use when the specific agent and intent of the poisoning cannot be definitively identified from the medical record.