Poisn by unsp prim systemic and hematolog agent, undet, subs

This code signifies a poisoning event involving an unknown substance that primarily affects the body's systems and blood, where the intent (accidental, intentional, etc.) of the poisoning cannot be determined. It is used when a patient is receiving follow-up care for such an exposure after the initial treatment phase.

Apply this code for patients presenting for ongoing management, monitoring, or evaluation of residual effects from a poisoning by an unidentifiable systemic or hematological agent. This includes situations like follow-up appointments for organ damage, blood dyscrasias, or other systemic complications where the initial cause and intent remain unclear.

• Always assign a seventh character of 'D' for subsequent encounters, indicating follow-up care.
• Ensure documentation clearly states the systemic or hematological nature of the poisoning, even if the specific agent is unknown.
• Do not use this code for initial encounters or sequelae; separate codes exist for those phases of care.