Poisoning by antidotes and chelating agents, undet, sequela

This code signifies a long-term or residual effect resulting from an unconfirmed poisoning by an antidote or chelating agent. It indicates that the initial acute event has resolved, but the patient continues to experience health problems directly attributable to the past exposure, and the intent of the poisoning (accidental, intentional self-harm, assault) could not be determined.

Apply this code when documenting a patient presenting with chronic conditions, disabilities, or other lasting health issues that are definitively linked to a prior poisoning by an antidote or chelating agent, where the circumstances of the original poisoning were never clarified. This is appropriate for follow-up encounters after the acute phase has passed.

• Always sequence this 'S' code after the code(s) for the specific sequela being treated.
• Ensure documentation clearly links the current condition to the past poisoning event and specifies the undetermined intent.
• Do not use for acute poisoning events; this code is exclusively for residual effects.