Toxic effect of cyanides, undetermined, sequela

This code signifies the long-term or residual effects resulting from a past exposure to cyanide, where the intent of the exposure (e.g., accidental, intentional self-harm, assault) cannot be determined. These sequelae can manifest as various chronic health issues affecting multiple organ systems, such as neurological deficits, cardiovascular problems, or respiratory complications, that persist after the acute phase of poisoning has resolved.

Apply this code when documenting chronic conditions or lasting damage directly attributable to a previous cyanide poisoning event, and the medical record does not specify whether the exposure was accidental, intentional, or assault. This is appropriate for follow-up encounters where the patient is being treated for the ongoing consequences of the undetermined cyanide exposure.

• Always sequence this code after the code(s) for the specific sequela being treated.
• Ensure documentation clearly links the current condition to the past cyanide exposure.
• Do not use for acute poisoning; this code is exclusively for residual effects.