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

This code signifies a long-term health condition or complication resulting from an exposure to an unknown substance that primarily affected the respiratory system. The original poisoning event's intent (accidental, intentional self-harm, assault) could not be determined.

Use this code when documenting a chronic respiratory issue, such as persistent asthma, chronic bronchitis, or pulmonary fibrosis, that is definitively linked to a past poisoning by an unidentified respiratory agent. The original poisoning event must have occurred in the past, and the current condition is a direct consequence.

• Requires a documented causal link between the past undetermined poisoning and the current sequela.
• Always sequence this code after the code for the specific respiratory condition being treated.
• Do not use for acute poisoning events; this code is exclusively for residual effects.