Toxic effect of carb monx from mtr veh exhaust, undet, init

This code signifies a patient presenting with symptoms of carbon monoxide poisoning specifically caused by exposure to motor vehicle exhaust, where the intent of the exposure (e.g., accidental, intentional) cannot be determined. The "initial encounter" indicates this is the first time the patient is receiving active treatment for this specific poisoning.

Use this code for emergency department visits or initial hospital admissions when a patient exhibits signs of carbon monoxide toxicity, and the source is confirmed as motor vehicle exhaust, but the circumstances surrounding the exposure are unclear. This applies when the provider cannot definitively classify the exposure as accidental or intentional at the time of the initial assessment and treatment.

• Always assign an additional code for the specific manifestations of carbon monoxide poisoning (e.g., headache, neurological symptoms).
• Only use "initial encounter" for the period when the patient is receiving active treatment for the toxic effect.
• If the intent of exposure is later determined (e.g., accidental, intentional self-harm), update the code to the appropriate T58.01-, T58.02-, or T58.03- subcategory.