Toxic effect of nitrogen oxides, undetermined, subs encntr

This code signifies a toxic reaction to nitrogen oxides, such as those found in industrial fumes or vehicle exhaust, where the intent of exposure is unknown. The patient is presenting for follow-up care or treatment of residual effects after the initial acute phase of the poisoning.

Apply this code when documenting ongoing care for a patient who previously experienced nitrogen oxide poisoning of undetermined intent. This includes scenarios like follow-up appointments for pulmonary complications (e.g., bronchiolitis obliterans), neurological sequelae, or other persistent symptoms. It is used after the initial acute treatment has concluded.

• Always assign a code for the specific manifestation of the toxic effect, such as a respiratory condition, in addition to this code.
• Ensure the documentation clearly indicates the "undetermined" intent of the exposure and that it is a subsequent encounter.
• Distinguish from initial encounters (A) or sequela (S) encounters, as the "D" indicates ongoing care during the healing or recovery phase.