Final answer:
The ICD-10 code for an increased pain pump dose due to unexpected, extreme post-thoracotomy pain is T80.89XA for a complication or G89.18/G89.12 for acute postoperative pain. The exact code depends on specific circumstances documented in the patient's medical records.
Step-by-step explanation:
The ICD-10 code for an increased pain pump dose due to unexpected, extreme pain post thoracotomy is T80.89XA, which represents a complication of an injected therapeutic substance. However, if the adjustment of the dose is routine postoperative care and not due to a complication, there is no specific ICD-10 code to reflect an increase in pain medication. Instead, the pain can be coded with G89.18 for acute postoperative pain not elsewhere classified if it falls within the normal expected postoperative pain or with G89.12 if it is an acute post-thoracotomy pain syndrome. Remember that precise coding is crucial for accurate medical records and billing, so the code should be chosen based on the exact circumstances as documented in the patient's medical records.