My husband, age 71, just had a thymectomy (90% robotically) for large 10 tumor, two days ago. His hands are puffy and his urine output is dark and not as much as I would expect (still with catheter, fentanyl epidural, now amiodarone because yesterday he started with a-fib and tachycardia. Heart rate now 70, and a-fib largely under control. What are the puffy hands from?