Postoperative Median Nerve Injury

You get a call from you orthopedic surgical colleague to say that the patient that you anesthetized for an 11-h spine surgery operation last week has developed a left median nerve conduction block. The diagnosis has been confirmed by a neurologist who is at a loss to find any reason for this. There is no evidence of infection, hematoma, or vascular insufficiency of the hand. The patient has no other problems and is otherwise happy with her surgery. You tell your colleague that you will get back to him. In reviewing your anesthetic record, you see that the anesthetic was uneventful with stable vital signs throughout. Your IV access included two large-bore IVs in the right forearm and the back of right hand. A right subclavian triple-lumen catheter had also been inserted. In addition, she had a left radial intraartery catheter. The arms were both placed forward alongside the head. You go and see the patient and apologize for what has happened. You ask to see her hand. There is nothing abnormal noted with the overlying skin of the left hand and the oxygen saturation reads 100%?