a 61-year-old man has a longstanding history of peripheral artery disease that has progressed in recent months to acute limb ischemia (ali). as a result, he has just undergone bilateral arterial bypass grafts and is postoperative day 1. the nurse's most recent assessment reveals that the patient's left foot is cold to touch and dusky in appearance with nonpalpable peripheral pulses. how should the nurse respond to this assessment finding?