A 65-year-old client is 12 hours postoperative following a total knee arthroplasty. During the shift assessment, the nurse notes that the client's capillary refill is 5 seconds, the foot is cool to the touch, and the pedal pulse is not palpable and can only be found by doppler. The client reports "extreme tingling" in the toes. Based on this assessment the nurse is most concerned for?