Review Question - QID 1019

C-reactive protein (CRP) should peak by 48 hours after surgical fixation of bony orthopedic injuries, and decrease thereafter. This is important to recognize, as an increasing CRP after 48 hours is predictive for postoperative infection, and is more predictive in the first postoperative week than local erythema, persistent serous drainage, and increasing serial ESR.

The first referenced study by Waleczek et al noted that CRP was the earliest sign of developing infection and that clinical diagnosis, ultrasound, and WBC counts all lagged significantly behind CRP as a diagnostic tool. They report that latency to the clinical diagnosis based on clinical signs, ultrasound, WBC in blood and wound drainage was up to 14 days, while there was no patient with CRP increasing after day 2 without an infection.

The second referenced article by de Zwart et al noted an increased sensitivity and specificity of CRP as compared to ESR in the scenario of a clinically suspected infection. They advocate for determination of two CRP-levels with a short interval to screen for a clinically suspected infection.

Furthermore, Mok et al found that CRP showed an exponential decrease with a half-life of 2.6 days in postoperative spine patients. They found that CRP is a reliable test in the early postoperative period compared with ESR.