CRP and infection: Kinetics studies demonstrated that serum CRP levels begun to elevate on postoperative day 1 (POD1), peaked from POD2 to POD3 (approximately 12–24 hours after peak levels of IL-6), and then declined to baseline levels on POD5 providing there was no complication or infection after major abdominal surgery [29, 39, 52, 53, 57, 79, 90, 96].