Dominguez-Comesana E, et al. - The accuracy of serum procalcitonin (PCT) and C-reactive protein (CRP) for early diagnosis of postoperative intra-abdominal infections (PIAI) after elective surgery for colorectal cancer was evaluated in this study. Although the positive predictive values were low for both PCT and CRP, PCT and CRP serum levels were correlated with the appearance of PIAI after colorectal cancer surgery. However, the negative predictive values were high.

Methods

• The researchers performed this prospective observational study including patients operated on for colorectal cancer between January and December of 2015.
• They measured serum PCT and CRP levels before surgery and daily until postoperative day 3.

Results

• The researchers included 120 patients.
• Out of them, 7 patients (5.8%) had PIAI.
• On postoperative days 1 and 3, PCT levels were significantly higher in patients with PIAI, while CRP levels only were significantly more elevated on postoperative day 3.
• In patients with PIAI, the ratio between CRP levels on postoperative day 3 and CRP levels on postoperative days 2 (CRP D3/CRP D2) and 1 (CRP D3/CRP D1) was significantly higher.
• For a cutoff of 0.45 ng/mL, PCT on postoperative day 3 had the best sensitivity (100%) with a specificity of 73.8%.
• For a cutoff of 1.8, the ratio CRP D3/CRP D1 yielded the higher specificity and positive predictive value (90.9 and 27.3%, respectively).
• They obtained the higher negative predictive value for PCT on postoperative days 1 and 3 (100%, with cutoff of 0.76 and 0.45 ng/mL, respectively) and for CRP on postoperative day 3 (100% with cutoff of 10 mg/dL).