3. Analysis of PCT and CRP
In the study period, according to local clinical guideline, postoperative daily serum samples including PCT, CRP, leukocytes, neutrophils, platelets, albumin were collected from postoperative day (POD) 1 to the day of discharge or the day of re-operation for AL.
Venous blood samples were collected into plain blood collection tube (BCT)s (BD Vacutainer® SST II Advance Tube, 5 mL, 13x100 mm, USA). Serum samples were separated from cellular fragments by centrifugation for 10 minutes at 1.500 g within one hour after blood sampling. Serum PCT levels were measured by the sandwich immunoassay using an immunoassay analyzer (Advia Centaur XP, Siemens Healthineers, Erlangen, Germany). The functional assay sensitivity of the Advia Centaur BRAHMS PCT is 0.05 ng/mL with an analytical range as 0.02-75 ng/mL. The reference range for a healthy adult population is lower than 0.1 ng/mL. A value of 2 ng/mL represents a high risk of severe sepsis or septic shock.
CRP levels were measured by a latex-immunoturbidimetric method with an AU5800 (Beckman Coulter Inc., USA) analyzer. The analytical range of the test is between 0.2 to 480 mg/L. The reference range for a healthy adult population is lower than 5 mg/L.