C-reactive protein but not procalcitonin may predict antibiotic response and outcome in infections following major abdominal surgery.

We aimed to evaluate the usefulness of C-reactive protein (CRP) and procalcitonin (PCT) as markers of infection, sepsis and as predictors of antibiotic response after non-emergency major abdominal surgery. We enrolled, from June 2015 to June 2019, all patients who underwent surgery due to abdominal infection (peritoneal abscess, peritonitis) or having sepsis episode after surgical procedures (i.e. hepatectomy, bowel perforation, pancreaticoduodenectomy (PD), segmental resection of the duodenum (SRD) or biliary reconstruction in a Tertiary Care Hospital. Serum CRP (cut-off value < 5 mg/L) and PCT (cut-off value < 0.1mcg/L) were measured in the day when fever was present or within 24 h after abdominal surgery. Both markers were assessed every 48 h to follow-up antibiotic response and disease evolution up to disease resolution. We enrolled a total of 260 patients underwent non-emergency major abdominal surgery and being infected or developing infection after surgical procedure with one or more microbes (55% mixed Gram-negative infection including Klebsiella KPC, 35% Gram-positive infection, 10% with Candida infection), 58% of patients had ICU admission for at least 96 h, 42% of patients had fast track ICU (48 h). In our group of patients, we found that PCT had a trend to increase after surgical procedure; particularly, those undergoing liver surgery had higher PCT than those underwent different abdominal surgery (U Mann-Whitney p < 0.05). CRP rapidly increase after surgery in those developing infection and showed a statistical significant decrease within 48 h in those subject being responsive to antibiotic treatment and having a clinical response within 10 days independently form the pathogens (bacterial or fungal). Further we found that those having CRP higher than 250 mg/L had a reduced percentage of success treatment at 10 days compared to those < 250 mg/mL (U Mann-Whitney p < 0.05). PCT did not show any variation according to treatment response. CRP in our cohort seems to be a useful marker to predict antibiotic response in those undergoing non-emergency abdominal surgery, while PCT seem to be increased in those having major liver surgery, probably due to hepatic production of cytokines.