OBJECTIVETo investigate the predictive value of procalcitonin(PCT) in postoperative intra-abdominal infections (IAI) after definitive operation of intestinal fistulae(IF).

METHODSWith the exclusion of emergence operation, preoperative clinical infection, preoperative renal or hepatic dysfunction, and age less than 18 years, a total of 356 consecutive patients who underwent elective digestive tract reconstruction of intestinal fistulae from February 2012 to December 2015 at Intestinal Fistula Center of Jinling Hospital were prospectively enrolled in the study. All the patients were divided into IAI group (26 cases, 21 of anastomosis leakage and 5 of peritoneal abscess) and non-IAI group (330 cases) based on the existence of postoperative IAI. The non-IAI group was then divided into two subgroups of other infection (93 cases) and non-infection(237 cases) according to the presence of other infections. Plasma PCT level, serum CRP concentration and WBC count were assessed preoperatively and on postoperative days (PODs) 1, 3, 5, 7 by immunofluorescence, turbidimetry and automatic blood analyzer, respectively. The predictive value of each marker for IAI was calculated by receiver operating characteristic (ROC) curve.

RESULTSThere was no significant difference in general clinical data between IAI and non-IAI group (all P>0.05). The proportions of multi-IF (53.8%, 14/26) and colectomy (61.5%, 16/26) in IAI group were higher than those of non-IAI group [20.0% (66/330), χ=15.847, P=0.000 and 31.2%(103/330), χ=9.961, P=0.002]. Differences of preoperative PCT, CRP and WBC levels among IAI, other infection and non-infection groups were not significant. These three markers all increased obviously and immediately after surgery. PCT and WBC values reached the peak point on POD 1, whereas CRP on POD 3. In IAI group, mean PCT values were (5.4±4.2) μg/L, (2.9±1.9) μg/L and (1.6±1.8) μg/L on POD 1, POD 3 and POD 5, respectively, which were higher than those of other infection group [(4.2±8.7) μg/L, (1.9±3.8) μg/L and (0.6±0.8) μg/L] and non-infection group [(2.7±5.8) μg/L, (1.1±1.7) μg/L and (0.5±0.7) μg/L, all P<0.05]. Mean CRP values in IAI group were 99.4 mg/L and 183.9 mg/L respectively on POD 1 and POD 3,and mean WBC values of IAI group on POD 1, POD 3 and POD 5 were 16.0×10/L, 10.8×10/L and 8.7×10/L, respectively, which were all significantly higher than those in the other 2 groups (all P<0.05). No significant differences were obtained between other infection group and non-infection group in all these three markers (all P>0.05). ROC curve demonstrated that PCT had the biggest area under the curve (AUC) of 0.86 and 0.84 on POD 3 and POD 5, with the cut-off value of 0.98 μg/L and 0.83 μg/L, 92.0% sensitivity and 74.0% specificity, 91.0% sensitivity and 73.0% specificity, respectively. The highest AUC was 0.72 on POD 3 for CRP and 0.71 on POD 3 for WBC, with 80.0% sensitivity and 54.0% specificity, 56.0% sensitivity and 73.0% specificity, respectively.

CONCLUSIONThe value of procalcitonin above 0.98 μg/L on POD 3 and 0.83 μg/L on POD 5 can predict the occurrence of IAI after definitive operations of intestinal fistulae.