508P - A retrospective study on peritoneal fluid analysis profiles to predict bacterascites associated with malignant ascites

Abstract

Background: Neutrocytic ascites, defined as a polymorphonuclear neutrophil count ≥250/mm3, is equivalent to spontaneous bacterial peritonitis in cirrhotics and a strong indicator of bacterascites. The same profile is occasionally reported following paracenteses to relieve abdominal distension caused by malignant ascites. This study aimed to find out laboratory parameters to predict bacterascites in malignant ascites. Methods: It was a retrospective study by reviewing electronic medical records at Emergency Department of National Cancer Center, Korea from January 2014 to Feb 2017. We analyzed clinical and laboratory data of the patients whose ascites profiles fulfilled the traditional criteria of neutrocytic ascites, polymorphonuclear neutrophils >250/mm3 while excluding patients with history of hepatocellular carcinoma or liver cirrhosis. Results: 1467 paracenteses to relieve malignant ascites were screened. Of these, excluding 98 follow-up paracentesis, 112 cases (8.2%) showed PMN >250/mm3. 27 of these (24.1%) proved to have bacterascites. Receiver Operating Characteristic analysis indicated that 0.90 (95% C.I. 0.82-0.95) was the area under curve for polymorphonuclear neutrophils ratio while 0.86 (95% C.I. 0.78-0.92) was for the PMN count. The difference was 0.042, not statistically significant (p = 0.29). Moreover, Youden’s statistics identified the best cutoff points: 70% for the ratio and 1500/mm3 for the count. In addition, sensitivity for the cutoffs was 81.5% and 74.1%; specificity, 85.9% and 84.6%, respectively.Table: 508PFive variables’ diagnostic parameters estimated by ROC analysis to predict bacterascitesPMN RatioPMN countAscites proteinAscites WBCSAAGOptimal cutoff70%1500/mm318.0 g/L3000/mm31.1Sensitivity(%)(95%C.I)81.5 (61.9-93.7)74.1 (53.7-88.9)40.7 (22.4-61.2)59.3 (38.8-77.6)65.4 (44.3-82.8)Specificity(%)(95%C.I)85.9 (76.2-92.7)84.6 (74.7-91.8)20.0 (11.7-30.8)70.5 (59.1-80.3)64.9 (52.9-75.6)+Predictability(%)(95%C.I)66.7 (52.9-78.1)62.5 (48.6-74.6)15.5 (10.3-22.7)41.0 (30.4-52.5)39.5 (30.1-49.8)−Predictability(%)(95%C.I)93.1 (85.8-96.7)90.4 (83.2-94.7)48.4 (35.1-61.9)83.3 (75.6-89.0)84.2 (75.4-90.3)AUC(95%C.I)0.90 (0.82-0.95)0.86 (0.78-0.92)0.73 (0.63-0.81)0.70 (0.60-0.78)0.68 (0.58-0.77) Open table in a new tab Conclusions: The ratio and count of PMN had such strong association with bacterascites of malignant ascites that clinicians may predict the culture results. Also, the cutoff values proposed may indicate the cases that need antimicrobial treatments. To do that, however, the natural history of the condition should be further researched. Legal entity responsible for the study: National Cancer Center, Korea Funding: Research grants (No.1731600-1) from the National Cancer Center, Goyang, Korea. Disclosure: All authors have declared no conflicts of interest.