Platelet index on admission as a predictor of bacteremia in acute cholangitis: a 7-year retrospective observational study

Bacteremia frequently occurs in patients with acute cholangitis, which could increase the risk of mortality. This single-center retrospective observational study was conducted from July 2013 to July 2020 to evaluate the predictive value of platelet index for bacteremia at admission for acute cholecystitis. A total of 285 patients with acute cholangitis were divided into bacteremia group and non-bacteremia group. The incidence of bacteremia in acute cholangitis was 48.42%. The bacteremia group had more grade III patients, higher 30d mortality rate [17(12.32%) vs 8(5.44%), p = .040] and higher incidence of thrombocytopenia [76(55.07%) vs 35(23.81%), p < .001]. Platelet counts and plateletcrit were significantly lower in the bacteremia group [84.5(60, 180) vs 162(102,225) x10(9)/L and 0.10(0.07, 0.21)% vs 0.18(0.12, 0.25) %, both p < .001]. ROC analysis indicated a high predictive value of platelet count and plateletcrit for bacteremia in patients with acute cholangitis and the area under the ROC curve (AUC) were 0.649 and 0.655, respectively. These results support the value of platelet count and plateletcrit in early prediction of bacteremia at admission for acute cholangitis. Plain Language Summary What is the context? Acute cholangitis is a fatal infectious disease. Bacteremia frequently occur in patients with acute cholangitis, which could increase the risk of mortality. The positive rate of blood cultures in patients with acute cholangitis ranged from 21% to 71%. Platelets play key roles in thromboembolism, inflammation, and immune regulation. To the best of our knowledge, whether platelet index facilitates to the diagnosis of bacteremia in acute cholangitis has not been investigated. What is new? In this study, we designed this 7-year retrospective, observational study to verify that platelet index could contribute to the early diagnosis of bacteremia in acute cholangitis. The results showed that: The patients with bacteremia had a higher incidence of thrombocytopenia. Thrombocytopenia, platelet count, plateletcrit, and procalcitonin were independent risk factors for bacteremia in acute cholangitis Platelet count and plateletcrit had positive predictive value for bacteremia in acute cholangitis. What is the impact? This study presents clinical characteristics of acute cholangitis complicated by bacteremia, and provides evidence that platelet index can be used to predict bacteremia in acute cholangitis.