Diagnosing Spontaneous Bacterial Peritonitis in Children: Tap-in for Higher Scores.

P ortal hypertension (PH) is an almost invariable complication of chronic liver disease in children and a field lacking evidence as far as natural history and response to treatment are concerned (1). On the contrary, in adults many studies allowed to provide proper guidelines on the management of manifestations of chronic liver disease, such as gastrointestinal bleeding, hepatic encephalopathy, spontaneous bacterial peritonitis (SBP), and hepatorenal syndrome (2). For this reason, children are often treated according to what has been shown to be effective in adults by simply applying the same protocols modified according to body size. Factors limiting the knowledge of PH in children should be sought in the early presentation of the majority of liver diseases leading to cirrhosis, and in the short follow-up of these patients who become candidate for liver transplantation (LT) in the first 2 years of life. In this setting, the careful selection of patients for listing before any major threat arises, and the relatively large availability of partial liver grafts, eliminate the chance to observe the natural history of PH (3). Although the definition of predictors of mortality in acute and chronic diseases is troublesome in paediatric centres having developed an LT program, it is not so in centres with large experience on the medical side but no availability of LT. This unfortunate situation may offer the opportunity to better understand the natural history of PH complications. In this issue of Journal of Pediatric Gastroenterology and Nutrition, Srivastava and coworkers describe a study on 262 children who received a paracentesis upon clinical presentation of ascites. SBP (simply defined as neutrophil count 250/mm in the ascitic fluid regardless of bacterial culture) was diagnosed in 28% of patients. SBP was not limited to cirrhotic PH, but, as previously reported, was also found in noncirrhotic (such as patients with extrahepatic portal vein obstruction) and in patients with acute liver failure (4–7). When positive, ascitic fluid culture most commonly grew gram-negative bacteria such as Escherichia coli, Klebsiella, Acinetobacter. The presence of fever, loose stools, abdominal pain, and/or tenderness was significantly more common in patients with SBP, although 50% had no clinical signs of infection at all. One-year mortality was 24%, and risk factors for poor outcome were the severity of liver disease (represented by higher Child-Pugh scores) and a recent episode of gastrointestinal bleeding. Remarkably, these results should be balanced against the advanced disease at presentation of ascites in this cohort of patients (with a median model for end-stage liver disease/paediatric endstage liver disease [PELD/MELD] of 23) (8). SBP is common in adult patients with chronic liver disease, associated with high hospital mortality (around 30%), high risk of recurrence (up to 70% after the first episode), and poor 1-year survival (9). For these reasons, the current guidelines of the European Association for the Study of the Liver (EASL) recommend to perform an aseptic paracentesis in cirrhotic patients presenting with ascites, and treat promptly with third-generation cephalosporins if neutrophil count is 250/mm (2). In children, any painful procedure is considered invasive and is usually performed under sedation/analgesia. Organisational constraints and excessive prudence may sometimes discourage to perform a paracentesis in a small child with new-onset ascites but an otherwise unchanged general condition. For these reasons, the first approach may start from evaluating the response to albumin and diuretics before moving on to perform an abdominal tap. In some centres, an empirical course of first-line antibiotics such as thirdgeneration cephalosporins, fluoroquinolones, or piperacillin/tazobactam may be started, missing the chance to identify the infectious agent and the local susceptibility to antimicrobials. A recent article reported data on 518 children with ascites hospitalised for a 27-year period. The underlying aetiologies included intrahepatic and extrahepatic causes of PH, and ascites was classified in different grades (from 1 to 3) based on radiological and clinical features. Remarkably, there was no mention of any diagnostic paracentesis in these patients (10). Despite the retrospective design and the peculiar epidemiology of the geographic area where the study of Srivastava has been carried out, this article represents the strongest proof that SBP is a threat in children as it is in adults. Likewise, although here we have no data on efficacy of treatment, it is probable that early diagnosis and antibiotic administration impact on survival of children with this complication. Should we therefore perform an abdominal tap in every child presenting with ascites? The correct answer may depend on local facilities, because in centres with an LT program receiving early referrals and having low wait-list mortality, SBP may be less prevalent, and an aggressive approach to any child with ascites may not significantly improve survival. Nevertheless, as shown by Srivastava’s study, we should now be aware that some 30% of children with advanced liver disease presenting with ascites do have SBP, and a quarter of them die within a year’s follow-up. It seems therefore advisable that children having a high end-stage liver disease score presenting with ascites should not be denied a diagnostic abdominal tap.