Incidence and prognostic role of pleural effusion in patients with acute pancreatitis: a meta-analysis

Pleural effusion (PE) is reported as a common complication in acute pancreatitis (AP), while the incidence of PE in AP varies widely among studies, and the association between PE and mortality is not clear. This study aimed to comprehensively analyze the pooled incidence of PE in patients with AP and to evaluate the influence of PE on mortality through a meta-analysis. Six databases (PubMed, Web of Science, EMBASE, Cochrane, Scopus, and OVID) were searched thoroughly for relevant studies. Data were extracted, and Stata SE 16.0 software was applied to compute the pooled incidence of PE and assess the association between PE and mortality, taking the risk ratio (RR) as the effect size. Thirty-five articles involving 7,675 patients with AP were eventually included in this meta-analysis. The pooled incidence of PE was 34% (95% CI: 28%-39%), with significant heterogeneity among studies (I =96.7%). Further analysis revealed that the pooled incidence of unilateral and small PE occupied 49% (95% CI: 21%-77%) and 59% (95% CI: 38%-81%) of AP patients complicated by PE, respectively. The subgroup analysis revealed that "region" and "examination method" may contribute to heterogeneity. PE may be associated with increased mortality in AP patients (RR 3.99, 95% CI: 1.73-9.2). This study suggested that PE is a common complication with high pooled incidence and that PE may be associated with increased mortality in AP patients. More studies should be performed to validate our findings.