Background: Hyponatremia has been identified as a marker of disease severity in various inflammatory conditions. However, its role in predicting acute complicated appendicitis (ACA) in children remains under investigation. This study evaluated the association between preoperative hyponatremia and ACA in a pediatric population. Methods: A retrospective study was conducted on pediatric patients treated for acute appendicitis in two major pediatric centers in Greece. Patients were categorized into groups based on the presence of acute uncomplicated appendicitis (AUA) and acute complicated appendicitis (ACA). Preoperative laboratory parameters were analyzed to identify potential predictors of ACA. Results: This study included 491 pediatric patients, with a mean age of 10 years. ACA patients exhibited significantly lower Na levels compared to those with AUA (136 vs. 138 mmol/L, p < 0.001). Hyponatremia (<135 mmol/L) was present in 38.4% of ACA cases compared to 2.2% of AUA cases (p < 0.001), and was associated with a significantly increased risk of ACA (OR = 18.30, p < 0.001). A sodium threshold of 135 mmol/L also demonstrated a sensitivity of 48% and a specificity of 92.1% Conclusions: Hyponatremia is a strong and specific predictor of ACA in children. When combined with other inflammatory markers, it may enhance early risk stratification, aiding in timely surgical decision making.

Introduction: Although serious trauma is rare in pediatric patients, the management of blunt force trauma to the abdomen remains a challenge for Child Surgery Departments. Pancreatic injury comprises the fourth most common injury among the solid organs and cases accompanied by rupture of the main pancreatic duct (MPD) present a further challenge for physicians (Fayza Haider et al.; Wood et al., 2010; Jobst et al., 1999; Grosfeld et al., 2006). Case presentation: Two adolescents, both 13 years old, where referred to our Pediatric Hospital, due to blunt force abdominal trauma. During admission, both patients were hemodynamically stable, in good general condition but suffering from abdominal pain and vomiting. After a full diagnostic check-up, grade IV pancreatic injury was diagnosed in both patients and they were taken to the operation room 3 and 6 days post-injury. Intra-operatively a distal pancreatectomy along with splenectomy was performed in both cases, with catheterization and ligation of the main pancreatic duct. Both patients were admitted to the pediatric ICU for 2 and 4 days. Both made an uneventful recovery and remain well 6 months postoperatively. Conclusion: While hemodynamically stable, patients with Grade IV pancreatic injury, benefit from sub-acute management, allowing for planning of the surgical intervention. Distal pancreatectomy with splenectomy, along with catheterization and ligation of the main pancreatic duct, has excellent post-operative results. The chief of the Pediatric Hospital, said that in 35 years at pediatric surgery, is the first time with the need of operative management, in pancreatic injury. The hepatobiliary surgical expert in adults, who was consulted in both cases, said that without the surgeries, both children were going to die. Highlights: