Deceptive air: Unravelling pseudo-peritonitis in peritoneal dialysis patients-A diagnostic challenge

Pneumoperitoneum, or free air in the peritoneal cavity, typically indicates visceral organ perforation requiring urgent surgical intervention. In peritoneal dialysis (PD) patients, however, it can occur without prior surgery or trauma, often due to technical errors, and may mimic peritonitis, risking misdiagnosis and unnecessary treatment. We report a case of a 73-year-old male PD patient presenting with fever, abdominal pain, and bowel ileus, initially raising concerns for organ perforation due to pneumoperitoneum. A comprehensive diagnostic workup and history taking, including molecular testing, excluded infections and chemical causes such as icodextrin, drugs, bile, faeces, blood, and malignancy. The cause was traced to improper PD technique, specifically a lapse in the 'flush-before-fill' method. Conservative management and retraining led to full symptom resolution and disappearance of the free air. This case highlights the importance of thorough diagnostic evaluations to rule out serious causes of pneumoperitoneum in PD patients, emphasizing the role of proper PD technique and patient education in preventing complications. Pneumoperitoneum in PD patients can mimic peritonitis, posing a diagnostic challenge. Comprehensive evaluation and adherence to proper PD practices are essential to avoid unnecessary interventions.