An unusual cause of refractory hypoxaemia after hiatus hernia surgery: a case report of platypnoea-orthodeoxia syndrome.

backgroundPlatypnoea-orthodeoxia syndrome (POS) is a clinical manifestation that arises from an underlying pathological process, most commonly a right-to-left intracardiac shunt such as a patent foramen ovale (PFO). The precise incidence of platypnoea-orthodeoxia syndrome remains undefined; nevertheless, it is widely regarded as an exceedingly rare clinical entity, particularly within the postoperative context. Its occurrence following upper gastrointestinal surgery is even more uncommon, with only a few cases scarcely reported in the literature. We describe an unusual case of POS following laparoscopic repair of a large type IV hiatus hernia with gastric volvulus reduction, highlighting the role of thoracoabdominal anatomical shifts in precipitating this syndrome. CASE PRESENTATION: A 74-year-old man with a history of obstructive sleep apnoea and a longstanding giant type IV hiatus hernia underwent laparoscopic gastric volvulus reduction, hernia repair, and gastropexy. Postoperatively, he developed profound hypoxaemia, initially attributed to atelectasis. However, during intensive care unit admission, his SpO

conclusionsThis case illustrates the potential for thoracoabdominal surgeries, such as hiatus hernia repairs with extensive mediastinal dissection, to unmask intracardiac shunts by altering venous return and cardiac geometry. It underscores the importance of considering POS in patients with unexplained postoperative or positional hypoxaemia. Early orthostatic oximetry and targeted imaging are critical for timely identification of the syndrome. A high index of suspicion for this rare but treatable condition is crucial, as prompt recognition and timely intervention have the potential to prevent diagnostic delays, reduce morbidity, and markedly improve perioperative outcomes in patients with otherwise unexplained refractory hypoxaemia.