Persistent Intraoperative Hypoxemia in the right lateral decubitus position: a case report.

Background: Platypnea-orthodeoxia syndrome is an extremely rare syndrome. Platypnea-orthodeoxia syndrome is a group of diseases characterized by hypoxemia and dyspnea in the upright position and improvement in the supine position. In this case, severe hypoxemia occurred in the intraoperative right lateral decubitus position and was suspected to be associated with Platypnea-orthodeoxia syndrome. Case Presentation An 85-year-old woman underwent surgery for a fracture of the left femoral neck. After the right lateral decubitus position, the patient presented with sustained low oxygen saturation and normal blood pressure which was maintained at the range of 180mmhg- 150mmhg/90-52mmhg lasting 45 minutes. Subsequently, arterial blood pressure and heart rate decreased. The patient was immediately placed in a supine position. In the supine position, all vital signs were back to normal. Conclusion: This case may be a clinical manifestation of a specific POS syndrome, which provides a new differential diagnosis for intraoperative posture-related hypoxemia. Severe hypoxemia due to intraoperative position changes can be highly suspected as POS.