A Novel Cause of Free Intraperitoneal Air in the Emergency Department.

Although all emergency physicians are familiar with catastrophic causes of free intraperitoneal air, we describe the case of a healthy 26-year-old woman who presented to our emergency department (ED) with a nonsurgical and previously unreported cause of pneumoperitoneum. The patient presented to our ED with complaints of shoulder and neck pain several hours after having undergone FemVue ultrasonography (Femasys, Suwanee, GA) for infertility evaluation. The technique uses an air and saline solution mixture injected into the uterine cavity to assess for tubal patency and uterine cavity morphology. Although the cause of her free air and pain was determined to be iatrogenic and ultimately benign, this complication is previously unreported and, without complaints of abdominal pain, presented a diagnostic challenge.