Colonic Ischemia in a High-Performance Aircraft Pilot

Abstract

Introduction: Those undergoing accelerated g-forces experience tissue ischemia due to pooling of blood within the extremities. While the most common side effect of accelerated g-forces is loss of consciousness, any part of the body at risk of decreased perfusion may be affected. Case Description: A 23 year old Japanese male with no significant past medical history was sent to the United States for flight training at a local Air Force base. During a mission he reportedly experienced a gravitational force of 4.5 which was the highest yet in his training. Following the flight he immediately developed abdominal cramping with hematochezia that gradually improved over the following three days. Colonoscopy was performed and was significant for patchy, erythematous and edematous mucosa within the recto-sigmoid junction concerning for colonic ischemia and was otherwise normal. Biopsies of the affected areas were obtained and revealed non-specific lamina propria congestion which may be seen in healing colonic ischemia. The patient denied a personal or family history of thromboembolic disorders, tobacco use, recent travel, prescription or over the counter medication use. The patient was treated conservatively and was able to return to regular flight duty without any further incidents. Discussion: Colonic ischemia (CI) is not uncommon but is rarely reported in those who are healthy and younger than 50. The cause of CI is thought to be related to hypoperfusion followed by a reperfusion injury. Often times a specific cause for ischemia is not identified and the incident is attributed to non-occlusive ischemia. Risk factors for CI include hypoperfusion states such as heart failure, sepsis and physical activity, mechanical colonic obstruction, medications, and perioperative. A review of the literature reveals two case reports of adults who developed CI after transatlantic flights with no other risk factors identified. To our knowledge this is the first case report of CI following exposure to increased g-force.