Evaluation of Serial Chest Radiographs of High-Altitude Pulmonary Edema Requiring Medical Evacuation from South Pole Station, Antarctica: From Diagnosis to Recovery

Abstract

ABSTRACT Introduction Chest radiography is a diagnostic tool commonly used by medical providers to assess high-altitude pulmonary edema (HAPE). Although HAPE often causes a pattern of pulmonary edema with right lower lung predominance, previous research has shown that there is no single radiographic finding associated with the condition. The majority of research involves a retrospective analysis of chest radiographs taken at the time of HAPE diagnosis. Little is known about the radiographic progression of HAPE during treatment or medical evacuation. Materials and Methods Three sequential chest radiographs were obtained from two patients diagnosed with HAPE at the Amundsen-Scott South Pole Station, Antarctica, who required treatment and medical evacuation. Deidentified and temporally randomized images were reviewed in a blinded fashion by two radiologists. A score of 0 (normal lung) to 4 (alveolar disease) was assigned for each of the four lung quadrants for an aggregate possible score ranging from 0 to 16 for each radiograph. Results Patient 1’s initial radiograph showed severe HAPE with an initial score of 13. Despite a rapid clinical improvement after medical evacuation, he continued to show multifocal radiographic evidence of disease in all the lung quadrants on day 1 (score of 11) and day 2 (score of 5). Patient 2’s radiographs showed less severe disease at presentation (score of 6). Despite the need for continued treatment, his radiographs showed a rapid improvement, with radiographic score decreasing to 3 on day 1 and 1 on day 3. Conclusion The chest radiographs showed serial improvement after medical evacuation in both patients. There was not a strong correlation between clinical symptoms and radiographic severity in subsequent images.