Pulmonary Thromboembolism at Extreme High Altitude: A Study of 7 Cases

Abstract Backgrounds: The high incidence of venous thromboembolic disease (VTE) in plateau area has aroused widespread concern. Through the collection and analysis of pulmonary thromboembolism (PTE) cases in extreme high altitude, to explore the epidemiological characteristics and possible risk factors of PTE in extreme plateau region.Methods: Seven cases of pulmonary thromboembolism occurring in extreme plateau region were prospectively collected in a high altitude hospital at 3800 m from May to November 2020. All patients were serving at 5000 m above sea level, and diagnosed with PTE by using computed tomography pulmonary angigraphy (CTPA).Results: Seven patients with an average age of 24±3.6 yr, the mean altitude is 5200±200 m at the onset of symptoms. And the time of them stay at high altitude between 8-210 days (99.29±77.31). Cough, expectoration, chest tightness, fever, short of breath, chest pain were the commonest symptom. 6 of 7 patients were initially diagnosed with pulmonary inflammation and 4 with HAPE by CT or X-ray. Most patients had an increase in inflammatory cells and all of them showed a high level of D-dimer in initial hematologic test during the course of the disease. Conclusions: Pulmonary thromboembolism has a high incidence in plateau areas and shows a younger age trend. Prodromal infection and high altitude pulmonary edema (HAPE) were the potential risk factors for its occurrence.