Pulmonary Embolism Masquerading as Low Back Pain During the Everest Base Camp Trek: A Case Report

Background and Purpose: Pulmonary embolism (PE) is a life-threatening condition that rarely occurs in high altitude (HA) environments. Typically PE does not present as musculoskeletal (MSK) pain. The purpose of this case report is to describe successful physical therapist (PT) management of a patient who presented with low back pain (LBP) during a HA expedition, where further evaluation and imaging identified primary impairment due to PE. Case Description and Intervention: A standardized clinical examination was conducted inside a tea house along the Everest Base Camp trek with limited resources. The patient complained of an intermittent “dull ache” at the left lumbar spine and left costovertebral angle, but the MSK examination was unremarkable. Initial differential diagnosis was acute mountain sickness (AMS) versus kidney stones. Fingertip oxygen saturation (SpO 2 ) was 68% at the PT evaluation but deteriorated to 45% after climbing to higher altitudes. Thus, helicopter evacuation to Kathmandu was coordinated to expedite emergency department evaluation. Outcomes: Radiographs showed left pleural effusion, laboratory results noted elevated D-dimer, and computed tomography (CT) scan revealed segmental bilateral PE. The patient recovered in the hospital for several days before flying home. At 3-month follow-up, the symptoms resolved, and follow-up testing was negative for PE. Discussion: Pulmonary embolism may present as referred LBP in conjunction or independent from AMS. Further research is recommended to investigate the incidence of PE presenting as MSK pain, and clinical signs that could be used as screening criteria to categorize risk for those planning high altitude expeditions.