Switzerland: Point-of-care ultrasound (POCUS) can be a valuable tool to aid clinical decision-making in remote, high altitude environment, according to a case report published in the journal Wilderness and Environmental Medicine. However, its role in high altitude medicine needs further investigation.

In the study, Flavia Wipplinger, Inselspital Bern University Hospital, Bern, Switzerland, and colleagues discussed the potential of POCUS to diagnose acute high altitude illness by lung ultrasound, optic nerve sheath diameter measurement, and echocardiography.

The case in question is of a healthy 32-y-old male who developed acute respiratory distress and neurologic impairment at 4321 m while participating in a high altitude medical research expedition.

The patient's symptoms began at 12,600 feet with a minor headache. It was the sixth night of a medical research expedition in the Khumbu valley on the Nepalese side of Mount Everest. He felt better the next day and continued trekking. Other members of the medical expedition group saw him running up to different viewpoints along the trail to take pictures.

That night, however, camped near Dingboche at an elevation of 14,200 feet, the 32-year-old Swiss climber's condition worsened.

"The patient became increasingly dyspneic during the night and developed severe orthopnea in the early morning hours of day eight," said Dr. Flavia Wipplinger of the department of anesthesiology and pain medicine, Inselspital Bern University Hospital, Switzerland.

They were equipped with handheld point-of-care ultrasound (POCUS) machines that allowed them to test (with the unfortunate help of the patient) the potential of POCUS to diagnose acute high-altitude illness by lung ultrasound (LUS), optic nerve sheath diameter (ONSD) measurement, and echocardiography.

Acute high-altitude illness includes acute mountain sickness, high-altitude pulmonary edema (HAPE), and high-altitude cerebral edema. These illnesses are caused by hypobaric hypoxia and can develop within a few days after ascent to altitudes above 8,200 feet.

Lung ultrasound was performed using a modified protocol with four chest areas per side instead of the usual eight to limit examination time in the cold, high-altitude environment. LUS findings were recorded for the upper anterior and basal lateral chest areas of each side.

"Ultrasound in combination with clinical findings helped us to exclude relevant differential diagnoses, start on-site treatment, and organize an evacuation," wrote the authors. "We used serial clinical and ultrasound examinations to assess the patient over time. Although its role in high altitude medicine needs further investigation, we believe that POCUS can be a valuable tool to aid clinical decision-making in remote, high altitude environments."

Reference:

The case report titled, "Point-of-Care Ultrasound Diagnosis of Acute High Altitude Illness: A Case Report," is published in the journal Wilderness and Environmental Medicine.

DOI: https://www.wemjournal.org/article/S1080-6032(21)00003-X/fulltext