Altitude Pre-Acclimatization with an Erythropoiesis-Stimulating Agent

INTRODUCTION: High altitude illness is a complication of rapid ascent above 2,500 m elevation. Ventilatory, circulatory and haematological adjustments, known as acclimatization, occur to maintain adequate delivery of oxygen. Although (non-)pharmaceutical strategies that modulate ventilation and circulation have long been accepted, the haematological approach has not. CASE DESCRIPTION: This report describes the application of a comprehensive strategy, including prior pre-acclimatization using an erythropoiesis-stimulating agent (ESA), in two healthy subjects ascending from sea level to 6,268 m. Following ESA administration 30 days prior to ascent, the subjects had a cumulative haemoglobin rise of 7.1% and 11.9%, respectively. Both subjects experienced minimal symptoms during four incremental ascents to the final altitude and no adverse events occurred. DISCUSSION: This report has limited external validity, lacking both a sample size and controls, but can serve as practical exploration of the concept. Administration of an ESA may be a safe and useful pre-acclimatization strategy but cannot be recommended based on current evidence. More comprehensive research is needed. LEARNING POINTS: High altitude illness (HAI) is a debilitating syndrome with potentially lethal consequences caused by ascent to a hypobaric atmosphere without acclimatization. Pharmacological strategies aimed at increasing oxygen delivery may be used to prevent and treat HAI. Administration of an erythropoiesis-stimulating agent may be a safe and useful pre-acclimatization strategy but cannot be recommended based on current evidence alone.