Time course of asymptomatic interstitial pulmonary oedema at high altitude

The time course of asymptomatic pulmonary oedema during high-altitude exposure and its potential relationship with changes in cardiac function remain to clarify. Eleven volunteers were rapidly exposed to 4350 m during a 4-day period. Each subject received clinical examination and thoracic ultrasonography to assess ultrasound lung comets (USLC) on day 1, 2 and 3 after arrival. Echocardiography was performed on day 2 and 4 at 4350 m. All subjects had a significant increase in the number of USLC on day 1 (n = 8 +/- 3), day 2 (n = 7 +/- 4) and day 3 (n = 3 +/- 2) compared to sea level (n =1 +/- 1) (P< 0.01). Although left ventricle diastolic function and systolic tricuspid regurgitation gradient were significantly different at altitude compared to sea level, they did not correlate with the number of USLC (P> 0.05). Asymptomatic pulmonary oedema seems to be transiently present in fast-ascending recreational climbers. The lack of correlation between the number of USLC and indices of cardiac changes suggest that non-cardiogenic mechanisms may underlie this transient increase in lung water. (C) 2012 Elsevier B.V. All rights reserved.