High Altitude Pulmonary Edema, Down Syndrome, and Obstructive Sleep Apneas

Abstract

A 24-year-old adult with a Down syndrome was admitted in December 2006 at the Moutiers hospital in the French Alps for an acute inaugural episode of high altitude pulmonary edema (HAPE) that occurred in the early morning of day 3 after his arrival to La Plagne (2000 m). This patient presented an interventricular septal defect operated on at the age of 7, a hypothyroidism controlled by 50 microg levothyrox, a state of obesity (BMI 37.8 kg/m(2)), and obstructive sleep apneas with a mean of 42 obstructive apneas or hypopneas per hour, treated with continuous positive airway pressure (CPAP). The patient refused to use his CPAP during his stay in La Plagne. At echocardiography, resting parameters were normal, with a left ventricular, ejection fraction of 60%, a normokinetic right ventricle, and an estimated systolic pulmonary artery pressure (sPAP) of 30 mmHg. At exercise, sPAP rose to 45 mmHg and the right ventricle was still normokinetic and not dilated. An exercise hypoxic tolerance test performed at 60 W and at the equivalent altitude of 3300 m revealed a severe drop in arterial oxygen saturation down to 60%, with an abnormal low ventilatory response to hypoxia, suggesting a defect in peripheral chemosensitivity to hypoxia. In conclusion, patients with Down syndrome, including adults with no cardiac dysfunction and regular physical activity, are at risk of HAPE even at moderate altitude when they suffer from obstructive sleep apneas associated with obesity and low chemoresponsiveness. This observation might be of importance since an increasing number of young adults with Down syndrome participate in recreational or sport activities, including skiing and mountaineering.

Hypoxia, energy balance and obesity: from pathophysiological mechanisms to new treatment strategies

“…). Obesity or BMI is not known as a risk factor for high altitude pulmonary oedema even though a recent case report in a subject with Down syndrome, OSA and a BMI of 38 would suggest that it may be .…”

Lung disease at high altitude

“…Indeed, the literature contains numerous cases of HAPE in patients with underlying PH secondary to congenital absence of one pulmonary artery [21,104], pulmonary artery occlusion from granulomatous mediastinitis [23], pulmonary embolism [105], Down's syndrome [22], anorexigen use [24] and various congenital cardiac abnormalities [106]. These can act as independent risk factors or in combination, as described in a recent case report [107]. While HAPE typically occurs at altitudes above 2500 m in otherwise healthy individuals, some patients with underlying PH have developed HAPE at significantly lower elevations of 1500-1750 m [22,104].…”

Accuracy and Reliability of Pulse O2 Saturation Measured by a Wrist-worn Oximeter

“…1, ▶table 1) and could mislead a diagnostic in case of first symptoms of a potential AMS. For example, with an error rate above 80 % and negative biases inferior to − 10 % (for SpO 2 values), it is well possible that an O 2 saturation below 65 %, sign of a high risk of a severe AMS and potentially able to induce life-threatening complications such as high altitude pulmonary/cerebral edema [30], could be displayed as a "safer" but erroneous 85 % by the Garmin watch. As this technology is relatively new in wrist-worn watches for consumer products, we don't have the hindsight necessary to analyze the reasons explaining such a gap between this product and the criterion yet.…”