Altitude Illness Among Tourists Flying to 3740 Meters Elevation in the Nepal Himalayas

Acute mountain sickness (AMS) is a syndrome that occurs at altitudes over 2500 m. It is more common among those who ascend rapidly.' Graded ascent is the best prophylaxis for AMS. Current recommendations are to avoid abrupt ascent to sleeping altitudes greater than 3000 m.Then each night spent above 3000 m should average not more than 300 m above the last, with a rest day every 2 or 3 days (or every 1000 m).'.2 The Mount Everest region of Nepal is a popular high altitude destination for tourists. Traditionally, visitors have trekked into the area from low altitude over several days, either starting fiom an airstrip at 2800 m or fiom walking in from 1860 ni over a longer period. A gradual ascent schedule assists acclimatization. Nevertheless, between 43% and 57% of trekkers experience AMS.- Over recent years, a small airstrip at Shyangboche (3740 m) has opened up to regular helicopter and fixed wing flights, thereby allowing more rapid access into the region.This airstrip was originally built to serve Hotel Everestview, a hotel situated near Shyangboche, which is at a 3860 m elevation that affords excellent views of Mount Everest. Guests typically fly directly from Kathmandu (1300 m) to Shyangboche, walk the short distance to the hotel, stay 1 or 2 nights, and then fly back to Kathmandu. Bottled oxygen is available at the hotel, but no trained medical personnel are in residence. Regular commercial flights to Shyangboche, unrelated to Hotel EverestView, are now also in progress.These flights provide the opportunity for large numbers of tourists to be rapidly transported to high altitude without the benefit of prior acclimatization. This new situation raises concerns about the risks of altitude illness.