野外與登山醫學----13---WMS 2019 update AMS/HACE Treatment Supplemental oxygen 13

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update
統一名詞翻譯
AMS 急性高山病
HACE 高海拔腦水腫
acute altitude illness 急性高海拔疾病

Supplemental oxygen
Oxygen delivered by nasal cannula or mask at flow rates sufficient to relieve symptoms provides a suitable alternative to descent. A peripheral capillary oxygen saturation (SpO2) >90% is usually adequate. Use of oxygen is not required in all circumstances and is generally reserved for mountain clinics and hospitals where supply is abundant. It should also be used when descent is recommended but not feasible or during descent in severely ill individuals. The inspired oxygen fraction will vary significantly between oxygen delivery systems, including nasal cannula, simple facemasks, Venturi masks, or non-rebreather masks. In addition, because of interindividual variability in inspiratory flow rates and minute ventilation, the inspired fractional concentration of oxygen (FIO2) can vary significantly between patients for any given common oxygen delivery system, with the exception of high flow systems. For this reason, supplemental oxygen should be administered to target an SpO2 of >90% rather than a specific FIO2. Oxygen supply may be limited at remote high altitude clinics or on expeditions, necessitating judicious use. Short-term oxygen use in the form of visits to oxygen bars or use of over-the-counter oxygen canisters has not been studied for AMS treatment and should not be relied on for this purpose.

Recommendation. When available, ongoing supplemental oxygen sufficient to raise SpO2 to >90% or to relieve symptoms can be used while waiting to initiate descent or when descent is not practical. Recommendation Grade: 1A