2025-06-27 15:32 血氧飽和度無法預測是否會發生AMS. 但血氧飽和度正常. 可初步排除HAPE
將不同文獻提到關於血氧飽和度的段落整理成一篇筆記
診斷HAPE的參數. 當SPO2 低於 86%-- 敏感度0.95 特異性0.93
使用氧氣治療AMS患者, 將血氧濃度提升到超過 90% 即可.
低流量氧氣(每分鐘 1-2 公升)持續使用兩小時. 會比大流量氧氣使用幾分鐘更好.
因此不建議使用小型罐裝氧氣. 或短暫進入氧氣酒吧. 來預防 AMS
發生高海拔腦水腫的患者, 如果當地有醫院或診所可以治療. 到院後應給予足夠的氧氣治療. 將血氧濃度提升到超過 90%
2024 WMS update
Individuals developing HACE in locations with access to hospitals or specialized clinics should receive supplemental oxygen sufficient to achieve an SpO2 of >90%.
高海拔肺水腫 HAPE (from uptodate.(文獻回顧 July 2024, 最後更新 2022-10-04)
2024 WMS update
Individuals developing HACE in locations with access to hospitals or specialized clinics should receive supplemental oxygen sufficient to achieve an SpO2 of >90%.
高海拔肺水腫 HAPE (from uptodate.(文獻回顧 July 2024, 最後更新 2022-10-04)
在固定的海拔高度, 測量一般健康人的血氧飽和度, 得到一個預期值(基礎值), 發生HAPE的人. 血氧飽和度, 會比一般健康人的數值低 10%
HAPE患者. 經過氧氣治療 10-15 分鐘之後. 血氧飽和度會迅速改善
血氧飽和度 — 脈搏血氧測定法顯示飽和度值 (SpO 2 ) 比海拔高度的預期低至少 10 個點，絕對值可能低至 40% 至 50%。通常情況下，考慮到低氧血症的嚴重程度，患者的表現比預期要好，並且氧飽和度在補充氧氣後會迅速改善（通常在 10 至 15 分鐘內）。在放射照片上看到的嚴重浸潤性肺部病變的情況下，這種 SpO 2和臨床狀態的快速校正實際上是HAPE 的特徵，因為其他肺部病變（例如肺炎、急性失代償性心臟衰竭）不會發生這種情況能夠引起嚴重的低氧血症並伴隨瀰漫性爆裂聲或乾囉音。
因此，脈搏血氧測定法通常是區分 HAPE 與其他病症的有用工具。然而，預期 SpO 2值會因多種因素而變化，包括海拔、適應程度和速度、患者的低氧通氣驅動以及測量方法（例如，脈搏血氧計之間的差異）；因此應該仔細解釋。 SpO 2在高海拔地區的第一天最低，並在四天內上升到接近最大值，通常比第一天高 3 到 5 個點。儘管正常人在任何給定海拔的預期值可能有很大差異，但將 SpO 2測量值與同一旅行團中一起到達高海拔地區的其他人進行比較可以幫助建立相對「正常」範圍。下圖提供了一定海拔範圍內SpO 2和其他參數的近似平均值
High-altitude pulmonary edema(from uptodate.(文獻回顧 July 2024, 最後更新 2022-10-04)
Oxygen saturation — Pulse oximetry reveals saturation values (SpO2) at least 10 points lower than expected for the altitude, and absolute values may be as low as 40 to 50 percent. Typically, the patient appears better than expected given the severity of hypoxemia, and the oxygen saturation improves promptly (usually within 10 to 15 minutes) in response to supplemental oxygen. This rapid correction of the SpO2 and clinical status with supplemental oxygen in the setting of a severe infiltrative lung process seen on radiograph are virtually pathognomonic for HAPE, as this does not occur with other pulmonary processes (eg, pneumonia, acute decompensated heart failure) capable of causing such severe hypoxemia and associated with diffuse crackles or rhonchi.
Thus, pulse oximetry is often a useful tool for distinguishing HAPE from other conditions. However, expected SpO2 values vary with a number of factors, including the altitude, degree and rate of acclimatization, patient's hypoxic ventilatory drive, and method of measurement (eg, variation among pulse oximeters); and therefore should be interpreted carefully. SpO2 is lowest on the first day at high altitude and rises over four days to a near-maximum value, usually 3 to 5 points higher than day one. Although expected values can vary widely in normal individuals at any given altitude, comparing SpO2 measurements with others in the same travel group who arrived at high altitude together can help to establish a relative "normal" range. The following figures provide approximate average values for SpO2 and other parameters at a range of altitudes
Oxygen saturation — Pulse oximetry reveals saturation values (SpO2) at least 10 points lower than expected for the altitude, and absolute values may be as low as 40 to 50 percent. Typically, the patient appears better than expected given the severity of hypoxemia, and the oxygen saturation improves promptly (usually within 10 to 15 minutes) in response to supplemental oxygen. This rapid correction of the SpO2 and clinical status with supplemental oxygen in the setting of a severe infiltrative lung process seen on radiograph are virtually pathognomonic for HAPE, as this does not occur with other pulmonary processes (eg, pneumonia, acute decompensated heart failure) capable of causing such severe hypoxemia and associated with diffuse crackles or rhonchi.
Thus, pulse oximetry is often a useful tool for distinguishing HAPE from other conditions. However, expected SpO2 values vary with a number of factors, including the altitude, degree and rate of acclimatization, patient's hypoxic ventilatory drive, and method of measurement (eg, variation among pulse oximeters); and therefore should be interpreted carefully. SpO2 is lowest on the first day at high altitude and rises over four days to a near-maximum value, usually 3 to 5 points higher than day one. Although expected values can vary widely in normal individuals at any given altitude, comparing SpO2 measurements with others in the same travel group who arrived at high altitude together can help to establish a relative "normal" range. The following figures provide approximate average values for SpO2 and other parameters at a range of altitudes
