重點整理
1. HAPE 患者經過10-15分鐘氧氣治療, 血氧飽和度會明顯改善. 這些患者的胸部X光看起來可能很嚴重. 但病患症狀會低於我們預期的嚴重度(看起來很糟, 症狀卻還好)
2. 血氧飽和度無法預測是否會發生AMS. 但血氧飽和度正常(相對於該海拔的預期血氧值). 可初步排除HAPE
3. 罹患HAPE, 血氧濃度會比該海拔高度預期值約低 10%.
4. HAPE相對於AMS而言發生機率很低(幾十倍差距). 為了預防或治療HAPE, 可考慮帶一個血氧機. 但並非一定必要. 血氧機售價不高. 重量輕. 購買容易. 一般而言應該不至於造成行李過重負擔.
這篇筆記彙整數個不同文獻的內容提到的血氧訊息
HAPE 高海拔肺水腫
2026-01-23
High altitude pulmonary edema from uptodate
血氧飽和度
脈搏血氧飽和度監測顯示，患者的氧飽和度（SpO₂）值比預期海拔低至少10個百分點，絕對值甚至低至40%至50%。通常情況下，考慮到低氧血症的嚴重程度，患者的狀況會比預期要好，並且在吸氧後氧飽和度會迅速改善（通常在10至15分鐘內）。在X光片顯示嚴重浸潤性肺部病變的情況下，吸氧後SpO₂和臨床狀況的快速改善幾乎是HAPE的特徵性表現，因為其他能夠引起如此嚴重低氧血症並伴有瀰漫性囉音或乾囉音的肺部疾病（例如肺炎、急性失代償性心臟衰竭）不會出現這種情況。
因此，脈搏血氧飽和度監測通常是區分HAPE與其他疾病的有效工具。然而，預期的SpO₂值受多種因素影響，包括海拔高度、適應程度和速度、患者的低氧通氣驅動以及測量方法（例如，不同脈搏血氧儀之間的差異）；因此，應謹慎解讀SpO₂值。 SpO₂在高海拔地區的第一天最低，並在四天內逐漸升高至接近最大值，通常比第一天高3至5個百分點。儘管正常個體在任何給定海拔高度的SpO₂值都可能存在較大差異，但將SpO₂測量值與同一旅行團中同時到達高海拔地區的其他人進行比較，有助於建立一個相對的「正常」範圍。下圖提供了不同海拔高度下SpO₂和其他參數的近似平均值（圖1和表3）。
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); therefore, they 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 (figure 1 and table 3).
2024-08-12 15:35pm
(筆記)Objective criteria for diagnosing high altitude pulmonary edema in acclimatized patients at altitudes between 2700 m and 3500 m(印度武裝部隊的研究)
診斷HAPE的參數. 當SPO2 低於 86%-- 敏感度0.95 特異性0.93
WMS 2024update- AMS/HACE治療選擇(筆記)
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
2024 WMS update
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%
Individuals developing HACE in locations with access to hospitals or specialized clinics should receive supplemental oxygen sufficient to achieve an SpO2 of >90%.
沒有留言:
張貼留言