這篇文獻提出高海拔肺水腫診斷.至少兩個以上的症狀(symptoms)及兩個以上徵象(signs).如果能照CXR更好. 但這種診斷標準並非普世通用的. 在WMS或 uptodate並沒有使用這種診斷依據.
2018-05-21 09:38am
StatPearls-High Altitude Pulmonary Edema(Archived)Jacob D. Jensen; Andrew L. Vincent.-Last Update: October 10, 2017.
簡介
HAPE是缺氧導致的非心因性肺水腫, 屬於臨床診斷, 特徵是疲倦, 呼吸困難, 運動時乾咳, 如果不治療, 會進展成休息時呼吸困難, 發紺, 死亡率可達 50%
Introduction
High Altitude Pulmonary Edema (HAPE) is a fatal form of severe high-altitude illness. HAPE is a form of noncardiogenic pulmonary edema that occurs secondary to hypoxia. It is a clinical diagnosis characterized by fatigue, dyspnea, and dry cough with exertion. If left untreated, it can progress to dyspnea at rest, rales, cyanosis, and a mortality rate of up to 50%.
HAPE通常發生於海拔 2500 公尺以上, 但也有2000公尺發生的案例(註: 其他文獻說3000公尺以下較少發生),
危險因子包括, 個體因素, 到達海拔, 快速上升, 男性, 使用安眠藥, 過度攝取鹽分, 低溫, 高強度體力活動, 其他前置因素會造成肺血流上升, 肺高壓., 肺血管反應增加, 開放性卵圓窗, 會有更高的HAPE發生率
Etiology
Along with other illnesses related to altitude, HAPE occurs above 2500 meters but can occur at altitudes as low as 2000 meters. Risk factors include individual susceptibility due to low hypoxic ventilatory response (HVR), the altitude attained, a rapid rate of ascent, male sex, use of sleep medication, excessive salt ingestion, ambient cold temperature, and heavy physical exertion. Preexisting conditions such as those leading to increased pulmonary blood flow, pulmonary hypertension, increased pulmonary vascular reactivity, or patent foramen ovale may have a higher predisposition towards the development of HAPE.
HAPE嚴重度決定於多項因素, 包括海拔, 初步認知, 處置, 尋求醫療協助, 在海拔 4500 公尺的發生率 0.6%-6%, 在海拔 5500 公尺的發生率高達 60%. 個人體能無法避免HAPE發生. (level of fitness.) 經過治療的死亡率 11%, 未治療死亡率 50%, 大約 50% HAPE患者會同時罹患AMS,. 14% 同時罹患HACE.
Epidemiology
The severity of HAPE will depend on multiple factors including altitude, initial recognition and management, and access to medical care. At 4500 meters the incidence is 0.6% to 6%, and at 5500 meters the incidence is 2% to 15%, with faster ascent time correlating to a higher incidence. Those with a prior incidence of HAPE have a recurrence rate as high as a 60%. One’s level of fitness is not proven to be a protective factor. Mortality rate, when treated, can be as high as 11% and as high as 50% when untreated. Up to 50% of cases may have concomitant acute mountain sickness (AMS), and up to 14% will have concomitant high altitude cerebral edema (HACE).
** 上面是我自己翻譯的.
下面偷懶就用google中文翻譯了**
病理生理學
HAPE 的發生是肺血管系統對缺氧的反應。在高海拔地區，身體會透過過度換氣來應對缺氧。這稱為缺氧通氣反應（HVR）。這種反應因人而異，並且具有遺傳成分。高海拔適應是一種有趣的現象，通常適用於長期生活在高海拔地區的人，但對於那些訪問高海拔地區的人來說並不常見。然而，在考慮來自高氣壓和高海拔低壓的影響和適應時，了解組織氧氣輸送的原理是有用的。海平面1公升空氣中的氧氣濃度為21%。該濃度在 4000 公尺（~13,200 英尺）處相同，但由於該高度的氣壓降低，與海平面相比，可用氧分子數量僅剩 63%。因此，為了將氧氣充分輸送到組織，特別是那些最需要氧氣進行有氧代謝的組織（大腦、心臟、肺、腎臟），必須發生某些適應。
Pathophysiology
The development of HAPE occurs as a response of the pulmonary vasculature to hypoxia. At altitude, the body responds to hypoxia by hyperventilation. This is known as the hypoxic ventilatory response (HVR). This response varies between individuals and has a genetic component. High altitude adaptation is an interesting phenomenon that regularly applies to individuals living at altitude for long periods of time but is not usual for those visiting altitude. Understanding the principles of tissue oxygen delivery, however, is useful when considering the effects and adaptations of those coming from higher barometric pressures to the lower pressures of high elevation. The concentration of oxygen in 1 liter of air at sea level is 21%. This concentration is the same at 4000 meters (~13,200 feet), but due to the decreased barometric pressure at this altitude, only 63% of the number of available oxygen molecules remain as compared to sea level. Thus, to adequately deliver oxygen to the tissues, particularly those that are most in need of oxygen for aerobic metabolism (brain, heart, lungs, kidneys), certain adaptations must occur.
有四種潛在的適應措施可以克服高山缺氧的限制：
（1）靜止通氣，
（2）缺氧通氣反應，
（3）動脈血紅素的氧飽和度，以及
（4）血紅素濃度。
對安第斯山脈和西藏山脈人口的研究表明，儘管處於相同的海拔高度，不同群體之間的適應性變化卻有所不同。來自西藏的人在前兩個特徵上比安第斯山脈艾馬拉人高出 0.5 個標準差，在後兩個特徵上比安第斯山脈艾馬拉人低了整整一個標準差。這項研究表明，同一海拔地區的不同人群如何適應高海拔壓力有遺傳傾向。對於短期前往高海拔地區的人來說，分鐘通氣量往往是低海拔健行者適應環境的機制。一般來說，促紅血球生成素水平需要長達 1 至 2 週的時間才能增加到足以引起造血和循環血紅蛋白增加。當一個人進入更高的海拔時，每分鐘通氣量幾乎立即增加，隨之而來的是呼吸性鹼中毒。這導致氧解離曲線向左移動（血紅蛋白對氧的親和力增加）。為了回應這種機制，腎臟開始增加質子重吸收，從而穩定血液 pH 值。RBC 2,3-DPG 水準在第 2 天和第 3 天開始增加。然後，Hgb-O2 解離曲線向右移動（血紅素對 O2 的親和力降低）。這使得氧氣更充足地輸送到組織，特別是由於攀爬和/或徒步旅行時的勞累而可能承受更大壓力的肌肉組織。如果 HVR 由於遺傳傾向或鎮靜劑而減弱，則會導致進一步缺氧，從而導致不均勻、過度的低氧性肺血管收縮 (HPV)。這種肺血管收縮會導致受影響肺泡的灌注增加，導致靜水壓力/壓力增加，從而增加血液屏障上的機械應力。血氣屏障受損導致毛細血管通透性增加以及隨後的不均勻肺水腫。這種水腫的形成會阻礙氧氣輸送，導致 HPV 傳播更廣泛且惡化。HPV 反應引起的交感神經刺激和循環血管收縮導致血管收縮，肺動脈高壓惡化，和毛細管壓力增加。如果個體缺乏對這些器官層面變化的先天適應，或者病情沒有被識別和治療，病情就會持續存在並繼續惡化。
註: 血紅蛋白對氧氣的親和力增加是壞事. 因為組織的細胞也需要氧氣. 血紅蛋白氧親和力越高. 組織細胞就越不容易搶到氧氣. 會加重組織缺氧狀態.
註2: 這段給醫護人員的. spesis 患者如果合併 tissue perfusion 不足. 會產生 lactate. 造成血液偏酸, 但酸性血液能讓氧氣更容易進入組織. 讓細胞利用. 因此不建議例行性使用 bicarbonate 較正 acidosis., 應該分析 acidosis 成因進行ˋ針對性治療(例如 hydraion, 較正anemia. 給予升壓劑, DKA患者給予insulin等等).
There are four potential adaptations to overcome the constraints of high altitude hypoxia: (1) resting ventilation, (2) hypoxic ventilatory response, (3) oxygen saturation of arterial hemoglobin, and (4) hemoglobin concentration. Studies of populations in the Andes and Tibetian ranges and ranges have shown different adaptive changes between groups despite being at the same altitude. Those from Tibet had mean 0.5 standard deviations above that of the Aymara people of the Andes for the first two traits and a full standard deviation below for the latter two traits. This research suggests a genetic predisposition to how different groups of people at the same altitude may adapt to high altitude stress. For those traveling to a high altitude for a short period, minute-ventilation tends to be the mechanism by which trekkers from low altitude will acclimate. In general, it takes as much as 1 to 2 weeks for erythropoietin levels to increase enough to cause hematopoiesis and increased circulating hemoglobin. As one enters higher elevations, minute-ventilation increases almost immediately and respiratory alkalosis ensues. This causes a shift in the oxygen-dissociation curve to the left (increased affinity of oxygen by hemoglobin). In response to this mechanism, the kidneys begin increasing proton reabsorption which stabilizes the blood pH. RBC 2,3-DPG levels which begin to increase on days 2 and 3. Then, the Hgb-O2 dissociation curve shifts to the right (decreased affinity for O2 by hemoglobin). This allows for a more adequate delivery of oxygen to the tissues, particularly muscle tissues that may be under greater levels of stress due to exertion with climbing and/or trekking. If the HVR is blunted, due to genetic predisposition or sedatives, it will lead to further hypoxia causing a non-uniform, exaggerated hypoxemic pulmonary vasoconstriction (HPV). This pulmonary vasoconstriction then results in increased perfusion to affected alveoli, causing increased hydrostatic stress/pressure and thus increased mechanical stress on the blood-gas barrier. Damage to the blood-gas barrier results in increased capillary permeability and subsequent non-uniform pulmonary edema. This edema formation impedes oxygen transport, resulting in more widespread and worsening HPV. Sympathetic stimulation and circulating vasoconstrictors from the HPV response result in vasoconstriction, worsening pulmonary hypertension, and increasing capillary pressures. If an individual lacks innate adaptation to these organ level changes or the condition is not recognized and treated, the disease condition will persist and continue to worsen.
History and Physical
HAPE 通常發生在到達高海拔地區後 2 至 5 天。發病隱匿，伴隨乾咳、運動耐受性下降、胸痛和勞力性呼吸困難。如果不治療，可能會發展為休息時呼吸困難和嚴重的勞力性呼吸困難。咳嗽可能會咳出粉紅色泡沫痰或帶血。患者也可能有囉音或喘息、中樞性發紺、呼吸急促和/或心跳過速。
SpO2 通常比海拔高度的預期低 10%，考慮到患者的低氧血症水平和 SpO2 值（通常在 40% 至 70% 左右），患者的表現通常會比預期要好。
History and Physical
HAPE typically occurs 2 to 5 days after arrival at altitude. It has an insidious onset with a non-productive cough, decreased exercise tolerance, chest pain, and exertional dyspnea. Without treatment, it can progress to dyspnea at rest and severe exertional dyspnea. A cough may become productive of pink and frothy sputum or frank blood. The patient also may have rales or wheezes, central cyanosis, tachypnea, and/or tachycardia. SpO2 is often 10% less than expected for altitude, and the patient often will appear better than expected given their level of hypoxemia and SpO2 value, which typically resides around 40% to 70%.
評估
HAPE 的
臨床診斷將包括以下至少兩種症狀或主訴：
胸悶或疼痛、咳嗽、休息時呼吸困難以及運動耐受性下降。它還
會有以下兩項檢查結果：中樞性紫紺、囉音/喘息、心跳過速和呼吸急促。如果有的話，CXR 可能顯示斑狀肺泡浸潤，縱膈/心臟大小正常，超音波可能顯示與肺水腫一致的 B 光。心電圖可能顯示電軸右偏和/或缺血的跡象。對於 CXR 上有浸潤的患者，透過補充氧氣快速糾正臨床狀態和 SpO2 是 HAPE 的特徵。即使可用，實驗室的效用也有限，臨床醫生應始終考慮伴隨的 AMS 和/或 HACE。
Evaluation
HAPE's clinical diagnosis would include at least two of the following symptoms or complaints: chest tightness or pain, cough, dyspnea at rest, and decreased exercise tolerance. It also would have two of the following exam findings: central cyanosis, rales/wheezes, tachycardia, and tachypnea. If available, CXR may show patchy alveolar infiltrates with normal-sized mediastinum/heart, and ultrasound may show B-lines consistent with pulmonary edema. ECG may show signs of right axis deviation and/or ischemia. In a patient with infiltrates on CXR, rapid correction of clinical status and SpO2 with supplemental oxygen is pathognomonic of HAPE. Even if available, labs are of limited utility, and the clinician should always consider concomitant AMS and/or HACE.
治療: 下降1000公尺. 或下降至症狀改善. 下降過程減少患者的運動量(減輕背包,背負下山). 如果有氧氣可以給氧, 可延緩惡化, 但下降仍是主要的治療手段. 氧氣攜帶量如果充足, 將血氧濃度維持在 90% 以上. 攜帶式加壓艙在無法下降的情況可考慮使用, 但需要有人持續在一旁照料, 某些狀況可能不太適合: 嘔吐, 幽閉空間恐懼症, 神智改變(例如同時罹患HACE), 當病患出加壓艙也有可能再次惡化, nifedipine 可降低肺血管收縮, 改善症狀, 可作為輔助治療, 但如果可以下降, 或者有充足的氧氣可供使用, 不宜將 nifedipine 作為唯一的治療方式. 沒有nifedipine也可以考慮使用 威而鋼或犀利士. 至於 acetazolamide, 乙型作用劑(氣管擴張劑), 利尿劑在臨床上沒有角色. (2013年NEJM說其他種類利尿劑無效.可能有害. 丹木斯雖未被證實能治療肺水腫, 但如果沒有不能服用的理由, 丹木斯可加速高度適應, 可考慮同時服用)
主要治療方法是下降 1000 米，或直到下降時症狀消失。在下降過程中，重要的是要盡量減少用力，因為用力可能會增加身體代謝需求引起的低氧血症，並使個人狀況惡化。如果可能的話，嘗試氧氣治療可能會改善症狀，並在下降技術上困難或延遲時幫助患者暫時緩解。也就是說，無論氧氣供應情況如何，治療的主要方法仍然是下降。透過高流量鼻插管和麵罩補充氧氣，滴定至 SpO2 大於 90% 是可行的合理替代方案。當無法下降時，也可以使用便攜式高壓艙，但這些通常需要持續護理，並且對於出現噁心或嘔吐、幽閉恐懼症、或伴隨 AMS/HACE 導致精神狀態改變。離開房間後還存在症狀復發的風險。硝苯地平作為輔助藥物可透過減少肺血管收縮來改善症狀，但如果可以選擇吸氧或下降，則不應將其用作唯一治療方法。如果硝苯地平不可用，磷酸二酯酶抑制劑可透過血管舒張來幫助降低肺動脈和毛細血管壓力。乙醯唑胺、B 受體激動劑或利尿劑的作用尚未被臨床證實。如果硝苯地平不可用，磷酸二酯酶抑制劑可透過血管舒張來幫助降低肺動脈和毛細血管壓力。乙醯唑胺、B 受體激動劑或利尿劑的作用尚未被臨床證明。如果硝苯地平不可用，磷酸二酯酶抑制劑可透過血管舒張來幫助降低肺動脈和毛細血管壓力。丹木斯(乙醯唑胺)、B 受體激動劑或利尿劑的作用尚未被臨床證實。
The mainstay of treatment is to descend 1000 meters or until there is a resolution of symptoms with the descent. During the descent, it is important to minimize exertion as exertion may increase hypoxemia from metabolic demands of the body and worsen an individual’s condition. If available, a trial of oxygen therapy may ameliorate symptoms and help temporize the patient if the descent is technically difficult or delayed. That said, the mainstay of treatment remains descent, regardless of oxygen availability. Supplemental oxygen via a high-flow nasal cannula and facemask titrated to Sp02 greater than 90% is a reasonable alternative when available. Portable hyperbaric chambers also may be used when descent is not possible, but these typically require constant care and may be difficult for individuals experiencing nausea or vomiting, claustrophobia, or altered mental status from concomitant AMS/HACE. There also exists the risk of recurrence of symptoms after exiting from the chamber. Nifedipine improves symptoms as an adjunct by decreasing pulmonary vasoconstriction but should not be used as the sole therapy if oxygen or descent are options. Phosphodiesterase inhibitors may be used to help to decrease pulmonary artery and capillary pressure through vasodilation if nifedipine is unavailable. There is no clinically proven role for acetazolamide, B-agonist, or diuretics.
小訣竅珍珠和其他問題
一旦症狀消退，個人可以考慮以適當的速度恢復上升，並且不再需要氧氣或血管擴張劑治療，並且與症狀出現相比，運動耐量有所增加。臨床醫生也應考慮使用硝苯地平、PDE 抑制劑或沙美特羅來預防先前患有 HAPE 的患者
Pearls and Other Issues
Individuals may consider resuming ascent at an appropriate rate once symptoms resolve and they no longer require oxygen or vasodilator therapy and have an increased exercise tolerance compared to symptom onset. Clinicians also should consider nifedipine, PDE inhibitors, or salmeterol as prophylaxis for those with a prior incidence of HAPE
