High elevation pulmonary edema

Classification according to ICD-10
T70.2	Other and unspecified damage from great heights
ICD-10 online (WHO version 2019)

A high altitude pulmonary edema (also inaccurate: Höhenödem ) HAPE, abbreviated (. Of English high-altitude pulmonary edema ), is a collection of fluid ( edema ) in the lungs , which can occur in mountaineering at high altitudes. Fluid leaks from the capillaries into the lung tissue (especially the alveoli ) and hinders breathing.

It can occur in connection with the altitude cerebral edema and / or within the symptom complex of altitude sickness , or it can appear completely independently without warning signs. Similar conditions were also observed after long-term oxygen ventilation (100% for days) in the form of the so-called respiratory lung.

Occurrence

High altitude pulmonary edema occurs in about 0.7% of climbers who are at an altitude of 3000 meters or higher. The mortality is around 40%.

causes

The development of altitude-related pulmonary edema has only been partially clarified. The low partial oxygen pressure at high altitudes leads, according to the Euler-Liljestrand mechanism, to a hypoxic- related vasoconstriction of the arterioles in the lungs ( high altitude hypoxia ).

As a result, the arterial blood pressure in the pulmonary circulation rises sharply. It has been described that at an altitude of over 4500 m in people who are susceptible to high-altitude pulmonary edema, this pressure is 30–50% higher than that of non-sensitive control persons. The increase in arterial pressure in the lungs is a major factor in the development of high-altitude pulmonary edema. A narrowing of arterioles generally leads to a decrease in blood pressure and thus in the filtration pressure in the downstream capillaries , since less blood can flow through the narrowed arterioles. The narrowing of the arterioles in the lungs occurs in high-altitude pulmonary edema patients to different degrees. Where the narrowing is very pronounced, increase the blood flow significantly (due to the increased arterial pressure) and the pressure in the downstream capillaries. It is believed that this leads to increased filtration and thus to the observed edema formation.

Narrowing of the veins and leakage of fluid from the arterioles have also been discussed as causes. However, these are not sufficient to explain the uneven distribution of high-altitude pulmonary edema in the early stages in x-rays. People are differently susceptible to the development of high altitude pulmonary edema when they are at high altitudes. Genetic factors also play a role.

Symptoms

In high-altitude pulmonary edema, the oxygen exchange is greatly reduced due to the fluid in the lung tissue. See: Asthma cardiale . In this phase, a sudden drop in performance is the main symptom. In addition, resting dyspnoea , cyanosis , dry cough , frothy cough, vomiting , fever, and a 24-hour urine volume less than 500 ml are signs of high altitude pulmonary edema.

Countermeasures

If correct therapeutic measures are taken, improvement usually occurs within a few hours.

By far the best therapy option is immediate descent. With supplementary oxygen breathing during the descent, lethality can be reduced. In addition, drugs such as nifedipine (calcium antagonist) or diuretics can be used, which sometimes improve the state of health quickly, but which can cause dangerous side effects. Furthermore, if available, special forms of ventilation are possible.

Various medications can reduce the likelihood of high altitude lung edema occurring. The prevention with acetazolamide is controversial ; it is even contraindicated for therapy because of possible aggravation . Dexamethasone is indicated for cerebral edema, but has no effect on high- altitude pulmonary edema. Theophylline , montelukast and ginkgo biloba are still under review in this regard.

Web links

• current, as yet unpublished 5 studies on training and receptivity, acetazolamide, ibuprofen and tadalafil. ClinicalTrials.gov, US National Institutes of Health, August 1, 2010, accessed August 1, 2010 . 
• Altitude.org
• Berger, MM: Why mountaineers get high-altitude pulmonary edema. (790 kB; PDF) In: Press release No. 134 of August 7, 2006. Heidelberg University Hospital, accessed on August 1, 2010 . 
• High elevation pulmonary edema, syn. HAPE (High Altitude Pulmonal Edema). SGGM Swiss Society for Mountain Medicine, accessed on December 28, 2015 . 
• Research in altitude medicine. Heidelberg University Hospital, accessed on August 1, 2010 : "Prof. Peter Bärtsch's working group, since 1984 field studies in Margherita-Hütte (Walliser Alps, 4559 m above sea level) on the pathophysiology, therapy and prophylaxis of acute mountain sickness and high altitude lung edema" 
• GIN health information network
• High-Altitude Pulmonary Edema, dexamethasone and tadalafil, Summary for Patients. In: Maggiorini, M. et al., Both Tadalafil and Dexamethasone May Reduce the Incidence of High-Altitude Pulmonary Edema: A Randomized Trial, Ann Intern Med ., 2006 Oct 3; 145 (7): 497-506. American College of Physicians, accessed August 1, 2010 : "dexamethasone appears to be more effective and is better than tadalafil" 

Individual evidence

1. ↑ Alphabetical directory for the ICD-10-WHO version 2019, volume 3. German Institute for Medical Documentation and Information (DIMDI), Cologne, 2019, p. 517
2. ^ Gerhard Brüschke (editor): "Handbook of Inner Diseases", Volume 1/1, Gustav Fischer Verlag , Stuttgart 1985, ISBN 3-437-10806-9 , page 642.
3. ^ FH Hertle, E. Fuchs and R. Ferlinz: "Diseases of the Respiratory Organs", in: Hanns P. Wolff and Jürgen Beyer (editors): "Internal Therapy", 5th edition, Urban & Schwarzenberg , Munich, Vienna, Baltimore 1984 , ISBN 3-541-07265-2 , page 456.
4. ↑ J. Widimsky "pulmonary heart", in: Gerhard Brüschke (Editor): "Handbook of Inner diseases", Gustav Fischer Verlag , Volume 1, Part 2, Stuttgart and New York, 1986, ISBN 3-437-10968-5 , Page 168.
5. ↑ ^{a b} Christoph Dehnert, Marc Moritz Berger, Heimo Mairbäurl, Peter Bärtsch: High altitude pulmonary edema: A pressure-induced leak . In: Respiratory Physiology & Neurobiology . tape 158 , no. 2-3 , September 2007, pp. 266 - 273 , doi : 10.1016 / j . or 2007.05.002 , PMID 17602898 .
6. ↑ Andreas Ruß: "Medicines pocket 2017", Börm Bruckmeier Verlag, Grünwald 2016, ISBN 978-3-89862-780-1 , page 219.

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !