This refers to the suggestion to try positive end-expiratory pressure (PEEP) for the treatment of high altitude pulmonary oedema (HAPO). The use of PEEP has already been tried and found useful [1,2]. However, in my experience a simple tight fitting facemask seems to work just as well.
It is agreed that the one-man HAPO bag has several limitations, but when it is used judiciously the results are most gratifying. Though monitoring patients is difficult, I have found the battery operated pulse oximeter most helpful as this little piece of equipment can be put into the bag with the patient and the pulse rate and SaO2 can be read off directly through one of the windows on the bag. The High Altitude Medical Research Centre (HAMRC) had recommended to the office of the DGAFMS in 2001 that each of the one-man HAPO bags must be supplied with such a pulse oximeter.
It is also to be reiterated that the safest and surest form of treatment of early HAPO is a quick and considerable descent. This is not always possible hence the second best treatment modality still remains bed rest and oxygen by facemask (with or without PEEP) given at a brisk rate of 8-10 L/min. The one-man HAPO bag is only the third option and is only a first-aid measure till the patient can be evacuated to hospital. But at remote posts from where evacuation is impossible or delayed, due to bad weather or enemy action, and the stock of oxygen cylinders is depleted then the third choice becomes the only choice and must be used despite all its limitations. Therein lies the importance of enhancing the capabilities of the one-man HAPO bag.
References
- 1.Feldman KW, Hernden SP. Positive expiratory pressure for the treatment of high altitudes pulmonary oedema. Lancet. 1977;1:1036–1037. doi: 10.1016/s0140-6736(77)91263-6. [DOI] [PubMed] [Google Scholar]
- 2.Schoene SC. High altitude pulmonary oedema and exercise at 4400 m on mount McKinley. Effect of expiratory positive airway pressure. Chest. 1985;87:330–333. doi: 10.1378/chest.87.3.330. [DOI] [PubMed] [Google Scholar]