High Altitude Pulmonary Oedema: An Observational Study

Arun Tyagi

Arun Tyagi

Keywords: High altitude, acclimatisation, AMS, HAPO, HACO, HAPAH

Abstract

High altitude pulmonary oedema (HAPO) is a potentially fatal, non-cardiogenic pulmonary oedema, which occurs in unacclimatized, susceptible individuals after rapid induction into a high altitude area.
Aims: An observational study of high altitude pulmonary oedema.
Methods and Material: Data was collected over a 3-year study period at a general hospital located in high altitude and catering to a population of over 100,000 people deployed at heights ranging from 3000m to 6000 m in the Himalayas. Prospective data collection was done of all patients received with a clinical diagnosis of HAPO.
Results: 686 cases of high altitude related illness namely acute mountain sickness (AMS), High Altitude pulmonary oedema (HAPO), high altitude cerebral oedema (HACO) and high altitude pulmonary arterial hypertension (HAPAH) were received and treated at this specialised centre. A total of 434 cases of HAPO were diagnosed during this period with maximum number of cases occurring in age group 21-25 years, predominantly affected Lowlanders, majority occurred within 24 h of induction to altitudes ranging from 3000m to 4500m. The clinical presentation included productive cough and dyspnoea with crepitations on auscultation and tachypneoa with majority having saturations less than 80%. Chest radiographs showed classical pulmonary infiltrates involving B/L lung zones in > 30%, right lower zone (RLZ) was the commonest.
Conclusion: High altitude pulmonary oedema is a significant and potentially serious health problem. Early diagnosis carries better prognosis. Greater understanding of the pathophysiology and strict adherence to acclimatisation schedule definitely reduces its incidence, mortality and morbidity.

References

1. StreamOO, Grisson CK. Update on High-Altitude Pulmonary Edema: Pathogenesis, Prevention, and Treatment. Wilderness & Environmental Medicine. 2008;19(4): 293–303.
2. Bartsch P, Mairbaurl H, Maggiorinni M, Swenson ER. Physiological aspects of high-altitude pulmonary edema. J ApplPhysiol. 2005;98: 1101-1110.
3. Hultgren HN, Honigman B, Theis K et al. Highaltitude pulmonary edema at a ski resort. West J Med. 1996; 164:222–227.
4. Busch T, Bartsch P, Pappert D et al. Hypoxia decreases exhaled nitric oxide in mountaineers susceptible to high-altitude pulmonary edema. Am J RespirCrit Care Med. 2001;163:368–373.
5. Cremona G, Asnaghi R, Baderna P et al. Pulmonary extravascular fluid accumulation in recreational climbers: a prospective study. Lancet. 2002;359:303–309.
6. Swenson ER, Maggiorini M, Mongovin S et al. Pathogenesis of high-altitude pulmonary edema: inflammation is not an etiologic factor. JAMA. 2002;287:2228–2235.
7. Berger M, Hesse C, Dehnert C et al. Hypoxia impairs systemic endothelial function in individuals prone to high-altitude pulmonary edema. Am J RespirCrit Care Med. 2005;172(6):763-7.
8. Droma Y, Hanaoka M, Ota M et al. Positive association of the endothelial nitric oxide synthase gene polymorphisms with high-altitude pulmonary edema. Circulation. 2002;106(7):826-30.
9. Peter Bärtsch, Erik R. Swenson. Acute High-Altitude Illnesses,N Engl J Med. 2013;368:2294-302.
10. Kapoor R, Narula AS, Anand AC. Treatment of acute mountain sickness and high altitude pulmonary oedema. MJAFI. 2004;60:384-387.
11. Hackett PH, Roach RC. High-altitude illness. N Engl J Med. 2001;345:107–114.
12. Bärtsch P. High altitude pulmonary edema. Med Sci Sports Exerc. 1999;31:(suppl 1). S23–S27.
13. Voelkel NF. High Altitude pulmonary edema. N Engl J Med. 2002;346:1606-1607.
14. Gabry AL, Ledoux X, Mozziconacci M, Martin C. Highaltitude pulmonary edema at low altitude(2,400m;7,870 feet) A series of 52 patients. Chest. 2003;123:49-53.
15. Vock P, Brutsche MH, Nanzer A, Bartsch P. Variable radiomorphologic data of high altitude pulmonary edema: features from 60 patients. Chest. 1991;100:1306– 1311.
16. Levine SJ, White DA, Fels AOS. An abnormal chest radiograph in a patient with recurring high altitude pulmonary edema. Chest. 1988;94:627–628.
17. Bärtsch P, Maggiorini M, Ritter M, Noti C, Vock P, Oelz O. Prevention of high-altitude pulmonary edema by nifedipine. N Engl J Med. 1991;325:1284–1289.
18. Sartori C, Allemann Y, Duplain H et al. Salmeterol for the prevention of high-altitude pulmonary edema. N Engl J Med. 2002;346:1631–1636.
19. Maggiorini M, Brunner-La Rocca HP, Peth S et al. Both tadalafil and dexamethasone may reduce the incidence of high-altitude pulmonary edema: a randomized trial. Ann Intern Med. 2006;145:497–506
20. Richalet JP, Gratadour P, Robach P et al. Sildenafil inhibits altitude-induced hypoxemia and pulmonary hypertension. Am J RespirCrit Care Med. 2005;171:275– 281.
21. Teppema LJ, Balanos GM, Steinback CD et al. Effects of acetazolamide on ventilatory, cerebrovascular, and pulmonary vascular responses to hypoxia. Am J RespirCrit Care Med. 2007; 175:277–281.