Guideline sources The following summarized guidelines for the management of acute altitude sickness are prepared by our editorial team based on guidelines from the Wilderness Medical Society (WMS 2019). 1 Guidelines 1. Respiratory support Supplemental oxygen: Consider administering ongoing supplemental oxygen, if available, sufficient to raise SpO to > 90% or to relieve symptoms while waiting to initiate descent or when descent is not practical. B Administer supplemental oxygen sufficient to achieve SpO of > 90% or to relieve symptoms while waiting to initiate descent when descent is infeasible and during descent in severely ill patients with high altitude pulmonary edema. A Positive airway pressure: Insufficient evidence to support the use of CPAP for the treatment of patients with acute mountain sickness. Consider administering CPAP or EPAP for the treatment of patients with high altitude pulmonary edema when supplemental oxygen or pulmonary vasodilators are not available or as adjunctive therapy in patients not responding to supplemental oxygen alone. C Hyperbaric oxygen therapy: https://web.pathway.md/diseases/rec1cXRcFXHv2p0dW 1/4 6/23/23, 1:40 AM Acute altitude sickness Pathway Use portable hyperbaric chambers, if available, in patients with severe acute mountain sickness or high altitude cerebral edema when descent is infeasible or delayed and supplemental oxygen is unavailable. B Consider using portable hyperbaric chambers in patients with high altitude pulmonary edema when descent is infeasible or delayed or supplemental oxygen is unavailable. B 2. Medical management Acetazolamide: Consider administering acetazolamide for the treatment of patients with acute mountain sickness. B Do not use diuretics or acetazolamide for the treatment of patients with high altitude pulmonary edema. D Dexamethasone: consider administering dexamethasone for the treatment of patients with acute mountain sickness. B Show 2 more Nifedipine: administer nifedipine for the treatment of patients with high altitude pulmonary edema when descent is impossible or delayed and reliable access to supplemental oxygen or portable hyperbaric therapy is unavailable. B Phosphodiesterase inhibitors: consider administering tadalafil or sildenafil for the treatment of patients with high altitude pulmonary edema when descent is impossible or delayed, access to supplemental oxygen or portable hyperbaric therapy is impossible, and nifedipine is unavailable. C Beta-agonists: insufficient evidence to support the use of -agonists for the treatment of patients with high altitude pulmonary edema. I Analgesics: consider offering acetaminophen or ibuprofen for the treatment of headache at high altitude. B 3. Nonpharmacologic interventions Descent: Advise descent in patients with: acute mountain sickness failed to resolve with other measures, or severe acute mountain sickness high altitude cerebral edema high altitude pulmonary edema. A 4. Preventative measures https://web.pathway.md/diseases/rec1cXRcFXHv2p0dW 2/4 6/23/23, 1:40 AM Acute altitude sickness Pathway Gradual ascent: Advise gradual ascent, defined as a slow increase in sleeping elevation, for the prevention of: acute mountain sickness high altitude cerebral edema high altitude pulmonary edema. B Pre-acclimatization: Consider advising staged ascent and prea-aclimatization, when feasible, for the prevention of: acute mountain sickness prevention high altitude pulmonary edema. B Consider offering hypoxic tents to facilitate acclimatization and prevent acute mountain sickness if sufficiently long exposures can be undertaken regularly over an appropriate number of weeks and other factors, such as sleep quality, are not compromised. C Chemoprophylaxis (acetazolamide): consider offering acetazolamide in travelers at moderate or high risk of acute mountain sickness with ascent to high altitude. B Show 3 more Chemoprophylaxis (corticosteroids): consider offering dexamethasone as an alternative to acetazolamide in adult travelers at moderate to high risk of acute mountain sickness. B Show 2 more Chemoprophylaxis (nifedipine): offer nifedipine for the prevention of high altitude pulmonary edema in high altitude pulmonary edema susceptible persons. B Chemoprophylaxis (tadalafil): consider offering tadalafil for the prevention of high altitude pulmonary edema in known susceptible persons not being candidates for nifedipine. B Chemoprophylaxis (salmeterol): do not use salmeterol for the prevention of high altitude pulmonary edema. D Chemoprophylaxis (analgesics): Consider offering ibuprofen for the prevention of acute mountain sickness in persons not wishing to take acetazolamide or dexamethasone or having allergies or intolerance to these medications. C Do not use acetaminophen for the prevention of acute mountain sickness. D Chemoprophylaxis (ginkgo biloba): do not use ginkgo biloba for the prevention of acute mountain sickness. D References 1. Andrew M Luks, Paul S Auerbach, Luanne Freer et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update. Wilderness Environ Med. 2019 Dec;30 4S S3 S18. Open https://web.pathway.md/diseases/rec1cXRcFXHv2p0dW 3/4 6/23/23, 1:40 AM Acute altitude sickness Pathway 2. Luks AM, McIntosh SE, Grissom CK et al. Medical Society Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update. Wilderness Environ Med. 2010 Jun;21 2 146 55. Open 3. Robert C Roach, Peter H Hackett, Oswald Oelz et al. The 2018 Lake Louise Acute Mountain Sickness Score. High Alt Med Biol. 2018 Mar;19 1 4 6. Open 4. M Yaron, N Waldman, S Niermeyer et al. The diagnosis of acute mountain sickness in preverbal children. Arch Pediatr Adolesc Med. 1998 Jul;152 7 683 7. Open https://web.pathway.md/diseases/rec1cXRcFXHv2p0dW 4/4