Symptomatic Hypotonic Hyponatremia Presenting at High Altitude

Abstract

We present a case of altered mental status and seizure that occurred at an altitude known to cause high altitude-related illnesses. Based on the presenting symptoms, the patient was initially transferred to the hospital with a presumptive diagnosis of high altitude cerebral edema. On review of imaging and laboratory data, she was found to be experiencing symptomatic hypotonic hyponatremia. This case presented an interesting diagnostic challenge and underscores the importance of maintaining a broad differential diagnosis when evaluating a patient with altered mental status from an alpine setting.

Statement of the 3rd International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015

“…EAH must be differentiated from other causes of collapse that may present with similar signs and symptoms including exertional heat illness,73 acute mountain sickness,39 hypernatraemia149 150 and exercise-associated postural hypotension 148. It is important for medical staff to perform a rapid history and physical examination to help determine the aetiology of these non-specific symptoms.…”

“…such as in a remote setting 39 118 151. In this situation, empiric treatment is justified using the same treatment recommendations described above for EAH documented with a [Na + ] measurement (box 4).…”

Exercise-Associated Hyponatremia, Hypernatremia, and Hydration Status in Multistage Ultramarathons

“…Serious causes of illness in this population include electrolyte disturbances, hydration imbalances, heat-related illness, and cardiovascular compromise. [2][3][4][5][6] Dysnatremia has been an area of significant interest in this population of runners. The majority of research has focused on exercise-associated hyponatremia (EAH), which is a potentially serious condition.…”

Wilderness Medical Society Clinical Practice Guidelines for the Management of Exercise-Associated Hyponatremia: 2019 Update

“…EAH has been documented in hikers, trekkers, climbers, and cold climate endurance athletes. [7][8][9][10][11] Thus, EAH is not solely associated with activities in warm climates but is reported in both environmental extremes. Furthermore, it is likely that many individuals with asymptomatic or symptomatic EAH go underreported.…”