Thrombotic Complications in Young Adults at High Altitude Areas: An Indian Experience.

High altitudes(HA) have been a source of great adventures to sea land natives during short visits. But they also result in life threatening situations. There is no definite protocol to predict these likely complications. Certain thrombotic tendencies have been identified as possible risks for these complications but there have been some times such complications can occur in the individuals otherwise not known to have any known abnormalities of thrombosis. Also the duration of exposure to high altitude required to trigger this complication is uncertain. We present 24 cases of high altitude associated thrombotic complications. All patients were incidentally males in an age group of 22–38 years (median age 28 years). They were all otherwise healthy individuals having undergone a basic medical examination before moving to HA (defined as an altitude above 9000 ft.). They all moved to HA by air and underwent standard acclimatization program before they were allowed to move out there. The duration of stay ranged between 2 weeks to 4 months. The complications encountered included deep vein thrombosis (DVT) of lower limbs (n- 18) pulmonary embolism(PE; n- 9), cortical venous thrombosis (CVT) in 5 cases and splenic infarctions in 5 cases. 25 of these also developed features of pulmonary hypertension as confirmed by echocardiography in these patients and pulmonary angiography in 3 cases who had developed pulmonary embolism. They all were treated with heparin followed by oral anticoagulation. These all patients were told to move out of HA at earliest possible opportunity. They were all investigated for possible thrombotic abnormalities. These tests included assays for Protein C,S,AT, APC resistance and mutation analysis for MTHFR and Factor V leiden. Two of the Five patients, who had developed splenic infarction were detected to have sickle cell trait. These patients underwent splenectomy besides anticoagulation. The anticoagulation was stopped 6 months later. They all later moved out of HA and were advised to avoid re-exposure to HA. These individuals arte on regular follow up and are free of any subsequent recurrence of thrombotic complications. We conclude that HA itself may be a risk for various thrombotic complications especially in individuals exposed to HA for a longer duration.