Patients were excluded if they had a history of severe reactions to blood or any blood-derived product; if they had a selective IgA deficiency or demonstrable antibodies to IgA; if they received blood or any blood product or derivative other than a commercially available IGIV within 3 months prior to study entry; if they had hepatic function abnormalities or a positive direct Coombs test at screening; if they had a pre-existing renal impairment, a history of drug or alcohol abuse in the previous 12 months or acquired medical condition known to cause secondary immune deficiency; if they were receiving long-term daily treatment with steroids at a dose of at least 1 mg/kg/day; if they had a requirement for pre-medication for IGIV infusion other than aspirin, acetaminophen, or other non-steroidal anti-inflammatory drug, or antihistamine; and if the received immunosuppressive or immunomodulatory drugs.
Exaggerated hypoxic pulmonary vasoconstriction has been attributed to an increased susceptibility of the pulmonary circulation – sustained elevation of cytoplasmic calcium concentration – to sympathetic activity and/or high levels of endothelin-1. Increased sympathetic activity and elevated norepinephrine plasma levels have been found in individuals with AMS and HAPE [19,38–40] . Rapid exposure to 4559 m almost doubles plasma endothelin-1 levels  , the highest values being measured in individuals with HAPE  . Both intensity of sympathetic activity  and plasma endothelin-1 levels are positively correlated with systolic pulmonary artery pressure [41,42] .
Edema is the swelling of tissues as a result of excess water accumulation. Peripheral edema occurs in the feet and legs. There are two types of edema, non-pitting edema and pitting edema. Causes of pitting edema is caused by systemic diseases (most commonly involving the heart, liver, and kidneys), and medications. Local conditions that cause edema are thrombophlebitis and varicose veins. Edema or swelling of the legs, feet, ankles, and face are common during pregnancy. Idiopathic edema is edema in which the cause is not known. Pitting edema is scored on pitting edema measurement scales. Edema is generally treated with medication.