Abstract: A method of treatment for third spacing is provided. The method includes identifying an adverse factor, which includes conditions causing an increase in vascular permeability resulting in third spacing. The method also includes diagnosing the patient with third spacing, which can include third spacing of fluids, materials, or both. The patient is treated with a therapeutically effective amount of a non-increased vascular permeability modifier loop diuretic, such as a non-sulfonamide loop diuretic like ethacrynic acid or ethacrynate sodium.