Methods and compositions for treating a patient for a condition characterized by an excess blood concentration of dissolved gas in at least one targeted region of the patient are provided. The method comprises administering a composition comprising a perfluorocarbon droplet emulsion into the blood of the patient； insonifying the at least one target region sufficient to achieve formation of microbubbles by droplet vaporization of at least a portion of the perfluorocarbon droplets present in the blood； whereby a concentration gradient favoring movement of gas molecules from the blood into the microbubbles is established for a time frame.
