What treatment maneuver is indicated for addressing air embolus?

The most appropriate treatment maneuver for addressing an air embolus is closed chest massage. In cases of an air embolism, air bubbles enter the vascular system, which can lead to obstruction of blood flow and subsequent cardiovascular collapse. Closed chest massage (or cardiopulmonary resuscitation, CPR) is indicated to help maintain circulation and prevent cardiac arrest as the air embolism is managed.

While other options listed may have roles in different medical emergencies, they do not specifically target the immediate complications associated with an air embolus. Elevation of the legs might be beneficial in certain hypotensive states, but in the case of an air embolus, it does not address the blockage caused by the air. Application of oxygen can assist in treating hypoxia that may result from decreased blood flow, but it does not resolve the issue of the air in the circulation. Fluid resuscitation may be helpful for blood volume issues, but again, it does not resolve the underlying problem of the embolism itself. Therefore, closed chest massage is the most direct and life-saving intervention in the context of an air embolus.