What symptom should prompt immediate evaluation for a potential air embolism in a patient with a central venous catheter?

Shortness of breath is a critical symptom that warrants immediate evaluation for a potential air embolism in a patient with a central venous catheter. An air embolism occurs when air enters the vascular system, potentially leading to serious complications such as respiratory distress, stroke, or even cardiac arrest. When air bubbles travel to the lungs, they can obstruct blood flow, making it difficult for the patient to breathe, which gives rise to shortness of breath.

When considering the other symptoms, nausea, fatigue, and coughing might indicate various issues but are less specific for an air embolism. Nausea could stem from numerous causes, including gastrointestinal distress, while fatigue may indicate general health concerns or the evolution of a different medical condition. Coughing can be attributed to many factors ranging from upper respiratory tract infections to irritants, but isolated coughing does not necessarily suggest an immediate life-threatening situation like shortness of breath can in this context. Thus, recognizing shortness of breath as a potential indicator of an air embolism supports timely and appropriate intervention.