Diagnosis question

Yes, you make sense. You can make any diagnosis a "Risk for". It can be tricky with the physiological diagnoses that a based upon the physical symptoms of disease. However, as long as you have done an assessment of the patient and you understand the underlying pathophysiology that is going on, and are sure there is no other nursing diagnosis that applies, go for it. Understand that with "Risk for" you are anticipating a problem.

With Gas Exchange, you have 2 etiologies. They would become your risk factors. The causes for Impaired Gas Exchange are physiological changes happening in the alveoli that you would want to "head off at the pass" (before they happen). Permanent changes would be pretty much out of the question, I would think, because they take so very long (years) to occur. But the inflammation of pneumonia or some of the other diseases such are avoidable with teaching and avoidance of the irritant.

NANDA encourages nurses to develop a nursing diagnosis for any nursing problem if one does not exist in the current list. The advantage of the current list and taxonomy is that all the work of the wording, identifying the etiologies and classifying the signs and symptoms have all been figured out for you. You merely need to look at a taxonomy reference. When you want to go maverick you have to develop you own nursing diagnosis label and figure out what your definition, etiology and defining characteristics are going to be for the problem or risk you are identifying. Good luck!