If a pt has pneumonia then is it the standard practise to try to get the pt to sit up in bed? is there any evidence that this may help in some way?

YES: This prevents settling of mucous and allows for expectoation and prevent aspiration. This is also the best position to receive pulmonary inhalation therapy.

Sitting up: Sitting up will open the back muscles and intercostal muscles for better excursions during inspiration/ expiration. Will also favor stronger cough and mobilizing secretions from the airways. Still the best measure in order to avoid aspiration pneumonia.

Yes: With pneumonia, the more you move and deep breathe, the better off you are. When people are put on strict bed rest, they can develop new pneumonia or have a worsening of their current pneumonia. Hope this helps!