Make eye contact with one or two, flash 'em a big ol' smile and sing out, "Excuse me, comin' thru!" then "Thank you!" and maybe something respectful but silly anyway ("You needed a short break, didn't ya?!" They ARE there to learn (for the time being it IS "their" hospital too), and I've found folks usually respond to cheerfulness and respect with the same. They are under a tremendous amount of stress, as are we, only in a different way. Growling begets the same. JMHO.

-- D