Balloon pump  

It's rare I'll agree with the medcrew but on this one there is a truth in what he is requesting.  The balloon pump once out of it's carrier only has a limited supply of helium.  For every inch of pressure change from the pressure altitude the balloon pump was calibrated at (the patients room) it will recalibrate and that costs helium.  There is only enough helium, assuming you started with everything full, for 6 changes.  So 3 on the climb, 3 on the descent.  The goal is to fly only high enough to be safe and legal.  Once you get to appx 1000' above where you started it will recal, if you go to 2000' it will do it again, this will continue every 1 inch change in pressure.  If you keep going up and down along the flight path, climb over a ridge, drop back down, then climb over a second ridge and down again you will cause extra calibrations and ensuing loss of helium.  Just get to where you need to be and stay there.  If you are flying in a larger aircraft that can accept the pump and its carrier than its not much of an issue.  For those of you flying in the mountains I'd be curious how you are doing balloon pumps where you are climbing up over large ranges and coming back down again.