Here are some thoughts: rig a hands-free setup for yourself. There are camisoles and bras designed for this purpose, or you can make one yourself by cutting holes out of a snug-fitting cami. Any chance you can sneak into a private room with a workstation? Then you can read images while pumping. It could actually be an ideal job for combining working and pumping! Or perhaps dictating reports while pumping. Even on an interventional month you could potentially use the pumping time for dictating procedure notes. Or writing H&P's on the EMR. If none of that is possible, you can at least combine pumping and eating lunch.
Pumping need not take half an hour. Some moms do take that long for ideal output, but if you have only 10 or 15 or 20 minutes, make use of that time. Any amount of pumping you can sneak into your day is good. More time-saving tips: the flanges and valves do not need to be washed with every pumping sessions. They should be fine at room temp in a bag between sessions. If you can stick them in the fridge, all the better. Or you can buy multiple sets of parts - so if you are going to pump twice a day, two sets of parts, for example. You can leave the milk for up to 8 hours at room temp, longer with a cooler pack, in case you don't have time to take the milk to a fridge for storage.
Even pumping twice a day should maintain your supply pretty well, even if it does not completely meet baby's daytime needs for expressed breast milk. One thing that is key is to avoid overfeeding during the day. One, that makes it hard for you to keep up. Two, that decreases baby's motivation to nurse when you are together, so your supply takes another hit. The rule of thumb is 1 - 1.5 oz per hour apart. Usually in 2 or 3 oz meals. So you might want to store milk in 2 or 3 oz sizes with 1 oz "toppers" to be used if baby is still hungry.
Here are some links on breastfeeding-friendly bottle-feeding:
http://www.llli.org/docs/00000000000...astfedbaby.pdf
http://kellymom.com/bf/pumpingmoms/e...reastfed-baby/
http://kellymom.com/bf/pumpingmoms/f...ottle-feeding/
And here are the storage guidelines
http://kellymom.com/bf/pumpingmoms/m...e/milkstorage/