Here is some information from an anesthesiologist friend of mine:
"The most common post-op complication that we see is a pulmonary problem. There are multiple reasons for is, and surgeons are quick to point the finger and say "it's the anesthesia." The cause is much more complex than that. A quick physiology lesson:
Think of your lungs as being a bunch of tiny balloons at the end of straws. When you exhale, you compress the balloons using your chest muscles to squeeze the air out. However, you never really empty them. A small amount of air remains in the balloon. This is called the "functional residual capacity" (FRC). However, some of the balloons (the ones at the base - bottom - of the lung) may indeed collapse. The only way to get these to open is to "pop" them open by taking deep breaths. There's the dreaded word - "deep breaths." After surgery, deep breaths are more difficult (painful) to take, and people tend to not do it because it hurts. Larger people have more work to do to move the chestwall, and it takes more effort to get those big breaths in.
When you don't keep those sacs (alveoli) open, you set up a situation in which bacteria like to grow. Bingo - pneumonia.
There a couple of things to keep in mind in your case:
1) I assume that you're basically in good health, and there's nothing other than what I mentioned above (surgery and size) keeping you from taking big deep breaths.
2) Laparoscopic surgery is MUCH less of an insult to the breathing mechanism. The incisions are small, it doesn't hurt as much, and you're less disinclined to deep breathe.
3) It sounds like your surgeon is a pro, and face it, you're good at what you do a lot of. Experience means faster surgery, and faster is better because there are a bunch of other pulmonary things that won't happen. (For a discussion of the effects of anesthesia on pulmonary function, see next week's lecture).
4) The difference between what they set as their "goal" for the spirometer and what you can actually do doesn't sound like much to me. The important thing is that you deep breathe and keep moving as much as the surgeon allows. Lying around in bed afterward sets you up for the things I mentioned. "