This an interesting article which sounds credible. It also seems like common sense to me. It might be helpful for you all to know when confronted by unhelpful or unsympathetic healthcare professionals. Essentially it's better for smokers not to give up prior to surgery if they are only doing so around the time of surgery. You need to give up months ahead to be in with a chance of deriving the supposedly possible benefits. Hit the link above for the full text or just read the quote below.
"Unfortunately, the picture is not so clear and simple. It seems to take at least 48 hours to begin to show an improvement in the increased sensitivity and increased bronchial reactivity that is seen in smokers. It probably takes as much as two weeks before these factors are improved as much as possible. So, just in terms of pulmonary effects, a short term cessation of smoking does not seem to make much of a difference.
In fact, a short term cessation may actually make things worse. It seems the effects of increased secretions, decreased ability to clear these secretions, small airway disease, etc. take as much as four to eight weeks to reverse. In fact, a couple of studies have shown that patients who quit smoking have an increased risk of pulmonary complications unless they have quit for four weeks or more. So while smokers may have more problems than nonsmokers, it seems that smokers that have recently quit actually do worse than those that keep smoking."