Excessive alcohol use is responsible for a myriad of health-related issues in this country, at a cost of billions of dollars per year. It also indirectly impacts other medical and mental health problems, making bad problems worse. This study is just one such example, with alcohol use (even acute, rather than chronic, use) contributing to significantly higher risk of pneumonia post-surgery. Seems that the immune system just isn't up to fighting off the infections in one's system if an individual has been consuming a significant amount of alcohol leading up to the procedure.
This has been common knowledge when considering the chronic alcoholic, but this study suggests that even acute use (say, 3-5 drinks per day in the days prior to surgery) also has this effect. This means it is vitally important for people to be honest with their doctors about the amount of alcohol they've consumed prior to having surgery. It also means that for individuals that are struggling with alcohol use, a non-emergency procedure may need to be postponed until the alcohol use is reduced/eliminated (yet another interaction between the world of medicine and mental health).