You’ll need to get your head well and truly around blood gases while you’re spending time with the anaesthetists. Scott Weingart has produced a 4 part podcast series on acid-base (with accompanying slides) because he thinks our medical education fails us in this area. Check them out here.
For blood gas analysis, also try anaesthesiamcq.com, as they have lots of information broken down into bite-sized links. It’s a really tricky topic, even for many experienced doctors.
Scancrit.com is written by two Scandinavian senior anaesthetic registrars, and they’ve put together a few links to learn the Stewart method of acid-base analysis.
Also check out an online textbook of anaesthesia.