Episode 29: PA catheters with Dr. Glenn Whitman

In this episode, episode 29, I welcome to the show Dr. Glenn Whitman.  Dr. Whitman is a cardiac surgeon and intensivist and runs the cardiac surgical ICU here at Johns Hopkins.  I interview Dr. Whitman about PA catheters.  We discuss when to place them, when not to place them, how to use them and when to take them out.

4 Replies to “Episode 29: PA catheters with Dr. Glenn Whitman”

  1. Excellent discussion! Extremely cogent arguments for the use of PA catheters in CT surgery but also a great basic discussion of them for those of us who are just starting to use them in training.

  2. Jed, your program rocks! I’m private practice in Sacramento and am education chair. Really frustrating trying to teach old dogs new tricks. A couple requests:
    1) hyperoxia talk was awesome. I adapted my practice to it. Any literature I can send to my colleagues. Most of colleagues run 100% O2.
    2) bicarbonate talk equally amazing. Any literature links for that as well?
    3) regarding pa catheter talk… if pt on higher fio2, say 70% and pao2 in hundreds, is SVO2 still accurate. In other words, if pao2 400, can SVO2 be above 100? Is svo2 still helpful if pao2 very high?
    Thanks again for your incredible work and I hope you continue this. What you’re doing is very important and valued!

    1. Hi Josh,

      Thanks so much, I’m glad you enjoy the show!

      For hyperoxia there are a bunch of references in this slide set that I think make a very clear argument against hyperoxia of any kind in the ICU. I’ll admit the case for avoiding hyperoxia intraoperatively is less ironclad, but I think it’s still a good one. There is no doubt that 100% fio2 is toxic, even in just a few hours. Whether it has permanent effects is hard to say, but why take the chance when you don’t need it? Additionally, you increase your shunt due to absorption atelectasis when you use 100% fio2. Slides with references are here: http://accrac.com/wp-content/uploads/2016/07/hyperoxia-slides.pptx

      For bicarb, I really like these two articles. Also good links in the references sections to other supporting evidence:
      Forsythe: https://www.ncbi.nlm.nih.gov/pubmed/10631227
      Sabatini: https://www.ncbi.nlm.nih.gov/pubmed/18322160

      Your SVO2 should still be accurate even with a high pao2. The reason is that your oxygen CONTENT of the blood is almost unchanged by having a high pa02. Remember you have to multiply the pa02 by 0.003 to get the oxygen content due to that pa02. So the difference between the content at a pa02 of 75 and a pa02 of 200 is only 0.375ml/dl. When a normal content is about 20ml/dl that’s only about a 2% difference. Your arterial saturation will never be above 100% and so your body will still extract the same amount (maybe minus that tiny bit that it gets from the higher pao2). Your SVO2 is a saturation, so it can never be over 100%. It’s a measure of how saturated your hemoglobin is. If you start at 100%, you will extract about 25% if you’re totally healthy, and more if you’re not, but your SVO2 will still be 75% or less and that tiny bit of increased O2 content won’t really change it.

      I hope that makes sense and helps. Thanks for listening and thanks for all you do out there every day!

      Best,
      Jed

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