This anxious young lady came in hyperventilating … just a little.

Her ABG had the highest pH and the lowest CO2 that I’ve ever seen.

So before clicking on this link to read about ABG interpretation, think about what symptoms you would expect this patient to have and why she would have those symptoms. Is the respiratory alkalosis compensated or uncompensated? Is there an A-a gradient? Why the low bicarb?

Then click on this link to read about hyperventilation syndrome.
One of the ways that I use to help determine whether or not a patient’s symptoms are related to hyperventilation is to do a trial of controlled hyperventilation. I breathe as deep and as fast as I can with them for a minute … or until I start to get symptoms. If the patient’s symptoms are recreated, then the problem is solved. I just write “trial of controlled hyperventilation reproduces symptoms” in the chart. The above article states that such trials may be “time-consuming and ineffective.” I typically find just the opposite. I had one young lady whose heart rate went from the 70s to the 130s on the cardiac monitor in less than a minute by hyperventilating. Her heart rate was back down to baseline within another minute. Made for some interesting monitor strips.

UPDATE SEPTEMBER 8, 2009
Had another patient with hyperventilation over a very long weekend. Did a trial of controlled hyperventilation and her heart rate went from 91 BPM at 00:09 AM to 160 BPM at 00:10 AM – in addition to recreating all of her symptoms.

This entry was posted on Tuesday, September 1st, 2009 at 6:05 am and is filed under Medical Topics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.