I wasn't always like this.
Ask co-interns and they will tell you I was the most notorious minutiae-obsessed physiology manipulator west of the Mississippi.
What changed? Well, I
grew up and realized that micromanaging physiology is most often a fool's
errand. Evolution was indeed a brilliant
chemist (Max Perutz), and I recognize my impotence in one-upping him. I can order zero ABGs or a dozen ABGs in a
week and little changes but the volume of blood that is flushed down the
drain.
So, using an example from earlier in the day, I'll lead you
through a stream of consciousness explanation of why I can most often do
without an ABG.
A man in his 30s is admitted for alcohol withdrawal (WD) for
the sixth time in 12 months. About half
of these times, his WD has been severe and he has required ICU admission. Overnight, during the administration of
benzodiazepines for his WD symptoms, he has become progressively tachycardic
and tachypneic and his oxygen needs have been steadily increasing. His saturation on the monitor displays a good
tracing at 95%. BIPAP is applied. I
can hear his respiratory rate at about 25, and based on the flow I hear from
the BIPAP machine, I can guess that his minute ventilation is about 15 liters
per minute (these guesses could be confirmed with RT).
Knowing nothing else about his case, I am asked if an ABG should be
ordered to assess his respiratory status.
Should it?
