Tuesday, April 12, 2011

Shifting the bell curve

The nurse at my doctor's office was checking my blood pressure last week when the following conversation ensued:

Nurse: (trying not to look worried) Um, have you ever had low blood pressure before?
Me:  No.  I've always had normal blood pressure.
Nurse: (now not hiding worry) Well, I'm getting 100/70 for you.
Me:  Yep.  Perfectly normal.

One of the residents today was telling me about a code he attended in the hospital yesterday.  The code was called for hypotension (dangerously low blood pressure).  The resident rushed into the room to find the patient sitting calmly, eating his breakfast.  The nurse informed the resident that the patient's blood pressure was 90/60.

My intention here is not to lambaste nurses.  They are merely following their protocols and experience.  The larger question, I think, is when did reasonable blood pressures become "low"?  Is it just because most of the blood pressures that nurses (and docs, for that matter) see are elevated? 

I can't separate the word "normal" from the picture of a bell curve in my head.  And I have to wonder if the bell curve for "normal" blood pressures isn't starting to shift toward the right.

I don't like the complacency toward a new norm that these events portend.  How can we convince our patients that their blood pressures are too high when the bell curve of normalcy has shifted?  I have started using the word "healthy" to describe desirable blood pressures instead of "normal."

Because, sadly, normal doesn't seem to be healthy anymore.


  1. I have that conversation with people all the time. It reminds me of when my son was born - normal pg, normal delivery, APGAR 10/10, no red flags of any kind - but he was 8 lbs 15 oz. The nurses said they had to give him formula. I said no because I wanted to nurse him. They said he was at risk of hypoglycemia. I said prove he has it. They did a BG which was allegedly 40 mg/dl. I told them to repeat it. They gave me the option of agreeing to let them give the formula, or them calling CPS and forcing me to give the formula. I was exhausted and frustrated and let them give it. After, I asked why, and they said the protocol requires all babies over 9 lbs to be fed formula or screened for hypoglycemia. I said he was not over 9 lbs - he was an ounce under. They said "well, he was almost 9 lbs, so we had to follow the protocol for babies over 9 lbs." My son is 10. I am still pissed about that and amazed at how illogical it was for those nurses to blindly follow an inapplicable protocol without looking at the patient.

  2. It's so frustrating! My normal blood pressure is 90/60 or thereabouts. I never hear the end of it. Reactions range from the congratulatory to the incredulous.
    And webhill's comment resonates with me also. My son was born 3 weeks early, perfectly healthy, normal vaginal delivery, 5lbs 11oz. A heel stick at birth showed 'hypoglycemia' and bought him 2 days in the NICU. My husband and I were pissed! There was no need; he was fine.
    Instead, he was kept away from me (though you'd better believe I planted myself in his room, only returning to my own when the nurses would call down so they could get my own vital), and resources were wasted, worry was created.
    Enough rambling! Great post.

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  4. How about the patient with cirrhosis who routinely runs a SBP under 90 and a serum sodium of 130?

    Common sense and clinical judgment often gives way to protocol and algorithms.