Temporary paralysis

A lot of people think they're allergic to morphine.  They're usually not really allergic, as I've mentioned previously; generally, they just have the side effects common to opioids, things like nausea, itching, sedation, and constipation.  Even respiratory depression (or "I stopped breathing," as patients usually phrase it) is not necessarily an allergic reaction, since opioids are respiratory depressants and "I stopped breathing" usually just means "I got too much."  ("I stopped breathing because my airway got all swelled up" is a different story, however.)

I was doing a preop evaluation of a pleasant 45-year-old woman who was going for brain surgery.  She'd been worked up for headaches and was found to have an intracranial aneurysm that required clipping, both for improvement of her headaches and to prevent rupture later in life.  She was in shape and healthy, so we were breezing quickly through the preop form when I got to the "Allergies" section.

"Ma'am, are you allergic to any foods or medications?" I asked her.

"Yes, I'm allergic to morphine," was the reply.

"Mm-hmm," I said, making a note, "and what happens when you get morphine?"

"I get temporary lower body paralysis."

I stopped and looked up from my notes.  Temporary lower body paralysis as a reaction to morphine?  Not something you hear every day.

"Tell me more about what happened," I said.

"Well, I last had morphine about 20 years ago," she told me.  "Pretty soon after I got it, I couldn't move my legs anymore, and that lasted for a couple of hours."

Weird, I thought.  "Any problems with your arms, or with breathing?"

"No, just my legs."

"Any itching, rash, or swelling of your lips, tongue, or throat?"

"No."

"And what was the context?  Why were they giving you morphine?"

"I was having a c-section for my first child," she replied.

A light clicked on in my mind.  I had a good idea what had happened, and it was no allergy.  I still had to ask some more questions to be sure.  "Ma'am, did you have your c-section awake?  Or did they put you to sleep and put a breathing tube in?"

"I was awake.  They just put a little shot in my back so I didn't have to go to sleep."

I'd figured it out by this point.  The patient had received intrathecal anesthesia (otherwise known as a spinal) for her c-section.  A typical c-section spinal dose consists of a long-acting local anesthetic combined with short- and long-acting opioids.  The local anesthetic numbs the nerve roots destined for the lower extremities, depriving the legs of both sensation and movement.  This lasts for about 90 minutes or so, at which point sensation and movement should both return.  I asked the patient if that's what she experienced and she said yes.

"Ma'am, from what you've told me it doesn't sound like you had an allergic reaction to morphine at all," I told her.  "It sounds like they did a spinal for your c-section and it did exactly what it was supposed to do."

The patient thought for a moment, then asked, "So, that temporary paralysis in my legs was normal?  It was expected?"

"Yes, from what you've told me," I answered.

The woman was shocked.  "I can't believe that no other doctor told me that!" she exclaimed.  "I've spent the last 20 years thinking I was allergic to morphine!"

I was a bit surprised about that, too.  "Has any doctor ever said, 'You're allergic to morphine?'"

"No," the patient said slowly, "they told me the spinal would take away the feeling but they didn't say anything about movement.  I guess I just assumed that was a problem, and my sister said it was probably the morphine."

"Is your sister medical?"

"No," the patient replied, blushing, "but I've told lots of doctors I was allergic, and none of them ever told me what you just did!"  It was clear she was a bit embarrassed.

"Well, I don't think you're allergic, ma'am," I told her.  "I think everything worked just like it was supposed to.  I'm a bit disappointed that no other doctor explained this to you."

I made appropriate documentation in the patient's chart regarding the nature of the "allergy," and the rest of the interview went smoothly.  I was, and still am, surprised that no physician had availed him or herself of the opportunity to educate this patient on the nature of her "allergy."  Or maybe someone had told her, and she just hadn't listened.  That happens very often, as well.  In any event, I felt I had done my due diligence in patient education.

The patient had her surgery the next day.  She received morphine and nothing happened to her.

Another medical mystery solved, and another life saved.  Sort of.