Friday, May 10, 2013

Mivacurium Induced Paralysis

On the Monday I was a guinea pig for a medical study where I was partially paralyzed by a commonly used but poorly understood neuromuscular blocking drug used for anesthesia during surgeries.  I was hooked up to two IVs, one to administer the drug and another to take blood samples, a heart monitor, and a computer that recorded the distance traveled of my fingers, which were induced to twitch in four short bursts every 15 seconds by an electrical pulse hooked up to my wrist with a sensor.  They dripped mivacurium into me for three hours until I was essentially paralyzed, while doing a series of tests every five minutes to monitor my muscle function, like a bite-test, lifting my head off the bed for five seconds, swallowing, and a hand squeeze.  It was given in three increasing doses, and each higher dose was given only when my muscle response to each test had stabilized over a few runs, every five minutes.  The first dose affected my eyes and eyelids most strongly; it was like being drowsy without being sleepy.  And my lips started to feel numb, not tingly, but less controlled.  After about an hour my muscle receptors had become as blocked as they were going to get, blood samples were drawn, and the next dose came flooding in.  Immediately I lost most control of my jaw and lips.  I could still blink, use my tongue normally, and swallow mostly normally.  I could only lift my hand a few inches off the table until it started sagging back down.  I could usually get a short burst of muscle retraction, like biting, but then I'd lose it and could think about trying to bite down without being able to use my muscles.  It was crazy.  The third dose wasn't as dramatic and was given 25 minutes after the second, and lasted about 35 minutes.  Then when they determined they had the data they wanted (mostly the curve generated by the electric pulse on my wrist and blood samples), the IV was pinched off and within minutes I was back to full strength, except for my eyes that took another hour to see straight.  

Essentially, I was just hanging out with these doctors, one visiting from Norway and another whose dad owns Feiner plumbing in Racine, WI.  Mivacurium is a common drug administered for surgeries, blocking muscles from receiving the signal to contract and rendering patients paralyzed so they don't fidget during the procedure.  Although it's been used commonly for decades, doctors don't quite understand why men and women have different responses to the drug and that's what the Norwegian doctor wants to know.  Another friend told me that the family of drugs from which mivacurium comes is related to the same drug that tips poisoned darts in the Amazon.  It has no sedative properties and you remain 100% crystal clear while unable to use any muscles.  The doctor told me that back in the day (not exactly sure the time scale) when researchers were first trying to figure out what this drug actually did (was it sedative, numbing, what was the pain response, etc) they'd put a tourniquet on the subjects arm, then administer the drug until 100% paralysis except for the one arm whose blood flow was restricted, thus unaffected by the drug.  The subject was still able to signal to doctors in response to their questions.  It was definitely a crazy experience and I probably would have done it for free, too.  It'd be funny if the real research the Norsk doctor was conducting was how stupid Americans voluntarily paralyze themselves for pocket change.

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