Monday, October 10, 2011

Banishing the Boo-Boos

When J.J. was four, he had a psychotic break at the doctor's office when they tried to give him his shots.  It took four adults to hold him down, and for years afterward, at every visit the nurse would chirp, "Oh, here's the strong one again!" Now that flu season is approaching, trypanophobia* is setting in again.

Then I saw a blurb in a parenting magazine about Buzzy, a vibrating ice pack used to reduce the pain of needlesticks:

"Getting shots is fun with Buzzy!"

There have been two small, randomized studies on Buzzy showing positive results, the first performed on adults using a crude but charming prototype:

Buzzy reduced the pain of IV insertion by a modest 1 point on a 10-point scale.  I wanted to try it on my own kids until I saw the $35 price tag.  For that amount, I could buy them a bottle of whisky and bullet to bite on.

The science behind Buzzy is that applying alternative sensations to the poked arm will keep the nerve fibers occupied, reducing conduction of pain impulses.  It's an often used strategy in pain control, though the efficacy varies widely according to the population being studied.  Another study applied this "vibrating instrument" to the opposite extremity to distract from the pain of immunization:

Combined with other measures, this contraption reduced pain in young children.  So go ahead, moms, feel free to bring your "personal handheld massagers" to the doctor's office!

You might wonder how researchers measure pain.  Pain is difficult to study, and even more so in children.  Pain scales using happy and sad faces can be used in older kids and their parents, but you have to get creative in infants and toddlers.  Scientists can measure duration of crying, heart rate and oxygen levels.  (You know that prolonged silence before a baby launches into The Serious Wail?  Well, he's holding his breath, and his oxygen levels are dropping.)  My personal favorite is the Neonatal Facial Coding System, which looks at 9 facial features to assess if an infant is in pain:

Though it's probably sensitive, I have reasons to doubt its specificity.  Here's JoJo after getting doused with a hose:

His score is a full 9, but he's not in pain -- only cold, wet and humiliated.

There are hundreds of randomized, controlled trials looking at ways to reduce needlestick pain.  The best validated is sugar water in infants, with at least 44 studies enrolling nearly 4000 babies.  No one knows for sure why this works.  It's not due to sucking, as sugar water is superior to breastmilk, formula or water, and it doesn't even have to be given during the shot.  Two milliliters given right before the needle is effective.  One theory is that the sweet taste results in a release of endogenous opioids, the same mechanism by which chocolate is thought to work.  But when one group of doctors gave Narcan, the heroin antidote, to babies receiving sugar water, they still cried less than babies who didn't get the sugar.  Anecdotally, sweet solutions are amazing. I gave J.J. a juice bottle throughout his circumcision, and he didn't make a peep. (That's right, I assisted in his back-alley circumcision -- but that's a subject for another blog post.)

The data on sweet solutions are more mixed in children over the age of 1.  Browsing through the abstracts on Pubmed, here are some of the strategies that have generally been shown to reduce needle pain, based on randomized, controlled trials:**
Others have shown more mixed results:
    And these are the useless ones:
      Finally, have you ever considered leaving the room while your child is being poked?  My husband does it all the time, since he gets faint at the sight of a needle. One randomized, controlled trial of parental presence vs. absence found that having a parent in the room during immunization increases the level of "behavioral distress," particularly crying, in kids 4 and over.  There was no difference between the two groups in the average heart rate, suggesting there was no true difference in their levels of acute pain.  Despite the subjective signs of increased distress, when asked afterwards whether they would want their parent with them during future shots, 86% of the kids said that they would.  I love that there's proof that kids play to their audience, and yes, I admit, it does make me feel needed.

      *Fear of needles
      **Unfortunately, all of these RCTs are small and prone to publication bias (i.e., a small positive study is more likely to be published than a small negative one).  They are also plagued by lack of blinding, and placebos reduce pain an average of 30-40%.  You could argue, though, that since most of these interventions aren't harmful, you might as well use them for their placebo effect.

      6 comments:

      1. Stephanie, thanks very much for a great post.

        However, there is one serious omission from your excellent overview of the research. The placebo with the strongest comforting effect is a parent's kiss or rub where their child hurts.

        Although I can find no evidence from RCTs to support my assertion, I would be astonished to be proved wrong.

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      2. Maybe there aren't any RCTs looking at a parent's kiss, but there are some showing that parental holding vs. not holding does reduce pain. Even if there weren't any studies, I think most of us would prefer to do so anyway (even they do tend to whimper more when they're around). Thanks for your comment!

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      3. Our pediatrician suggested a topical analgesic (similar to the ones they give you at the dentist's office). We were told to pick it up prior to her next visit and put it on (like a patch) an hour before. I think putting my daughter to sleep is the only way to prevent her from kicking and screaming bloody murder.

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      4. Those anesthetic patches and creams work pretty well. I had an anesthesiologist friend who used to sneak it out of her hospital for me, but unfortunately, my dealer has since moved away.

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      5. Love this blog! I'm the doc who invented the Buzzy after my son had a HORRIBLE experience at age 4. I had put the cream on, the nurse said "that stuff doesn't work" and aimed OUTSIDE the blanched area, while telling my son "You sit there and hold still or this is really going to hurt." I was so furious I experimented, then made a prototype (that's my husbands arm demoing the ginormous clunky first Buzzy), got grants, etc. We just finished our nIH trial analysis of adolescents, and have the data but haven't started analyzing BUzzy for the 4-6m, 12-15m, and 4-6year olds. email me and I'll send you more data and lit reviews. - Dr. Amy Baxter, abaxter@mmjlabs.com

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      6. By the way, while EMLA is very effective for the poke, it does really require an hour to be effective and is prescription. LMX, however, is over the counter and only takes 30 minutes. You can put it on using Glad Press-N-Seal (the brand matters), that's what we do for the kids with leukemia who are getting spinal taps. Also, for kids younger than 6, parental attitudes can predict 50% of the distress, and a warm but firm demeanor is most effective at decreasing distress. Distraction (like in the Berberich study you reference with the hand held "massager" on the contralateral side) can also reduce distress by up to 50% in the critical 4-6 year group. Visual distraction actually seems to be the best, with finding and counting tasks being the most effective.

        ReplyDelete