Nobody likes to see a baby in pain. But it's been surprisingly hard for doctors to figure out how to make shots and other medical procedures hurt less.
The solution might be as simple as giving a baby a bit of sugar water before the shot. Or it might not be so simple at all.
How do we know when a baby's hurting? A parent might be able to tell the difference between a cry of pain, the wet diaper cry, and the boy I'm tired cry. Doctors and nurses lack that intimate knowledge.
"One of the things we're struggling with is measures of pain," says Renee Manworren, a pediatric pain researcher at Connecticut Children's Medical Center in Hartford. "With babies, I joke that they just refuse to tell us how much they're hurting."
Over the past decade, sugar has become the gold standard for pain relief from needle sticks in babies under age 1. More recently that standard's been questioned because of disagreements over how to measure that pain.
A roundup of the medical evidence by the Cochrane Review on using sugar for pain relief reflects that struggle, giving sugar a less enthusiastic thumbs up than an earlier Cochrane analysis. "There is insufficient evidence to confidently judge the effectiveness of sweet-tasting solutions," the reviewers wrote. "The treatments do, however, appear promising."
Most of the studies the Cochrane crew reviewed used the amount of time a baby cries as a measure of pain. But quite a few studies have used sugar-coated pacifiers to deliver the sugar. Babies typically don't cry when they've got a pacifier. But does that mean they're not in pain?
"If you were screaming and I put a piece of duct tape over your mouth, I wouldn't hear you screaming any more," Manworren says. "Can I say you're not in pain?"
The conflict over measuring babies' pain accelerated in 2010, when British researchers measured the nerve circuitry of babies given sugar to alleviate pain. They saw no change in brain activity. But it's not clear that that's a good measure of infant pain, either.
It may be better to think of sugar as a compensating pleasure, rather than an analgesic that removes pain, according to an article published earlier this year in the Archives of Pediatric and Adolescent Medicine.
Fascinating as this may be for pain researchers, it leaves parents asking if sugar will help ease their baby's pain for immunizations and other painful routine procedures.
"What do we have available?" Manworren replies when asked by Shots. Research has shown that acetaminophen isn't very effective, and ibuprofen isn't recommended for small babies.
"We still have individual studies that show strong evidence" for sugar, at least up till age one. "The other thing absolutely is to use topical anesthetics," she says, like lidocaine. "I'm a believer that more is better as long as you're attacking the pain pathways in separate ways."