Babies, pain and hurtful memories

infant getting vaccinated

Until fairly recently, there was a belief among medical professionals that babies could not feel pain. Since all the nerves in the infant’s nervous system have not yet developed myelin, a fatty sheath that protects nerve fibers and is needed for the effective transmission of nerve impulses, doctors believed that the pain impulse could not adequately travel along the nerves and reach the brain.

But Linda Hatfield, a clinician educator in the Penn School of Nursing and director of research and evidence-based practice at Pennsylvania Hospital, says doctors and nurses now realize that infants do indeed experience pain, and there is growing concern about how the pain should be treated and managed.

Hatfield’s ongoing research is investigating that issue by exploring pediatric pain and the ways in which it can be identified and treated. She says infants’ small size and the lack of knowledge about how their bodies react to different drugs make it difficult to come up with a practical therapeutic plan. “Since there isn’t a lot of evidence out there, [medical professionals] are searching for effective interventions,” she says.

Infants have the anatomical and physical capabilities to transmit “noxious stimuli” by the time they are 24 weeks gestation in utero, Hatfield says. Moreover, she explains, for the first two months of life infants experience more pain than adolescents or adults, and must endure many agonizing procedures during their earliest days.

“At two months of age, they go for their immunizations,” Hatfield says. “If the pediatrician office doesn’t combine immunizations, they’ll get as many as five immunizations in that visit all at one time. And we don’t give them anything for the pain.”

Because babies are pre-verbal, Hatfield says that she considers their body language and position, the tone and pitch of their crying, and their facial expressions—such as whether their eyes are squeezed shut, their cheeks are raised or their mouths are wide open—to determine if an infant is in pain.

“Those facial expressions go across all genders, all age groups, all cultures,” she says. “If you stub your toe, you’re going to have that exact look on your face.”

While the existence of pediatric pain is now an accepted given, Hatfield says some doctors and nurses still believe that while infants can feel pain, they will not remember it.

But Hatfield contends babies can remember pain, too.

“It’s stored in their long-term memory,” she argues. “But, of course, as infants they don’t communicate with words so when they are older they don’t really know how to express what they’re feeling.”

Hatfield asserts that the pain infants experience in their early months of life can have lasting effects into childhood and even adulthood, leading to permanent changes in the central nervous system, needle phobia, or a fear or avoidance of doctors.

In infants, Hatfield says, simple table sugar can have the same effect on the spinal cord as morphine, although in much shorter duration. When babies are given sugar two minutes before a painful procedure, she says, it has the ability to reduce pain.

“It’s a nice intervention for managing short-term procedural pain,” she explains.

Parents can also play a key role in helping alleviate pediatric pain, Hatfield says, although many are not aware that they can intervene. “There are many parents, even today, that are unaware that they can ask their pediatricians for something for their infant’s pain,” she says. “That’s a public health message I’d like to see get out there, that parents actually could be very, very powerful.”

Hatfield, who sits on the Pennsylvania Pain Coalition, says she is pleased that pediatric pain is getting more attention. But, she says, the field is “still an orphan.”

“There are not that many people studying it, and so the interventions and advances are not as robust as they are in adult pain,” she says. “I would like to see more things going on for babies and young children.”

Originally published on September 16, 2010