Newborn babies experience pain much like adults and may even have a much lower pain threshold, according to a new Oxford study. The findings have important implications as many procedures are still performed on babies without painkillers.
As recently as the 1980s it was common practice for babies to be given neuromuscular blocks but no pain relief medication during surgery. In 2014, a review of neonatal pain management practice in intensive care highlighted that although such infants experience an average of 11 painful procedures per day 60 percent of babies do not receive any kind of pain medication.
“Thousands of babies across the UK undergo painful procedures every day but there are often no local pain management guidelines to help clinicians. Our study suggests that not only do babies experience pain but they may be more sensitive to it than adults,” said lead author Dr. Rebeccah Slater of Oxford University’s Department of Paediatrics.
“We have to think that if we would provide pain relief for an older child undergoing a procedure then we should look at giving pain relief to an infant undergoing a similar procedure.”
The research involved 10 healthy infants between one and six days old and 10 healthy adults aged 23-36 years. Infants were recruited from the John Radcliffe Hospital, Oxford (UK) and adult volunteers were Oxford University staff or students.
For the study, the babies, who were accompanied by parents and clinical staff, were placed in a Magnetic Resonance Imaging (MRI) scanner where most fell asleep. MRI scans were then taken of the babies’ brains as they were ‘poked’ on the bottom of their feet with a special retracting rod creating a sensation ‘like being poked with a pencil.’
The poking was mild enough to not wake them up. These scans were then compared with brain scans of adults exposed to the same pain stimulus.
“Up until recently people didn’t think it was possible to study pain in babies using MRI because, unlike adults, they don’t keep still in the scanner!” said Slater.
“However, as babies that are less than a week old are more docile than older babies, we found that their parents were able to get them to fall asleep inside a scanner so that, for the first time, we could study pain in the infant brain using MRI.”
The findings showed that 18 of the 20 brain regions active in adults experiencing pain were also active in babies. In fact, scans revealed that babies’ brains had the same response to a weak ‘poke’ as adults did to a stimulus four times as strong. This suggests that not only do babies experience pain much like adults but that they also have a much lower pain threshold.
“This is particularly important when it comes to pain: obviously babies can’t tell us about their experience of pain and it is difficult to infer pain from visual observations.
“In fact some people have argued that babies’ brains are not developed enough for them to really ‘feel’ pain, any reaction being just a reflex — our study provides the first really strong evidence that this is not the case,” said Slater.
Source: University of Oxford