The Ortolani and Barlow manouvers are probably the two most requested parts of the physical exam that students ask to be shown. We line up several medical students who take turns applying the steps of abduction and then adduction, testing the stability of the hips. We routinely give oral sucrose, position in kangaroo care or breastfeed while performing other noxious stimuli such as heel lancing but at least in my centre give nothing for manipulating the hips in such a fashion.
How can we determine if a newborn feels pain?
In a recent paper entitled Neurophysiological and behavioral measures of pain during neonatal hip examination by Pettersson M et al they used three methods to assess pain during the newborn hip exam. These were the Premature Infant Pain Profile‐Revised (PIPP‐R) scale which is generally used for such assessment as well as two relatively novel ways in the use of near‐infrared spectroscopy (NIRS) and galvanic skin response (GSR). In essence if the a region of the brain becomes more active during a painful experience more oxygen will be extracted during that time. By using auscultation of heart rate with a stethoscope as a control procedure which should not elicit pain the authors were able to compare in a controlled fashion 28 newborns undergoing both activities. The use of NIRS was previously demonstrated as valid in the paper Pain activates cortical areas in the preterm newborn brain. Galvanic skin response has also been demonstrated to correlate with pain and measures changes in skin conductance in the paper Skin conductance compared to a combined behavioural and physiological pain measure in newborn infants.
So the authors set out to compare findings in these 28 infants and standardized the study as much as they could by having one Neonatologist perform all hip exams and having a video recording of the infant’s face during the procedure assessed by two independent reviewers in order to assign the PIPP-R scores. While not a randomized trial, for the type of intervention being studied this was the right approach to take to determine the answer to their question.
Interesting findings indeed. Statistically significant differences were noted in bilateral changes in oxygen extraction during hip examination as well as for the GSR small peaks. The PIPP-R scores as well were vastly different between the two groups suggesting that the areas of the brain responsible for perception of pain were indeed activated more so with manipulation of the hip than with auscultation of the heart.
What can we take from this?
The hip exam may elicit responses indicating pain but there remains the question of how much is actually elicited. Nonetheless, the authors findings are intriguing as they certainly challenge the notion that this is a quick exam that should be just done and gotten over with. Clearly bundling or Kangaroo Care are not an option here due to the nature of what is being done. The next time you are planning on doing such tests though should you at least consider non-nutritive sucking on a pacifier or sucrose solution if readily available? If not readily available then should it be?