The Effect of Giving a Pacifier Dipped in Breast Milk, Heel Warming, and Applying Both Together on Pain and Salivary Cortisol Levels During Heel Stick in Preterm Newborns: Randomized Controlled Study.

Health professionals should be able to evaluate pain, reduce or eliminate pain in pain management of neonates in interventional applications. Pharmacologic and nonpharmacologic methods are used in pain management. When these methods are applied together, their effectiveness increases in pain related to invasive interventions. Pharmacologically, opioid analgesics, sedatives and local anesthetics are used. Nonpharmacologic methods include breastfeeding, pacifier, oral sucrose, music, warm application, massage, therapeutic touch and positioning such as nesting, fetal positioning, swaddling, kangaroo care, rocking and holding.

In many studies, nonpharmacologic interventions have been applied and compared to reduce pain during heel prick in preterm newborns. In the routine of the clinic, heel prick blood collection from preterm newborns is performed by hugging the mother in her lap. The swaddling procedure for preterm newborns in the control group is recommended by the American Academy of Pediatrics. The swaddling method supports flexion and lateral posture, which is the developmental position of the newborn. With this position, the newborn comes to its position in the uterus, which is familiar to it, ensuring its physiological stability and improving its capacity. In a systematic review of 3396 participants, preterm newborns were calmed and immediately stabilized by kangaroo care, non-nutritive sucking and swaddling methods. Since these methods reduce pain and stress in preterm newborns, they are also reported to be included in "Individualized Supportive Developmental Care" practices.

Many studies have shown that giving pacifiers to newborns is effective in reducing pain. In addition, oral administration of breast milk alone, without breastfeeding, has been found to reduce pain during heel prick, nasopharyngeal aspiration, venipuncture and retinopathy examination in preterms. In the study conducted by Lan et al., breast milk was sniffed to the newborn during heel prick blood collection or tasted by dropping into the newborns mouth with a syringe. As a result, they reported that sniffing and plus tasting breast milk was effective in alleviating pain in newborns.

In the literature, it is emphasized that the pain that occurs during heel blood collection is closely related to the squeezing of the heel to collect blood, not during the needle insertion into the heel, and it is thought that keeping the newborn in an upright position during heel blood collection may facilitate blood flow through gravity and reduce the amount of squeezing required to obtain the sample. However, there are studies showing that heel warming is effective in reducing pain in newborns. It has been stated that with warm application to the heel -with the effect of vasodilation- fewer needling is performed in the heel, the amount of blood required for the procedure increases and the procedure is completed in a shorter time. It is predicted that the heel of the newborn will be squeezed less thanks to the warm application.

However, there is a very limited number of studies evaluating the effectiveness of different nonpharmacologic interventions during heel prick blood collection and measuring the stress marker cortisol. In addition, no study was found to investigate the effectiveness of other interventions (heel warming and giving a pacifier dipped in breast milk) in combination with wrapping among nonpharmacological interventions.