Management of Pain in Neonates

By  Dr. R.M.Mudiyanse

 

Introduction

     Pain assessment in neonates becomes more difficult, not only because they do not talk, but also their expressions are not consistent and reliable. Observable features of pain vary according to age, maturity, disease condition and degree of sedation. Therefore, pain assessment in neonates depends on tools developed based on combinations of several physiologic and behavioral indicators. Physiologic indicators of pain include changes in heart rate, respiratory rate, blood pressure, oxygen saturation, vagal tone, palmar sweating, and plasma cortisol or catecholamine concentrations. Behavioral indicators include changes in facial expressions, body movements, and crying, but these may be absent in some neonates who are neurologically impaired or pharmacologically paralyzed. Some of the tools take the maturity and sedation in to consideration. List of tools available for clinical practice and research are given in the table 1 along with a brief description. Some of these instruments have been validated but others are not. Selecting an appropriate tool for regular use is the role of the neonatal team involved. Adequate training of the entire team and familiarizing the team with the tools will be useful to establish a proper pain management practice in a unit.

     When neonates experience prolonged pain or repeated pain, the initial phase of psycho-physiological activation exhibited by physiologic and behavioral indicators tend to shut down, and they become passive and calm indicated by reduced body movements, an expressionless face, decreased heart rate and respiratory variability, and decreased oxygen consumption. These adaptations are suggestive of conservation of energy.  Therefore, when the pain is long lasting routine observations become unreliable to evaluate or monitor the pain intensity.  Neonatal Pain, Agitation, and Sedation Scale (N-PASS) and Neonatal Pain and Discomfort Scale (EDIN) are suitable scales to assess prolong pain.

 

Table 1. Different scales available for pain assessment

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DAN score (Douleur Aiguë du Nouveau-né)

     This acute pain rating scale depends on the observation of facial expression, limb movements and vocal expression of neonates. Table 2 summarizes how these parameters are assessed giving scores for relevant observation.

Table 2 – DAN score; acute pain rating scale in neonates

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pain Relief in Neonates

     Pain relief in neonates needs special consideration due to difficulties in pain assessment and differences of their drug metabolism. However, these difficulties should not preclude proper pain management in neonates. Paracetamol is not effective in controlling neonatal procedural pain. Safety of ibuprofen in neonates of less than 6 months of age has not been established. Codeine requires the conversion to its active component, morphine. This enzymatic conversion activity is <10% of that seen in adults. Therefore, uses of commonly used drugs are not appropriate for pain relief in neonates.

     Neonatal pain relief also requires a multidisciplinary, multimodal approach. Reduction of painful events and use of non-pharmacological approaches is very important. Neonates have got a narrow margin between therapeutic and toxic levels of a drug and, therefore, using multiple therapeutic interventions helps to minimize the drug adverse reactions.

     Number of painful events could be minimized by avoiding unnecessary or non-essential investigations and procedures. Certain interventions could be done simultaneously to avoid repetitions. Repeated attempts of the same procedure should be avoided.

     Non-pharmacologic methods have been very useful in preterm and term neonates in reducing pain from  a venipuncture or subcutaneous injections and are generally more effective when used in combination than when used alone. These include use of oral sucrose/glucose, breastfeeding, non-nutritive sucking, “kangaroo care" (skin-to-skin contact), facilitated tuck (holding the arms and legs in a flexed position), swaddling, and developmental care, which includes limiting environmental stimuli, lateral positioning, use of supportive bedding, and attention to behavioral clues.

     Use of sucrose has been found to be safe and effective in reducing neonatal procedural pain. Sucrose act by endogenous opioid release and by stimulating perception of sweet taste signaling pain pathways.  When sucrose is given using a pacifier it enhances analgesic effect.  Pacifier may promote sucking and calming that increase pain threshold by reducing stress/anxiety. The suggested solution for practical purposes is sucrose 25 gram dissolved in 100cc of sterile water, or D25W. Two techniques of using sucrose for procedural pain relief in neonates are given below.

A. Two minutes prior to the procedure, put the pacifier soaked with sugar solution in baby’s mouth. Coat the pacifier with the solution repeatedly during the procedure.

B. Two minutes prior procedure, slowly (over 30sec) administer 2cc of the solution to the tongue, then allow him to suck the pacifier during the procedure

 

References

Anand, et al. Consensus statement for the prevention and management of pain in the newborn. Archives Pediatric Adolescent Medicine. 2001; 155 (2): 173-80.

Ancora G, Mastrocola M, Bagnara C. Influence of gestational age on the EDIN score: an observational study. Arch Dis Child Fetal Neonatal Ed. 2009; 94: 35-38.

Ann RS, David H. Prevention and Management of Pain in the Neonate: An Update. Pediatrics. 2006; 118 (5): 2231-2241.

Frank SL, Cox S, Allen A, Winter I. Parental concern and distress about infant pain. Arch Dis Child Fetal Neonatal Ed. 2004; 89: 71-75.

O’Sullivan A, O’Conner M, Brosnerhan O.  Sweeten, soother and swaddle for retinopathy of prematurity screening: a randomised placebo controlled trial. Arch Dis Child Fetal Neonatal Ed. 2010; 95: 419-422.