Pain is "an unpleasant sensory and emotional experience associated with actual or potential tissue damage". Evaluation of pain in neonates is difficult due to the subjective nature of pain and the inability of neonates to verbally express pain. Surrogate measures used to describe pain in neonates include motor responses, facial expressions, cry and changes in physiologic parameters like heart rate, blood pressure, oxygen saturation and respiratory rate. Various changes have been compiled to create various scores. Validated scores for the assessment of pain include Neonatal Facial Coding System, Neonatal Infant Pain Scale or Premature Infant Pain Profile. These reactions to pain may contribute to the development of hypoxia, hypercarbia, acidosis, ventilator asynchrony, pneumothoraces, reperfusion injury and venous congestion and subsequent late intraventricular hemorrhage (IVH) or late extension of early intraventricular hemorrhage and periventricular leukomalacia. These behavioral changes may also disrupt postnatal adaptation, parent-infant bonding and feeding schedules.

Newborn infants routinely undergo painful invasive procedures, even after uncomplicated birth. Evidence shows that neonates do feel pain and may even have increased sensitivity to pain and to its long term effects compared with older infants. Treating procedural pain has become a crucial part of neonatal care. In healthy infants, the most common painful procedures are heel lance and venipuncture. Though minimally invasive, lancing is a painful procedure that activates cortical areas in brain .Repetitive procedural pain can lead to changes in the pain sensitivity threshold therefore, adequate analgesic control is needed. Pharmacological treatments are rarely used during these procedures because of concerns about their effectiveness (topical local anesthetics or paracetamol for heel pricks) and potential adverse effects (central analgesics). Therefore, non-pharmacological interventions are valuable alternatives. Recent interventions such as sweet oral solutions (sucrose or glucose) and non-nutritive sucking have been used frequently to alleviate pain.

Use of sucrose in preterm neonates has been advocated uniformly for pain relief. However, recently few reports have raised concerns over its safety and effect on neurodevelopment. Glucose has been used in pain relief in neonates but its therapeutic efficacy in comparison to oral sucrose in direct adequately powered RCT with pain assessment tools has not been evaluated in the Indian subcontinent. The present study was planned to evaluate the efficacy of 25% glucose solution with 24% sucrose solution for analgesia during heel lance in preterm neonates.

LACUNAE IN EXISTING KNOWLEDGE Existing literature on efficacy of glucose vs. sucrose is inconclusive on superiority of either. When a Medline search was carried out it returned limited results and no results returned from the Indian subcontinent which compared the two solutions using a multidimensional pain assessment tool. There is a need for an efficacious and cheap substitute which is readily available in NICU settings and sterile. Hence, the role of 25% Glucose in neonatal pain relief and safety associated with its use needs to be evaluated.