SUMMARY

The study was an open-label three-arm, randomized controlled trial which was done in KLES Dr Prabhakar Kore Hospital and Medical Research Centre, Belagavi and Rukmini Nagar Urban Health Centre, Belagavi from September 2020 to September 2021. The study objective was to compare the pain reduction efficacy of topical local anesthetic spray with vapocoolant and EMLA cream during immunization. 228 children between the age of 9 and 11 weeks who were brought for immunization with 2^nd dose of liquid pentavalent vaccine were enrolled for the study. They were randomized to three groups according to the random number table and were subjected to the assigned intervention.

They were subjected to Modified Behavioral Pain Scale by the observer to assess the pain experienced by the infant before the injection, after 1 minute, and after 5 minutes of injection. The 10-point MBPS assesses 3 behavioral components (facial expression, movements, and cry) as an indication of a child’s experience of pain. The total score is the sum of scores in each parameter. The maximum score of 10 indicates the worst pain experience and the least possible score of 0 indicates no pain. Parents also recorded their interpretation of pain experienced by their children using the Visual Analog Scale which is a validated, subjective measure on a 10-point scale for acute pain where zero is designated as “no pain” and 10 the “worst possible pain”.

It was observed that the post-injection MBPS pain scores were significantly low in the two intervention groups when compared to the control. The mean MBPS score at 1 minute was least in the group using the topical local anesthetic spray with vapocoolant (5.11±1.1) followed by the EMLA group (6.22±1.14) whereas the control group (7.62±0.89) exhibited the maximum pain score values. The same trend when also observed when parental VAS scores were compared. The mean VAS score is least in the group using the topical local anesthetic spray with vapocoolant (3.66±1.66) followed by the EMLA group (4.5±1.31) whereas the control group (5.82±2.56) exhibited the maximum pain score values as per parents.

We also observed that the parents were good at predicting pain in their children as the parental VAS scores correlated clinically to the MBPS scores and the order of pain scores obtained across each intervention group is same, which is maximum in the control group and least in the group subjected to LA spray. There was no difference in pain scores with respect to gender observed.

The study proves that LA spray is beneficial in reducing injection pain during vaccination of infants and can potentially be used in immunization clinics conveniently, easily, and cost-effectively.