Cooling to Reduce the Pain Associated with Vaccination: A Systematic Review

Background: Vaccine injections are the most common cause of iatrogenic pain in childhood and a cause of anxiety in adulthood. Skin cooling techniques, including icepacks and vapocoolants, may provide pain relief during intramuscular injections.

Objective: To identify the effects of skin cooling techniques on pain associated with immunisation.

Methods: MEDLINE (Ovid), CINAHL, EMCARE, INFORMIT and Scopus were searched for randomised controlled trials (RCTs) investigating the use of skin cooling techniques on pain associated with vaccination. Study and intervention details, outcomes measures and results were extracted and risk of bias assessed using the Cochrane Risk of Bias tool. Due to heterogeneity of studies, a narrative synthesis was performed.

Results: Thirteen trials were included, involving 689 paediatric and 829 adult participants. All studies used vapocoolant or ice as one of the interventions. Comparator groups included topical EMLA cream, breastfeeding, distraction techniques and tactile stimulation. Vapocoolant reduced vaccination-related pain in all adult studies and six paediatric studies however the use of ice packs in paediatric patients was not effective.

Conclusion: The use of cooling techniques reduces pain associated with vaccinations in adults. Paediatric studies show mixed results for vapocoolants and an inability for ice to decrease vaccine-injection pain. Larger RCTs are required to determine the most effective administration techniques and optimise the analgesic effects of skin cooling.