A study protocol for a randomised controlled trial of ice to reduce the pain of immunisation: The ICE trial.

BACKGROUND AND OBJECTIVES: Vaccine injections commonly cause iatrogenic pain. Ice may reduce pain. This is a study protocol for a prospective randomised controlled trial aiming to investigate the efficacy of ice packs to decrease vaccine-related pain in adults. METHOD: The intervention group (n = 45) will receive ice packs (0 °C) and the control group (n = 45) receive placebo cold packs (10 °C) on the injection site for 30 seconds prior to vaccination. RESULTS: The primary outcomes will test the hypothesis that applying an ice pack will significantly reduce pain of vaccination when compared with a cold pack. The primary dependent variable will be pain score recorded on a visual analogue scale. Secondary outcomes aim to assess potential adverse reactions. The main analysis of data will follow the intention-to-treat principle. The primary dependent variable will be compared using an independent t-test or a Mann-Whitney U test. Multivariable logistic regression analysis may be used. DISCUSSION: The trial may guide general practitioners in the use of ice packs to reduce injection-related pain in adults.

A Randomised Controlled Trial of Ice to Reduce the Pain of Immunisation-The ICE Trial.

BACKGROUND AND OBJECTIVES: vaccine injections are a common cause of iatrogenic pain and anxiety, contributing to non-compliance with scheduled vaccinations. With injection-related pain being recognised as a barrier to vaccination uptake in both adults and children, it is important to investigate strategies to effectively reduce immunisation pain. This prospective randomised controlled trial investigated the effects of applying an ice pack on vaccine-related pain in adults. METHODS: medical students receiving the flu vaccination were randomised to receive an ice pack (intervention) or placebo cold pack (control) at the injection site for 30 s prior to needle insertion. Immediate post-vaccination pain (VAS) and adverse reactions in the proceeding 24 h were recorded. RESULTS: pain scores between the intervention (n = 19) and control groups (n = 16) were not statistically significant (intervention: median pain VAS = 7.00, IQR = 18; control: median pain VAS = 11, IQR = 14 (p = 0.26). There were no significant differences in the number of adverse events between the two groups (site pain p = 0.18; localised swelling (p = 0.67); bruising p = 0.09; erythema p = 0.46). DISCUSSION: ice did not reduce vaccination-related pain compared to cold packs. COVID-19 related restrictions impacted participant recruitment, rendering the study insufficiently powered to draw conclusions about the results.

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.