The assessment of ice pack effect in pain reduction during digital nerve block: A randomized clinical study

Digital nerve block is a painful procedure. Several methods have been proposed to decrease the injection pain. Applying an ice pack is a pertinent choice due to its effectiveness on pain reduction, convenience, and low costs. In this study, the degree of injection pain reduction was assessed after applying an ice pack to the site of anesthetic injection.

One hundred participants with traumatic finger injury were assessed. Digital nerve block was performed in fifty patients in the intervention group after 6 min of ice application. In the control group, this procedure was done without ice. The primary outcome was the difference between the needle stick and infiltration pain scores with and without ice pack. The secondary outcome the patient satisfaction score. The protocol of this study was approved by the Institutional Review Board, and it is registered in the Iranian Registry of Clinical Trials.

The pain score was assessed using a Numeric Rating Scale. Both the needle skin and infiltration pain scores were statistically significantly lower in the intervention group (P < 0.001). The mean and median needle stick pain scores were 1.5 and 1.0 in the intervention group and 6.8 and 7.0 in the control group, respectively. Moreover, the mean and median infiltration pain scores were 2.7 and 2.0 in the intervention group and 8.5 and 9.0 in the control group, respectively. Patient satisfaction score was significantly higher in the intervention group.

Ice pack is inexpensive, readily available, and is easy to apply. We recommend this method to reduce the injection pain before digital nerve block in the emergency department.