Effect of the Local Heat on the Pain of Vitamin K Injection in the Infants

BackgroundThe absence of pain relief in infants can lead to harmful effects; so, this study aimed to investigate the effect of local heat on the pain of vitamin K injection in the infants.
Materials and MethodsThis randomized clinical trial was conducted on 80 healthy infants. For the control group, 1 mg vitamin K was injected into the vastus lateralis muscle by a nurse. In the 3 intervention groups, respectively 5, 10 and 15 minutes before the injection, hot-water bag at 37 °C was placed on the quadriceps muscle and then injection was done with the same condition as in the control group. Immediately after the injection, the Neonatal Infant Pain Scale (NIPS) was completed. Data analysis was done using SPSS version 21.0 software.
Results41(51.25%) girls and 39 (48.75%) boys were participated. First-minute Apgar of all samples were 8.64±0.557. Birth weight was 3335.37±339.51 grams and the minimum gestational age 36.37±1.01 weeks. The mean pain score in the first minute in the control group was 3.6± 2.136, which was 3.3± 1.976 in the 5-minute warm-up group, and this amount was reached to 1.6± 1.569 in 10-minute warm up group, and 0.6± 0.821 in 15 minute warm-up group (P=0.008). The mean pain scores in the control group for the second minute was 1.0±1.835, which was reduced to 0.25± 0.716 in the 10-minute and 15-minute warm-up group (P=0.023).
ConclusionLocal heating before the injection procedure can be effective in reducing pain in infants and the pain will reduce by increasing the local heating time (15 minutes).