Effects of Rapid Vaccine Injection Technique without Aspiration and Manual Pressure Application on Pain Severity and Crying Duration in 4-6-Month-Old Infants

This is a double-blind randomized-controlled study and was performed to compare effects of 10-second manual pressure on the injection site before vaccination and rapid injection technique without aspiration on pain severity and crying duration in 4-6-month-old infants given DaBT-IPA-Hib (the 5-in-1 vaccine). The study population included all the infants presenting for 5-in-1 vaccine injection to Merkez Cumhuriyet and Aksu Family Health Centers of Çankırı Public Health Directorate in Turkey between April and August in 2015. The study sample included 128 infants based on confidence interval of 95% and statistical power of 80%. The sample was divided into four groups; i.e. manual pressure, rapid injection without aspiration, manual pressure combined with rapid injection without aspiration and control groups. There were 32 infants in each group. Gender was matched in all groups. Stratified and blocking randomizations were used. Ethical approval was obtained from Clinical Research Ethical Committee of Ege University Medical School and Çankırı Public Health Directorate. Data were collected with a Baby Information Form, a Neonatal Infant Pain Scale (NIPS), a video camera and a pulse oximetry. After oral and written informed consent was obtained from the parents, the infants were randomized into the groups through a draw. Video recording was performed before, during and after the injections to determine pain severity and crying duration were independently evaluated by pain experts using NIPS. Obtained data were analyzed with Statistical Package For Social Sciences (SPSS 20,0).Gender, age (month), weight, height, weight percentiles and number of IM injections were similar among the interventions and control groups. Pain severity scores and crying duration during and after the injections were significantly lower in the three intervention groups than in the control group (p=0.001). There was a strong, positive and significant correlation between crying duration and mean pain scores during and after the injections. In both the intervention and the control groups, as mean pain scores during and after the injections increased so did crying duration. The lowest increase in the mean heart rate during and after the injections occurred in the rapid injection without aspiration group (p<0.05). In addition, the mean oxygen saturation before, during and after the injections was significantly lower in this group than in the other groups (p<0.05). However, two infants in the rapid injection without aspiration group had pain and low oxygen saturation levels starting before the injections, which reduced the mean oxygen saturation in this group. In addition, there was not a significant difference in the mean oxygen saturations of this group before, during and after the injections. As a result, it can be suggested that lower oxygen saturations in the rapid injection without aspiration group cannot be due to vaccines or the techniques used. In conclusion, manual pressure and rapid injection tecnique without aspiration are effective and useful in elimination of pain and reduction of crying duration during the vaccine injections in 4-6-month-old infants. Easy and quick non-pharmacological methods without preparations should be preferred and their effects should be monitored in practice and investigated in further studies.