Experiencing anxiety and fear prior to any medical procedure, particularly in children, could entirely affect the procedure. Any probable further damage could be decreased by reducing the stress and anxiety (
8,
9). It has been well-studied that tranquilizers and sedatives are also of analgesic effects to some extent. However, to choose the most appropriate option, not only the sedation efficiency but also side effects or contraindications of the drugs should be considered. Most of the previously-performed studies focused on either single drug or multiple drug combinations such as ketamine, midazolam, atropine, diphenhydramine, glycopyrrolate, meperidin and fentanyl; in these studies, the administration route was either oral or IV (
10).
Diphenhydramine, prescribed as a hypnotic-sedative agent, also has antihistaminic and anticholinergic effects. Paul and Jason compared the efficiency of oral midazolam and ketamine for inducing sedation in children before suturing their wounds; it was shown that ketamine was superior to midazolam and children who received ketamine tolerated the local anesthesia before the procedure much better than the ones received midazolam (
7). In a similar study, Cengiz et al. compared the sedative effects of diphenhydramine-midazolam with single midazolam before MRI in children. In this study, deeper sedation onset was obtained much earlier in combination induction. In contrast, the children receiving single midazolam had lower and inadequate sedation levels. Nonetheless, in contrast with our study, there was no significant difference for sedation onset in both groups. Similar to our study, Cengiz et al. showed that diphenhydramine-midazolam had much more sedative properties in comparison with single midazolam in children before MRI, and it seemed that the combination medication had fewer side effects as well (
11). In a study performed by Warner et al. combination of strawberry-flavored midazolam and ketamine, 20 minutes before operation in children aged 1 - 5 years, significantly reduced their stress and anxiety before general anesthesia (
12). Munro et al. also showed that combination of midazolam and ketamine had noticeable impact on sedation of children before procedures with no significant side effect (
13). In addition, in a study performed on maxillofacial surgeries, it was suggested that administration of ketamine, midazolam or glycopyrrolate before minor facial surgeries was associated with considerable effects in children; in addition, dysphoria and muscle rigidity, induced by ketamine, could be controlled by midazolam administration (
14). In a study by Weber et al. it was revealed that intranasal administration of ketamine-midazolam prepared relaxed condition for the preschool children before general anesthesia (
15). Most studies have highlighted the fact that combination medication has been more efficient in sedation of children compared to a single agent. Although some studies such as Younge et al. (
7) or Taghiporanvari et al. (
9) showed that sedation induced by midazolam as a single agent could be less efficient compared to other agents, other studies have suggested that combination of midazolam with other sedatives could play a central role in inducing sedation in children.
Our result also showed that diphenhydramine-midazolam is more significantly efficient in comparison with single diphenhydramine in reducing pain. Eskandarian et al. assessed the effect of midazolam-ketamine on behavior changes compared with midazolam-hydroxyzine for dental procedures (
2). Similar to our study, ketamine-midazolam could control the movement in children successfully. Ketamine-midazolam, in comparison with hydroxyzine-midazolam, more efficiently induced hypnosis, controlled crying and body movement, and assessed the child's behavior. Our study showed that diphenhydramine-midazolam was more advantageous over single diphenhydramine in inducing sedation in children.
Overall, it could be concluded that diphenhydramine-midazolam could act as an appropriate medication to induce sedation in children in ER prior to numerous procedures. Combination of diphenhydramine-midazolam in comparison with single diphenhydramine provided higher quality of sedation, with fewer complications before diagnostic and therapeutic procedures in children.