This randomized clinical trial was conducted on 100 women referred to Vali-e-Asr Hospital, Fasa, Iran for natural vaginal delivery. The study was performed after obtaining permission from the research vice-chancellor of Fasa University of Medical Sciences, dean of the hospital, and maternity ward of the hospital. This study was ethically approved by Fasa University of Medical Sciences with (ethics committee code: IR.FUMS.REC.1395.114; and was also approved in Iranian Registry of Clinical Trials at 2018 - 05 - 22 with a registration code IRCT20160830029608N2.
According to a study carried out by the same method by Franchy by taking into account 20% sample loss due to emergency cesarean and instrumental delivery, the sample size for the study was considered to be 100 subjects and assigned to one of two groups of XYLA cream and lidocaine injection. According to the findings of Kargar et al. (
18), The standard deviation of pain in the two groups was 2.5 and 2.2. In addition, by using the comparison formula between the two groups, considering the 95% confidence level, and test power of 90%, the minimum required sample size was 80 (40 in each group). Because of the probability of sample loss, the sample size was considered as 50 in each group. P < 0.05 was considered statistically significant.
In this study, participants were randomly allocated to either XYLA cream or lidocaine injection groups. Randomization was conducted with sealed envelopes containing computer-generated randomization numbers. The researcher generated the random allocation sequence, research assistant enrolled participants and assigned participants to interventions. Those assessing outcomes blinded after assignment to interventions. After explaining the study procedures to the eligible participants, written informed consents were obtained. Then their personal characteristics such as age, weight, gestational age, and cervical dilation were recorded. The inclusion criteria were gestational age > 37 weeks, normal pregnancy without skin allergies, singleton pregnancy, and cephalic presentation. On the other hand, patients with assisted delivery, need for emergency cesarean section, cervical rupture, and the existence of several types of rupture were excluded. It should be mentioned that mediolateral episiotomy was done by a midwifery specialist in all patients. Finally, 98 people remained in the study. Two of the XYLA cream group were excluded from the study due to the need for emergency cesarean section.
XYLA is a 30gr topical cream, which is packed in 5gr sterile tubes. In the XYLA cream group, 5 gr XYLA cream was applied to the mediolateral incision area on the perineum at 9 cm cervical dilation an hour prior to the approximate time of delivery. Since sodium hydroxide, which is one of the components of XYLA cream can irritate infants’ eyes, the remainder of the cream was removed before the head was delivered. It should be noted that no other anesthetics were used in this group. After the end of delivery, 5 gr XYLA cream was applied to the healthy skin around the episiotomy site and repairing was done after 10 minutes. In case of active bleeding, packing method was used. In the second study group, 5 cc lidocaine 2% was injected to the incision site before performing an episiotomy. After the end of delivery also, 5 cc lidocaine 2% was injected to the incision line and repairing was done after 10 minutes. In case of need for more anesthetics, lidocaine 2% was used in the two study groups.
Before moving the patients out of the delivery room, delivery characteristics such as duration of the third stage of labor, infant’s weight and head circumference, and 1st and 5th minute Apgar scores were recorded. Additionally, the patients were asked to report their pain intensity while episiotomy performance and repair on the visual analogue scale (VAS). The VAS is a 10-point vertical linear scale in which, 0 and 10 represent no pain and the greatest pain possible, respectively. The patients were also asked about their satisfaction with the applied technique using a 5-point Likert scale with the following options: completely satisfied, satisfied, no idea, dissatisfied, and completely dissatisfied. Utilization of further lidocaine injections was recorded, as well. In order to prevent wound area infection, similar antibiotic regimen was prescribed for both study groups. Moreover, episiotomy wound infection signs such as pain, discharge, fever, vulvar edema, and red and swollen mucosa were explained to the patients at discharge. They were also examined for episiotomy wound infection a week later.
The data were analyzed using the SPSS statistical software, version 22. Number and percent were used for qualitative variables, while mean and standard deviation (SD) were used for quantitative ones. Chi-square test was employed to compare the two groups regarding qualitative variables and satisfaction with the applied technique. Also, independent t-test was utilized to compare the study groups with respect to quantitative variables and pain intensity. P < 0.05 was considered statistically significant.