Length of analgesic effect of cryotherapy to relief perineal pain after childbirth: a randomized controlled trial

• Grant number: 12/19957-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2013
• End date: August 31, 2015
• Field of knowledge: Health Sciences - Nursing - Obstetrical Nursing
• Principal Investigator: Sonia Maria Junqueira Vasconcellos de Oliveira
• Grantee: Adriana Amorim Francisco
• Host Institution: Escola de Enfermagem (EE). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Ice packs have been used after vaginal delivery in the perineum to decrease swelling and avoid bruising. Relieving perineal pain using an ice pack is unusual, because evidence is lacking to provide this practice safely and effectively. Using ice in the treatment of perineal pain is justified because it is easy to apply, noninvasive, inexpensive, with few side effects and contraindications, and by the ability of localized cooling of reducing the inflammatory reaction, edema and pain. However, the length of analgesia after application of the ice packs in the perineum is not clear and it makes impossible to establish the interval between sessions and developing protocols for clinical practice. Objective: to evaluate perineal analgesia 2h following the application of the ice pack for 20min. Method: a randomized controlled trial in which the evaluator is blinded, will be carried out at Amparo Maternal, São Paulo. The participants will be women after normal birth in rooming-in care, according inclusion criteria: age greater than or equal 18 years old, with full-term, live, singleton, fetus in cephalic presentation, from 6 to 24 hours following childbirth, perineal pain greater than or equal 3 on a numeric scale at the moment of the inclusion in the study, did not receive anti-inflammatory, ice application or any localized treatment in the perineum at the first 24h after delivery, without obstetric or clinical complications, newborn within good clinical condition. The women will be allocated to one of the two treatment groups: Group A- those who will receive an ice pack for 20 min and Group B-those who will not receive an ice pack. The sample size was calculated based in a pilot study developed at the same maternity. It identified 30% pain relief on 71.2% in the experimental group and 41.2% in the control group. Supposing treatment effect similar to the pilot study, setting alpha 5% and power level of 80%, resulting in a sample size of 33 patients per group. A randomized list to a computer-generated with numeric code will be used. Each number will be separated and placed in an opaque, numbered, sealed envelope to be opened by a researcher at the inclusion of the women in the study. The intervention will be an application of the ice pack in a single instance, for a 20min period in the perineal region. The primary outcome measure will be the pain magnitude evaluated by the numeric scale, before, immediately after and 2h after application of the ice pack. The secondary outcomes will be: perineal temperature, analgesic consumption and the impact of the therapy in daily activities. The qualitative variables will be presented by using frequencies and the quantitative variables by using mean, median and measures of dispersion. Adherence of the quantitative variables to normal distribution will be assessed by using the Kolmogorov-Smirnov test and the homoscedasticity of the variances by Levene test. If the variables have normal distribution and reasonable variance between the averages, they will be submitted to t test, if the variables do not meet the requirements for parametric tests, corresponding nonparametric tests will be used. The dependent variable perineal pain will be dichotomized and related with the variables: age, parity, perineal trauma, suture and newborn weight, by using the chi-square test or Fisher's exact test. Those with statistical significance equal to or less than 0.20, will be related by multiple regression. All statistics analyses will adopt the significance level 0.05 and confidence level 95%. The pilot study was approved by the Ethics Committee of the School of Nursing (no1119/2012/CEP-EEUSP). This project is an extension of the pilot study concerning the postpartum period, therefore an addendum will be sent to the committee to detail the specifics of the current project. The participation of the women will be voluntary, after signing the consent form. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

FRANCISCO, Adriana Amorim. The duration of the analgesic effect of cryotherapy in postpartum perineal pain: a randomized controlled trial. 2015. Doctoral Thesis - Universidade de São Paulo (USP). Escola de Enfermagem (EE/SBD) São Paulo.