Efeito da terapia lase de baixa intensidade na dor pós cesariana: ensaio clínico cego, randomizado e controlado

Abstract

Background and Objective: Pain in the region of the cesarean incision is the main complaint of women in the immediate postpartum and considered post-cesarean morbidity for the mother and the newborn. This study aimed to evaluate the effect of LLLT for pain relief in the region of the surgical incision of women undergoing cesarean section. Desing/Materials and Methods: Blind randomized controlled clinical trial to determine the effect of two consecutive LLLT sessions on pain in women undergoing cesarean surgery. A total of 88 women in the immediate puerperium who underwent cesarean section were included in this study. Participants were randomized into four groups and recruited on spontaneous demand: control group (n=22, without LLLT of 660nm), sham group (n=22, LLLT of 660nm without radiation emission), experimental group I (n=22, LLLT of 660nm with dose of 4J/cm2 ) and experimental group II (n=22, LLLT of 660nm with dose of 2J/cm2 ). The study presented three phases: (I) evaluation of sociodemographic and clinics variables, evaluation of primary outcome by Numerical Pain Scale and algometry 12 hours after delivery (evaluation 1); (II) treatment period for two consecutive days (posterior evaluation 1 and evaluation 2); (III) reevaluation of primary outcome and second outcome between 20-24 hours postpartum (evaluation 2) and 44-48 hours postpartum (evaluation 3). In the statistical analysis, data were analyzed using the software SPSS 20.0 (Statistical Package for the Social Sciences) for Windows, assigning a level of significance of <5%. The normality of the data of each group was evaluated by the Shapiro-Wilk test. The repeated-measures analysis of variance (ANOVA) was used to evaluate the effect of the intervention on the visual numerical and algometry variables with the effects of the independent time variables (Time: evaluation 1, 2 and 3) and the interaction effect between the time-group variables. The test with Sidak adjusted post hoc analysis for multiple comparisons was used to determine the mean differences between groups. ANOVA one-way was used to evaluate the pain in each time and the perception of global change together the Tukey post-test to identify the difference. Mean differences and 95% confidence intervals were calculated to indicate the accuracy of the estimates. The size of the effect was demonstrated by Cohen's d. Results: There was a statistically significant difference between the groups in the third numerical evaluation of pain (p = 0.03) and algometry (p = 0.04). There was also a significant difference between the groups in the first PGIC evaluation (p = 0.04) and in the second evaluation (p = 0.02). Considering the numerical scale of pain, the effect size was 0.11% (placebo group), 43% (control group), 71% (experimental group I) and 68% (experimental group II). Was observed interaction time vs group significant for the numerical evaluation of pain F (2,40) = 36,80, p <0,001 and algometry F (1,70) = 27,18, p <0,001. Considering the numerical scale of pain, the effect size in the nonintervention groups was 0.11 (sham group) and 0.43 (control group). In the experimental I group was 0.71 and in the experimental II group was 0.69. In relation to algometry, the effect size was 0.26 (sham group) and 0.27% (control group), 0.91 (experimental I group) and 0.88 (experimental II group). Conclusion: The use of LLLT had beneficial effects on operative wound pain in postpartum women submitted to cesarean section. In addition, there was improvement in the clinical perception in the intervention group. The effect size also showed better results for the intervention group.