Effects from a single application of photobiomodulation on pain intensity from perineal trauma related to childbirth:...

To analyze the effects of a single photobiomodulation (PBM) application on perineal pain and healing in women in the immediate postpartum period.

Randomized controlled trial, double-blind, two-center, with 60 postpartum women with perineal trauma and pain scoring 4 or more on the Numeric Rating Scale (NRS). The experimental group received red light to the lesion and infrared light around it, while the sham group received a simulation. We assessed pain with the NRS and Short-Form McGill Pain Questionnaire (SF-MPQ); tissue healing with the REEDA scale (Redness, Edema, Ecchymosis, Discharge, Approximation) at baseline, 30 min (primary outcome), and 12-36 h after intervention and satisfaction with a Likert scale 7-10 days post-intervention. We conducted bivariate analyses and an analysis of variance for repeated measures.

The experimental and sham groups showed pain reduction with no difference between them for pain scores or healing 30 min post-intervention (mean ± SD: NRS 3.63 ± 2.57 vs 2.53 ± 2.15; P = 0.089; SF-MPQ 7.83 ± 8.32 vs 5.10 ± 6.42; P = 0.108; and REEDA 5.57 ± 3.05 vs 4.47 ± 2.42; P = 0.175). Analysis of variance revealed no significant interaction between time and group at any time point evaluated. Of the participants, 84.09% were satisfied or very satisfied with the intervention.

Although both groups experienced a reduction in pain after the intervention, a single PBM application with these parameters was not superior to a sham treatment. Future research could explore multiple applications or different parameters.

Laser for Pain Relief in Nipple and Perineal Trauma in Postpartum; UTN code U1111-1279-3594 (https://ensaiosclinicos.gov.br/rg/RBR-2qm8jrp/1).