Efficacy of Low Level Laser Therapy on The Post Midline laparotomy Wound Pain in upper and lower Gastrointestinal (GI) Surgical Procedure : a randomized clinical trial

Introduction Painkiller drugs play an important role in reducing pain after surgery. These drugs might have unavoidable side effects and by the identification of new side effects, the needs for non-drug agents have been increased gradually. Therefore we decided to investigate the effect of low-power laser therapy on pain control after surgery.

In this study, 106 patients as candidate for elective gastrointestinal tract surgery after exclusion 6 case were divided into two groups with 50 patients after being randomized. The intervention group and control group underwent low level laser therapy and placebo by daily manner respectively after surgery. Then both groups were evaluated and compared in terms of pain intensity and amount of pethidine consumption.

There was no significant difference between two groups in terms of average age, sexual frequency and perioperative inflammatory factors and skin complications. The average pain intensity at 0, 24, 48, 72, 96 hours after surgery was 7.2, 5.3, 4.2, 3.66, 2.44 for the intervention group and it was 7.14, 6.3, 5.3, 4.3, 2.7 for the control group respectively. Also, the average use of pethidine was evaluated in 24-hour intervals until the fourth day, which was 53, 29, 10, 5.5 mg for the intervention group and 54, 37.5, 22.5, 8.5 mg for the control group respectively. At the first 24 hours and 96 hours after the operation, difference of pain intensity and pethidine consumption between the two groups was not significant, but in period 24-96 hours after surgery, the pain intensity and also the average pethidine consumption significantly decreased in the intervention group compared to the control group.

The findings of this study showed that the low level laser therapy can be used to control the pain and can be proposed as an alternative method to painkillers drugs. Competing Interest Statement The authors have declared no competing interest. Clinical Trial IRCT20221018056225N1 Funding Statement The author(s) received no specific funding for this work. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Before starting the study, the informed consent and the study protocol was approved by the regional ethics committee with the ethical code IR.BMSU.BAQ.REC.1401.029 I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability Data are available from corresponder author (contact via corresponder email or phone number) for researchers who meet the criteria for access to confidential data.