Evaluation of the effect of topical sodium bicarbonate injection on pain after inguinal hernia surgery

determine of the effect of topical sodium bicarbonate injection on pain after inguinal hernia surgery

Two arm parallel group randomised trial with blinded postoperative care and outcome assessment design of 100 patient.The rand function of Excel software was used for randomization.

In the participating patients of this study (Imam Ali Hospital and Shahid Madani Hospital in Karaj), all surgeries will be performed by a single surgeon and an anesthesiologist. The surgery will be done under general anesthesia with a classic incision. After repairing the defect and placing the mesh for the inguinal hernia, the surgical site will be irrigated with a solution (drug/placebo) once. Then, the patients' pain will be measured 12 and 24 hours after the operation. The study is double-blind (both the evaluator and the patient), the preparation of the solution is done by another person, and patients will be introduced to the evaluator with a code.

Participants: Candidate patients for inguinal hernia repair surgery / Entry conditions: indirect inguinal hernia, informed consent of patient, not recurrence inguinal hernia / Conditions of non-entry: psychopathy, drug addiction, chronic use of Analgesics, sensory and motor disorders, complications of strangulation and gangrene, loss of consciousness, patients with acute problems and needing emergency surgeries, recurrent inguinal hernia.

In the participants of this study, the surgery will be performed under general anesthesia using a classic incision. After repairing the defect and placing the mesh for the inguinal hernia, the surgical site will be irrigated once with a solution (Intervention group: Sodium bicarbonate or control group: Normal saline) and then stitched up.

The patient's pain score is based on Visual Analogue Scale (VAS)

Block randomization method will be used for sampling. The length of the block for each of the treatment groups is considered to be 4, which means that each block will include two people from the intervention group and two people from the comparison group. If we show the people of the intervention group with the letter A and the people of the comparison group with the letter B, in this case according to the formula n!/r!(n!_r!) We will have 6 combinations of four in the form of (AA,BB), (AB, BA), (BA, BA), (BA, BA), (BB, AA), and (AB, BA). Then random codes will be generated for each of these blocks. Then one of these blocks will be randomly selected and based on the sequence of letters A and B in the selected block, eligible people will be assigned to treatment or comparison groups. This random process of selecting blocks and assigning people to the intervention and comparison groups will continue until the desired sample size is reached. This method solves the problem of imbalance that can occur in simple randomization. To ensure the blinding of patients and assessors, each of these blocks will be identified with a code. On the other hand, the injection of normal saline containing sodium bicarbonate (intervention) and normal saline without sodium bicarbonate (placebo) will be done in the same amounts and using the same syringes.

The purpose of blinding, depending on its type, is not to inform the patients and the investigator about the outcome of assigning people to treatment groups. In such studies, patients should not know which group they belong to.This point is very important, especially when a type of subjective measurement such as pain (result of this study) is involved. Therefore, this study was designed as a double blind. In this way, the evaluator and the subject (patients) are not aware of the status of assigning people to the study groups. For the study subjects, the procedure is explained before random assignment and receives one of the two treatments randomly And the medicine used for people is not known in advance, On the other hand, the injection of normal saline containing sodium bicarbonate (intervention) and normal saline without sodium bicarbonate (placebo) will be done in the same amounts and using the same syringes to irrigate the surgical field. in such a way that it is not possible for the patient to distinguish them from each other, Therefore, the patient will be unaware of which group she is in. The evaluator and the patient will not be aware of the patients belonging to the treatment groups. The process of sampling and preparing the material for spraying (Irrigate) is done by another person.