Impact of intraoperative and post operative low dose ketamine infusion on neuropathic pain component in chronic persistent postsurgical pain following breast cancer surgery . A randomized controlled double blind study

Rationale: Chronic persistent post-surgical pain is a debilitating complication following breast cancer surgery. Therefore, it is important to evolve strategies that limit the development of chronic persistent post-surgical pain.

Objectives: To assess and compare NRS pain scores, multiple neuropathic pain scores (DN4, NPSI, PDQ scores), rescue analgesia, SF-12 Quality of Life scores and adverse effects in the study group as compared to similar scores in control group following breast cancer surgery.

Study design: Randomised, controlled, double blind study.

Time frame: Study will be conducted from March 2024 to August 2026.

Participants: Adult female patients aged 18 to 65 years of age, diagnosed as carcinoma breast scheduled for elective breast cancer surgery.

Procedure: Patients will be randomly divided into two groups of 30 patients in each group. Study group will receive ketamine as a bolus before skin incision followed by low dose ketamine infusion intraoperatively and postoperatively for 24 hours whereas we will use normal saline in control group in same dosing and time period as study group.

Patients will be assessed for NRS-pain score and multiple neuropathic scores (DN4, NPSI, PDQ scores) at 1hour, 6 hours, 24 hours, 72 hours, 1 month, 2 months and 3 months post-breast cancer surgery.

Outcome measures: NRS-pain scores, DN4 questionnaire score, NPSI score, PDQ score, SF-12 quality of life scores, rescue analgesia required and adverse events will be assessed and compared between study group and control group.

Sample size: One hundred adult female patients diagnosed a carcinoma breast.

But because of limitations in the availability of cases of carcinoma breast in our clinical setup for breast cancer surgery, we shall be taking up 30 patients per arm; though every effort would be made to target calculated value of patients per arm.

Statistical analysis: Data will be analysed by SPSS statistical software version 20. The data will be summarised for continuous variable in mean (SD) or median (25th to 75th percentile) and qualitative data will be reported with number and percentage.

Baseline patient characteristics will be compared using unpaired t-test and “Chi-square test” using two arms. All continuous variables will be tested for normality using box whisker plot and Kolmogorov Smirnov test.Level of significance for present studywill be fixed as 5 % or p< 0.05.