The Model of Research Post-Cholecystectomic Pain Syndrome in Experiment

Abstract

The number of surgeries performed by the laparoscopic method is constantly increasing due to the low trauma and fast patients recovery after surgery. However, despite the small surgery traumatism, most patients have the distinct pain syndrome, felt in the post-operative period and directly aff ects the post-operative prognosis. Despite the low trauma, pain after laparoscopic cholecystectomy has two pathways: parietal (somatic) and visceral. Given all the diffi culties in assessing the visceral component of post-operative pain, there is an urgent need to create a research model. The mucosa of the rabbit’s cheek was selected to model the visceral component of post cholecystectomy pain. The pain syndrome in the post-operative period was modeled on rabbits due to the formation of a burn wound on the mucosa of the left and right cheeks. The eff ectiveness of its treatment was studied with the help of combinations of analgesics. The burn wound was created by electrocoagulation EHVCH-300 «ELEPS» on the mucous surfaces of the right and left cheeks, under general anesthesia with propofol at a rate of 7.5 mg/kg. On the experimental (left) side, the studied combinations of analgesics were introduced: 1st group application mixture of 2.0 ml 0.5% bupivacaine with 2.0 ml with 5% dexketoprofen; Group 2 with a mixture of 2.0 ml of 0.5% bupivacaine with 0.5 ml of 1% nalbuphine; Group 3 was injected under the mucosa a mixture of 2.0 ml of 0.5% bupivacaine with 0.5 ml of 1% nalbuphine. The wound on the right cheek was a control, used for comparison. Pain syndrome was assessed by the reaction to fi nger pressure on the outside of the right and left cheeks separately, and refusal to eat (based on the dynamics of the daily diet). Pain control was performed in 6, 12, 24, 48, and 72 hours after surgery. Additionally, there was made an analysis of the dynamics of maintaining the daily diet.The first group there were revealed distinct diff erences in the severity of pain between the controlled (right) and left (experimental) parts for 6 (p˂0.01) and 12 (p˂0.05) hours after surgery, which indicates the clinical signifi cance of local use of a combination of bupivacaine with dexketoprofen. In the 2nd group, there were distinct diff erences in the severity of pain test between the right controlled cheek and left parts for 6 (p˂0.01), 12 (p˂0.01), and 24 (p˂0.05) hours. That is, the inclusion of a narcotic analgesic prolonged the analgesic effect by 100% (from 12 to 24 hours). In the 3rd group, there were distinct diff erences in the severity of pain for 6 (p˂0.01), 12 (p˂0.01), 24 (p˂0.01), and 48 (p˂0.05) hours. On the third day, all animals (20) did not show pain eff ect on the left (experimental) side. However, the resorptive eff ect of the studied combination of bupivacaine with nalbuphine was revealed by submucosal injection.Analysis of the frequency and duration of rabbits’ refusal to eat revealed this criterion in 16 (80%) animals of the fi rst group, and in 17 (85%) animals of the second group. Thus, the application methods of local anesthesia acted locally but had an insu ffi cient analgesic eff ect. In the third group, the refusal to eat was not detected in the majority (60%) of rabbits during this period. This indicates a greater strength and resorptive mechanism of analgesic action in the third group.Therefore, in clinical use, to block the visceral mechanism of suppression of pain impulses in laparoscopic cholecystectomy, it’s prognostically better to use the application method, which provides a certain local analgesic eff ect and clinically insignifi cant resorptive eff ect. This requires an additional and further study of the quantity and quality of analgesics for recommendations on local clinical use.