Immunomodulatory Effect of Dexmedetomidine as an Adjuvant Drug in Laparoscopic Cholecystectomies

Trauma triggers a tissue response involving the central nervous system, the hypothalamic-pituitary-adrenal axis and the immune system. There are many surgical and anesthetic factors that affect the response to trauma, and the control of the inflammatory factor is considered the most important. (KÜÇÜKEBE, O.B. ET AL, 2017). Dexmedetomidine is a specific α2-adrenergic agonist. By direct action on the sympathetic nervous system, α2-adrenergic agonists can exert beneficial effects on the immune system through neuroimmune interactions. Its administration can induce an anti-inflammatory response due to different central (increase parasympathetic tone, promoting control of the inflammatory condition) and peripheral effects (stimulating innate immunity). (MILLER, 2015). This study aims to evaluate the effect of dexmedetomidine administration in association with general anesthesia in a medium-sized surgical model, videolaparoscopic cholecystectomy.

The present study is a randomized, single-blind, prospective clinical trial. Its objective is to evaluate the possible qualitative changes in organic function and in the systemic inflammatory response when using dexmedetomidine associated with general anesthesia for laparoscopic cholecystectomy surgeries. The study was designed and executed according to the surgical routine of the Hospital Universitário Gaffré e Guinle - RJ. The anesthesiology service is recognized by the Ministry of Education and the Brazilian Society of Anesthesiology. Participant registration data will be replaced by codes for the preservation of personal information. The following were used in the elaboration of the study: 1) Selection of ASA I and II patients listed for elective procedures and standardization of the anesthetic technique. 2) A standardized data collection system in a specific form and fed with the residents with adequate supervision; 3) procedures converted into open surgery were excluded, since they imply an increase in surgical trauma and absence of pneumoperitoneum perfusion-reperfusion syndrome;4) Two groups with similar characteristics were used and the only difference will be the administration or not of dexmedetomidine in the procedure under study;5) Study with single blinding: the patient, also called the object of study, does not know which group he belongs to. The investigator does. Continuous infusions of dexmedetomidine or 0.9% saline (placebo) were used. Dexmedetomidine was used in the intervention group as follows: beginning in anesthetic induction after obtaining venous access at 1mcg/kg/h for 20 minutes, followed by 0.2 - 0.5 mcg/kg/h until surgery was completed. The placebo group will receive 0.9% saline infusion at the same rates as the intervention group. Venous blood samples were collected at three times (T1, T2 and T3): Before anesthetic induction with collection in the preoperative environment on the day of surgery or during venoclysis before anesthetic induction (sample 1, T1); 6 hours after starting orifice closure and completion of drug or placebo infusion (sample 2, T2); and the last blood sample will be collected by me on the morning after the postoperative period, close to hospital discharge (sample 3, T3). Will be measured in all venous blood samples: IL-6, cortisol, CRP and glycemia (dosing techniques -chemiluminescence or ELISA).

Eligibility Criteria:
Inclusion Criteria:

* Patients ASA I and II
* Elective Videolaparoscopic Cholecystectomy Surgery
* Patients who signed the Free and Informed Consent Form

Exclusion Criteria:

* Patients ASA \> II
* Conversion to open surgery
* Emergency Surgeries