Comparison of ultrasound guided intercostal nerve block with ropivacaine against Ropivacaine and Dexmedetomidine on reduction of postoperative pain in patients undergoing thoracotomy: a randomized clinical trial

The aim of this study is to assess the effect of adding Dexmedetomidine to Ropivacaine on pain after thoracotomy.

Double-blind clinical trial, with parallel, randomized groups, phase 3 on 74 patients, randomization using www.Randomizer.org service

Thoracotomy patients in Ahvaz Imam Khomeini Hospital undergo intercostal nerve block. Physician in charge of injection, the patients and the outcome assessors are blinded to the study by using a transparent label coded syringe. only the physician in charge of preparing the syringe is aware of the contents.

Inclusion Criteria: Age 18 to 60 years, American Society of Anesthesiologists physical status Class I, II or III, Body Mass Index less than 40, No history of substance or alcohol abuse, No pregnancy or breastfeeding, No history of coagulation problems or use of anticoagulants, Ejection fraction above 30%, No history of cardiac conduction block (except for first-degree cardiac block and controlled atrial fibrillation), No acute or chronic hepatitis, No history of psychiatric illness, No need for renal supplementation or a history of kidney failure, Absence of Neuropathy, Exclusion Criteria: Hypersensitivity to study medication

At the end of thoracotomy, after extubation and hemodynamic stability, the intercostal nerve block is done using a code labeled transparent syringe under ultrasound guidance (M7, MindRay China) by a Pain Fellowship. the intercostal nerve block is done one space above and two spaces below the surgical incision site. Control Group: 5 cc Ropivacaine (Molteni Farmaceutici, Italy) 0.25% is injected in the three spaces. Intervention Group: in Addition to Ropivacaine (5cc, 0.25%), Dexmedetomidine (Exir Pharmaceutical Co., Iran), 0.5 mcg/kg is injected, divided between the three spaces.

Post operative Pain

Using Research Randomizer(freely available at www.randomizer.org) 74 random numbers are generated. this unsorted series of numbers are then used to assign coded drugs to patients.

After obtaining a series of unsorted random numbers from the website, the numbers are used to divide consecutive patients into two groups. This data is then given to the anesthesiologist in charge of the study. This specialist, who is aware of patient assignments, Prepares study medications for injection in a transparent syringe, labeled with the code of each patient and provides them to a second anesthesiologist. this second anesthesiologist, who is unaware of the contents of the syringe then puts patients, who are unaware of the used medications, under intercostal nerve block. Patients are then transferred to the intensive care unit and monitored. Here, the patient data is collected in coded forms by the data collection team, who are unaware of patient assignment to groups. This information is provided to the statistical analyzer in numbered forms along with the information related to the assignment to the groups for statistical analysis.