Comparison of the muscle relaxant effects of rocuronium and vecuronium with dexmedetomidine

General anesthesia is an anesthetic technique composed as a combination of an intravenous anesthetic, an opioid and a neuromuscular blocker for induction, as well as N2O with an inhalation anesthetic for maintanence. Vital signs of the patient such as mean arterial pressure (MAP), heart rate (HR), etc is monitorized during the operation. Another monitorization technique of TOF is used for the effect of neuromuscular blocker (NMBIn recent years, facing the fact that the inhalation anesthesia was unsuccessful in reducing the stress response against surgical trauma, using a short acting hypnotic, opioid or dexmedetomidine during anesthesia procedures is gained more popularity. In reports about the influence of dexmedetomidine on neuromuscular blocking agents, there are some results of increasing their action times besides the opposite thoughts. The purpose of this study was to compare the effects of rocuronium and vecuronium, together with their interactions by the use of dexmedetomidine as an adjuvant drug during general anesthesia120 patients of ASA (American Society of Anesthesiologists) category of 1-2, who has been operated under elective conditions, were taken into account. They were divided into two groups. Group 1 was given rocuronium and group 2 was given vecuronium as a NMB. The patients of each group were divided to three groups randomly. They were labeled as group 1A-1B-1C and group 2A-2B-2C. Groups A in each category were control groups for rocuronium and vecuronium; groups B were aimed to compare the interaction of NMBs with the loading doses of dexmedetomidine, and groups C were intended to evaluate the affairs of NMBs with the infusion doses of dexmedetomidine. Group 1B and group 2B were given the loading infusions of 1 µg/kg/h dexmedetomidine for 10 minutes and they were given the maintenance infusions of 0.2 µg/kg for the rest of the operation. Group 1C and group 2C were only given the maintenance infusion of 0.2 µg/kg dexmedetomidine during the operation without pre-loading doses. Each and every one cases of the study were given 2-3 µg/kg fentanyl followed by 2-2,5 mg/kg propofol for induction. Group 1 and group 2 were continued above mentioned drug scheme. Following NMB injection, patients were entubated subsequent to declined twitch value to the 5% of baseline. During induction period, MAP and HR of every one cases were evaluated at 3 and 10 minutes. For anesthesia maintenance, the patients were given 60% nitrous oxide and 3% desflurane. Dexmedetomidine doses were titrated as regulating the blood pressure in a range of ± 20% of preoperative values. MAP and HR values of each patient were evaluated at 10th, 30th and 60th minutes of the operation and during the extubation period. Besides the recorded hemodynamic and respiratory parameters, 25%, 50%, 75%, and 90% of TOF values were also taken into account. As soon as the effects of NMBs has been ended, the usual monitoring of the patients were continuedFindings: T1 values during induction period were found to be statistically different in groups who were given 0.2 µg/kg dexmedetomidine infusion (p:0.03 for rocuronium, p:0.02 for vecuronium). Analysing the values of 50%, 75% and 90% TOF during the operation shows that the TOF values for vecuronium groups were prolonged statistically in both dexmedetomidine loading groups and non-loading groups; whereas in rocuronium groups a statistically different result were not foundConclusion: By means of dexmedetomidine infusion, the T1 reaction times of rocuronium and vecuronium during induction were lowered statistically. When compared to loading dexmedetomidine groups, this result is thought to be connected with the less stress on hemodynamics. Using dexmedetomidine did not change the rocuronium elimination time, despite the fact that the vecuronium elimination time was prolonged statistically. This gives us an idea about it could be a result of lowered perfusion rate of kidneys by means of hemodynamic stress via dexmedetomidine.