Influence of glucocorticoids on sugammadex action

Muscle relaxation has a significant role in general anesthesia, indications for the use of muscle relaxants (MR) are endotraheal intubation, surgical procedures on thorax and abdomen and microscopic surgery where it is necessary for patients to be fully relaxed. There are depolarising (succynilcholine) and nondepolarising (benzylisoquinolines, aminosteroids) MR. The reversal of neuromuscular blockade (NMB) at the end of anesthesia has to be achieved either by conventional acetylcholinesterase inhibitors (AChE inhibitors) or with new reversal agent sugammadex which introduced completely new concept of NMB reversal.Sugammadex encapsulates aminosteroid MR and therefore reduces the circulating MR concentration which by concentration gradient removes MR molecules from neuromuscular junction (NMJ). Complex sugammadex-MR is excreted in urine within 1-4 hours. Sugammadex therefore provides more rapid reversal of even deeper or more intensive NMB compared to broadly used AChE inhibitors. It is a drug of choice in reversing NMB in patients with neuromuscular disease (e.g. miasthenia gravis) and in patients with heart or lung disease in whom use of AChE inhibitors in less desirable due to their unfavorable side effects. Glucocorticoids are widely used agents as part of patient's daily regimen as well as an antiemetic agent during anaesthesia. The similarity of molecular structure of glucocorticoid and aminosteroid MR rises concerns whether the concurrent use of glucocorticoid could affect the efficiency of sugammadex. In our prospective randomised study we will include 60 patients anesthetized for elective surgery (abdominal, thoracic). Patients enrolled into observational group will receive dexamethasone 0,15 mg/kg for prevention of postoperative nausea and vomiting (PONV), whereas patients in controlled group will receive granisetron 1 mg for the same purpose. Anesthesia will be conducted and maintained in standard fashion, muscle relaxation will be achieved using rocuronium, which will be added according to TOF (train of four) values. At the end of the operation we will draw the first sample of blood before application of sugammadex and the second one after regaining full muscle strength according to TOF. We will compare the blood levels of rocuronium (both groups) and dexamethasone (observational group) before and after sugammadex application which will allow us to indirectly evaluate possible dexamethasone encapsulation by sugammadex. The aim of our study is to asess whether concurrent use of dexamethasone affects the efficacy of sugammadex.