Effects of Intravenous Lidocaine Associated With Magnesium Sulfate on the Cisatracurium-Induced Neuromuscular Block

The magnesium sulfate and lidocaine have been increasingly used alone or in combination during anesthesia procedure to meet various objectives, such as reduction of pain, use of smaller anesthetic doses and stabilization of hemodynamic parameters. These medicines are often used in combination with neuromuscular blocking agents, which may contribute to the occurrence of residual block in some patients after anesthetic procedures. It was estimated that only 1-3 % of patients with residual block developing clinically apparent events. In a small proportion of patients, the consequences of residual blockade are very serious and even lethal. It is estimated that 40 % of patients with muscle paralysis come to the post-anesthesia care unit (PACU). Considering that: (a) magnesium sulfate and lidocaine are showing an increasing number of applications in various areas of medicine, (b) these medications stand out for their properties analgesic, anti-inflammatory, anti-arrhythmic, neuroprotective and capable of reducing the demand of anesthetics and opioids, (c) magnesium sulfate as lidocaine has been important part of the therapeutic arsenal to control a large number of diseases (d) the patient surgical surgery or potentially have benefited in particular from its effects, (and) these drugs have been used routinely in many medical services as well as adjuvants in anesthesia, (f) previous studies have shown that magnesium sulfate is able to prolong the duration of neuromuscular blockade by different types of muscle relaxants, with controversies about its effect on latency (g) the effect of lidocaine on the action of muscle relaxants in current literature have shown great controversy and (h) do not exist in the literature studies involving both drugs; the investigators aimed to investigate the effects of magnesium sulphate infused alone or associated with lidocaine on the neuromuscular blockade promoted by cisatracurium, as well as evaluate its possible hemodynamic repercussions. For this purpose the SM was infused in bolus, prior to tracheal intubation and continuously during the maintenance of general anesthesia; the Lidocaine, when associated and the Isotonic Solution were used in the same way and timeline as SM. As secondary objectives it has been proposed to evaluate if the Lidocaine with Magnesium Sulfate would be able to interfere with the hemodynamic stability of the patients in the study.