Lidocaine alone or combined with Magnesium Sulfate stabilizes hemodynamic parameters during General Anesthesia without prolonging the Neuromuscular Blockade: a randomized, double-blind, controlled trial

Abstract BackgroundLidocaine and magnesium sulfate have become increasingly utilisedin general anaesthesia. The present study evaluated the effects of these drugs, isolated or combined on the hemodynamic parameters as well as on the cisatracurium-induced neuromuscular blockade (NMB).MethodsAt a University hospital, 64 patients, ASA physical status I and II, undergoing elective surgery with similar pain stimulus, were randomly assigned to four groups. Patients received a bolus of lidocaine and magnesium sulfate before the tracheal intubation and a continuous infusion during the operation respectively: 3 mg.kg-1 and 3 mg.kg-1.h-1 (Lidocaine -L group), 40 mg.kg-1 and 20 mg.kg-1.h-1 (Magnesium - M group), equal doses of both drugs (Magnesium plus lidocaine - MLgroup) and, a equivalent volume of isotonic solution (Control - C group). Haemodynamic parameters and neuromuscular blockade features were continuously monitored until spontaneous recovery of the Traino of Four ratio (TOF=0.9).ResultsThe Lidocaine group presented a highly significant small hemodynamic fluctuation during the anesthesia induction and maintenance period (p<0.0001) with no change at NMB. The magnesium sulfate infusion alone or combined with lidocaine prolonged all the recovery characteristics (p< 0.0001). The onset time was not influenced by the studied drugs. The percentage of patients who achieved a TOF ratio of 90% without recovering the first Twich (T1-95%) was higher in the M and ML groups.ConclusionIntravenous lidocaine plays a significant role in the hemodynamic stability in patients under general anesthesia without exerting any additional impact on the NMB even combined with magnesium sulfate. Aside from prolonging all NMB recovery characteristics without altering the onset speed, magnesium sulfate enhances the TOF recovery rate without T1 recovery. Our findings may aid clinical decisions involving the use of these drugs by encouraging their association in multimodal anesthesia or other therapeutic purposes.Trial registrationNCT02483611 (registration date: 06-29- 2015).