Effects of magnesium chloride on rocuronium-induced neuromuscular blockade and sugammadex reversal in an isolated rat phrenic nerve–hemidiaphragm preparation

摘要

BACKGROUND Magnesium potentiates the effects of nondepolarising muscle relaxants. However, few studies have used magnesium chloride (MgCl_(2)). Sugammadex reverses neuromuscular block by steroidal nondepolarising muscle relaxants. OBJECTIVES To assess the effects of MgCl_(2)on rocuronium-induced neuromuscular blockade and its reversal by sugammadex. DESIGN In-vitro experimental study. SETTING Animal laboratory, Asan Medical Center, Seoul, South Korea, from 20 March 2016 to 3 April 2016. ANIMALS Forty male Sprague Dawley rats. INTERVENTION Left phrenic nerve–hemidiaphragms from 40 Sprague Dawley rats were allocated randomly to four groups (1, 2, 3 and 4?mmol l~(-1)MgCl_(2)group, n ?=?10 each). Rocuronium was administered cumulatively until the first twitch of train-of-four (TOF) disappeared completely. Then, equimolar sugammadex was administered. MAIN OUTCOME MEASURES The effective concentration (EC) of rocuronium was obtained in each group. After administering sugammadex, recovery of the first twitch height and the TOF ratio were measured for 30?min. RESULTS EC_(50), EC_(90)and EC_(95)significantly decreased as the concentration of MgCl_(2)increased (all P ?≤?0.001), except the comparison between the 3 and 4?mmol l~(–1)MgCl_(2)groups. After administration of sugammadex, the maximal TOF ratio (%) was lower in the 4?mmol l~(-1)MgCl_(2)group than the 1?mmol l~(–1)MgCl_(2)group [median 91.7 interquartile range (83.4 to 95.8) vs. 98.3 interquartile range (92.2 to 103.4), P ?=?0.049]. The mean time (s) from sugammadex injection to achieving maximal first twitch was significantly prolonged in the 4?mmol l~(–1)MgCl_(2)group vs. the 1?mmol l~(–1)MgCl_(2)and 2?mmol l~(–1)MgCl_(2)groups [1483.9 (±?237.0) vs. 1039.0 (±?351.8) and 926.0 (±?278.1), P ?=?0.022 and 0.002, respectively]. CONCLUSION Increases in MgCl_(2)concentration reduce the ECs of rocuronium. In addition, administering sugammadex equimolar to the administered rocuronium shows limited efficacy as MgCl_(2)concentration is increased. TRIAL REGISTRATION The in-vitro study was not registered in a database.