Neuromuscular Refractoriness, Prejunctional Block and MgSO4 in the Pig

A new method for accurate determination of the refractoriness of neuromuscular (NM) transmission has recently been developed.1 Changes in the NM refractoriness may be pathognomonic of Mg-induced prejunctional NM block.1 We attempted to establish a pig model for the electromyographic (EMG) study, to determine the dose-response relationship of Mg-induced NM block, and to quantify the effects of Mg++ on the refractoriness of NM transmission.