Failure of nondepolarizing neuromuscular blockers to inhibit succinylcholine-induced increased intraocular pressure, a controlled study

Abstract

The effects of pretreatment with two nondepolarizing muscle relaxants, d-tubocurarine (dTc) and gallamine, on SCh-induced elevation of intraocular pressure was investigated in adults and children. d-Tubocurarine was given as pretreatment before SCh to ten children (mean age 6 years) and ten adult patients (mean age 33.9 years) and saline solution pretreatment was given before SCh to ten children (mean age 6.7 years) and ten adult patients (mean age 33.6 years). dTc and saline pretreatment did not alter baseline IOP's which were similar in all four groups. After iv administration of SCh there were elevations of IOP in all four groups. The responses were also similar: the numbers of patients showing increases in IOP of more than 6 torr were: 5 saline control and 5 dTc-pretreatment adults; 9 saline control and 8 dTc-pretreatment children. In the double-blind gallamine- or dTc-pretreatment study, IOP's were similarly increased in both groups following SCh administration. Showing increases of more than 6 torr in IOP were nine gallamine-pretreatment patients and ten dTc-pretreatment patients. Ten children received saline solution instead of muscle relaxants and had their tracheas intubated with only halothane anesthesia. IOP's measured when the children were just asleep and later just prior to endotracheal intubation sere similar. Immediately following endotracheal intubation IOP was significantly elevated. However, IOP following endotracheal intubation after only halothane was significantly lower than IOP with gallamine or dTc pretreatment before SCh. One of 10 children whose tracheas were intubated using only halothane had an increase of IOP of more than 6 torr. Of 40 patients pretreated with nondepolarizing muscle relaxants before SCh, observable muscle fasciculations developed in only two (5%). Of 20 patients pretreated with saline solution before SCh, all of the adults and seven of ten children (85% of the combined group) had fasciculations.