Onset and duration of action of rocuronium – from tracheal intubation, through intense block to complete recovery

Abstract

The PTC method can be used to predict the time to first response to TOF nerve stimulation during intense rocuronium induced neuromuscular blockade. The relation between PTC and the time to T1 was prolonged after 1.2 mg/kg compared with 0.6 mg/kg and 0.9 mg/kg. No further improvement in intubation conditions at 60 s was evident by increasing the rocuronium dose from 0.9 mg/kg to 1.2 mg/kg.

Efeito da utilização de 2 mg.kg-1 de lidocaína endovenosa na latência de duas doses diferentes de rocurônio e na resposta hemodinâmica à intubação traqueal

“…the hypothesis that lidocaine could potentiate the neuromuscular blockade of rocuronium, decreasing its latency, was not demonstrated in the present study. the results were able to demonstrate statistical significance of the comparison among the latencies of two different doses of rocuronium, 0.6 mg.kg -1 and 1.2 mg.kg -1 , which has been widely divulgated in the literature 29,44 . Using the dose of 1.2 mg.kg -1 , indicated for rapid-sequence intubation, the latencies obtained were 47.40 seconds in the group that did not receive lidocaine, and 48.60 seconds in the group that received lidocaine, i.e., nearly ident ical.…”

Performing post-tetanic count during rocuronium blockade has limited impact on subsequent twitch height or train-of-four responses

“…PTC = post-tetanic count; R/L = right/left; T1 = first twitch height; TOF = train-of-four; T4/T1 = train-of-four ratio minutes, which is close to the recommended interval (six minutes) used in previous studies. [1][2][3][4][5][6] The PTC comprises a tetanic stimulation at 50 Hz for five seconds (250 impulses), followed by a three-second pause and then a series of 15 test stimuli at 1 Hz . Thus, the duration of this stimulation pattern is 23 sec with a total of 265 impulses.…”

“…Most studies have been performed with a six-minute delay between successive PTC stimulation without any firm evidence for the value. [1][2][3][4][5][6] Using the contralateral arm as control, Motamed et al found that repeating PTC every three minutes did not affect the time course of recovery during atracurium blockade. 8 Their findings contrast with those of Feldman et al who reported that, when an extremity is subjected to repeated tetanic stimulation, neuromuscular function remains enhanced when compared with the contralateral (control) arm.…”

“…When no twitch or TOF response is present before applying PTC, one or several twitch responses may be seen in response to 1-Hz stimulation after the 50-Hz tetanus, due to post-tetanic facilitation. The number of visible PTC responses is inversely related to the depth of the blockade, and it can be used as a guide either to predict the time remaining until recovery of visible TOF response [1][2][3][4][5][6] or to determine the dose of sugammadex or other reversal agents required for adequate reversal. 7 The PTC technique relies on inducing a transient improvement of neuromuscular transmission in the monitored muscle, usually the adductor pollicis.…”

“…[1][2][3][4][5][6] The principle behind this monitoring modality is based on the view that prolonging high frequency stimulation for a few seconds can produce enhanced neuromuscular transmission which continues after the stimulation is withdrawn. 1 This phenomenon is called post-tetanic facilitation.…”