Use of the Post-Tetanic Count to Monitor Recovery From Intense Neuromuscular Blockade in Children

Abstract

The post-tetanic count was investigated as a method of monitoring intense neuromuscular blockade in children. One of five myoneural blockers (atracurium, vecuronium, pancuronium, tubocurarine or alcuronium) was given to groups of six children during nitrous oxide-oxygen-halothane anaesthesia. During recovery, the first post-tetanic response always preceded the first train-of-four response. The interval between the appearance of the first post-tetanic response and the first train-of-four response was typically 5-10 min for the intermediate-acting agents vecuronium and atracurium, and 20-30 min for the long-acting agents pancuronium, alcuronium and tubocurarine. A post-tetanic count of 6 with alcuronium and tubocurarine, or 7 with vecuronium, atracurium and pancuronium indicated that recovery of the first train-of-four response was imminent.

Evaluation of the applicability of sevoflurane during post-tetanic myogenic motor evoked potential monitoring in patients undergoing spinal surgery

“…The success rate for "all muscles" indicates the percentage of patients with MEP responses from all muscle recording sites is followed by a post-tetanic increase in twitch tension (i.e., post-tetanic fasciculation of transmission). The post-tetanic count after tetanic stimulation at 50 Hz for 5 s has therefore become an accepted technique to quantify the degree of intense neuromuscular bockade under the condition in which responses to single-twitch stimulation are no longer obtained [20][21][22]. Kakimoto et al [14] hypothesized that the application of tetanic stimulation to peripheral nerves prior to transcranial stimulation might augment the amplitudes of MEPs from the muscles that were innervated by the nerve subjected to the tetanic stimulation.…”

Neuromuscular block and current treatment strategies for its reversal in children

“…In this situation, a tetanic stimulation may increase the ACh concentration high enough to allow detection of repetitive single twitch responses. This phenomenon is employed to determine a post‐tetanic count (13,16,17). Children recover from an NMB quicker than adults, and time from a certain number of post‐tetanic counts until a train‐of‐four (TOF) response can be detected is also shorter in children than in adults (18).…”

A close relationship between post-tetanic twitch and train-of-four responses during neuromuscular blockade by vecuronium

“…The PTC which coincided with the first appearance of TOF 1 was 9.4 ± 2.6 (range [4][5][6][7][8][9][10][11][12][13][14]. Figure 1 summarizes the mean time to the appearance of the first detectable TO F 1 as a function of the number of PTT responses present (i.e.…”

“…They al~o reported that this interval increased under nitrous oxide and fentanyl anesthesia by 1 min on an average, which was not clinically significant. Gwinnutt et al 6 reported that in pediatric patients with vecuronium (0.08 mg.kg-1 Lv.) under nitrous oxide and halothane anesthesia, this interval was 5.8 min, and the PTC at onset of TOF was 7.3 on an average.…”