Duration of exposure to sevoflurane affects dose-response relationship of vecuronium

The TOFr of 0.75 to 0.85 is the optimal timing for IONM during thyroid surgery: a prospective observational cohort study

BACKGROUD

Recurrent laryngeal nerve (RLN) injury is one of the serious complications of thyroid tumour surgery, surgical treatment of thyroid cancer requires careful consideration of the RLN and its impact on glottis function. There has been no unified standard for precise neuromuscular block monitoring to guide the monitoring of RLN in thyroid surgery. This study aimed to investigate the correlation between Train-of-four stabilization ratio (TOFr) and neural signal values of intraoperative neurophysiological monitoring (INOM) during thyroid operation, and further to determine the optimal timing for INOM during thyroid operation.

METHODS

Patients scheduled for thyroid tumour resection with INOM and RLN monitoring from April 2018 to July 2018 in our center were recruited. Electromyography (EMG) signals and corresponding TOFr were collected. All nerve stimulation data were included in group VR. Vagus nerve stimulation data were included in Subgroup V. RLN stimulation data were included in Subgroup R. The timing of recording was as follows: Vagus nerve EMG amplitude after opening the lateral space between the thyroid and carotid sheath and before the initiation of thyroid dissection, RLN EMG amplitude at first recognition, RLN EMG amplitude after complete thyroid dissection (Repeat three times), and Vagus nerve EMG amplitude after resection of the thyroid (Repeat three times). Correlation analysis of continuous variables was described by a scatter diagram. Pearson correlation analysis or Spearman correlation analysis was used for the two groups of variables.

RESULTS

Finally, 134 vagus nerve signals and 143 RLN signals were analysed after matching with TOFr. The EMG amplitude in the VR group and subgroups after nerve stimulation was positively correlated with TOFr (p < 0.05). In the VR, V and R group, the incidence of EMG ≥ 500 µV in the 0.75 < TOFr ≤ 0.85 interval was significantly higher than the 0 < TOFr ≤ 0.75 interval (P = 0.002, P = 0.013 and P = 0.029), and has no statistical difference compared to 0.85 < TOFr ≤ 0.95 interval (P > 0.05).

CONCLUSIONS

The EMG signals of the RLN and vagus nerve stimulation during thyroid surgery were positively correlated with TOFr. TOFr > 0.75 could reflect more than 50% of the effective nerve electrophysiological signals, 0.75 < TOFr ≤ 0.85 interval was the optimal timing for IONM during thyroid surgery.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR1800015797) Registered on 20/04/2018. https://www.chictr.org.cn .

High-dose rocuronium-induced paralysis of the adductor pollicis muscle facilitates detection of the timing for tracheal intubation in elderly patients: a randomized double-blind study

Purpose

Methods

Results

Conclusions

The effect of low-dose rocuronium on rapid tracheal intubation using a video laryngoscope: A randomized double blind controlled study

BACKGROUND

The aim of this study was to investigate the clinical effectiveness of rocuronium in low doses on conditions during rapid tracheal intubation using video laryngoscope.

METHODS

Ninety-eight patients undergoing otolaryngologic surgery were randomly divided into 2 groups: group L using 0.3 mg/kg of rocuronium intravenously (n = 49) and group C using 0.6 mg/kg of rocuronium (n = 49). Sixty seconds after rocuronium administration, tracheal intubation was performed using a video laryngoscope. The overall intubation condition was evaluated along with specific conditions, including laryngoscopy condition, vocal cord position, and intubation response. Intubation profiles, including Cormack-Lehane grade, 1st attempt success rate, and intubation time, were also evaluated.

RESULTS

Overall intubation conditions showed a significant difference between group L and group C (P = .003). Although the incidence of vigorous response after tracheal intubation was higher in group L than in group C (P = .022), laryngoscopy condition and vocal cord position were similar between the 2 groups (P = .145 and .070, respectively). Intubation profiles showed no differences between the 2 groups. The frequency and amount of additional rocuronium administration during surgery were also similar.

CONCLUSIONS

Low-dose rocuronium provided significantly worse overall intubation conditions compared to the conventional dose of rocuronium for rapid tracheal intubation. However, when using a video laryngoscope, it may provide clinically acceptable laryngeal muscle relaxation.

The neuromuscular effects of rocuronium under sevoflurane-remifentanil or propofol-remifentanil anesthesia: a randomized clinical comparative study in an Asian population

Background

We conducted a prospective, randomized, multicenter study to evaluate the differences in the blocking effect of different doses of rocuronium between sevoflurane- or propofol-remifentanil anesthesia in an Asian population.

Methods

A total of 368 ASA I–II patients was enrolled. Anesthesia was induced with 2.0 mg/kg propofol and 0.1 μg/kg/min remifentanil (TIVA) or 5.0 vol.% sevoflurane with 0.1 μg/kg/min remifentanil (SEVO). Tracheal intubation was facilitated at 180 s after the administration of rocuronium at 0.3, 0.6, or 0.9 mg/kg and then intubation condition was evaluated. The time to maximum block and recovery profile were monitored by TOF stimulation of the ulnar nerve and by recording the adductor pollicis response using acceleromyography.

Results

The numbers of patients with clinically acceptable intubation conditions were 41, 82, and 97 % (TIVA) and 34, 85, and 90 % (SEVO) at each dose of rocuronium, respectively. There were no significant differences in the time to maximum block between groups at each rocuronium dose. There were significant differences in the recovery to a train-of-four ratio of 90 % between the groups: 42.7 (19.5), 74.8 (29.9), and 118.4 (35.1) min (TIVA) and 66.5 (39.3), 110.2 (43.5), and 144.4 (57.5) min (SEVO) at 0.3, 0.6, and 0.9 mg/kg, respectively (P < 0.001).

Conclusions

There are no significant differences in intubation conditions between propofol-remifentanil and sevoflurane-remifentanil anesthesia at the same dose of rocuronium. The type of anesthetic does not significantly influence the time to maximum block by rocuronium. Rocuronium at a dose of 0.9 mg/kg should be used for better intubation conditions with both anesthesia regimens in an Asian population.

Trial registration

UMIN-CTR Clinical Trial (http://www.umin.ac.jp/ctr/index.htm; UMIN#000007289; date of registration 14^th February 2012).

Effects of single-shot and steady-state propofol anaesthesia on rocuronium dose-response relationship: a randomised trial

BACKGROUND

Similar to volatile anaesthetics, propofol may influence neuromuscular transmission. We hypothesised that the administration of propofol influenced the potency of rocuronium depending on the duration of the administration.

METHODS

After consent, patients scheduled for elective surgery randomly received rocuronium either after induction of anaesthesia with propofol (2 min of propofol, n = 36) or after 30 min of propofol infusion (30 min of propofol, n = 36). Remifentanil was given in both groups. Neuromuscular monitoring was performed by calibrated electromyography. The dose-response relationship of rocuronium was determined with a single-bolus technique (0.07, 0.1, 0.15, 0.2, 0.3 and 0.45 mg/kg rocuronium). The primary endpoints were the ED50 and ED95 of rocuronium after 2 and 30 min propofol. Data are presented as means with (95% confidence interval). The trial is registered with the Eudra-CT: 2009-012815-16.

RESULTS

A total of 72 patients were included. Time to maximal neuromuscular blockade was significantly shorter in patients after 30 min of propofol [3.3 min (2.9-3.7)] compared with patients anaesthetised with 2 min of propofol [4.6 min (4.0-5.2)]. After 30 min of propofol, the slope of the dose-response curve was significantly steeper (30 min of propofol: 4.34 [3.62-5.05]; 2 min of propofol: [3.34 (2.72-3.96)], resulting in lower ED95 values of rocuronium (30 min of propofol: 0.287 mg/kg [0.221-0.368]; 2 min of propofol [0.391 mg/kg (0.296-0.520)]. The ED50 were not different between groups.

CONCLUSION

The potency of rocuronium was significantly enhanced after propofol infusion for 30 min. Estimates of potency those are usually determined during steady-state anaesthesia might underestimate rocuronium requirements for endotracheal intubation at the time of induction.

Neuromuscular Blockade by Vecuronium during Induction with 5% Sevoflurane or Propofol

This randomized trial investigated whether 5% sevoflurane potentiated neuromuscular blockade by vecuronium. General anaesthesia was induced with 5% sevoflurane in oxygen in 16 patients or with propofol in 16 patients. After loss of consciousness, vecuronium was administered to all participants at randomly assigned doses of 25, 30, 35 or 40 μg/kg. Neuromuscular blockade was assessed by use of acceleromyography to measure responses to train-of-four stimuli in the adductor pollicis and corrugator supercilii muscles. Maximum blockade was significantly more intense in the adductor pollicis among patients in the sevoflurane group than in the propofol group, whereas there was no significant between-group difference at the corrugator supercilii muscles. In both groups, maximum blockade at the corrugator supercilii was significantly less intense than that achieved at the adductor pollicis. In the dose–response analysis, the 50% and 95% effective doses were lower for sevoflurane than for propofol in both muscles, although this did not reach statistical significance. It is concluded that induction of general anaesthesia with sevoflurane might provide improved conditions for intubation and reduce airway problems.

Infusion requirements and reversibility of rocuronium at the corrugator supercilii and adductor pollicis muscles

BACKGROUND

The aim of this study is to compare the infusion rates required to maintain a constant neuromuscular block and the reversibility of rocuronium at the corrugator supercilii muscle (CSM) and the adductor pollicis muscle (APM).

METHODS

We randomly allocated 30 female patients into two groups of 15 patients each to monitor neuromuscular block at either the CSM or the APM. After induction of anaesthesia and laryngeal mask insertion, contraction of the CSM to the facial nerve stimulation or that of the APM to the ulnar nerve stimulation was quantified using an acceleromyograph during 1.0-1.5% end-tidal sevoflurane anaesthesia. All the patients received a bolus of 1 mg/kg rocuronium. When the first twitch (T1) of train-of-four (TOF) recovered to 10% of the control, rocuronium infusion was commenced and maintained at T1 of 10% of the control at the CSM or APM for 120 min. Immediately after rocuronium infusion was discontinued, the time required for 0.04 mg/kg neostigmine-facilitated recovery to a TOF ratio of 0.9 was recorded.

RESULTS

Rocuronium infusion dose after a lapse of 120 min was significantly larger in the CSM than in the APM [7.1 (2.3) vs. 4.7 (2.6) microg/kg/min; P=0.001]. The time for facilitated recovery was shorter in the CSM than in the APM [11.4 (3.8) vs. 16.2 (6.0) min; P=0.016].

CONCLUSION

A larger rocuronium infusion dose was required to maintain a constant neuromuscular block at the CSM. Neostigmine-mediated reversal was faster at the CSM.