Practice Guidelines for Monitoring Neuromuscular Blockade-Elements to Change to Increase the Quality of Anesthesiological Procedures and How to Improve the Acceleromyographic Method.

Neuromuscular blocking agents are a crucial pharmacological element of general anesthesia. Decades of observations and scientific studies have resulted in the identification of many risks associated with the uncontrolled use of neuromuscular blocking agents during general anesthesia or an incomplete reversal of neuromuscular blockade in the postoperative period. Residual relaxation and acute postoperative respiratory depression are the most serious consequences. Cyclic recommendations have been developed by anesthesiology societies from many European countries as well as from the United States and New Zealand. The newest recommendations from the American Society of Anesthesiologists and the European Society of Anesthesiology were published in 2023. These publications contain very detailed recommendations for monitoring the dosage of skeletal muscle relaxants in the different stages of anesthesia-induction, maintenance and recovery, and the postoperative period. Additionally, there are recommendations for various special situations (for example, rapid sequence induction) and patient populations (for example, those with organ failure, obesity, etc.). The guidelines also refer to pharmacological drugs for reversing the neuromuscular transmission blockade. Despite the development of several editions of recommendations for monitoring neuromuscular blockade, observational and survey data indicate that their practical implementation is very limited. The aim of this review was to present the professional, technical, and technological factors that limit the implementation of these recommendations in order to improve the implementation of the guidelines and increase the quality of anesthesiological procedures and perioperative safety.

Low-dose sugammadex reverses moderate rocuronium-induced neuromuscular block in horses.

BACKGROUND: Neuromuscular block (NMB) during general anaesthesia has an implicit risk of inadvertent residual NMB during recovery. Reversal of NMB is commonly encouraged to decrease this risk, and has historically been performed with neostigmine/atropine, two agents with important cardiac and gastrointestinal side effects. Sugammadex is a new selective relaxant binding agent that can reverse rocuronium-induced NMB efficiently and without these complications. Recommended doses are possibly cost-prohibitive. OBJECTIVES: To measure the recovery time from rocuronium-NMB after administration of low-dose sugammadex, compared with spontaneous recovery. STUDY DESIGN: Nonrandomised in vivo experiments. METHODS: Fourteen adult horses undergoing different research procedures were anaesthetised with detomidine and isoflurane. All horses received NMB with rocuronium 0.3 mg/kg IV. Neuromuscular function was measured with acceleromyographic train-of-four (TOF) ratio. Recovery occurred spontaneously in five horses weighing (median [range]) 548 (413-594) kg and was enhanced with sugammadex 200 mg (total dose) in nine horses (433 [362-515]) kg. Recovery time from moderate NMB to a TOF ratio 1.0, and total duration of NMB were compared between groups. Cases of recurarisation (decrease in the TOF ratio <0.9 after recovery) were identified within 30 min after sugammadex. RESULTS: The dose of sugammadex was 0.46 (0.39-0.55) mg/kg. The recovery period lasted 21 (17-39) minutes for spontaneous and 4 (3-7) minutes for sugammadex. Total duration of NMB was 58 (41-70) minutes for spontaneous and 36 (21-43) for sugammadex (both p ≤ 0.003). There were no instances of recurarisation. MAIN LIMITATIONS: Small sample size. CONCLUSIONS: A dose of sugammadex of approximately 0.5 mg/kg substantially shortened the recovery period from rocuronium-induced NMB from a median of 21 to 4 min, when given at a moderate depth of NMB. No recurarisation was observed within the next 30 min.

Sugammadex for reversal of moderate-to-deep rocuronium block in a clinical setting: A retrospective report of 10 dogs.

OBJECTIVE: To compare recovery times of sugammadex with spontaneous recovery from rocuronium-induced neuromuscular block (NMB) in dogs. STUDY DESIGN: Retrospective, unmatchedcase-control study. ANIMALS: A total of 10 dogs administered sugammadex and 10 dogs recovering spontaneously from rocuronium-induced NMB. METHODS: Files of dogs administered rocuronium between March and August 2023 were inspected. The train-of-four (TOF) count at the time of sugammadex administration and the time between administration and TOF ratio >90% (recovery time) were recorded. The recovery time for those not administered reversal agents was considered from the first TOF value >0 until TOF ratio >90%. The dose of sugammadex and the cumulative dose of rocuronium were recorded. Rocuronium doses and recovery times were compared using Mann-Whitney tests. The coefficient of determination (R2) between the cumulative rocuronium dose and sugammadex dose and the recovery time were calculated. RESULTS: Dogs in the sugammadex and spontaneous recovery groups were administered intravenously (IV) 0.76 (0.4-2.6) and 0.61 (0.3-2.9) mg kg-1 of rocuronium, respectively (p = 0.325). Recovery time after 3.9 (2.9-5.5) mg kg-1 of sugammadex IV was 1 (1-3) minutes and was 20 (10-35) min for spontaneous recovery (p < 0.0001). The R2 for rocuronium and sugammadex doses and recovery times were 0.19 (p = 0.2) and 0.012 (p = 0.758). CONCLUSIONS AND CLINICAL RELEVANCE: Sugammadex 2.9-5.5 mg kg-1 reversed moderate (TOF count 1-3) or deep (TOF count 0) rocuronium-induced NMB within 3 minutes, substantially faster than spontaneous recovery.

Performance of a new auxiliary device based on wrist brace to improve accuracy and feasibility in neuromuscular monitoring with acceleromyography in prone-positioned patients undergoing lumbar spine surgery: a prospective randomized clinical trial.

Accuracy of acceleromyography (AMG) is not be comparable to that of mechanomyography or electromyography (EMG). In particular, the prone position may reduce the accuracy and feasibility of AMG. We developed a new device based on wrist brace to allow free thumb movement and fix the other parts of the hand and wrist. We aimed to test whether the brace applied to the AMG would increase precision of AMG and agreement with the EMG in the prone position. Fifty-seven patients, undergoing lumbar surgery under general anesthesia, were randomly assigned to groups to which AMG was applied with or without (no) brace (29 in group B vs. 28 in group NB). EMG was performed in the contralateral arm. Repeatability coefficients of the first twitch height (T1) and train-of-four (TOF) ratio were assessed from nine consecutive measurements during spontaneous recovery from rocuronium-induced neuromuscular block and the AMGs of the two groups were compared in prone position. The agreement between AMG and EMG in each group was assessed using the Bland-Altman method. In group B, the repeatability coefficient of T1 was significantly lower during the recovery to T1 of 25% and TOF ratio of 0.9 (P = 0.017 and 0.033, respectively), indicating higher precision. The mean differences of bias (95% limits of agreement) between AMG and EMG in TOF ratio of 0.9 were 6.839 (- 26.54 to 40.22) in group NB and 3.922 (- 21.83 to 29.67) in group B. The wide limits of agreement in group NB was slightly narrowed in group B but without significance. Trial registration: registered on the UMIN Clinical Trials Registry in August 2020 (UMIN000041310).

Duration of neuromuscular block is more variable and recovery time is shorter with rocuronium than cisatracurium in anesthetized dogs.

OBJECTIVE: To compare the variability in the duration of action of a single dose of rocuronium or cisatracurium, and duration of subsequent top-up doses in anesthetized dogs. ANIMALS: Thirty dogs requiring ophthalmic surgery with neuromuscular block. PROCEDURES: Neuromuscular function was monitored with train-of-four (TOF) and acceleromyography. Dogs received an initial dose of rocuronium 0.6 mg/kg, or cisatracurium 0.15 mg/kg IV, which produced complete neuromuscular block. Upon return of the first response (T1) of TOF, a third of the initial dose was repeated. The duration of the initial dose and its variability were compared between agents. Duration of subsequent top-up doses was assessed with mixed effect models. Spontaneous (from last return of T1) or neostigmine-enhanced (from administration to complete recovery) recovery times were measured for each agent. RESULTS: Duration of action of the initial dose was [median (range)] 25 (10-60) min with rocuronium and 35 (15-45) min with cisatracurium (p = .231). The variability of rocuronium was 3.25 times larger than cisatracurium (p = .034). Duration of top-up doses did not vary for either agent. Spontaneous recovery was shorter for rocuronium [15 (10-20) min] than cisatracurium [25 (15-45) min] (p = .02). Neostigmine-enhanced recovery times were 5 (5-25) for rocuronium and 10 (5-10) for cisatracurium (p = .491). CONCLUSIONS: Duration of action for a single dose is significantly more variable with rocuronium than cisatracurium. Time to spontaneous recovery was longer for cisatracurium, and cases of unexpectedly long recovery times were observed with both agents. Objective monitoring is recommended.

Comparison of the neuromuscular effects of two infusion rates of rocuronium in anesthetized pigs.

BACKGROUND: Neuromuscular blocking agents are frequently administered to pigs used for research. In humans, administration of the drugs is not without risk and may result in accidental awareness under general anaesthesia and postoperative residual neuromuscular blockade that can lead to serious respiratory complications. Despite the extensive administration, the pharmacodynamics of neuromuscular blocking agents are not thoroughly studied in pigs. Therefore, this study investigates the neuromuscular response of two infusion rates of rocuronium, a commonly used non-depolarizing neuromuscular blocking agent. A group of 14 female Danish Landrace-Yorkshire-Duroc pigs used for supervised surgical training, weighing 40.3 ± 2.1 kg (mean ± SD), were included in the study. They received a loading dose of 0.85 mg/kg rocuronium intravenously followed by infusion of either 2.5 mg/kg/hour (L, low dose) or 5 mg/kg/hour (H, high dose) rocuronium for 30 min. Neuromuscular monitoring was performed with acceleromyography using train-of-four (TOF) stimulation. Onset time, time to reappearance of T1, T4, TOF ratio 90% and 100% were recorded. RESULTS: All pigs in group H experienced loss of T1 throughout rocuronium infusion, whereas six out of seven pigs in group L had reappearance of T1 during rocuronium infusion, with additional reappearance of T4 in three of these pigs. The time to recovery of TOF ratio 90% was 14.0 ± 5.4 (L) and 21.7 ± 6.1 (H) minutes and recovery to TOF ratio 100% was 18.7 ± 6.5 (L) and 27.9 ± 9.2 min (H) (mean ± SD). Substantial inter-animal variation in neuromuscular recovery time was observed. CONCLUSION: The large inter-animal variation in pharmacodynamic profiles emphasizes that individual neuromuscular monitoring and titration to effect should be used routinely in research protocols that include rocuronium. In addition to other important measures, these actions are key in order to avoid overdosing and limit the risk of residual neuromuscular blockade.

Assessment of the New Acceleromyograph TOF 3D Compared with the Established TOF Watch SX: Bland-Altman Analysis of the Precision and Limits of Agreement between Both Devices-A Randomized Clinical Comparison.

The new acceleromyograph TOF 3D was compared with the established TOF Watch SX in patients undergoing elective laparoscopic gynecological surgery. Neuromuscular transmission was assessed by simultaneous recording with both devices. Measurements were performed simultaneously at the left and the right M. adductor pollicis (Group A, 25 patients), or the M. corrugator supercilii (Group CS, 25 patients). The repeatability, time course, and limits of agreement (Bland-Altman) were compared. The primary endpoint was the 90% train-of-four recovery time (TOFR 0.9). Other endpoints included onset time of block, maximum T1 depression, time to 25% T1 recovery, the recovery time course of T1 response, and TOF ratio, respectively. In group CS, the repeatability coefficient of the TOF 3D was lower (4.66 (1.6)) than of the TOF Watch SX (6.02 (1.9); p = 0.026). In group A, the onset of the block was faster when measured by the TOF 3D (98.7 (30) s vs. 112.2 (36) s (mean (SD)); p = 0.032). In group A, time to recovery to a TOFR of 90% was measured earlier by the TOF 3D (bias -0.71 min, limits of agreement from -8.94 to +7.51 min). The TOF 3D provides adequate information with high precision and sensitivity. It is suitable even for measurement sites with small muscle contractions such as the M. corrugator supercilii.

Comparison of a new EMG module, AF-201P, with acceleromyography using the post-tetanic counts during rocuronium-induced deep neuromuscular block: a prospective, multicenter study.

Recent advances in neuromuscular monitors have facilitated the development of a new electromyographic module, AF-201P™. The purpose of this study was to investigate the relationship between post-tetanic counts (PTCs) assessed using the AF-201P™ and the acceleromyographic TOF Watch SX™ during rocuronium-induced deep neuromuscular block. Forty adult patients consented to participate in this study. The integrated AF-201P™ stimulating and sensing electrode was placed over the ulnar nerve on the distal volar forearm and the belly of the abductor digiti minimi muscle of one arm. The TOF Watch SX™ was applied with the provided hand adaptor on the opposite arm, to observe twitch responses of the adductor pollicis muscle. After stabilization of train-of-four (TOF) responses, rocuronium 0.9 mg kg-1 was administered intravenously. Then, PTCs were observed every 3 min using both monitors. Whenever the TOF count was detected with the TOF Watch SX™, rocuronium 0.2 mg kg-1 was administered, and successive PTC measurements were continued. A total of 1732 paired PTC data points were obtained and analyzed. Regression analysis showed no significant difference in PTCs between the two monitors (PTCs measured by the TOF Watch SX™ = 0.78·PTCs measured by AF-201P™ + 0.21, R = 0.56). Bland-Altman analysis also showed acceptable ranges of bias [95% CI] and limits of agreement (0.3 [0.2 to 0.5] and - 4.6 to 5.3) for the PTCs. The new EMG module, AF-201P™, showed reliable PTCs during deep neuromuscular block, as well as the TOF Watch SX™.

Vigilance: the behavioral impact of quantitative monitoring on administration and antagonism of neuromuscular blocking agents.

PURPOSE: The aim of this study was to determine whether use of acceleromyography (1) changes dosing of neuromuscular blocking agents (NMBAs), and (2) increases the time between neostigmine administration and extubation, when compared with subjective assessment of neuromuscular blockade. METHODS: For this retrospective study, data were collected from patient electronic medical records. Patients were included if they had received an NMBA as part of a general anesthetic in 2013 and 2014. Data were analyzed by category of monitoring device: quantitative monitor (acceleromyograph [AMG]) or subjective device (peripheral nerve stimulator [PNS]). Outcomes measured were the total dose of NMBA administered and, the timing of the last dose of NMBA and anticholinesterase relative to tracheal extubation. RESULTS: Results from multivariate models showed that use of acceleromyography was not associated with a change in the total dose of NMBA administered. In contrast, the number of times any monitor was used, as determined by the frequency with which the train-of-four count (TOFC) was recorded, correlated with the administration of greater amounts of rocuronium (P < 0.01) and vecuronium (P < 0.01). The use of acceleromyography did not prolong the time interval between neostigmine administration and tracheal extubation. The number of times any monitor was used during an anesthetic was associated with a decrease in this time interval. The interval decreased an average of 2.7 min each successive time the TOFC was recorded (P < 0.01). CONCLUSIONS: The data presented provides insight about the behavioral engineering inherent to the practice of anesthesiology. Introduction of neuromuscular blockade assessment appeared to increase provider vigilance in dosing of NMBAs-regardless of assessment method. The frequency of intraoperative monitoring (quantitative or subjective) was associated with an increased total dose of NMBA administered and decreased time interval between the last dose of neostigmine and extubation.

Comparison of the TOFscan and the TOF-Watch SX during pediatric neuromuscular function recovery: a prospective observational study.

BACKGROUND: TOFscan is a three-dimensional acceleromyography neuromuscular monitoring device that does not require initial calibration before muscle relaxant injection. This study aimed to compare TOFscan with TOF-Watch SX, the currently widely accepted uni-dimensional acceleromyography, for use among the pediatric population. We aimed to assess the agreement between TOFscan with TOF-Watch SX in the pediatric population's neuromuscular recovery. METHODS: A total of 35 children aged 6-12 years were enrolled. Prior to any muscle relaxant injection, TOFscan and TOF-Watch SX were applied at each opposite arm and monitoring began concurrently throughout neuromuscular recovery. Calibration was performed for TOF-Watch SX, and train-of-four values were recorded every 15 s. Agreement between the two devices was evaluated with Modified Bland-Altman analysis. RESULTS: The bias between TOF-Watch SX and TOFscan were all within the 95% limits of agreement. The bias and standard deviation were smaller and the limit of agreement was narrower in the normalized group than in the non-normalized group [normalized bias -0.002 (95% CI, -0.013 to 0.010), standard deviation (SD) 0.111 vs non-normalized bias 0.010 (95% CI, -0.003 to 0.0236), SD 0.127]. CONCLUSIONS: TOFscan reliably demonstrated lack of bias and good concordance with TOF-Watch SX throughout the neuromuscular recovery, especially when normalized. Despite technical limitations, the two devices were unbiased along the path of spontaneous and pharmacological reversal in pediatric patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT03775603. Registered on 13 March 2018.

Exploratory Outlier Detection for Acceleromyographic Neuromuscular Monitoring: Machine Learning Approach.

BACKGROUND: Perioperative quantitative monitoring of neuromuscular function in patients receiving neuromuscular blockers has become internationally recognized as an absolute and core necessity in modern anesthesia care. Because of their kinetic nature, artifactual recordings of acceleromyography-based neuromuscular monitoring devices are not unusual. These generate a great deal of cynicism among anesthesiologists, constituting an obstacle toward their widespread adoption. Through outlier analysis techniques, monitoring devices can learn to detect and flag signal abnormalities. Outlier analysis (or anomaly detection) refers to the problem of finding patterns in data that do not conform to expected behavior. OBJECTIVE: This study was motivated by the development of a smartphone app intended for neuromuscular monitoring based on combined accelerometric and angular hand movement data. During the paired comparison stage of this app against existing acceleromyography monitoring devices, it was noted that the results from both devices did not always concur. This study aims to engineer a set of features that enable the detection of outliers in the form of erroneous train-of-four (TOF) measurements from an acceleromyographic-based device. These features are tested for their potential in the detection of erroneous TOF measurements by developing an outlier detection algorithm. METHODS: A data set encompassing 533 high-sensitivity TOF measurements from 35 patients was created based on a multicentric open label trial of a purpose-built accelero- and gyroscopic-based neuromuscular monitoring app. A basic set of features was extracted based on raw data while a second set of features was purpose engineered based on TOF pattern characteristics. Two cost-sensitive logistic regression (CSLR) models were deployed to evaluate the performance of these features. The final output of the developed models was a binary classification, indicating if a TOF measurement was an outlier or not. RESULTS: A total of 7 basic features were extracted based on raw data, while another 8 features were engineered based on TOF pattern characteristics. The model training and testing were based on separate data sets: one with 319 measurements (18 outliers) and a second with 214 measurements (12 outliers). The F1 score (95% CI) was 0.86 (0.48-0.97) for the CSLR model with engineered features, significantly larger than the CSLR model with the basic features (0.29 [0.17-0.53]; P<.001). CONCLUSIONS: The set of engineered features and their corresponding incorporation in an outlier detection algorithm have the potential to increase overall neuromuscular monitoring data consistency. Integrating outlier flagging algorithms within neuromuscular monitors could potentially reduce overall acceleromyography-based reliability issues. TRIAL REGISTRATION: ClinicalTrials.gov NCT03605225; https://clinicaltrials.gov/ct2/show/NCT03605225.

Counting train-of-four twitch response: comparison of palpation to mechanomyography, acceleromyography, and electromyography.

BACKGROUND: Train-of-four twitch monitoring can be performed using palpation of thumb movement, or by the use of a more objective quantitative monitor, such as mechanomyography, acceleromyography, or electromyography. The relative performance of palpation and quantitative monitoring for determination of the train-of-four ratio has been studied extensively, but the relative performance of palpation and quantitative monitors for counting train-of-four twitch responses has not been completely described. METHODS: We compared train-of-four counts by palpation to mechanomyography, acceleromyography (Stimpod™), and electromyography (TwitchView Monitor™) in anaesthetised patients using 1691 pairs of measurements obtained from 46 subjects. RESULTS: There was substantial agreement between palpation and electromyography (kappa = 0.80), mechanomyography (kappa = 0.67), or acceleromyography (kappa = 0.63). Electromyography with TwitchView and mechanomyography most closely resembled palpation, whereas acceleromyography with StimPod often underestimated train-of-four count. With palpation as the comparator, acceleromyography was more likely to measure a lower train-of-four count, with 36% of counts less than palpation, and 3% more than palpation. For mechanomyography, 31% of train-of-four counts were greater than palpation, and 9% were less. For electromyography, 15% of train-of-four counts were greater than palpation, and 12% were less. The agreement between acceleromyography and electromyography was fair (kappa = 0.38). For acceleromyography, 39% of train-of-four counts were less than electromyography, and 5% were more. CONCLUSIONS: Acceleromyography with the StimPod frequently underestimated train-of-four count in comparison with electromyography with TwitchView.

Philips Intellivue NMT module: precision and performance improvements to meet the clinical requirements of neuromuscular block management.

The variability or inaccuracy of acceleromyographic measurements could interfere with the interpretation of the train-of-four (TOF) ratio during neuromuscular block (NMB) recovery. This study evaluated the precision and performance of the Philips Intellivue NMT module (NMT) before (part 1) and after (part 2) several technical upgrades (i.e., firmware upgrade, new cable, and hand adapter) that were recently available. Two cohorts of 30 patients who were scheduled to undergo rhino/septoplasty under general anesthesia were included in the study. TOF ratios were recorded simultaneously every 15 s on both hands with the NMT and a TOF-Watch SX installed inside a SL TOF-Tube (TWX). Before rocuronium was administered and once final responses were stabilized, the average of the four successive measurements that determined the baselines and repeatability coefficients were compared using a z test. Simultaneous measurements were recorded at different NMB stages: onset, depth of NMB after intubation, when TWX recovered TOF count 2, TOF ratios 0.5 and 0.9, and when NMT recovered TOF ratio 0.9. The results were compared using a Student t test; p < 0.05 was considered significant. The NMT repeatability coefficients obtained in part 1 were significantly higher than with the TWX, they were significantly lower in part 2. Initially, the NMT significantly overestimated NMB recovery at every stage. Conversely, in the second part of the study, no difference reached statistical significance. With the recent upgrades and the new hand adapter, the NMT provided similar results compared with the TWX, Their implementation should be recommended in clinical practice.

A comparison of a prototype electromyograph vs. a mechanomyograph and an acceleromyograph for assessment of neuromuscular blockade.

The extent of neuromuscular blockade during anaesthesia is frequently measured using a train-of-four stimulus. Various monitors have been used to quantify the train-of-four, including mechanomyography, acceleromyography and electromyography. Mechanomyography is often considered to be the laboratory gold standard of measurement, but is not commercially available and has rarely been used in clinical practice. Acceleromyography is currently the most commonly used monitor in the clinical setting, whereas electromyography is not widely available. We compared a prototype electromyograph with a newly constructed mechanomyograph and a commercially available acceleromyograph monitor in 43 anesthetised patients. The mean difference (bias; 95% limits of agreement) in train-of-four ratios was 4.7 (-25.2 to 34.6) for mechanomyography vs. electromyography; 14.9 (-13.0 to 42.8) for acceleromyography vs. electromyography; and 9.8 (-31.8 to 51.3) for acceleromyography vs. mechanomyography. The mean difference (95% limits of agreement) in train-of-four ratios between opposite arms when using electromyography was -0.7 (-20.7 to 19.3). There were significantly more acceleromyography train-of-four values > 1.0 (23%) compared with electromyography or mechanomography (2-4%; p < 0.0001). Electromyography most closely resembled mechanomyographic assessment of neuromuscular blockade, whereas acceleromyography frequently produced train-of-four ratio values > 1.0, complicating the interpretation of acceleromyography results in the clinical setting.

Shortening of the twitch stabilization period by tetanic stimulation in acceleromyography in infants, children and young adults (STSTS-Study): a prospective randomised, controlled trial.

Acceleromyography is characterised by an increase of the twitch response T1 (first twitch of the train-of-four [TOF]) during first 30 min of monitoring known as the staircase phenomenon. In adults the staircase phenomenon can be avoided by tetanic prestimulation. This study examined, if tetanic prestimulation eliminates the staircase phenomenon in children. After written informed consent, the neuromuscular function of 80 children, 10 in each age group (< 6 months, 6-12 months, 12-24 months, 2-3 years, 3-6 years, 6-12 years, 12-18 years, and ≥ 18 years) was measured on both arms simultaneously over 30 min under general anaesthesia. The ulnaris nerve was stimulated using the TOF technique every 15 s. The twitch response (T1, TOF ratio [TOFR]) was measured by acceleromyography. Before calibration, tetanic prestimmulation (50 Hz for 5 s) was administered to one randomly selected arm. The effect of tetanic prestimulation and age was analysed using general linear models based on the normalized T1 and TOFRs of both arms. Tetanic prestimulation significantly affected T1 values avoiding the staircase phenomenon (p < 0.0001). After 5.8 min [1.0-17.2 min] the normalized T1 values increased to 117% [102-147%] without prestimulation (p < 0.0001) independent of the age group (p = 0.539). The normalized TOFR was stable throughout the observation period of 30 min 100% [95-107%]. Infants (> 12 weeks), children, and young adults (< 18 years) develop similar characteristics of the staircase phenomenon than adults. Tetanic prestimulation prevents the staircase phenomenon in these age groups. The stability of the TOFR reading confirms its value to monitor neuromuscular function over time.Registration: The study was registered as NCT02552875 on Clinical Trials.gov on July 29, 2014.

[Algorithm-based preventive strategies for avoidance of residual neuromuscular blocks]. / Algorithmusbasierte Präventionsstrategien zur Vermeidung neuromuskulärer Restblockaden.

BACKGROUND: Postoperative residual neuromuscular block (train of four ratio <0.9) is an outcome-relevant problem in balanced anesthesia, which increases postoperative morbidity and mortality. Implementation of medium and short-acting muscle relaxants, quantitative neuromuscular monitoring and pharmacological reversal of muscle relaxation reduce the incidence of residual neuromuscular block. The question arises whether this is suitable to create a pragmatic algorithm integrating these three individual methods to reduce paralysis-associated complications? METHODS: A selective literature search was carried out in PubMed and guidelines of national specialist societies were searched using special terms. RESULTS: The incidence of residual neuromuscular block varied among the studies but was as high as 93%. Using calibrated acceleromyography it is possible to identify a residual relaxation with a negative predictive value of 97% (95% confidence interval, CI 83-100%). Reversal by administration of the acetylcholinesterase inhibitor neostigmine reduces the incidence of residual neuromuscular block to 15.4%, in combination with calibrated acceleromyography to 3.3%. Reversal with sugammadex can nearly completely eliminate residual neuromuscular block. Quantitative neuromuscular monitoring and pharmacological reversal can be suitably integrated into a stage-based, pragmatic treatment algorithm. CONCLUSION: The algorithm-based concept of quantitative neuromuscular monitoring and pharmacological reversal using neostigmine and sugammadex enables residual neuromuscular block to be treated within 10 min before extubation of the patient. Ongoing educational programs are essential for implementation of modern muscle relaxant management concepts. Quantitative neuromuscular monitoring should be mandatory for all patients receiving neuromuscular blocking drugs. It would be desirable that German-speaking societies for anesthesiology make appropriate recommendations in guidelines.