Antagonism of profound cisatracurium and rocuronium block: the role of objective assessment of neuromuscular function
ABSTRACT The purpose of this study is to determine the incidence of significant (train-of-four [TOF] ratio <0.70), but clinically undetectable (TOF ratio >0.40), residual neuromuscular block after neostigmine antagonism of profound cisatracurium (CIS) or rocuronium (ROC) block.
Prospective, randomized, open-label study.
Forty ASA physical status I and II undergoing elective surgical procedures.
Anesthesia was induced with propofol 1.5 to 2.5 mg/kg IV plus fentanyl 2 to 4 mug/kg and maintained with N(2)O/desflurane plus narcotic supplementation. The electromyographic response of the adductor pollicis was recorded. Train-of-four stimulation was given every 20 seconds. Twitch height (T1) and TOF fade ratio were continuously recorded. In group 1 (n = 20), neuromuscular block was induced with CIS 0.10 mg/kg, and T1 was maintained at 5% of control by a constant infusion of CIS until the end of surgery. One minute after the termination of the infusion, neostigmine 0.05 mg/kg was administered. T1 and TOF values were monitored continuously for the next 20 minutes. Group 2 (n = 20) is identical to group 1 except that the initial drug was ROC 0.60 mg/kg, and paralysis was maintained with an infusion of ROC.
There were no significant differences in the recovery patterns of CIS vs ROC. The duration (bolus to end of infusion) in both groups averaged 2.7 hours, and the mean cumulative dose of relaxant approximated 4 x the ED(95). T1 at the time of reversal was 6% (4%-10%) of control. Mean TOF ratios at 10, 15, and 20 minutes were 0.55, 0.71, and 0.0.81, respectively. Return to a TOF ratio >0.40 was always achieved in 15 minutes or less. However, at 20 minutes postreversal, 5 of 40 subjects had TOF ratios <0.70 and only 11 individuals had recovered to a TOF ratio of 0.90 or greater.
Most clinicians cannot detect tactile fade once the TOF ratio exceeds 0.40. When reversing profound block, an objective monitor of neuromuscular function is required if the extent of residual block is to be assessed with any confidence.
Article: Monitoraggio della curarizzazione[Show abstract] [Hide abstract]
ABSTRACT: La curarizzazione intraoperatoria deve essere adattata agli imperativi di miorilassamento dettati dalle procedure anestetiche e chirurgiche. Il monitoraggio neuromuscolare deve essere interpretato come un aiuto alla prescrizione e deve accompagnare il medico durante tutta la procedura anestetica e chirurgica, come raccomandano i nostri referenziali professionali. La differenza della sensibilità dei muscoli ai curari è un concetto fondamentale che giustifica un approccio ragionato al monitoraggio neuromuscolare senza il quale il medico anestesista non può raggiungere i suoi obiettivi. L’acceleromiografia e la cinemiografia sono le uniche tecniche attualmente utilizzate nella pratica clinica corrente. Si utilizzano due siti: il nervo ulnare a livello del polso per valutare l’adduttore del pollice e il ramo temporale del nervo facciale per il muscolo sopracciliare. Il train of four (TOF) applicato all’adduttore del pollice è quello utilizzato più frequentemente, per non dire esclusivamente, ma è ormai necessario padroneggiare la conta posttetanica per rispondere ad alcuni imperativi chirurgici e alle regole di prescrizione del nuovo agente di inversione dei curari steroidi, il sugammadex. Gli agenti di inversione devono essere largamente utilizzati e guidati dal monitoraggio. Il loro impiego non dispensa dal verificare il recupero completo del blocco neuromuscolare. Il sugammadex è una terapia innovativa. Il suo impiego associato al monitoraggio neuromuscolare dovrebbe permettere di risolvere il problema della curarizzazione residua postoperatoria.01/2011; 16(3):1–10. DOI:10.1016/S1283-0771(11)70648-X
- [Show abstract] [Hide abstract]
ABSTRACT: Neuromuscular blocking agents are used to facilitate tracheal intubation in patients undergoing ambulatory surgery. The use of high-dose neuromuscular blocking agents to achieve muscle paralysis throughout the case carries an increased risk of residual post-operative neuromuscular blockade, which is associated with increased respiratory morbidity. Visually monitoring the train-of-four (TOF) fade is not sensitive enough to detect a TOF fade between 0.4 and 0.9. A ratio <0.9 indicates inadequate recovery. Quantitative neuromuscular transmission monitoring (e.g., acceleromyography) should be used to exclude residual neuromuscular blockade at the end of the case. Residual neuromuscular blockade needs to be reversed with neostigmine, but it's use must be guided by TOF monitoring results since deep block cannot be reversed, and neostigmine administration after complete recovery of the TOF-ratio can induce muscle weakness. The development and use of new selectively binding reversal agents (sugammadex and calabadion) warrants reevaluation of this area of clinical practice.12/2014; 4(4):290-302. DOI:10.1007/s40140-014-0073-6
- [Show abstract] [Hide abstract]
ABSTRACT: Studies show the importance of monitoring neuromuscular function in preventing the residual block. However, most anesthesiologists in their daily practice base their evaluation of the recovery of neuromuscular function on clinical data. The aim of this study was to assess the degree of neuromuscular blockade in children undergoing general anesthesia at the time of block reversal and the removal of the endotracheal tube. We evaluated children between 3 months and 12 years of age undergoing general anesthesia with the use of atracurium or rocuronium. Monitoring was initiated at the time of reversal of neuromuscular blockade and/or removal of the endotracheal tube. The anesthesiologist was not informed about the T₄/T₁ value; he/she was only alerted when the time was inadequate for the removal of the endotracheal tube. Since the start of the monitoring process, the degree of neuromuscular blockade was registered, as well as the interval of recovery of the T(4)/T₁ ≥ 0.9 ratio, the doses of neostigmine and blocker used, the expired fraction of the inhalational agent, the duration of the anesthesia, and core and peripheral temperatures. Neuromuscular blockade was reversed in 80% of the children of the Rocuronium Group and in 64.5% of the Atracurium Group. The reversal was incorrect in 45.8% of the Rocuronium Group and in 25% of the Atracurium Group. The incidence of T₄/T₁ < 0.9 at the time of the removal of the endotracheal tube was 10% in both groups. When deciding to remove the endotracheal tube based on clinical criteria, 10% of children had T₄/T₁ < 0.9 regardless the blocker received. A considerable number of patients had the neuromuscular blockade incorrectly reversed when the blockade was still too deep or even already recovered.Revista brasileira de anestesiologia 03/2011; 61(2):145-9, 150-5, 78-83. DOI:10.1016/S0034-7094(11)70019-8 · 0.42 Impact Factor