An incomplete postoperative recovery of neuromuscular function (postoperative residual curarization - PORC) represents a common problem in post-anesthesia care units (PACU), potentially exposing the patient to adverse respiratory events. Quantitative and objective evaluation of neuromuscular function using the train acceleromyographic method -of-four ratio (TOFR) at the level of the adductor muscle of the thumb represents the best way to minimize this risk after administration of non-depolarizing neuromuscular agents. Study endpoints Primary endpoint * incidence of postoperative residual curarization Secondary endopoints * number of possible respiratory adverse events during the stay in the PACU and during the hospital stay * estimation of a logistic regression model to define the risk factors associated with residual curarization
Neuromuscular blocking agents are commonly used in clinical anesthetic practice to facilitate tracheal intubation and allow muscle relaxation during surgical interventions. Anesthesiologist's subjective qualitative assessment of the patient's recovery of muscle strength before extubation is not predictive of adequate neuromuscular recovery even if many surveys conducted at an international level \[1,2,3\] demonstrate how this modality of evaluation is often used above all due to the not always widespread availability of tools for quantitative monitoring of neuromuscular blockade3. An incomplete recovery of neuromuscular function at the end of surgery (Postoperative residual curarization - PORC) exposes the patient to potential adverse respiratory events and a Consensus Statement \[4\] of experts in 2018 suggested a quantitative and objective evaluation of neuromuscular function using the train acceleromyographic method -of-four ratio (TOFR) at the level of the adductor muscle of the thumb represents the best way to minimize this risk after administration of non-depolarizing neuromuscular agents. In case of TOFR ≤ 0.9, reversal of the neuromuscular block is normally performed with drugs belonging to the class of acetylcholinesterase inhibitors (e.g. neostigmine 0.03-0.05 mg/kg, associated with an antimuscarinic agent such as atropine to counteract the cholinergic effects) or by sugammadex (2 or 4 mg/Kg), a selective antagonist of rocuronium and vecuronium which acts by encapsulating the neuromuscular blocking molecule making it ineffective. Recurrence of neuromuscular blockade may, however, occur primarily due to mechanisms of redistribution of the muscle relaxant or if insufficient doses of the reversal drug are administered.
Study Type
OBSERVATIONAL
Enrollment
90
Upon arrival of the spontaneously breathing patient in the Post-Anesthesia Care Unit, a researcher will evaluate the TOFR to detect any residual neuromuscular block using the acceleromyographic method at the level of thumb adductor.2 TOFR measurements will be performed 30 seconds apart. If the difference between the two measurements will be ≤ 0.1, the average value will be considered for the purposes of the analysis. In case of a difference \> 0.1, a third measurement will be taken and the average of the two closest results will be considered. If a residual block is detected sugammadex will be administered (2 mg/kg in the case of at least 2 contraction responses to TOF stimulation or 4 mg/kg in the case of no contraction response) to restore normal neuromuscular function , assessed by subsequent TOFR measurement.
Fondazione Policlinico Universitario Agostino Gemelli IRCCS
Rome, Italy
postoperative residual neuromuscular block
evaluation of the incidence of postoperative residual neuromuscular block upon arrival in the post-anesthesia care unit (PACU), defined as a TOFR≤0.9, by acceleromyographic method in interventions in which non-depolarizing neuromuscular blockers with intermediate duration of action were administered at the time of tracheal intubation and/or for maintaining a condition of myoresolution during surgery.
Time frame: within 5 minutes from admission in the postoperative care unit
number of respiratory adverse events
Number of any adverse respiratory events that occurred during the stay in the PACU and during the hospital stay. Respiratory adverse events will be defines as episodes of desaturation (SpO2\<92%) requiring oxygen supplementation or the finding of atelectasis, pneumonia or pleural effusion of non-cardiac origin found on thoracic imaging tests possibly performed during the hospital stay;
Time frame: within 7 days
evaluation of possible risk factors for residual curarization
Estimation of a logistic regression model to define risk factors for residual curarization Will be considered as possible risk factors those reported in the literature : the patient's age, the duration of anesthesia, the type of anesthesia administered (inhalation or totally intravenous), the number of administrations and the total dose of neuromuscular blocker, reversal or not of the neuromuscular blockade, the antagonist drug and the type of neuromuscular blocker used during surgery \[7\].
Time frame: 4 months
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