Bloqueo neuromuscular residual

Bloqueo neuromuscular residual: lecciones no aprendidas. Parte I: definiciones, incidencia y efectos fisiológicos del bloqueo residual neuromuscular. Residual neuromuscular block: lessons unlearned. Part I: definitions, incidence, and adverse physiologic effects of residual neuromuscular block. Murphy GS, Brull SJ. Department of Anesthesiology, NorthShore University HealthSystem, 2650 Ridge Ave., Evanston, IL 60201, USA. dgmurphy2@yahoo.com Anesth Analg. 2010 Jul;111(1):120-8. Epub 2010 May 4 Abstract In this review, we summarize the clinical implications of residual neuromuscular block. Data suggest that residual neuromuscular block is a common complication in the postanesthesia care unit, with approximately 40% of patients exhibiting a train-of-four ratio <0.9. Volunteer studies have demonstrated that small degrees of residual paralysis (train-of-four ratios 0.7-0.9) are associated with impaired pharyngeal function and increased risk of aspiration, weakness of upper airway muscles and airway obstruction, attenuation of the hypoxic ventilatory response (approximately 30%), and unpleasant symptoms of muscle weakness. Clinical studies have also identified adverse postoperative events associated with intraoperative neuromuscular management. Large databased investigations have identified intraoperative use of muscle relaxants and residual neuromuscular block as important risk factors in anesthetic-related morbidity and mortality. Furthermore, observational and randomized clinical trials have demonstrated that incomplete neuromuscular recovery during the early postoperative period may result in acute respiratory events (hypoxemia and airway obstruction), unpleasant symptoms of muscle weakness, longer postanesthesia care unit stays, delays in tracheal extubation, and an increased risk of postoperative pulmonary complications. These recent data suggest that residual neuromuscular block is an important patient safety issue and that neuromuscular management affects postoperative outcomes. http://www.anesthesia-analgesia.org/content/111/1/120.full.pdf+html    Bloqueo neuromuscular residual: lecciones no aprendidas. Parte II: métodos para reducir los riesgos de debilidad residual Residual neuromuscular block: lessons unlearned. Part II: methods to reduce the risk of residual weakness. Brull SJ, Murphy GS. Department of Anesthesiology, Mayo Clinic College of Medicine, 4500 San Pablo Rd., Jacksonville, FL 32224, USA. SJBrull@me.com Anesth Analg. 2010 Jul;111(1):129-40. Epub 2010 May 4. Abstract The aim of the second part of this review is to examine optimal neuromuscular management strategies that can be used by clinicians to reduce the risk of residual paralysis in the early postoperative period. Current evidence has demonstrated that frequently used clinical tests of neuromuscular function (such as head lift or hand grip) cannot reliably exclude the presence of residual paralysis. When qualitative (visual or tactile) neuromuscular monitoring is used (train-of-four [TOF], double-burst, or tetanic stimulation patterns), clinicians often are unable to detect fade when TOF ratios are between 0.6 and 1.0. Furthermore, the effect of qualitative monitoring on postoperative residual paralysis remains controversial. In contrast, there is strong evidence that acceleromyography (quantitative) monitoring improves detection of small degrees (TOF ratios >0.6) of residual blockade. The use of intermediate-acting neuromuscular blocking drugs (NMBDs) can reduce, but do not eliminate, the risk of residual paralysis when compared with long-acting NMBDs. In addition, complete recovery of neuromuscular function is more likely when anticholinesterases are administered early (>15-20 minutes before tracheal extubation) and at a shallower depth of block (TOF count of 4). Finally, the recent development of rapid-onset, short-acting NMBDs and selective neuromuscular reversal drugs that can effectively antagonize deep levels of blockade may provide clinicians with novel pharmacologic approaches for the prevention of postoperative residual weakness and its associated complications. http://www.anesthesia-analgesia.org/content/111/1/129.full.pdf+html   Bloqueo residual postoperatorio en la unidad de cuidado postanestésico más de dos horas después de la administración de dosis única de atracurio para intubación Postoperative residual block in postanesthesia care unit more than two hours after the administration of a single intubating dose of atracurium. Varposhti MR, Heidari SM, Safavi M, Honarmand A, Raeesi S. Assistant Professor of Anesthesiology, Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. J Res Med Sci. 2011 May;16(5):651-7. Abstract BACKGROUND: Residual neuromuscular blockade continues to be a clinical problem after surgical procedures. The purpose of this study was to determine the incidence of residual paralysis in the postanesthesia care unit (PACU) after a single intubating dose of twice of the 95% estimated dose (ED95) of a nondepolarizing muscle relaxant with an intermediate duration of action. METHODS: Two hundred and sixteen patients scheduled for elective surgery under general anaesthesia requiring tracheal intubation were included in the study. They received a single intubating dose of intravenous atracurium (0.5 mg/kg) to facilitate tracheal intubation. At the end of surgery, if train of four (TOF)-ratio was ≤ 0.9, neostigmine 40 μg/kg intravenously was given. If TOF-ratio was ≥ 0.9, no neostigmine was given. Also, in awake patients with TOF > 0.9, residual neuromuscular paralysis was evaluated by using clinical tests such as head lift test and tongue depressor test. RESULTS: TOF was less than 0.9 in 48 (22.2%) patients while after 120 minutes, no patients had TOF less than 0.9. Of 33 patients whose operation lasted less than 120 minutes, 4 patients had TOF less than 0.9 at the end of surgery. There was no case of hypoventilation or hypoxia at PACU. The incidence of negative value in clinical tests was high. CONCLUSIONS: Our study gave the impression that more than two hours between the administration of a single intubating dose of an intermediate-acting nondepolarizing muscle relaxant (atracurium) and arrival to the PACU can probably guarantee the lack of a residual paralysis. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3214377/?tool=pubmed

Atentamente Anestesiología y Medicina del Dolor www.anestesia-dolor.org