부산대학교 도서관

INTRODUCTION: Anaesthesiology practitioners, like other trained professionals regardless of their technical skills, are not always able to make decisions based on a rational analysis (they are subject to cognitive biases), especially when they experience external pressure coming from a medical emergency or a complex clinical scenario that must be quickly grasped and resolved. Furthermore we must sum to that some intrinsic difficulty in the interpretation of probabilistic data. Even if we have population data on the action of a drug is a priori not possible to know the precise effect of the same drug from a single patient standpoint without any supplementary measure made after administration. On the other hand there has been constant safety improvements in anaesthesiology practice derived from concepts originally developed in other field (such as the concept of situational awareness in commercial aviation). Classical neuromuscular monitoring systems (mechanomyography) do not have a suitable using profile in clinical practice. Acceleromyography has spread as the main method of monitoring in clinical practice. Recent publications have stressed the need of a reliable stabilization and normalization of basal values during neuromuscular monitoring in order to get a useful record when comparing the responses and values to guide clinical decisions. In the context of monitoring and neuromuscular block repeated electrical stimulation given to a motor nerve muscle result in contractions of increasing amplitude. This phenomenon is known as the staircase phenomenon (FF). The FF is influenced by the duration, type and intensity of the stimulus and can have an influence on the beginning and recovery from neuromuscular block recorded on the monitor. The application of a tetanic stimulation before starting to monitor stabilizes the muscular responses and neutralizes the FF. Current guidelines on neuromuscular blockers research approve his use. HYPOTHESIS AND OBJECTIVES: The staircase phenomenon could have repercussions on the onset and recovery time following administration of a neuromuscular blocking agent. We aim to assess the magnitude of the staircase phenomenon and its impact on various aspects of neuromuscular blockade. MATERIALS AND METHODS: This is a randomized controlled double blind trial. Control group: stabilization of 20 minutes. Study Group: tetanic stimulation prior to the stabilization of 20 minutes. CONCLUSIONS: The staircase phenomenon obtained during neuromuscular monitoring by acceleromyography in the adductor pollicis muscle produces prolonged onset of action of rocuronium a dose of 0.6 mg / kg. The staircase phenomenon lengthens recovery times up to 25% of the height of the stimulus T1 and time to spontaneous recovery from a value of TOF-r 0,9. TOF-R time values standardized according to the control value are not influenced by the FF. Furthermore the linear relationship between baseline TOFR and the time difference between raw and normalized values of TOFR 0,9 can not be explained by this phenomenon. The administration of a tetanus stimulus leads the calibration process to set a lower sensitivity threshold thus the monitor is more sensitive to movements of the thumb.