After a single dose of intermediate-duration muscle relaxant and no reversal, residual paralysis is common, even more than 2 h after the administration of muscle relaxant. Quantitative measurement of neuromuscular transmission is the only recommended method to diagnose residual block.

Background An adequate airway management plan is essential for patient safety. Recently, new tools have been developed as alternatives to direct laryngoscopy and intubation. Among these, video-laryngoscopy has enjoyed a rapid increase in popularity and is now considered by many as the first-line technique in airway management. This paradigm shift may have an impact on patient safety. Principal findings Studies show that video-laryngoscopes are associated with better glottic visualization, a higher success rate for difficult airways, and a faster learning curve, resulting in a higher success rate for intubations by novice physicians. Thus, unanticipated difficult intubations may be less frequent if video-laryngoscopy is used as the first-line approach. In addition, on-screen viewing by the operator creates a new dynamic interaction during airway management. The entire operating room team can assess progress in real time, which enhances communication and improves teaching. However, if video-laryngoscopes become standard tools for tracheal intubation, these more costly devices will need to be widely available in all locations where airway management is conducted. Furthermore, algorithms for difficult intubation will require modification, and the question of selecting alternate devices will arise. If the incidence of difficult intubation decreases, the lack of motivation to teach and learn the use of alternative devices might adversely impact patient safety.

Support was provided solely from institutional and/or departmental sources. Benoît Plaud and Bertrand Debaene have participated in the clinical development of sugammadex as coinvestigators in two phase III studies funded by Schering-Plough Corporation, Oss, The Netherlands. François Donati and Jean Marty have no conflicts of interest. The figures and tables in this article were prepared by Dimitri Karetnikov, 7 Tennyson Drive,

Purpose Preoxygenation increases oxygen reserves and duration of apnea without desaturation (DAWD), thus it provides valuable additional time to secure the airway. The purpose of this Continuing Professional Development (CPD) module is to examine the various preoxygenation techniques that have been proposed and to assess their effectiveness in healthy adults and in obese, pregnant, and elderly patients. Principal findings The effectiveness of preoxygenation techniques can be evaluated by measuring DAWD, i.e., the time for oxygen saturation to decrease to\90%. Clinically, preoxygenation is considered adequate when end-tidal oxygen fraction is[90%. This is usually achieved with a 3-min tidal volume breathing (TVB) technique. As a rule, asking the patient to take four deep breaths in 30 sec (4 DB 30 sec) yields poorer results. Eight deep breaths in 60 sec (8 DB 60 sec) is equivalent to TVB 3 min. The DAWD is decreased in obese patients, pregnant women, and patients with increased metabolism. Obese patients may benefit from the head-up position and positive pressure breathing. A TVB technique is preferable in the elderly. Failure to preoxygenate is often due to leaks, which commonly occur in edentulous or bearded patients. In cases of difficult preoxygenation, directly applying the circuit to the mouth might be a useful alternative. Supplying extra oxygen in the nasopharynx during apnea might increase DAWD. Conclusion Since ventilation and tracheal intubation difficulties are unpredictable, this CPD module recommends that all patients be preoxygenated. The TVB 3 min and the 8 DB 60 sec techniques are suitable for most patients; however, the 4 DB 30 sec is inadequate. Continuing Professional Development objectivesAfter reading this review, the reader should be able to:• understand the physiological principles of preoxygenation;• describe the slow and fast techniques for preoxygenating patients; • apply the proper techniques in healthy adults with normal weight; • modify these techniques in obese patients, pregnant women, and the elderly; • briefly describe preoxygenation devices other than the face mask.The purpose of preoxygenation is to increase the oxygen reserves of the body, thus preventing hypoxia during a planned or unexpected period of apnea. The term ''denitrogenation'', indicating that nitrogen in the lungs is replaced by oxygen, is sometimes used instead of ''preoxygenation''. However, the latter is generally preferred because the primary goal is to provide oxygen, not to remove nitrogen. With adequate preoxygenation, patients can tolerate a longer period of apnea, and an increased margin of safety is created between induction of anesthesia and the moment the airway is secured. This extra time may prove particularly valuable if mask ventilation is difficult or contraindicated and if laryngoscopy and tracheal intubation are more difficult than expected.The purpose of this Continuing Professional Development (CPD) module is to summarize the physiological principles 123Can J Anesth/J Can Anesth (2009...