PERIOPERATIVE MEDICINE Anesthesiology 2010; 113:873–9 Copyright © 2010, the American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins A Two-handed Jaw-thrust Technique Is Superior to the One-handed “EC-clamp” Technique for Mask Ventilation in the Apneic Unconscious Person Aaron M. Joffe, D.O.,* Scott Hetzel, M.S.,† Elaine C. Liew, M.D.‡ ABSTRACT Background: Mask ventilation is considered a “basic” skill for airway management. A one-handed “EC-clamp” tech- nique is most often used after induction of anesthesia with a two-handed jaw-thrust technique reserved for difficult cases. Our aim was to directly compare both techniques with the primary outcome of air exchange in the lungs. Methods: Forty-two elective surgical patients were mask- ventilated after induction of anesthesia by using a one- handed “EC-clamp” technique and a two-handed jaw-thrust technique during pressure-control ventilation in random- ized, crossover fashion. When unresponsive to a jaw thrust, expired tidal volumes were recorded from the expiratory limb of the anesthesia machine each for five consecutive breaths. Inadequate mask ventilation and dead-space ventilation were defined as an average tidal volume less than 4 ml/kg pre- dicted body weight or less than 150 ml/breath, respectively. Differences in minute ventilation and tidal volume between techniques were assessed with the use of a mixed-effects model. Results: Patients were (mean  SD) 56  18 yr old with a body mass index of 30  7.1 kg/m 2 . Minute ventilation was 6.32  3.24 l/min with one hand and 7.95  2.70 l/min with two hands. The tidal volume was 6.80  3.10 ml/kg predicted body weight with one hand and 8.60  2.31 ml/kg predicted body weight with two hands. Improvement with two hands was independent of the order used. Inadequate or dead-space ventilation occurred more frequently during use of the one-handed compared with the two-handed technique (14 vs. 5%; P = 0.013). Conclusion: A two-handed jaw-thrust mask technique im- proves upper airway patency as measured by greater tidal volumes during pressure-controlled ventilation than a one- handed “EC-clamp” technique in the unconscious apneic person. P ROVISION of artificial ventilation to the unconscious and apneic patient via a mask applied to the patient’s face is the most “basic” of airway management skills. None- theless, bag-valve mask ventilation is not always easy. Upper airway obstruction may be encountered at the level of the nares, soft palate, lips (when the mouth is closed), base of the tongue, tonsillar pillars, epiglottis, or even vocal cord inlet. To generate and maintain upper airway patency during arti- ficial breathing, performance of the “triple airway maneuver” is advocated. This includes advancing the mandible forward until the lower teeth are in front of the upper teeth (jaw thrust), lifting the chin and maximally tilting the head back- wards (chin lift, head tilt), and maintaining the mouth in an open position. As originally described, these airway maneu- vers were performed with the operator positioned behind and at the head of the patient and using two hands. 1,2 Place- ment of both hands on the mask, however, necessitates a second operator to squeeze the bag, which may be impracti- cal if performed routinely. As an alternative to the two-operator approach, pressure- controlled ventilation (PCV) can be applied by most modern * Clinical Assistant Professor, Pulmonary, Allergy and Critical Care, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. † Biostatistician, Department of Biostatistics and Medical Informatics, University of Wisconsin–Madison, Madi- son, Wisconsin. ‡ Assistant Professor, Department of Anesthesiol- ogy, Keck School of Medicine, University of Southern California, Los Angeles, California. Received from the University of Wisconsin Hospital and Clinics, Madison, Wisconsin. Submitted for publication January 15, 2010. Accepted for publication June 2, 2010. Support was provided solely from institutional and/or departmental sources. Address correspondence to Dr. Joffe: Department of Anesthesi- ology and Pain Medicine, University of Washington-Harborview Medical Center, 325 Ninth Ave, Box 359724, Seattle, Washington 98104. joffea@uw.edu. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. ANESTHESIOLOGY’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue. What We Already Know about This Topic ❖ No study has systematically compared ventilatory effective- ness between one-handed and two-handed mask-hold techniques. What This Article Tells Us That Is New ❖ Two-handed mask ventilation achieved greater tidal volume during pressure-controlled ventilation than one-handed mask ventilation in anesthetized, nonparalyzed patients with oro- pharyngeal airway inserted. Anesthesiology, V 113 • No 4 • October 2010 873 Downloaded from anesthesiology.pubs.asahq.org by guest on 06/02/2020