A Two-handed Jaw-thrust Technique Is Superior to the One-handed "EC-clamp" Technique for Mask Ventilation in the Apneic Unconscious Person

Pulmonary, Allergy and Critical Care, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
Anesthesiology (Impact Factor: 5.88). 10/2010; 113(4):873-9. DOI: 10.1097/ALN.0b013e3181ec6414
Source: PubMed


Mask ventilation is considered a "basic" skill for airway management. A one-handed "EC-clamp" technique 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.
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 randomized, 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 predicted 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.
Patients were (mean ± SD) 56 ± 18 yr old with a body mass index of 30 ± 7.1 kg/m. 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).
A two-handed jaw-thrust mask technique improves 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.

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    • "Because we aimed to simulate a scenario in which airway management was not optimized when emergency ventilation was needed or difficult mask ventilation occurred, the subject’s head was placed on a pillow and elevated about 10 cm from the operating room table, but no backward head tilt, jaw thrust, or mouth closing was performed. Airway patency was indirectly assessed by measuring expired tidal volume (Vte) by using the plethysmograph at a given peak inspiratory pressure over PEEP (PIP/PEEP) [16]. "
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