Potential Maneuvers for Providing Optimal Tidal Volume Using the One-Handed EC Technique

Abstract

Bag-valve-mask is a device that manually provides positive oxygen pressure. The grip technique of the character E and C shape is recommended to carry out this effectively. However, when applying this method, the hand in which the direction of the EC technique should be performed and the degree of adhesion pressure while performing the technique are unknown. This study aims to identify the factors influencing tidal volume and to determine the ideal sealing method between mask and face in the one-handed EC technique to optimize the Vt. A simulation study was conducted using a mechanical lung model in a scenario that resembled respiratory arrest. Multiple regression analyses identified high peak pressure, high left spot adhesion strength of the mask, and low right spot and bottom spot adhesion strength of the mask as significant factors. To provide an optimal Vt, it may be necessary to apply more strength to the left area of the mask when forming the “C” shape with the thumb and index finger of left hand using the one-handed EC technique.

Effects of weights applied to the apex of a bag-valve-mask and pinch strength on tidal volume: a prospective simulation study

“…The mean Vt by sex and grade in this study were 356 mL and 330 mL, respectively; the Vt at the 3rd grade was 347 mL and that at the 4th grade was 323 mL. These results are not only lower than the results of previous studies 16 , 20 , but also less than the volume (6–7 mL/kg) recommended by the American Heart Association. Regarding the variation in Vt according to weight, although the mean Vt increased when the weight increased from 100 to 200 g, the Vt at 300 g was 5 mL lower than that at 200 g. This result was attributed to the difference in the number of pendulums applied to the apical area of the mask during BVM bagging.…”

“…Based on this result, more strength can be applied to the middle finger used for “C” shape and the finger maintaining the “E” shape. Maintaining the “E” shape when performing the E–C technique is essential for keeping the airway open during BVM bagging 1 , 5 , 10 , 20 . Thus, the pinch strength that affects the E–C technique during BVM bagging is the tripod pinch strength and applying a 200 g weight to the apex of the mask is considered to be a method for improving ventilation by increasing adhesion through the EC technique.…”

“…Based on the results of our previous studies 16 , 20 , we further investigated the effect of ventilation by weighing the apical area for mask adhesion and measuring the pinch strength required to maintain the E–C technique. Thus, this study aims to identify the varying effects on Vt according to four weights (0 g, 100 g, 200 g, 300 g) applied to the apical area of the mask and pinch strength.…”

A special face mask with integrated angle meter to optimize the head position for bag-valve-mask ventilation—a prospective simulated proof-of-concept study

“…Moreover, this was a completely standardized model regarding ventilation through the face mask fixed to manikin with duct tape. This fixing was made to avoid the confounding effects such as mask leakage, multiple mask positions due to diverse grips being used by the care providers and because of applying mechanical ventilation [16,17]. A higher number of participants would be required to control such confounding elements in a clinical study.…”