Providing effective ventilation and oxygenation using a bag mask is probably the single most important component of airway management. Bag-mask-ventilation (BMV) refers to the use of a bag-mask unit, most of which but not all have valves (in which case they are referred to as Bag-Valve-Mask units or BVMs) system/device to deliver gas rich in oxygen either passively or actively by manually ventilating the patient using a face-mask interface. Examples of non-valved bag-mask devices include Mapleson E (Jackson Rees Modification of Ayres T-piece) and other t-piece occlude systems. Manual noninvasive ventilation also accurately describes the use of a BMV device to provide positive pressure ventilation (PPV). This should be differentiated from mechanical noninvasive ventilation, which also uses a face-mask interface but provides respiratory effort assistance (PPV) delivered by specialized ventilator.
Is There Still a Role for Bag-Mask-Ventilation in This Advanced World of Difficult Airway Devices?
Definitive airway management has traditionally been defined as the secure placement of an endotracheal tube (ETT) in the trachea. Although few would argue that there has been a philosophical and evidence-based shift away from defining airway management by the method of gas exchange to focus on the goals of resuscitation namely, maintaining patient's oxygenation and ventilation while preserving hemodynamic status. In other words, ETTs don’t save lives, whereas providing adequate perfusion and gas exchange does. Optimal oxygenation and ventilation may be provided using ETTs, extraglottic devices (EGDs), BMV devices, and surgical methods. Which method is most appropriately employed will depend on patient characteristics, the clinical situation, and practitioner's skill.
Bag-mask-ventilation particularly in the pre-hospital setting has been shown to be no less effective than endotracheal intubation (ETI) or EGD use.1-4 In a large prospective population-based study of out-of-hospital cardiac arrest (OHCA) patients (649,654), survivors who received BMV had more favorable neurologic outcomes compared to those who had their airway managed by ETI or EGD.5 With increasing controversy regarding the value of pre-hospital ETI, other means of maintaining oxygenation and ventilation including BMV are being reaffirmed as an airway management priority.6-12
For OHCA, ventilation has been de-emphasized in the early phase of adult non-asphyxia-related resuscitation where oxygen delivery is more dependent on blood flow than on arterial oxygen content. There is consensus that advanced airway management should not be considered a priority over high-quality chest compressions as preformed in cardioplumonary resuscitation (CPR) and defibrillation and has the potential of causing harm by interrupting CPR, from complications of airway management, impairing cerebral perfusion (EGDs), and perhaps inadvertent hyperventilation.1,11 While there is a theoretical advantage in using EGDs in the context of cardiac arrest where chest compressions can continue uninterrupted, prospective data to support the preferred approach for pre-hospital airway management in OHCA is lacking and awaits further study (AIRWAYS-2 & PART). While the focus of current studies is determining which advanced airway best serves this patient ...