After failing to achieve sufficient ventilation, what should be the next step if unable to obtain ETCO2 during mask ventilation?

When dealing with a situation where mask ventilation has failed to achieve sufficient ventilation and simultaneous attempts to obtain ETCO2 are unsuccessful, placing an oral airway (OAW) is a vital next step. This intervention can help maintain an open airway, especially when the patient's anatomy might be obstructing airflow during the mask ventilation attempts. The OAW may assist in relieving any potential obstruction caused by the tongue or other anatomical structures, thereby improving overall ventilation effectiveness.

By ensuring the airway is appropriately managed, the healthcare provider can create a better environment for either continued bag-mask ventilation or preparation for advanced airway management, such as intubation. This step is especially important as it can directly address the issue of inadequate airflow, which is critical in emergency scenarios.

The effectiveness of other options may be limited if the airway has not been appropriately managed. For instance, increasing FiO2 or using the O2 flush valve to fill the reservoir bag might not resolve the underlying issue of obstruction, while administering a muscle relaxant without securing the airway could lead to further respiratory complications. Thus, utilizing an OAW is the most immediate and effective intervention in this context.