Airway Management & Ventilation
Oxygenation and ventilation support the arrest and post-arrest patient, but they must never come at the cost of good compressions. This chapter covers bag-mask technique, advanced airways, and confirming placement with waveform capnography.
Bag-mask ventilation and avoiding hyperventilation
During CPR without an advanced airway, deliver 2 breaths after every 30 compressions, each over about 1 second with enough volume to make the chest rise visibly. Over-ventilating is a common and harmful error: forcing in too many or too large breaths raises intrathoracic pressure, which impedes venous return to the heart and lowers cardiac output and coronary perfusion. It also inflates the stomach and risks aspiration. For a patient in respiratory arrest but WITH a pulse, give rescue breaths at 1 breath every 6 seconds (10 breaths/min).
Advanced airways and confirming placement
Once an advanced airway (endotracheal tube or supraglottic device) is placed, ventilation and compressions become asynchronous: continuous compressions at 100-120/min with 1 breath every 6 seconds (10 breaths/min). Continuous quantitative waveform capnography is the recommended standard for confirming and continuously monitoring tube placement — it detects esophageal placement or later dislodgement and reflects CPR quality. A persistently low ETCO2 (for example, under 10 mmHg after 20 minutes) suggests poor perfusion and a low likelihood of ROSC, while an abrupt rise in ETCO2 may be the first sign of return of spontaneous circulation.