ACLS — Advanced Cardiovascular Life Support — All Questions

Once an advanced airway (e.g., endotracheal tube) is in place during cardiac arrest, how should ventilations be delivered?

• a.Pause compressions and give 30:2 cycles
• b.Give 1 breath every 6 seconds (10 breaths/min) with continuous compressions✓
• c.Give 1 breath every 3 seconds with continuous compressions
• d.Give 20 breaths per minute synchronized to compressions

With an advanced airway, rescuers no longer pause for ventilation. Compressions become continuous at 100-120/min while one breath is delivered every 6 seconds (10 breaths/min). This asynchronous approach maintains a high compression fraction and avoids the harmful hyperventilation that raises intrathoracic pressure and reduces venous return.

What is the most reliable method to confirm and continuously monitor correct endotracheal tube placement during CPR?

• a.Auscultation of breath sounds alone
• b.Continuous quantitative waveform capnography✓
• c.Chest x-ray obtained after the code
• d.Pulse oximetry readings

Continuous quantitative waveform capnography is the recommended standard for confirming and monitoring ET tube placement. It verifies the tube is in the trachea (a sustained CO2 waveform), detects dislodgement in real time, and gauges CPR quality — a sudden abrupt rise in ETCO2 often signals return of spontaneous circulation. Auscultation and oximetry are adjuncts, and a chest x-ray is too slow to guide the resuscitation.

During bag-mask ventilation, delivering breaths too rapidly and forcefully is harmful mainly because it:

• a.Cools the patient too quickly
• b.Increases intrathoracic pressure, which reduces venous return and cardiac output✓
• c.Improves oxygenation beyond what is needed
• d.Has no measurable effect on the resuscitation

Excessive ventilation raises intrathoracic pressure, which impedes venous return to the chest and lowers cardiac output and coronary perfusion during CPR. It can also cause gastric inflation and aspiration. Deliver each breath over about 1 second with just enough volume to produce visible chest rise, and avoid over-ventilating.