Guide — Emergency Respiratory Care
Cardiopulmonary Resuscitation: Airway & Ventilation
The respiratory therapist usually owns the airway and ventilation in an adult code. This guide covers high-quality CPR, the airway and ventilation sequence, the right ventilation rates with and without an advanced airway, how capnography confirms the tube and tracks CPR quality and ROSC, and why hyperventilation kills. Real resuscitations follow current ACLS algorithms, local protocol, and physician orders.
10 min read · Emergency Respiratory Care
Written by Apex Respiratory Editorial Team
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
Overview
In an adult cardiac arrest the respiratory therapist usually owns the airway and ventilation. The priorities are high-quality chest compressions, effective oxygenation and ventilation without overdoing it, and using capnography to guide the resuscitation. Care follows current ACLS algorithms and local protocol.
Key Concepts
- High-quality CPR is the foundation. Push hard (at least 2 inches / 5 cm, no more than 2.4 inches / 6 cm) and fast (100-120/min), allow full chest recoil, minimize interruptions, rotate compressors every 2 minutes, and keep the chest compression fraction above 60%.
- Ventilation rate depends on the airway. Without an advanced airway, use a 30:2 compression-to-ventilation ratio. With an advanced airway (endotracheal tube or supraglottic airway), give continuous compressions plus asynchronous ventilation at 1 breath every 6 seconds (10/min). Each breath lasts about 1 second and is just large enough to see the chest rise, with 100% oxygen.
- Avoid hyperventilation. Excessive rate or volume raises intrathoracic pressure, which reduces venous return, lowers coronary and cerebral perfusion, and worsens survival.
- Bag-valve-mask technique matters. Aim for a good seal (E-C clamp), two-person ventilation when possible, an oral airway adjunct, and 100% oxygen, delivering smooth breaths.
- Defibrillation treats shockable rhythms. VF and pulseless VT are shockable; the RT ensures the oxygen source and airway are clear during the shock.
| Scenario | Rate / Ratio | Detail |
|---|---|---|
| No advanced airway | 30:2 | Pause compressions to deliver 2 breaths after every 30 compressions |
| Advanced airway (ETT or supraglottic) | 10/min | 1 breath every 6 seconds with continuous, uninterrupted compressions |
| Each breath | ~1 sec | Just enough volume to see the chest rise, with 100% oxygen |
Assessment & Findings — Capnography in the Code
Continuous waveform capnography (EtCO₂) is the RT’s most valuable monitor during resuscitation. It answers four questions at once: is the tube in, are compressions working, has circulation returned, and how is the arrest trending?
| Use | EtCO₂ | What It Means |
|---|---|---|
| Confirm tube placement | Sustained waveform | Most reliable confirmation of endotracheal tube placement after intubation |
| Monitor CPR quality | < 10 mmHg | Reflects cardiac output and pulmonary blood flow; a persistently low value suggests inadequate compressions |
| Detect ROSC | > 35-40 mmHg | An abrupt rise in EtCO₂ signals returning spontaneous circulation |
| Prognostication | ≤ 10 mmHg at 20 min | Failure to exceed 10 mmHg after 20 minutes is one factor (among many) in prognostication |
A sustained waveform after intubation is the most reliable confirmation of endotracheal tube placement. Because EtCO₂ tracks cardiac output and pulmonary blood flow, a value persistently under about 10 mmHg suggests inadequate compressions — push harder or switch compressors. An abrupt rise (often above 35-40 mmHg) signals return of spontaneous circulation.
RT Priorities & Interventions
- Own the airway and the rate. Establish and maintain the airway, ventilate at the correct rate, and never hyperventilate.
- Confirm and monitor. Confirm placement and monitor with continuous waveform capnography.
- Support the team. Anticipate suction, advanced-airway equipment, and post-ROSC ventilator setup.
- Manage the post-ROSC patient. Avoid both hypoxia and hyperoxia (titrate FiO₂ to SpO₂ 92-98%), avoid hyperventilation (target normocapnia), and support targeted temperature management.
Common Pitfalls
- Hyperventilating during the arrest — the most common and most harmful RT error in a code.
- Interrupting compressions for intubation — minimize the pause.
- Reading an EtCO₂ of zero as “dead” without first confirming compressions and circuit integrity (it may be no flow or a disconnection).
- Over-oxygenating the patient after ROSC.
Board Exam Pearls
- With an advanced airway: 1 breath every 6 seconds (10/min) with continuous compressions.
- Without an advanced airway: 30:2.
- Compressions 100-120/min, at least 2 inches deep, full recoil, fraction above 60%.
- Capnography confirms the tube, tracks CPR quality (EtCO₂ under 10 means push harder), and signals ROSC (abrupt rise).
- Avoid hyperventilation — it lowers venous return and survival.
FAQ
How fast should I ventilate during a code?
Without an advanced airway, ventilate 30:2 with compressions. Once an advanced airway is in place, give one breath every 6 seconds (10/min) with continuous, uninterrupted compressions - each breath just large enough to see the chest rise.
Why is hyperventilation so harmful in cardiac arrest?
Each positive-pressure breath raises intrathoracic pressure and impedes venous return to the heart. Too many breaths reduce the blood that compressions can circulate, dropping coronary and cerebral perfusion and lowering survival.
How does capnography help in a code?
Continuous waveform capnography confirms endotracheal tube placement, gauges CPR quality (an EtCO₂ near or below 10 mmHg means compressions must improve), and signals return of spontaneous circulation as an abrupt rise in EtCO₂.
What are the oxygen targets after ROSC?
Avoid both hypoxia and hyperoxia - titrate FiO₂ to an SpO₂ of about 92-98%, and ventilate to normocapnia rather than hyperventilating, while the team manages temperature and the underlying cause.
Put it to work
After ROSC, the gas guides the next move. Practice reading the post-arrest acid-base picture.
Open the ABG Interpreter →Related Resources
Sources
- Kacmarek RM, Stoller JK, Heuer AJ. Egan's Fundamentals of Respiratory Care. 12th ed. Elsevier; 2021. Cardiopulmonary resuscitation and emergency cardiac care chapters.
- Panchal AR, Bartos JA, Cabanas JG, et al. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020;142(16_suppl_2):S366-S468.