Unit 2: Primary Assessment
Ventilation & Respiratory Support
Knowing when and how to assist a patient’s breathing is a critical skill for Emergency Medical Technicians (EMTs). Inadequate ventilation can quickly lead to oxygen deprivation, respiratory arrest, and cardiac arrest. This NREMT study guide lesson explains bag-valve-mask ventilation, appropriate ventilation rates, and the use of continuous positive airway pressure (CPAP). After reviewing these techniques, answer five NREMT practice questions to strengthen your understanding of respiratory support.
Ventilation is the movement of air into and out of the lungs. When a patient cannot breathe effectively, EMTs must provide appropriate respiratory support to maintain oxygen delivery and remove carbon dioxide.
A patient may be breathing spontaneously but still require assisted ventilation if their breaths are too shallow or ineffective.
Recognizing Inadequate Ventilation
EMTs must distinguish between a patient who is breathing adequately and one who needs immediate ventilation assistance.
Signs of inadequate ventilation include:
- Very slow, shallow, or irregular breathing.
- Rapid breathing with poor chest movement.
- Decreasing respiratory effort or extreme fatigue.
- Altered mental status.
- Poor air movement or diminished breath sounds.
- Cyanosis or other signs of inadequate oxygenation.
For example, an unconscious patient breathing four times per minute is not ventilating adequately, even though some spontaneous breathing is present.
Patients who are not breathing or are breathing inadequately require immediate ventilatory support.
Bag-Valve-Mask (BVM) Ventilation
A bag-valve-mask (BVM) is a handheld device that delivers positive-pressure ventilation to patients who are not breathing adequately.
A BVM consists of:
- A self-inflating bag.
- A one-way valve.
- A face mask.
- An oxygen inlet and reservoir.
BVMs are available in adult, pediatric, and infant sizes.
A BVM can deliver breaths without an oxygen supply, but connecting supplemental oxygen and a reservoir allows it to deliver a much higher oxygen concentration.
BVM ventilation is commonly used for patients experiencing respiratory arrest, severe respiratory depression, or respiratory failure.
Performing BVM Ventilation
Effective BVM ventilation requires an open airway, the correct mask size, and a tight seal between the mask and the patient’s face.
Basic steps include:
- Position the patient and open the airway using an appropriate maneuver.
- Insert an airway adjunct when indicated.
- Select the correct mask size and position it over the nose and mouth.
- Create a tight seal between the mask and the face.
- Squeeze the bag over approximately one second, delivering enough air to produce visible chest rise.
- Allow the chest to fall before delivering the next breath.
Avoid squeezing the bag too forcefully or delivering excessive amounts of air.
Two-rescuer BVM ventilation is generally more effective than a single-rescuer technique.
With two rescuers, one EMT uses both hands to maintain the airway and mask seal while the other squeezes the bag. This improves ventilation and reduces air leakage.
When assisting a conscious or partially responsive patient’s breathing, explain the procedure when possible and coordinate assisted breaths with the patient’s respiratory efforts.
Ventilating a Patient With a Pulse
When a patient has a pulse but is not breathing or is breathing inadequately, EMTs should provide assisted ventilation at an appropriate rate.
The recommended ventilation rates are:
| Patient | Ventilation Rate |
| Adult | 1 breath every 6 seconds (10 breaths/min) |
| Child | 1 breath every 2–3 seconds (20–30 breaths/min) |
| Infant | 1 breath every 2–3 seconds (20–30 breaths/min) |
These recommendations apply to patients with a pulse who require assisted ventilation.
For example, an adult experiencing respiratory arrest from an opioid overdose may have a pulse but no effective breathing. The EMT should provide assisted ventilation while following appropriate treatment protocols.
If a patient does not have a pulse, begin CPR and follow the appropriate cardiac arrest guidelines.
Recognizing Effective Ventilation
EMTs must continuously evaluate whether assisted ventilation is effective.
Signs of adequate ventilation include:
- Visible, equal chest rise and fall.
- Improvement in skin color and oxygen saturation.
- Improved heart rate when abnormalities were caused by inadequate oxygenation.
- Improvement in the patient’s overall respiratory condition.
If the chest does not rise during BVM ventilation, check for:
- An improperly opened airway.
- A poor mask seal.
- An airway obstruction.
- Incorrect equipment positioning.
Correct the problem and reassess ventilation.
Avoiding Excessive Ventilation
Positive-pressure ventilation forces air into the lungs by increasing pressure within the chest.
Unlike normal spontaneous breathing, positive-pressure ventilation increases intrathoracic pressure, which can reduce venous blood return to the heart.
Excessive ventilation can cause:
- Reduced cardiac output.
- Gastric inflation (air entering the stomach).
- Vomiting and possible aspiration.
- Excessive pressure within the lungs.
To avoid these complications, deliver breaths at the recommended rate and use only enough volume to produce visible chest rise.
Continuous Positive Airway Pressure (CPAP)
Continuous positive airway pressure (CPAP) provides constant positive pressure through a tightly fitted mask while the patient breathes spontaneously.
CPAP helps keep the airways and alveoli open, improving oxygenation and reducing the work of breathing.
It may be used for patients experiencing moderate to severe respiratory distress caused by conditions such as:
- Pulmonary edema: Fluid accumulation in the lungs, often associated with congestive heart failure.
- COPD: Chronic obstructive pulmonary disease, which can interfere with normal airflow.
- Other respiratory conditions: When CPAP is appropriate under local EMS protocols.
Unlike a BVM, CPAP does not deliver individual rescue breaths. The patient must continue breathing adequately enough to use the device.
CPAP Contraindications
CPAP is not appropriate for every patient experiencing respiratory difficulty.
Important contraindications or reasons to avoid CPAP include:
- Respiratory or cardiac arrest.
- Inability to maintain or protect the airway.
- Active vomiting.
- Suspected pneumothorax.
- Significant facial trauma preventing an adequate mask seal.
Low blood pressure and an inability to follow instructions are also important concerns because positive airway pressure can worsen hemodynamic instability and interfere with safe treatment.
During CPAP therapy, monitor the patient’s breathing, mental status, oxygen saturation, and blood pressure.
If the patient deteriorates or can no longer breathe adequately, discontinue CPAP and provide appropriate assisted ventilation.
EMTs should administer CPAP only when authorized by their training and local EMS protocols.
Key Tip
Supplemental oxygen and assisted ventilation are not the same thing. A patient who is breathing adequately but has low oxygen saturation may need supplemental oxygen. A patient who is not breathing effectively needs assisted ventilation, usually with a BVM. Always evaluate the patient’s breathing effort and chest movement rather than relying on oxygen saturation alone.