Airway, Respiration, and Ventilation Study Guide for the EMT Test

Airway Opening

When a patient is unresponsive, it is essential to maintain an open airway. Obstruction of the airway due to the tongue falling to the back of the throat is common in unconscious patients.

Maneuvers

Patients should be placed in the supine position if the situation allows, as this position is most effective for opening the airway. There are a few different methods to open a patient’s airway. It’s important to assess the situation and the patient’s condition before choosing a technique. Using the wrong method could possibly result in further injury to the patient.

Head Tilt-Chin Lift

The head tilt-chin lift is the preferred technique for opening a patient’s airway. The technique is performed by gently lifting the patient’s mandible up while simultaneously pressing down on the forehead. Using a head tilt-chin lift places the patient in the sniffing position, which is preferred for manual ventilation and if intubation is needed.

Jaw Thrust

A jaw thrust is an alternative way to open the airway and should be used in patients who have a suspected spine or neck injury. The jaw thrust technique involves moving the jaw upward by placing your fingers behind the angles of the jaw and gently lifting.

Opening Mouth

Opening the airway using either a jaw thrust or a head tilt-chin lift will not necessarily result in the patient opening their mouth. If the patient’s mouth does not open naturally, you need to open it to effectively ventilate. Open the patient’s mouth by using your thumb and index finger. Push the lower teeth down with your thumb while pushing the upper teeth upward with your index finger.

Suctioning

Secretions, such as mucus, blood, and vomit, can block a patient’s airway and need to be suctioned out of the mouth and possibly the nose. Suctioning is also often necessary before intubation to visualize the vocal cords. In some instances, it will be obvious that a patient needs to be suctioned, such as if you see large amounts of blood or vomit. In other cases, you may hear gurgling noises coming from the patient’s mouth, which also indicates suctioning is needed.

Equipment

Suctioning equipment may include a fixed, mounted suction unit inside the rig or a portable suction device. Either device provides vacuum pressure to remove secretions. A suction catheter should be selected based on the needs of the patient. There are two main types of suction catheters: a rigid tip catheter called a Yankauer, for suctioning in the mouth, and a soft tip flexible catheter, sometimes referred to as a French catheter, for suctioning the nose, trachea, stomas, and liquid secretions in the mouth.

Techniques

Make sure you have gathered the needed equipment, including the type of suction catheter you intend to use. Turn on the suction device and make sure it is set at 300 mmHG. Measure the catheter for the correct depth by measuring from the corner of the patient’s mouth to the edge of their earlobe or angle of the jaw. Place the tip of the catheter in the patient’s mouth to the depth measured. Apply suction as you are withdrawing the catheter from the patient’s mouth. Limit the time you suction to 15 seconds in adults, 10 seconds in children, and 5 seconds in infants.

Terms/Concepts to Know: Yankauer, French catheter

Airway Adjuncts

Airway adjuncts are used to keep a patient’s airway open. They work by preventing the tongue from blocking the airway. There are two types of airway adjuncts: an oropharyngeal and nasopharyngeal airway. Before selecting which airway adjunct is appropriate, it is essential to assess your patient and determine his or her level of consciousness. It is also critical to use the correct size airway device for your patient.

Oropharyngeal

An oral airway is inserted into the mouth to prevent the tongue from relaxing and blocking the airway. It can be used in patients who are breathing and those who require manual ventilation. It should only be used in patients who are unresponsive and do not have an intact gag reflex.

Nasopharyngeal

A nasal airway can also be used to maintain a patent airway. It is usually better tolerated in patients who have an intact gag reflex. It can also be used in patients who have an altered level of consciousness and may not be able to protect their airway.

Terms/Concepts to Know: adjunct airway, oropharyngeal airway, nasopharyngeal airway

Maintaining the Airway

If your patients do not have a suspected spinal injury, you may want to consider placing them in the recovery position to maintain their airway. The recovery position involves rolling the body onto one side, extending the lower arm, and placing the upper hand under the cheek. This position helps prevent the tongue from blocking the airway and also decreases the risk of aspiration if the patient vomits.

Terms/Concepts to Know: recovery position

Supplemental Oxygen

Supplemental oxygen is needed in patients who are hypoxic. Hypoxia can lead to symptoms including shortness of breath, confusion, and bluish skin and nail beds. Supplemental oxygen should also be used when manually ventilating a patient.

Oxygen Sources and Their Use

Different devices can be used to deliver supplemental oxygen, including cylinders and liquid oxygen. Cylinders come in different sizes, with the D and M cylinders being the most commonly used. Liquid oxygen is typically not used in the field but may be available for patients to use at home.

Equipment

In addition to an oxygen delivery device, if you are using an oxygen cylinder, you need to have a pressure regulator. A pressure regulator decreases the pressure of oxygen being released to a safe level of 40 psi to 70 psi. A flowmeter, which allows you to deliver a specific liter flow, is also needed. Many newer regulators incorporate a flow meter, which allows you to dial in a liter flow.

Procedures

When administering oxygen to a patient, you must inspect the cylinder and remove the seal. The cylinder also needs to be cracked, which involves opening and closing the valve with a tank key (wrench).

Attach the regulator and flowmeter to the tank by following the design of the pin system. When you select the oxygen delivery device (mask, nasal cannula), attach it to the nipple on the flowmeter/regulator. Turn the flowmeter to the desired liters per minute to be delivered.

Hazards

Oxygen will not spontaneously burn, but it can support combustion. Be aware of the environment oxygen is used in. Oxygen should not be used near flames or sparks, such as a fireplace or lit cigarette. It’s also important to not leave a cylinder standing or leaning against a wall. Place the cylinder down unless it is in an oxygen cart. Oxygen toxicity is also a consideration when administering supplemental oxygen. Damage to the cellular tissue can occur if oxygen levels in the blood become too high. However, it is critical to not deprive a hypoxic patient of oxygen due to fears of oxygen toxicity.

Terms/Concepts to Know: pressure regulators, flowmeter, oxygen toxicity

Delivery Equipment

Supplemental oxygen in the prehospital setting is usually delivered through a nasal cannula, nonrebreather mask, or a bag-valve mask. A nonrebreather should be set at 10 to 15 liters per minute and can deliver approximately 95 percent oxygen. It should be used in patients who are breathing on their own but are suspected to be hypoxic. A nasal cannula can be used at flow rates of 1 to 6 liters per minute and may be appropriate for patients who do not tolerate a mask. A cannula can deliver about 24 to 44 percent oxygen. A bag-valve mask should also be used to deliver oxygen in patients who require ventilatory assistance. Flows should be set at 15 liters per minute and can deliver close to 100 percent oxygen.

Terms/Concepts to Know: nonrebreather, nasal cannula, partial rebreathing mask, bag-valve mask, Venturi mask

Artificial and Assisted Ventilation

In instances when your patient is apneic or not breathing adequately, you need to provide assisted ventilation. Assisted ventilation can be provided with a bag-valve mask, a continuous positive airway pressure (CPAP) machine, or a mechanical ventilator.

Terms/Concepts to Know: mechanical ventilation, gastric distention, passive ventilation

CPAP

CPAP can be used to deliver continuous positive pressure to the lungs. It should only be used in spontaneously breathing patients. CPAP can improve tidal volumes and oxygenation while decreasing the work of breathing.

Terms/Concepts to Know: BiPAP, compliance

Special Respiratory Issues

You may encounter special situations that require respiratory airway management different from what is listed above.

Stomas

A stoma is an opening made in the skin midline in the neck. A stoma is typically used to insert a tracheostomy tube, but the stoma itself can also be an independent airway without a trach tube. Since the upper airway is bypassed, humidification should be administered to the stoma to prevent mucus plugs from developing. If delivering oxygen to a patient with a stoma, use a tracheostomy mask. If you need to ventilate a patient manually and he or she has a trach tube, attach the bag-valve mask to the trach tube to ventilate. In patients who have only a stoma, a child’s mask can be connected to the bag and placed over the stoma to ventilate.

Terms/Concepts to Know: tracheostomy, stoma

Obstruction of Airway

An airway obstruction can be caused by mucus plugs that block the flow of air into the lungs or by the swelling of the tissues of the airway. More commonly, obstruction of the airway is caused by a foreign body that blocks the flow of air into the lungs. Food is a common foreign body. In young children, everything from toys to coins can become lodged in the airway. Signs of an airway obstruction include wheezing, stridor, and a weak cough. Signs of a complete obstruction include cyanosis, inability to speak, and loss of consciousness.

Terms/Concepts to Know: mild airway obstruction, severe airway obstruction, stridor