In this section of our NREMT Study Guide, we will help you prepare for the airway portion of the exam. It covers airway management and oxygen therapy, opening a patient’s airway using different maneuvers, airway adjuncts used by EMTs, and oxygen-delivery equipment used on patients with difficulty breathing or mild to moderate hypoxia.
After you have reviewed this section of the study guide, there will be five practice questions to test your knowledge of the material you have read.
Airway Management and Oxygen Therapy
The respiratory system comprises the structures in the body that form the airway, which helps oxygenate the body through respiration (breathing). Other structures that help us breathe include the diaphragm, the accessory muscles of breathing, the muscles of the chest wall, and the nerves running from the brain and spinal cord to those muscles.
Ventilation is the exchange of air between the environment and the lungs. The rise and fall of the chest that accompanies normal breathing is due to the diaphragm and the chest wall muscles working together. This could not be achieved without the upper and lower airways.
The Upper Airway
The upper airway is the anatomic airway structures above the vocal cords, including the nose, mouth (oral cavity), jaw, pharynx, and larynx. The primary functions of the upper airway are to filter, warm, and humidify air as it enters the body through the mouth and nose.
The pharynx (throat) is a muscular tube extending from the mouth and nose to the level of the trachea and esophagus. The larynx is a cartilaginous structure that allows air to pass from your pharynx to the trachea and then to the lungs. The larynx also contains the vocal cords, known as the voice box.
The Lower Airway
The trachea (windpipe) and lungs make up the lower airway, which is responsible for pulling in air from the upper airway, absorbing oxygen, and releasing carbon dioxide from the body. The trachea divides into two main bronchi called the right and left mainstem bronchi at the anatomical point called the carina. The bronchi then branch into the right and left lung, respectively. The bronchi continue branching into smaller tubes called bronchioles, which are the same thickness as hair. At the end of each bronchiole are tiny air sacs called alveoli, where the gas exchange of oxygen and carbon dioxide occurs.
Opening a Patient’s Airway
As an EMT, one of the first aspects of medical care is to ensure the patient has an open airway. Effective emergency care cannot be provided if the patient does not have a patent airway. When you arrive at a scene and have an unconscious patient without obvious trauma, you must quickly assess their airway, breathing, and circulation (ABC). If there are obvious signs of trauma, the order of priority will change to CAB to ensure bleeding control is performed first. One of the first steps following the ABCs is to open the patient’s airway and assess breathing.
To open the patient’s airway, the first step is to have the patient in a supine position. If the patient is in the prone position, they need to be log rolled onto their back. If trauma is suspected, care should be taken to manually maintain cervical precautions as the patient is rolled.
Several maneuvers are used to open a patient’s airway once they are supine. The type of maneuver used depends on whether the patient has sustained or if there is suspected spinal trauma.
Head Tilt-Chin Lift Maneuver
The head tilt-chin lift maneuver is used on patients who do not have suspected spinal trauma or have not sustained a spinal injury. Sometimes, this maneuver is all that is needed for an unresponsive patient to start breathing. When the head is tilted and the chin is lifted, the tongue moves forward from the back of the throat. This technique would clear the airway if it were blocked by the tongue, which is the number one cause of airway obstruction.
There are four simple steps to the head tilt-chin lift maneuver:
- Position yourself next to the supine patient’s head.
- Place the heel of your hand on the patient’s forehead. Apply firm pressure with your palm, tilting the patient’s head backward.
- Place the fingertips of your other hand under the patient’s jaw near the bony part of the chin. Be careful not to compress the soft tissue under the chin, as it can block the patient’s airway.
- Lift the chin up, bringing the lower jaw with it. Lift so the teeth are nearly brought together but do not close the mouth completely. Continue keeping your palm on the patient’s forehead to maintain the backward tilt of the patient’s head. This maneuver will open the airway in the majority of patients.
Jaw-Thrust Maneuver
If a spinal injury is suspected, the jaw-thrust maneuver is the preferred option for opening the airway. The jaw thrust maneuver does not involve tilting the head, which could cause further injury if there is spinal trauma. However, if the jaw-thrust maneuver does not open the patient’s airway, the head tilt-chin lift maneuver can be used as a last resort. Follow these steps to perform this maneuver:
- Kneel above the patient’s head, placing your fingers behind the angles of the lower jaw. Carefully move the jaw upward while using your thumbs to position the lower jaw.
- When this maneuver is completed, the patient’s mouth should be slightly open, with the jaw jutting forward.
Opening the Mouth
Once you have opened the patient’s airway, their mouth might be closed. You will use the cross-finger technique to open their mouth to insert airway adjuncts or assess for foreign body obstruction. To perform this procedure, place the tip of your thumb and index finger on the patient’s teeth. Open the mouth by pushing your index finger on the upper teeth and your thumb on the lower teeth. When using this technique, your index finger and thumb will cross over each other, hence the name.
Airway Adjuncts
The primary function of an airway adjunct is to prevent obstruction of the upper airway by the tongue and allow the passage of air and oxygen to the lungs. There are two adjuncts used by EMTs: The oropharyngeal airway (OPA) and the nasopharyngeal airway (NPA).
Oropharyngeal Airways
An oropharyngeal (oral) airway has two principal purposes. The first is to keep the tongue from blocking the upper airway. The second is to make it easier to suction the oropharynx if necessary. Suctioning is possible through an opening down the center or along either side of the oropharyngeal airway.
Indications for the oral airway include:
- Unresponsive patients without a gag reflex (breathing or apneic)
- Any apneic patient being ventilated with a bag-mask device
Contraindications for the oral airway include the following:
- Conscious patients
- Any patient (conscious or unconscious) who has an intact gag reflex
The gag reflex is a protective mechanism that prevents food and other particles from entering the airway. If you try to insert an OPA in a patient with a gag reflex, the result can be vomiting or a spasm of the vocal cords (laryngospasm). If the patient gags while you are attempting to insert an oral airway, immediately remove the adjunct and prepare to log roll the patient and suction the oropharynx, should vomiting occur.
If the OPA is too large, it could push the tongue back into the pharynx, causing an airway obstruction. On the other hand, too small of an OPA could block the airway directly. Here are the steps to measuring and inserting an oral airway.
Step 1: Size the airway by measuring from the patient’s earlobe to the corner of the mouth.
Step 2: Open the patient’s mouth with the cross-finger technique. Hold the airway upside down with your other hand. Insert the airway with the tip facing the roof of the mouth.
Step 3: Rotate the airway adjunct 180°. Insert the airway until the flange rests on the patient’s lips and teeth. In this position, the airway will hold the tongue forward.
Nasopharyngeal Airways
A nasopharyngeal (nasal) airway is generally used on an unresponsive patient or a patient with an altered level of consciousness who has a gag reflex and cannot spontaneously maintain their airway.If a patient has sustained severe trauma to the head or face, use extreme caution when inserting an NPA.
This type of airway is usually better tolerated than an oropharyngeal airway by patients who have a gag reflex and is not as likely to cause vomiting. Indications for an NPA include:
- Semiconscious or unconscious patients with an intact gag reflex
- Patients who will not tolerate an oropharyngeal airway
Contraindications for using a nasopharyngeal airway include the following:
- Severe head injury with blood draining from the nose
- History of fractured nasal bone
Follow these steps to ensure the correct placement of the NPA.
Step 1: Select the proper size. Measure from the tip of the patient’s nose to the earlobe. In almost all patients, one nostril is larger than the other. Generously apply water-soluble lubricant to the NPA.
Step 2: The NPA should be placed in the larger nostril, with the curvature of the device following the curve of the floor of the nose. If using the right nare (nostril), the bevel should face the septum. If using the left nare, insert the airway with the tip of the airway pointing upward, which will allow the bevel to face the septum.
Step 3: Advance the airway gently. If using the left nare, insert the nasal airway until resistance is met. Then rotate the nasal airway 180° into position. This rotation is not required if using the right nostril.
Step 4: When completely inserted, the flange rests against the nostril. The other end of the airway opens into the posterior pharynx. If the patient becomes intolerant of the nasal airway, you may have to remove it. Gently withdraw the airway from the nasal passage.
Oxygen-Delivery Equipment
Generally, the oxygen delivery equipment used in the field may be limited to nonrebreathing masks, partial rebreathing masks, bag-mask devices, and nasal cannulas, depending on your local protocol. However, you may encounter other devices depending on where you work.
Nonrebreathing Mask
The nonrebreathing mask (nonrebreather) is used to administer high concentrations of oxygen to significantly hypoxemic patients who are otherwise breathing adequately. With a good mask-to-face seal and a flow rate of 15 L/ min (liters per minute), the nonrebreather is capable of providing up to 90% inspired oxygen.
This mask is a combination mask and reservoir bag system, with a one-way valve separating the two. When using a nonrebreather, you must be sure the reservoir bag is filled before the mask is placed on the patient. Adjust the flow rate so the bag does not fully collapse when the patient inhales, which is about 10 to 15 L/min. Make sure the bag stays inflated. Should the bag collapse when the patient inhales, increase the flow rate of oxygen.
In addition, if oxygen therapy is discontinued, remove the mask from the patient’s face. Leaving the mask in place while oxygen is not flowing allows the patient to rebreathe exhaled carbon dioxide. Use a pediatric nonrebreathing mask, which has a smaller reservoir bag, with infants and children, as they will inhale a smaller volume.
Nasal Cannula
A nasal cannula delivers oxygen through two small, tubelike prongs that fit into the patient’s nostrils. This device can provide 24% to 44% inspired oxygen when the flowmeter is set at 1 to 6 L/min. For your patient’s comfort, flow rates above 6 L/min are not recommended with a nasal cannula. Typically, the cannula is used in patients with mild hypoxemia.
Partial Rebreathing Mask
The partial rebreathing mask is similar to a nonrebreathing mask, but there is no one-way valve between the mask and the reservoir. Consequently, patients rebreathe a small amount of their exhaled air. This has some benefits when you want to increase the patient’s Paco2, which makes this the ideal mask for patients who you think are experiencing hyperventilation syndrome. The oxygen enriches the air mixture and delivers a gas mix of approximately 80% to 90% oxygen.