Basic Airway Management
Objectives
At the conclusion of this article you should be able to:
1.
2.
3.
4.
5.
Understand the principles of ventilation and oxygenation.
Identify the causes of airway obstruction.
Identify the signs and symptoms of airway obstruction.
Describe the correct techniques for opening a patient's airway.
Describe the correct technique for inserting an airway adjunct and using a bag
valve mask ventilator.
Case
You and your partner are sent to a respiratory distress call at a local high school. The
patient is a 28 year-old male teacher that became unconscious after choking on an apple
slice. The dispatcher informs you that the patient began choking and bystanders
attempted the Heimlich maneuver four times to no effect. Shortly thereafter, the patient
became limp and unresponsive. You and your partner are led to the teacher’s lounge at
the back of the cafeteria by the assistant principle. Arriving on the scene, you enter a
room with a couch and lounge chairs on one end and a long, rectangular dining table at
the other end. The patient is lying supine on the floor next to the end of the table closest
to the door. Two bystanders are attempting to remove the foreign body obstruction from
the unconscious patient while beginning CPR. You calmly ask the bystanders to stop and
step aside. You look, listen, and feel for signs of spontaneous respiration while your
partner prepares supplemental oxygen with a bag valve mask. There is no visible chest
rise and no sound of air movement through the nose or the mouth. The patient’s skin is
cool and pale to the touch with no palpable pulse. Because there is no danger of spinal
cord damage or head trauma, you attempt to open the airway utilizing the head tilt-chin
lift maneuver. There is still no sign of spontaneous respirations after repositioning. Using
the bag valve mask and maintaining the opened airway, your partner attempts to
administer two breaths, but feels resistance. Your partner repositions the head and tries
again to no effect. After chest compressions, you notice a foreign object resting at the
back of the nasopharynx. Because the patient has no gag reflex, you are able to visualize
and remove the foreign object from the airway using forceps. You immediately begin
rescue breathing with the bag valve mask while your partner attaches the monitor/AED
pads to the patient. The patient remains unresponsive with no pulse or breathing. The
AED shows that the
patient is in a nonshockable rhythm. You
and your partner begin
CPR. Your partner
inserts an
oropharyngeal airway to maintain an open airway during transport. Bystanders inform
you that the patient has no medical history or daily medications. Continuing CPR, you
and your partner transport the patient to the nearest emergency facility.
Introduction
In the initial assessment and management of any critically ill patient, the ABC's are the
first priority. Hypoxia will begin to cause irreversible brain injury within four to six
minutes.4 After ten minutes, some areas of the brain will have irreversible damage. Thus,
airway management must precede any other treatment. Therefore, the ability to establish
and maintain an open airway in a patient and to ensure adequate ventilation and
oxygenation of the patient, are essential skills for the emergency medical technician.
Recognition of a patient in respiratory distress, respiratory failure, and respiratory arrest
are skills that must be learned and perfected, so that the reaction of EMS is immediate.
The reasons for inadequate chest ventilation include inadequate respiratory effort, airway
obstruction or a combination of both.4 A proficient emergency care provider must be able
to minimize the amount of time necessary to come to the proper diagnosis and initiate the
proper treatment when dealing with a patient with airway problems.
Regardless of training, EMS units carry the devices and abide by the protocols for their
use determined by their prehospital medical director. Protocols determine the scope of
practice. Standing orders are orders that are subsets of the protocols that are to be carried
out before contact with medical control. For example, a standing order may be in place
that, in the event of cardiac arrest, the patient is to be intubated.
Anatomy and Physiology
Effective airway management starts with a thorough understanding of the anatomy and
physiology of the human airway. The respiratory system has two major sub-divisions: the
upper airway and the lower airway.5 The upper airway consists of the mouth and nose,
the nasal passageways, the nasopharynx, the oropharynx, the pharynx, and the epiglottis.
The lower airway consists of the larynx, the trachea, the carina, the bronchi, the
bronchioles and the alveoli.
Pulmonary ventilation is the physical movement of air in and out of the lungs.5
Respiration is the exchange of oxygen and carbon dioxide. The two phases of respiration
are external respiration and internal respiration. External respiration occurs in the lungs
between the inspired air and the pulmonary capillaries.5 Internal respiration occurs
between the red blood cells and tissue cells of the body.5 Various mechanisms control
respiration and ventilation. Primarily, the breathing controls are involuntary, originating
in the inspiratory and expiratory centers of the medulla at the base of the brain.5 The
activities of the respiratory centers are determined by chemical changes in the blood due
to oxygen and carbon dioxide concentrations.5 One can also voluntarily control
respiration and ventilation by hyperventilating or holding one’s breath.
Causes of Airway Problems
The first priority of patient care of the patient with respiratory compromise is establishing
and maintaining a patent airway. Foreign body airway obstructions result in around 3000
deaths in the United States every year.6 Obstruction may occur at any point within the
airway. The most common obstruction occurs in the upper airway.4 Airway obstructions
are either partial or complete. The Heimlich Maneuver is utilized to help a conscious or
unconscious patient remove a foreign obstruction. The tongue most commonly causes
airway obstruction in the unconscious patient. Laryngeal spasm and edema can also
obstruct the airway and interrupt ventilation.4 Infections, allergic reactions, thermal
injuries, strangulation, or drowning may cause swelling around the vocal cords and the
epiglottis.6 Fractures to the airway are most commonly caused by motor vehicle
collisions. A fracture of the larynx can result in a blockage by the vocal cords or edema
that interferes with the airway.2 Lower airway obstructions are usually a result of
aspiration.5 Aspiration is the inhalation of a foreign body into the lower airway.
Aspiration can lead to pneumonia, hypoventilation, pulmonary edema, and hypoxemia.
Diseases and abnormal conditions can also cause airway disruptions:5
1. Depressed respiratory drive caused by head injury or nervous system depressants
2. Paralysis due to spinal injury or neuromuscular disease
3. Passageway resistance and decreased lung compliance caused by chronic
obstructive pulmonary disease, infections, lung cancer, or connective tissue
disease
4. Chest wall abnormalities such as flail chest or scoliosis
5. Decreased perfusion caused by pulmonary embolus, pulmonary edema,
myocardial infarction, shock, or anemia
History and Airway Assessment
The overall status of the patient must be assessed immediately upon arrival on scene.
First, an evaluation of respiratory rate, regularity, and effort indicate respiratory problems
or distress.6 Patients in respiratory distress often breathe at a rate above or below the
normal 12-20 breaths per minute. Numerous irregular breathing patterns indicate
respiratory problems such as agonal, bradypnea, tachypnea, Cheyne-Stokes, Kussmaul, or
hyperventilation.6 The patient could complain of chest pain or chest tightness. EMS
crews should look for signs of increased respiratory effort. In order to breathe more
easily, patients in respiratory distress prefer the upright sniffing position, the tripod
position, or the semi-Fowler’s position.4 The EMS crew may witness gasping for air,
cyanosis, nasal flaring, pursed-lip breathing, and retractions of the intercostal or subcostal
muscles. Regularity and effort can also be evaluated by auscultation with or without a
stethoscope. During expiration or inspiration, the patient could have wheezing, crackles,
or rales that indicate possible breathing difficulties.4
Second, a detailed history of the patients past airway problems must be sought. Obtain a
detailed history from the patient, the family, or medical records of previous difficult
intubation, congenital abnormalities, previous airway trauma, previous airway surgery,
and pre-existing medical conditions.2 Determining the onset, evolution, and duration of
the respiratory problems are extremely important to patient care. Certain questions are
helpful obtaining an accurate history of symptoms:5
1.
2.
3.
4.
Do the symptoms continue constantly or occur sporadically?
What makes the symptoms better?
What makes the symptoms worse?
Any associated symptoms like chest pain, cough, or fever?
5. Have any medications for breathing been taken such as albuterol?
6. Has the patient taken all medications as prescribed?
Oxygen Therapy
Supplemental oxygen therapy is the primary medical treatment for medical and trauma
difficulties. Increasing oxygen in the atmosphere increases the amount of oxygen
available in the blood.5 This allows the patient to compensate for breathing difficulties
without increasing respiratory effort. Supplemental oxygen can be delivered via several
different devices: nasal cannula, simple face mask, and nonrebreather mask. The nasal
cannula is designed to deliver low concentrations of oxygen at a flow rate of up to 6 liters
per minute directly into the nose.5 The cannula is contraindicated with patients with
severe hypoxia and apnea. The simple face mask conforms to the patient’s face to cover
the nose and mouth. The oxygen fed through the mask mixes with the atmospheric air in
order to deliver medium concentrations of oxygen to the patient.5 The flow rate of
oxygen through the simple face mask should be between 6 and 10 liters per minute. High
concentrations of oxygen are delivered to a patient via a nonrebreather mask. As with the
simple face mask, the nonrebreather mask should conform to the patient’s face and fit
firmly over the nose and the mouth. The reservoir bag must be filled before being placed
on the patient’s face. The oxygen flow rate for the nonrebreather mask should be between
10 and 20 liters per minute, high enough to ensure that the reservoir remains at least two
thirds full.
Opening the Airway Manually
There are two main maneuvers utilized to open the airway in unconscious patients: the
head tilt-chin lift and the jaw thrust. The head tilt-chin lift should only be used if one is
confident that there is no risk of injury to the cervical spine.2 Standing on the patient's
right hand side, the left hand is used to apply pressure to the forehead to extend the neck.
The tips of the index and middle finger of the right hand are used to elevate the mandible,
which will lift the tongue from the posterior pharynx. The combination of both
movements will serve to extend the airway and remove the most common airway
obstruction in unconscious patients.2
If there is risk of cervical spine injury, such as with a patient who is unconscious as a
result of a head injury, then the airway should be opened using a maneuver that does not
require neck movement.2 The jaw thrust is performed by having the EMT stand at the
head of the patient looking down at the patient. The middle finger of the right hand is
placed at the angle of the patient's jaw on the right. The middle finger of the left hand is
similarly placed at the angle of the jaw on the left. An upward pressure is applied to
elevate the mandible that will lift the tongue from the posterior pharynx.2
Airway Adjuncts
Choosing the appropriate size of an airway adjunct is of paramount importance. An
incorrectly sized airway adjunct will more likely lead to an obstructed airway than create
a patent one. Basic airway devices include oropharyngeal airways and nasopharyngeal
airways.
The oropharyngeal airway is a plastic or rubber
device inserted in the oropharynx to create an
airway between the tongue and the palate.3 This
device should not be used on a patient with an
intact gag reflex. OPA’s look like spoons that are
designed to lift the tongue away from the posterior
aspect of the oropharynx.3 When choosing an
oropharyngeal airway, measure it by placing it
along side the patient's face. A correctly sized
airway will span the distance between the patient's
earlobe and the corner of the patient's mouth.3
When positioning a properly sized oropharyngeal
airway, the device is introduced into the patient's
mouth in an inverted position and moved toward
the back of the throat until the tip of the device
contacts the soft palate. Then the OPA is rotated
180° in order to catch the back of the tongue. Finally, the flange of the device is placed
outside the patient's teeth. When properly inserted, the airway will lift the back of the
tongue and hold it away from the back of the throat while the flange will rest comfortably
on the patient's teeth.3
The nasopharyngeal airway is a rubber tube inserted into the nostrils and extending into
the oropharynx. The NPA is designed to create an airway between the tongue and palate.
Nasopharyngeal airways bypass the anatomical obstruction created by the tongue resting
against the posterior aspect of the oropharynx.3 It may be used in a semiconscious patient.
It also may be used to supplement positioning in maintaining an open airway. When
choosing a nasopharyngeal airway, it should span the distance between the patient's
earlobe and the tip of the patient's nose.3 Do not stretch the airway in an effort of span
this distance, but allow it to assume its natural curvature.3 When introducing a properly
sized nasopharyngeal airway, start by lubricating it with a water-soluble lubricant. Assess
the size and shape of both nares. Usually one nostril will be larger than the other, thus
choose the larger of the two as the initial insertion point. The tip of the airway is
introduced into the nare, close to the septum, with the curvature of the airway matching
the natural curvature of the nasopharynx and nasal passageways. Introduce the airway
gently, and direct it straight back toward the back of the head, not up toward the crown of
the skull. The nasal passageways go straight back and the delicate nasal tissues associated
with the sinuses, some of which are superior to the nasal passageways, are easily
damaged.3 If the passageways are scraped by the tip of the airway, then unwanted
bleeding may occur. If any resistance is encountered while inserting the airway, withdraw
the NPA, re-lubricate it, and try the other side. The nasopharyngeal airway is designed to
follow the natural curvature of the nasopharynx.3 When fully inserted, the tip should be
located in the back of the pharynx immediately posterior to the tongue. This type of
airway is better tolerated by patients who have a gag reflex, but the NPA is
contraindicated in patients with trauma to the nose or face.3 The flexible nature of the
airway and the presence of adequate water-soluble lubricant, allow the airway to be easily
placed. If there is any possibility of basilar skull fracture, the tip of the airway may enter
the hole caused by the fracture and end up in brain tissue.3
Ventilation Devices
EMS crews provide emergency patient ventilation using rescue breathing, mouth to mask
breathing, bag-valve-masks, or automatic ventilators. Rescue breathing requires the EMT
to use expired air to directly and forcefully inflate the patient’s lungs.4 Numerous
complications are associated with mouth to mouth, mouth to nose, or mouth to stoma
rescue breathing including body fluid contact and gastric distention. The pocket mask is a
plastic and rubber mask is designed to protect the rescuer during rescue breathing.4 It has
a one-way valve to isolate patient secretions and an oxygen port to supplement the
rescuer's exhaled oxygen. First responders use the pocket mask when a bag valve mask is
not available. The Bag-valve-mask is a combination of face mask and self-inflating
resuscitation bag. It should have an oxygen reservoir and tubing. It is used in conjunction
with positioning, NPA, OPA, and endotracheal tubes to provide oxygenation and
ventilation to the apneic or hypoventilating patient.4 A demand valve mask is an oxygenpowered resuscitator-mask combination and are activated by the rescuer pushing a
button. Although easy to use, these units do not allow the operator to feel the
effectiveness of ventilation or lung compliance.3 Consequently, demand valve masks are
not used often. Automatic ventilators are electronic devices that provide pressure to
ventilate. There are many different types of ventilators utilized by EMS crews. Refer to
medical control for protocols about automatic ventilators.
Suction devices
Suction devices are used to remove secretions from the mouth, oropharynx, and
nasopharynx. Suctioning an airway is a process of removing obstacles that inhibit
ventilation.6 For the most part, obstacles will be some type of fluid, although suctioning
can also be used to remove solid and semi-solid obstacles. Suction is especially important
when treating unconscious patients or patients with a tracheostomy tube.6 Numerous
types of suction units are used in EMS, including portable hand-powered, portable
battery-powered units, as well as wall-mounted units. Battery powered devices require
regular maintenance, including battery charging, and testing the effective suctioning
action of the device. Look to local protocols for guidance on suctioning time limits,
remember those limits, and stick to them.6
Special Considerations
Special considerations should be taken when dealing with the pediatric airway. This
begins first with the understanding of the anatomy and physiology of the normal pediatric
airway. The differences in the pediatric and adult airways are less striking as the child
reaches approximately 8 years of age, when the airway assumes adult proportions.1 The
face is small relative to the other parts of the head. The nostrils are small with small
passageways. The infant is primarily a nose breather until approximately 3-6 months of
age; thus any obstruction may produce obstructive apnea.1 Simple upper respiratory
infections will lead to inflammation of the nasal mucosa and result in upper airway
obstruction. Due to the compact nature of the sinuses and reduced drainage this causes,
the adenoids and tonsils frequently may be enlarged.1 Adenoidal and tonsillar edema in
the child may result in snoring and progress to airway obstruction. The oropharynx
contains a large tongue. The large, floppy tongue can occlude the oropharynx in a
sleeping or sedated child. It may also be a problem in the child with a congenitally small
mouth or large tongue as with Down Syndrome.1 The epiglottis is large and omega
shaped. The epiglottis and the pharynx may cause breathing difficulties more readily in
the child because of viral infection, bacterial infection, or inhalation injuries. The larynx
is short and narrow with prominent false cords. Whereas the vocal chords are the
narrowest point in adults, the narrowest portion of the laryngotracheal lumen in pediatric
patients is located below the vocal cords at the level of the cricoid cartilage.1 The trachea
is short and the tracheal rings may be floppy. Inflammation of the tracheal mucosa from
infections, such as viral croup or bacterial tracheitis or inhalation injuries produce
subglottic narrowing of the tracheal lumen.1 This may be a mild croupy stridor that can
quickly progress to frank subglottic airway obstruction. The infant chest wall
infrastructure is not completely calcified and is more compliant than that of the adult. The
bronchi are small in diameter and minor narrowing from respiratory infections or
bronchospasm may result in profound airway difficulties.1 The tracheobronchial tree of
the child is also prone to problems because of relatively narrow lumens that can obstruct
and produce significant respiratory distress because of bronchospasm or inflammation.
The lung volumes of the child are small in relation to the child’s metabolic needs. The
small lung volumes and functional residual capacity in relation to the infant’s metabolic
needs means that he has less reserve and apnea can quickly yield significant arterial
desaturation and cyanosis.1
Conclusion
Airway, breathing, and circulation are the first concerns of emergency medical personnel.
Without the ability to control the airway adequately, all other interventions are futile.
EMS can make its greatest contribution to minimizing the effects of airway illness and
reducing mortality by rapidly maintaining airway patency.
Bibliography
1. Auble TE, Menegazzi JJ, Nicklas KA: Comparison of automated and manual ventilation in a prehospital pediatric model. Prehosp Emerg
Care 1998 Apr-Jun; 2(2): 108-11.
2. Deakin CD: Prehospital management of the traumatized airway. Eur J Emerg Med 1996 Dec; 3(4): 233-43.
3. Falk JL, Sayre MR: Confirmation of airway placement. Prehosp Emerg Care 1999 Oct-Dec; 3(4): 273-8.
4. Regel G, Stalp M, Lehmann U, Seekamp A: Prehospital care, importance of early intervention on outcome. Acta Anaesthesiol Scand Suppl
1997; 110: 71-6.
5. Sanders, M. Mosby’s Paramedic Textbook: Revised Second Edition. Mosby, Inc. St Louis, MS, 2001: 930-934,1225-1226,1255-1257.
6. Wayne MA, Delbridge TR, Ornato JP, et al: Concepts and application of prehospital ventilation. Prehosp Emerg Care 2001 Jan-Mar; 5(1):
73-8.