emt chapter 11

aerobic metabolism

Metabolism that can proceed only in the presence of oxygen.

aerosol-generating procedure

Any airway manipulation that induces the production of aerosols that may present a risk for airborne transmission of pathogens, such as CPR.

agonal gasps

Abnormal breathing pattern characterized by slow, gasping breaths, sometimes seen in patients in cardiac arrest.

airway

The upper airway tract or the passage above the larynx, which includes the nose, mouth, and throat.

alveolar minute volume

The volume of air moved through the lungs in 1 minute minus the dead space; calculated by multiplying tidal volume (minus dead space) and respiratory rate.

alveolar ventilation

The volume of air that reaches the alveoli. It is determined by subtracting the amount of dead space air from the tidal volume.

American Standard Safety System

A safety system for large oxygen cylinders, designed to prevent the accidental attachment of a regulator to a cylinder containing the wrong type of gas.

anaerobic metabolism

The metabolism that takes place in the absence of oxygen; the main by-product is lactic acid.

apnea

Absence of spontaneous breathing.

apneic oxygenation

A technique in which oxygen administered via a high-flow nasal cannula is left in place during an intubation attempt, allowing for continuous oxygen delivery into the airways during all phases of the procedure.

aspiration

In the context of the airway, the introduction of vomitus or other foreign material into the lungs.

ataxic respirations

Irregular, ineffective respirations that may or may not have an identifiable pattern.

automatic transport ventilator (ATV)

A ventilation device attached to a control box that allows the variables of ventilation to be set. It frees the EMT to perform other tasks while the patient is being ventilated.

bag-mask device

A device with a one-way valve and a face mask attached to a ventilation bag; when attached to a reservoir and connected to oxygen, it delivers more than 90% supplemental oxygen.

barrier device

A protective item, such as a pocket mask with a valve, that limits exposure to a patient's body fluids.

bilateral

A body part or condition that appears on both sides of the midline.

bronchioles

Subdivision of the smaller bronchi in the lungs; made of smooth muscle and dilate or constrict in response to various stimuli.

capnography

A noninvasive method to quickly and efficiently provide information on a patient's ventilatory status, circulation, and metabolism. It effectively measures the concentration of carbon dioxide in expired air over time.

capnometry

The use of a capnometer, a device that measures the amount of expired carbon dioxide.

carina

Point at which the trachea bifurcates (divides) into the left and right main stem bronchi.

chemoreceptors

Monitor the levels of oxygen, carbon dioxide, and pH of the cerebrospinal fluid and then provide feedback to the respiratory centers to modify the rate and depth of breathing based on the body's needs at any given time.

Cheyne-Stokes respirations

A cyclical pattern of abnormal breathing that increases and then decreases in rate and depth, followed by a period of apnea.

compliance

The ability of the alveoli to expand when air is drawn in during inhalation.

continuous positive airway pressure (CPAP)

A method of ventilation used primarily in the treatment of critically ill patients with respiratory distress; can prevent the need for endotracheal intubation.

dead space

Any portion of the airway that does contain air and cannot participate in gas exchange, such as the trachea and bronchi.

denitrogenation

The process of replacing nitrogen in the lungs with oxygen to maintain a normal oxygen saturation level during advanced airway management.

diffusion

Movement of a gas from an area of higher concentration to an area of lower concentration.

direct laryngoscopy

Visualization of the airway with a laryngoscope.

dyspnea

Shortness of breath.

endotracheal (ET) intubation

Insertion of an endotracheal tube directly through the larynx between the vocal cords and into the trachea to maintain and protect an airway,

end-tidal co2

The amount of carbon dioxide present at the end of an exhaled breath.

esophageal intubation

Improper placement of an advanced airway device into the esophagus rather than into the trachea.

exhalation

The passive part of the breathing process in which the diaphragm and the intercostal muscles relax, forcing air out of the lungs.

external respiration

The exchange of gases between the lungs and the blood cells in the pulmonary capillaries; also called pulmonary respiration.

gag reflex

A normal reflex mechanism that causes retching; activated by touching the soft palate or the back of the throat.

gastric distention

A condition in which air fills the stomach, often as a result of high volume and pressure during artificial ventilation.

glottis

The space in between the vocal cords that is the narrowest portion of the adult's airway; also called the glottic opening.

good air exchange

A term used to distinguish the degree of distress in a patient with a mild airway obstruction. With good air exchange, the patient is still conscious and able to cough forcefully, although wheezing may be heard.

gum elastic bougie

A flexible device that is inserted between the glottis under direct laryngoscopy; the endotracheal tube is threaded over the device, facilitating its entry into the trachea.

head tilt-chin lift maneuver

A combination of two movements to open the airway by tilting the forehead back and lifting the chin; not used for trauma patients.

hemothorax

A collection of blood in the pleural cavity.

hypercarbia

Increased carbon dioxide level in the bloodstream.

hypoxia

Deficient oxygen concentration in the tissues.

hypoxic drive

A "backup system" to control respiration; senses drops in the oxygen level in the blood.

inhalation

The active, muscular part of breathing that draws air into the airway and lungs.

internal respiration

The exchange of gases between the blood cells and the tissues.

intrapulmonary shunting

Bypassing of oxygen-poor blood past nonfunctional alveoli to the left side of the heart.

jaw-thrust maneuver

Technique to open the airway by placing the fingers behind the angle of the jaw and bringing the jaw forward; used for patients who may have a cervical spine injury.

labored breathing

The use of muscles of the chest, back, and abdomen to assist in expanding the chest; occurs when air movement is impaired.

larynx

A complex structure formed by many independent cartilaginous structures that all work together; where the upper airway ends and the lower airway begins; also called the voice box.

mediastinum

Space within the chest that contains the heart, major blood vessels, vagus nerve, trachea, major bronchi, and esophagus; located between the two lungs.

metabolism

The biochemical processes that result in production of energy from nutrients within the cells; also called cellular respiration.

mild airway obstruction

Occurs when a foreign body partially obstructs the patient's airway. The patient is able to move adequate amounts of air, but also experiences some degree of respiratory distress.

minute volume

The volume of air that moves into and out of the lungs per minute; calculated by multiplying the tidal volume and respiratory rate; also called minute ventilation.

nasal cannula

An oxygen-delivery device in which oxygen flows through two small, tubelike prongs that fit into the patient's nostrils; delivers 24% to 44% supplemental oxygen, depending on the flow rate.

nasopharyngeal (nasal) airway

Airway adjunct inserted into the nostril of an unresponsive patient or a patient with an altered level of consciousness who is unable to maintain airway pa-tency independently.

nasopharynx

The part of the pharynx that lies above the level of the roof of the mouth, or palate.

nonrebreathing mask

A combination mask and reservoir bag system that is the preferred way to give oxygen in the prehospital setting; delivers up to 90% inspired oxygen and prevents inhaling the exhaled gases (carbon dioxide).

oropharyngeal (oral) airway

Airway adjunct inserted into the mouth of an unresponsive patient to keep the tongue from blocking the upper airway and to facilitate suctioning the airway, if necessary.

oropharynx

A tubular structure that forms the posterior portion of the oral cavity, which is bordered superiorly by the hard and soft palates, laterally by the cheeks, and inferiorly by the tongue.

oxygenation

The process of delivering oxygen to the blood by diffusion from the alveoli following inhalation into the lungs.

oxygen toxicity

A condition of excessive oxygen consumption resulting in cellular and tissue damage.

parietal pleura

Thin membrane that lines the chest cavity.

partial pressure

The term used to describe the amount of gas in air or dissolved in fluid, such as blood.

passive ventilation

The act of air moving into and out of the lungs during chest compressions.

patent

Open, clear of obstruction.

phrenic nerves

The two nerves that innervate the diaphragm; necessary for adequate breathing to occur.

pin-indexing system

A system established for portable cylinders to ensure that a regulator is not connected to a cylinder containing the wrong type of gas.

pneumothorax

An accumulation of air or gas in the pleural cavity.

poor air exchange

A term used to describe the degree of distress in a patient with a mild airway obstruction. With poor air exchange, the patient often has a weak, ineffective cough, increased difficulty breathing, or possible cyanosis and may produce a high-pitched noise during inhalation (stridor).

preoxygenation

The process of providing oxy-gen, often in combination with ventilation, prior