Diffusion
How CO2 moves from blood into the air sac
Airway divided into
upper and lower airway
Upper airway consists of?
Nose, mouth, jaw, oral cavity, pharynx, and larynx
Upper airway function
warm, filter, and humidify air as it enters the body through the nose and mouth
Pharynx?
Throat; muscular tube that extends from the nose and mouth to the level of the esophagus and trachea; composed of nasopharynx, oropharynx, and the laryngopharynx
Laryngopharynx?
Hypopharynx splits into two lumens, the larynx anteriorly and the esophagus posteriorly
During inhalation?
air enters the body through the nose and passes into the nasopharynx
Epiglottis?
leaf shaped cartilaginous structure that helps separate the digestive system from the respiratory system
When swallowing occurs?
The larynx is elevated and the epiglottis folds over the glottis to prevent aspiration of contents into the trachea
Larynx marks?
Where the upper airway ends and the lower airway begins
Glottis
space in between the vocal cords and the narrowest portion of the adult's airway
Vocal chords
Lateral borders of the glottis; contain defense reflexes that protect the lower airway, causing a spasmodic closure to the lower airway to prevent substances from entering the trachea
Adam's apple?
Laryngeal prominence formed by two plates that join in a V structure
First ring of the trachea and the only lower airway structure that forms a complete ring?
Cricoid cartilage
Function of lower airway?
xchange O2 and CO2
Trachea
Windpipe, conduit for air entry into the lungs
Lungs consist of?
entire mass of tissue that includes the smaller bronchi, bronchioles and alveoli
Lungs surrounded by a serous membrane called?
Pleura
All lung tissue is covered with a?
Thin, slippery outer membrane called visceral pleura
Parietal pleura?
Lines the inside of the thoracic cavity
Each bronchus divides into?
Smaller bronchi, which in turn subdivides into bronchioles
Bronchioles?
Thin, hollow tubes made of smooth muscle
Alveoli?
Located at the end of the airway; millions of thin-walled ballon-like sacs that serve as the functional site for the exchange of O2 and CO2
Surrounding each alveoli sac is?
An intricate bed of blood vessels known as pulmonary capillaries
When are intercostal muscles used in breathing?
When a patient is in respiratory distress
Between the lungs is a space called?
Mediastinum which is surrounded by connective tissue; contains the heart, great vessels, esophagus, trachea, the major bronchi, and nerves
Phrenic nerve?
Found in thorax, innervates the diaphragm muscle, allowing it to contract; necessary for adequate breathing to occur
Arteries carry oxygenated blood?
Away from the heart and branch into arterioles and capillaries
Once in the capillaries?
The xchnge of nutrients and waste products takes place
All veins carry?
Deoxygenated blood to the heart
Pg. 323-324
...
Deoxygenated blood enters?
The right side of the heart through the right atrium, where it is pumped through the tricuspid valve, right ventricle, and pulmonary artery before being pumped to the lungs for oxygenation and removal of CO2
Ventilation?
Physical act of moving air into and out of the lungs
Oxygenation
Process of loading O2 molecules onto hemoglobin molecules in the bloodstream
Respiration
Actual exchange of O2 and Co2 in the alveoli as well as the tissues of the body
Required for adequate respiration?
Ventilation
Diaphragm is a voluntary muscle t or f
F; It is a voluntary muscle and performs an automatic function during sleep
Autonomic regulation of breathing resumes under?
Control of the brain stem
Lungs have no
muscle tissue; therefore, they cannot move on their own
Partial pressure?
Term used to describe the amount of gas in air or dissolved in fluid, such as blood
Partial pressure of O2 in air residing in the alveoli?
104 mm Hg
CO2 enters the alveoli form the blood causes a CO2 partial pressure of?
40 mm Hg
Oxygenated arterial blood form the heart has a partial pressure of O2 that is?
Lower than the partial pressure of CO2 in the pulmonary capillaries
Air pressure outside the body is normally?
Higher than the air pressure within the thorax
Alveolar ventilation
volume of air that reaches the alveoli; determined by subtracting the amount of dead space air form the tidal volume
Tidal volume?
measure of depth of breathing; amount of air in mL that is moved into or out of the lungs during a single breath
Average tidal volume for a man?
500 mL
Breathing becomes deeper as the?
Tidal volume responds to the increased metabolic demand for O2
Dead space?
Portion of the tidal volume that odes not reach the alveoli and thus does not participate in the gas exchange
Minute ventilation?
Minute volume, amount of air moved through the lungs in 1min minus the dead space; calculated by subtracting the dead space from the tidal volume, then multiplying that number by the respiratory rate
Vital capacity?
Amount of air that can be forcibly expelled from the lungs after breathing deeply
Residual volume?
air that remains after maximal expiration
Does exhalation require muscular effort?
No
Air will only reach the lungs if?
It travels through the trachea
Changes in O2 demand are regulated by?
pH of the cerebrospinal fluid
COPD?
Chronic obstructive pulmonary disease; difficulty eliminating CO2 through exhalation
Hypoxic drive?
Secondary control of breathing, based on levels of O2 dissolved in plasma
Hypoxic drive is typically found?
In end stage COPD
Dyspnea?
Shortness of breath
Early signs of hypoxia?
restlessness, irritability, apprehension, fast hr and anxiety
Late signs of hypoxia?
Mental status changes, weak pulse, and cyanosis
Oxygenation?
process of loading O2 molecules onto hemoglobin molecules in the bloodstream
Oxygenation requires?
air used for ventilation contains an adequate percentage of O2
Is it possible to ventilate w/o O2?
Yes, but you generally cannot oxygenate w/o ventilation
____ has a much greater affinity for hemoglobin than O2
CO2
External respiration?
Process of breathing fresh air into the respiratory system and exchanging O2 and CO2 between the alveoli and blood in the pulmonary capillaries
Fresh air contains?
21% O2, 78% nitrogen, and .3% CO2
Surfactant?
reduce surface tension within the alveoli and keeps them expanded
Once O2 crosses the alveolar membrane?
It is bound to hemoglobin, an iron containing molecule that has a great affinity for O2 molecules
Internal respiration?
Exchange of oxygen and CO2 between the systemic circulatory system and the cells of the body
Chemoreceptors?
Monitor levels of O2, CO2, H ions and the 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
Dorsal respiratory group?
Responsible for initiating inspiration based on the info received from the chemoreceptors
Ventral respiratory group?
Primarily responsible for motor control of the inspiratory and expiratory muscles
Dorsal and ventral respiratory group are affected by?
The apneustic center and the pneumotaxic center of the pons
Apneustic center?
Stimulates the dorsal respiratory group, resulting in longer, slower respirations
Pneumotaxic center?
Helps in shutting off the dorsal respiratory group, resulting in shorter, faster respirations
What must be matched to permit gas exchange by simple diffusion?
Ventilation and perfusion
Normal resting minute ventilation?
6L/min
Ratio of ventilation to perfusion is highest at?
Apex of the lung and lowest at the base
A V/Q mismatch could lead to?
Hypoxemia and possibly death
Most common airway obstruction in patient?
Tongue
Snoring respirations and the position of head or neck are good indicators?
The tongue may be obstructing the airway
Lower resp rate and tidal volume will decrease?
The overall minute volume as as well the alveolar ventiliation; this increases the amount of CO2 in the respiratory and circulatory systems resulting in an increase of CO2 levels in the bloodstream
Hypercarbia
overall increase of CO2 levels in the bloodstream
Conditions that reduce the surface area for gas exchange?
Decrease the body's O2 supply
Intrapulmonary shunting
Blood enters lungs from the right side of the heart, bypasses the alveoli and return to the left side of the heart in an unoxygenated state
Blood loss and anemia result in?
A decreased ability of blood to carry O2
Hypovolemic shock?
Abnormal decrease in blood volume that causes inadequate O2 delivery to the body
Vasodilatory shock?
Diameter of blood vessel increases, bp in circulatory system decreases and O2 is not delivered to the tissues in an effective manner
Should you be able to see or hear a person breathe?
No, unless you are directly assessing the patient's airway
Signs of normal breathing?
1) 12-20 breaths/min 2) Regular pattern of inhalation and exhalation 3) Clear and equal lung sounds on both sides of the chest 4) Regular and equal chest rise and fall 5) Adequate depth
Respiratory status of a patient should be noted?
At the beginning of the radio report after mental status
Agonal gasps?
Gasping breaths after heart has stopped
Agonal gasps require?
artificial ventilation and chest compressions
Cheyne Stokes respirations?
Irregular respiratory pattern in which the patient breathes with an increasing rate and depth of respirations that is followed by a period of apnea
Apnea?
lack of spontaneous breathing, followed again by a pattern of increasing rate and depth of respiration
Serious head injuries may cause?
Changes in the normal respiratory rate and pattern of breathing; result may be irregular, ineffective respirations that may or may not have an identifiable pattern (ataxic respirations)
Kussmaul respirations
deep, gasping respiration commonly seen in patients with metabolic acidosis
Patients with inadequate breathing is best recognized by?
patients who are unable to speak in complete sentences when at rest or who have a fast or slow respiratory rate
Carbon monoxide poisoning may be present?
In a residence with gas heating
Pale skin and mucous membranes known as?
pallor
Hemoglobin delivers?
97% of the O2 delivered to the body's tissues
Pulse oximeter provides?
a rapid, reliable noninvasive, real time indication of respiratory efficiency; measures the % of hemoglobin saturation
An SaO2 of less than 96% may indicate?
Hypoxemia
Inaccurate pulse oximetry reading caused by?
1) hypovolemia, 2) anemia 3) severe peripheral vasoconstriction 4) Time delay 5) Dark or metallic nail polish 6) Dirty fingers 7) Carbon monoxide poisoning
Does adequate breathing = adequate airway?
No
Causes of airway obstruction?
Relaxation of tongue 2) Foreign objects 3) Blood clots, broken teeth 4) Airway tissue swelling 5) Aspirated vomitus
When should the jaw thrust maneuver be used?
Suspect a cervical spin injury and can't use head tilt chin lift
Assess breathing by?
Look, listen, and feel technique
Oropharyngeal airway has what 2 purposes?
1) Keep tongue from blocking upper airway 2) Make it easier to suction the oropharynx
Indications for oral airway?
1) Unresponsive patients w/o a gag reflex 2) Apneic patient being ventilated with a bag mask device
Contraindications for oral airway?
1) Conscious patients 2) Any patient who has an intact gag reflex
Nasopharyngeal airway used?
An unresponsive patient or a patient with an altered level of consciousness who has an intact gag reflex
Contraindications for nasopharyngeal airway
Severe head injury with blood draining from the nose 2) History of fractured nasal bone
If you hear gurgling?
The patient needs suctioning
Tonsil tips?
Rigid pharyngeal suction tips
Suction catheter?
Hollow, cylindrical device that is used to remove fluids from the patient's airway
Best type of catheter for suctioning the oropharynx?
Tonsil-tip catheter
Stoma
opening through the skin that goes into an organ
French or whistle tip catheters are used?
To suction the nose and liquid secretions in the back of the mouth and in situations in which a patient has a stoma
Never suction the mouth or nose for more than __ for adults, __ for children, __ for infants
15, 10, 5 seconds
If a patient produces frothy secretions as quickly as you can suction, you should?
1) Suction the patient's airway for 15 secs and then ventilate for 2 mins ; continue until all secretions are clear
Position used to help maintain a clear airway in an unconscious patient who is not injured and is breathing on his own?
Recovery position
Recovery position not appropriate for?
Patients with spinal injuries or patients who are unconscious
Never withhold ____ from any patient who might benefit from it, especially if you must assist ventilations?
O2
When ventilating any patient in cardiac or respiratory arrest you must use?
High concentration supplemental O2
Most commonly found O2 cylinders on ambulance?
D (or super D) and M size cylinders
A puncture or hole in an O2 tank cold cause the cylinder to become?
A deadly missile
Compressed gas industry has established what to prevent an O2 regulator from being connected to a CO2 cylinder and vice versa
Pin indexing system
Volume of D size cylinder in L
350
Safety system for large cylinders?
American Standard System
Purpose of ASS
prevent accidental attachment of a regulator to a wrong cylinder
Pressure of gas in a full 02 cylinder?
2000psi
Pressure compensated flowmeter must be?
Always maintained in an upright position for an accurate flow reading
Bourdon gauge flowmeter is not affected by?
Gravity and can be used in any position
Major disadvantage of flowmeter?
Does not compensate for backpressure
Does O2 burn or explode?
No, but it does support combustion
Nonrebreathing mask?
preferred way of giving O2 in prehospital setting to patients who are breathing adequately but are suspected of having or showing signs of hypoxia
Should the bag collapse when the patient inhales?
Increase the flow rate of O2
If O2 therapy is discontinued, you should?
Remove the mask from the patient's face
Nasal cannula?
Delivers O2 through 2 small tube like prongs that fit into patient's nostrils; can provide 24-44% inspired O2 when flowmeter is set 1-6L/min
Ideal mask for patients with hyperventilation?
Partial rebreathing masks
Venturi principle?
causes air to be drawn into the flow of O2 as it passes a hole in the line
Nasal cannula delivers?
Dry O2 directly into the nostrils, which over prolonged periods can cause dryness or irritate the mucous membrane lining of the nose
If you anticipate a long transport time w/ nasal cannula you should?
Consider humidification
Main advantage of venturi mask?
Fine adjustment capabilities in the long term management of physiologically stable patients
People with tracheostomies do not?
Breathe through their mouth and nose
If you do not have a tracheotomy mask, use?
A face mask instead
Humidified O2 is usually indicated only for?
Long term O2 therapy
Fast, shallow breathing can be just as dangerous as?
Very slow breathing
Patients with inadequate breathing require?
Assisted ventilations with some form of positive pressure ventilation
2 options when a patient is in severe respiratory distress?
1) assisted ventilations 2) continuous positive airway pressure (CPAP)
Signs and symptoms associated with inadequate ventilation?
1) altered mental status 2) inadequate minute volume 3) excessive accessory muscle use and fatigue from labored breathing
Bag mask device procedure?
1) Explain procedure to patient 2) place mask over the patient's nose and mouth 3) squeeze bag each time patient breathes 4) after 5-10 breaths, slowly adjust the rate and deliver an appropriate tidal volume 5) adjust rate and tidal volume to maintain an
When positive pressure ventilation is initiated?
More air is needed to achieve the same oxygenation and ventilatory effects of normal breathing
It is imperative the EMT regulate the rate and volume of artificial ventilations to?
To help prevent drop in cardiac output bc blood flow is decreased due to increased pressure on chest
Cardiac output =
Stroke volume x heart rate
Stroke volume?
Amount of blood ejected by the ventricle in one cardiac cycle
Cardiac output is the amount of blood?
Ejected by the left ventricle in 1 min
Gas you exhale contains __ O2?
16%
With the mouth to mask system, the patient?
Gets the additional benefit of significant O2 enrichment with inspired air
You know you are providing adequate ventilations if?
You see the patient's color improving, the chest rise adequately, and do not meet resistance when ventilating
If supplemental O2 is available, deliver a tidal volume of? If not?
500 to 600mL over 1-2 secs/ If not, 700 to 1000mL over 2 seconds
A bag mask device can deliver nearly?
100% O2
Bag mask provides less?
tidal volume than mouth to mask ventilation
Most common ventilation method in field?
Bag mask
Bag mask device can be used with or without O2 t or F
T
Bag mask device used for patients in?
Respiratory arrest, cardiopulmonary arrest, and respiratory failure
Total volume in adult bag mask device
1200-1600mL
Volume of O2 delivered to patient base on
Chest rise and fall
If ventilation is adequate, what problems may hinder respiration?
Flail chest, foreign body airway obstruction, injury to spinal cord that disrupts phrenic nerve
Prevent or alleviate distention you should?
1) Ensure patient's airway is properly positioned 2) Ventilate patient at the appropriate rate 3) Ventilate patient with appropriate volume
When using a bag mask or any ventilation device, be alert for?
Gastric distention, inflation of the stomach with air
Major advantage to manually triggered ventilation device?
Allows single rescuer to use both hands to maintain a mask to face seal while proving positive pressure ventilation
Manually triggered ventilation devices should not be used?
On patients with COPD or suspected cervical spine or chest injuries
Compliance?
Ability of alveoli to expand when air is drawn in during inhalation
Common complication associate with manually triggered ventilation devices and the ATV?
Barotrauma
EMT needs to asses for ___ when using ATV
full chest recoil
ATV?
Automatic transport ventilator
CPAP?
Increases pressure in the lungs opens collapsed alveoli, pushes more O2 across the alveolar membrane and forces interstitial fluid back into the pulmonary circulation
Caution should be used when considering CPAP in patients with?
Potentially low blood pressure
Guidelines for CPAP candidates?
1) patient alert 2) moderate to severe respiratory distress from pulmonary edema or COPD 3) breathing rapidly (>26 breaths/min) 4) Pulse oximetry is <90%
Contraindications for CPAP use?
1) respiratory arrest 2) pneumothorax or chest trauma 3) Patient who has a tracheostomy 4) active gastrointestinal bleeding or vomiting 5) Unable to follow verbal commands
PEEP?
Positive end-expiratory pressure; the resistance a patient exhales against
Typical CPAP unity will deplete a full D cylinder of O2 in?
15-30 mins
If gastric distention makes it impossible to ventilate the patient and an ALS provider is not available to perform orogastric tube or nasogastric tube decompression, you should?
Apply pressure over upper abdomen
Tracheostomy
opening at the center front and base of neck
What opening is the only one that can be used to put air into the patient's lungs?
Midline opening
Are head tilt-chin lift or jaw thrust maneuver required for ventilating a patient with a stoma?
No
If you are unable to ventilate a patient with a stoma?
Try suctioning the stoma and the mouth with a french or soft tip catheter before giving the patient artificial ventilation through the mouth and nose
Good air exchange?
Patient can cough forcefully, might hear wheezing between coughs
Wheezing is usually?
an indicator of lower airway obstruction
Stridor is an indication of?
Upper airway obstruction
Perform the ___ to clean an obstruction that has been caused by tongue and throat muscles?
Head tilt-chin maneuver
If spinal trauma is suspected?
Open the airway using the jaw-thrust maneuver
Most effective method of dislodging and forcing an object out of the airway of a conscious adult/child
Abdominal thrusts
For the unresponsive patient with a severe foreign body airway obstruction?
Reassess to confirm apnea and inability to ventilate 2) Begin chest compressions (30 compressions to 2 breaths ratio) 3) After 30, perform tongue-jaw lift by grasping the jaw with thumb and index finger.
Patent?
Open, clear of obstruction