CH 11 Lecture Flashcards
Tidal Volume
Dead space
Air that doesn’t make it into your lungs
Exhalation
Passive. Diaphragm and intercostal muscles relax, and smaller thorax compresses air into the lungs
Hypoxia
Not enough oxygen
Regulation of ventilation - mechanism
PH changes in the blood and cerebrospinal fluid
Hypoxic drive
Breathing based on low oxygen. Typically seen in patients with end-stage COPD
Oxygenation
Process of loading oxygen molecules onto hemoglobin molecules in the bloodstream
Respiration
Actual exchange of oxygen and carbon dioxide in the alveoli and tissues
Internal Respiration
Exchange of oxygen and carbon dioxide between . . .
External respiration
Ventilation/Perfusion ratio and mismatch
Air and blood flow must be directed to same place at same time
Ventilation and perfusion must be matched
Failure to match can cause gas exchange not to take place -> lack of O2 in blood stream, CO2 is recirculated in bloodstream, hypoxia occurs
Intrinsic vs Extrinsic factors
External vs internal factors
Examples: internal: pneumonia, COPD. External: partial pressure of oxygen in atmosphere
pneumothorax
Open pneumothorax
Hemothorax
Hemopneumothrax
Hypovolemic Shock
Vasodilatory shock
AGPs
Aerosol Generating Procedures. Include CPR, Nebulizer treatments (Nebs), Endotracheal intubation, continuous positive airway pressure
Recognizing adequate breathing
12-20 breaths/min
Regular pattern of inhalation and exhalation
Regular, equal chest rise and fall
Adequate depth (tidal volume)
Clear and equal lung sounds
Abnormal breathing signs
Less than 12 breaths/min
more than 20 breaths/min
Irregular rhythm
Diminished, absent, or noisy auscultated breath sounds
Reduced flow of expired air at nose and mouth
Unequal or inadequate chest expansion
Increased effort of breathing
Shallow depth
Skin that is pale, cyanotic, cool, or moist
Skin pulling in around ribs or above clavicles during inspiration–this indicates use of accessory muscles
Cheyne-Stokes breathing
irregular respirations followed by a period of apnea. Often seen in patients with head injuries
Agonal Gasps
Appearance of breathing after heart is stopped
Ataxic respirations
Irregular or unidentifiable pattern
Often associated with head injuries
Kussmaul respirations
Deep, rapid respirations
Common in patients with metabolic acidosis
Measuring maximal CO2 at the end of an exhaled breath: Low CO2 level
Hyperventilation
Decreased CO2 return to the lungs
Reduced CO2 production at the cellular level
Measuring maximal CO2 at the end of an exhaled breath: High CO2 level
Ventilatory inadequacy
Apnea
End Tidal CO2 - normal range
35-45 mmHg
Most common airway obstruction
The patient’s own tongue
Head Tilt - Chin Lift Maneuver
Jaw Thrust Maneuver
Place your fingers behind the angles of the lower jaw. Move the jaw upward. Use your thumbs to help position the lower jaw. Note, unless you have an oral airway in, you have to hold the jaw thrust to maintain the airway (can’t let go)
Opening the mouth - cross finger technique
Place the tips of your index finger and thumb on the patient’s teeth. Push your thumb on the lower teeth. Push the index finger on the upper teeth. The index finger and the thumb cross over each other.
Suctioning unit test pressure
Test the suctioning unit to ensure vacuum pressure of more than 300 mm Hg
Maximum suction time
Never suction the nose and mouoth more than 15 seconds for adults, 10 for childeren, and 5 for infants.
When patients have secretions or vomitus that cannot be suctioned easily
If the patient produces frothy secretions
Suction for 15 seconds (less for infants and children)
Ventilate for 2 minutes
Continue this alternating pattern until all the secretions have been cleared
Indications for an oropharyngeal airway
Unresponsive patients without a gag reflex
Apneic patients being ventilated with a bag-mask device
Contraindications for an oropharyngeal airway
COnscious patient
gag reflex
Nasopharyngeal airway
Semiconscious or unconscious patients with an intact gag reflex
Patients who will not tolerate an oropharyngeal airway
Contraindications for nasopharyngeal airway
Severe head injury with blood in the nose
History of fractured nasal bone
When to use the recovery position
Use to help maintain a clear airway in an unconscious patient who is not injured and is breathing on his or her own
When to give oxygen
Always give oxygen to patients who are hypoxic. Never withhold oxygen from any patient who might benefit from it.
Hazards of supplemental oxygen
Combustion
Oxygen toxicity - SpO2 meter can’t read over 100%. You don’t know if your patient is over 100% if it’s reading 100%
Target oxygen saturation
When pulse oximetry is available, tailor oxygen therapy to maintain 94%
Nonrebreathing masks
Preferred way to give oxygen in the prehospital setting. Must inflate the bag; don’t let the bag run out of oxygen.
Bag Mask Devices
Provides less tidal volume than mouth-to-mask ventilation. An experienced EMT can provide adequate tidal volume. Can deliver nearly 100% . . .
Nasal cannulas
1-6 L/min. Can provide 24% to 44% inspired oxygen. Used in patients with mild hypoxemia. A patient who breaths through the mouth or has a nasal obstruction will NOT benefit. When you anticipate a long transport time, consider using humidification.
Partial rebreathing masks
There is no one-way valve between the mask and the reservoir; patients rebreathe a small amount of exhaled air
Venturi Masks
Delivers 24%-?
Signs of inadequate ventilation
Altered mental status, inadequate minute volume, excessive accessory muscle use and fatigue
When assisting with a bag-mask device
Explain the procedure to the patient; place the mask over the nose and mouth; squeeze the bag each time the patient breathes; After the initial 5 to 10 breaths, deliver an appropriate tidal volume; Maintain an adequate minute volume.
Normal ventilation vs Positive Pressure ventilation
In normal breathing, the diaphragm contracts and negative pressure is generated in the chest cavity. Positive pressure ventilation is generated by a device that forces air into the chest cavity.
Side affects of positive pressure ventilation
Increased intrathorac. . .
Gastric Distention
Occurs when artificial ventilation fills the stomach with air. (Overfilling the stomach, even with air, will cause vomiting.) Most likely to occur when you ventilate the patient too forcefully or too rapidly. May also occur when the airway is obstructed.
Alleviating Gastric Distention
Passive Ventilation
Expansion and contraction create a “pump for air movement. Benefits patients who are receiving chest compressions. Can be enhanced with oral airway and supplemental oxygen
CPAP
Continuous Positive Airway Pressure. Increases pressure in the lungs. Opens collapsed alveoli. Pushes more oxygen across the alveolar membrane. Forces interstitial fluid back into pulmonary circulation. Use caution with patients with potentially low blood pressure
Indications of CPAP
MUST HAVE RESPIRSTORY DRIVE. Alert and able to follow commands. Obvious moderate to severe respiratory distress. Respiratory distress occurs after a submersion incident. Patient is breathing rapidly. Pulse oximetry reading is less than 90%
Contraindications for CPAP
Respiratory arrest. Hypoventilating. Cannot speak. Unresponsive and cannot follow verbal commands. Hypotensive. Sygns and symptoms of pneumothorax or chest trauma
Tracheostomy. Active gastrointestinal bleeding or vomiting. Patient has experienced facial trauma. Cardiogenic shock. Cannot sit upright. Cannot tolerate mask
Application of CPAP
7.0 to 10.0 cm H2O is acceptable
CPAP complication
Claustrophobic. Risk of pneumothorax. Can lower blood pressure.
Giving mouth-to-mouth with a stoma
Seal the stoma while giving mouth-to-mouth. (Use barrier device over patient’s mouth)
Mild airway obstruction
Patients can still exchange air, but will have respiratory distress. With good air exchange, do not interfere with patient’s efforts to expel object. Poor air exchange (cyanosis, stridor, etc), treat immediately.
Dental appliances
Can cause airway obstruction. Leave well fitting dentures in place. Loose dentures interfere with the process and should be removed.
Breathing is controlled by an area in the
brainstem
EMT should asses a patient’s tidal volume by
Observing for adequate chest rise
When an unconscious patient begins to vomit
Turn patient onto side, THEN remove oral airway
