Airway Management - Oxygen & Ventilation Flashcards
Always give oxygen to patients who are ___
Hypoxic
When ventilating any patient in cardiac or respiratory arrest, use ___
High-concentration supplemental oxygen
Oxygen is usually stored as ___
Compressed gas in green, seamless, steel or aluminum cylinders
Aluminum cylinders are tested every ___
5 years
Composite cylinders are tested every ___
3 years
Two common sizes of oxygen cylinders
D (or jumbo D): Can be carried
M: Remains onboard your unit as the main supply tank
Less common sizes of oxygen cylinders
A, E, G, H, & K
New naming convention for oxygen cylinders
M (for medical) followed by a number
Liquid oxygen cylinders need to be stored ___
Upright
Volume of D cylinder
350 L
Volume of Jumbo D cylinder
500 L
Volume of E cylinder
625 L
Volume of M (MM) cylinder
3000 L
Volume of G cylinder
5300 L
Volume of H, A (M4), K cylinder
6900 L
Computing oxygen cylinder flow duration
((Gauge pressure - Safe residual pressure) x Cylinder constant) / Flow rate in L/min = Duration of flow in minutes
Do not handle an oxygen cylinder by ___
The neck alone
When oxygen cylinders are on the ambulance, store them ___
In brackets
A system established for portable cylinders to ensure that a regulator is not connected to a cylinder containing the wrong type of gas
Pin-indexing system
The outlet valves on portable oxygen cylinders are designed to accept ___
Yoke-type pressure-reducing gauges, which conform to the pin-indexing 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
American Standard Safety System
How does the American Standard Safety System prevent attaching the wrong regulator valve to the wrong cylinder?
The thread pitches are different in different cylinders
Pressure of oxygen in a full cylinder
About 2000 psi
Pressure regulators typically reduce the pressure to ___
40 to 70 psi
After the pressure is reduced, the final attachment for delivering the oxygen to the patient is usually ___
- A quick-connect female fitting that will accept a quick-connect male plug from a pressure hose or ventilator/resuscitator
- A flowmeter that will permit the regulated release of gas measured in L/min
Flowmeters are usually permanently attached to ___
Pressure regulators on emergency medical equipment
Two types of flowmeters
- Pressure-compensated flowmeters
- Bourdon-gauge flowmeters
Incorporates a float ball within a tapered calibrated tube. The flow of gas is controlled by a needle valve located downstream of the float ball
Pressure-compensated flowmeter
A pressure-compensated flowmeter must be kept ___
Upright
A pressure gauge that is calibrated to record flow rate
Bourdon-gauge flowmeter
Newer flowmeters incorporate a ___
Fixable setting with either a dial or a knob that sets the flow, making the bourdon gauge not necessary
If the cylinder was commercially filled, it will have a ___
Plastic seal around the valve stem covering the opening in the stem
Purpose of cracking the cylinder open briefly before use
Make sure that dirt particles and other possible contaminants do not enter the oxygen flow
On one side of the valve stem, you will find ___
Three holes, the larger one on top is the true opening
What is found at the oxygen outlet on the valve stem?
A metal-bound elastomeric sealing washer
Most EMS systems consider a cylinder with a pressure less than ___ to be too low to keep in service
500 to 1000 psi
The flowmeter will have a second gauge or selector dial that indicates the ___
Oxygen flow rate
Damage to cellular tissue due to excessive oxygen levels in the blood
Oxygen toxicity
Increased cellular oxygen levels contribute to the production of ___
Oxygen free radicals
Free radicals may lead to ___
Tissue damage and cellular death in some patients
Some patients that may react negatively to excessive supplemental oxygen include ___
COPD, cerebral vascular incidents, and myocardial infarction
Oxygen may be administered to patients experiencing signs of a myocardial infarction when they ___
Have signs of heart failure, are short of breath, or have a room air oxygen saturation less than 94%
Patients experiencing signs of shock should be placed on ___
Oxygen
Hypoxemia is immediately life-threatening, whereas oxygen toxicity ___
Is not
When in doubt, or if unable to measure oxygen saturation, supplemental oxygen should be ___
Administered
Exceptions to the minimum oxygen saturation of 94%
Patients who have been exposed to CO, patients with potential anemia, or patients with shock
Oxygen delivery equipment used in the field should be limited to ___
Nonrebreathing masks, bag-mask devices, and nasal cannulas
Nasal cannula flow rate
1 - 6 L/min
Nonrebreathing mask with reservoir flow rate
10 - 15 L/min
Bag-mask device with reservoir flow rate
15 L/min
Nasal cannula oxygen delivered
24% to 44%
Nonrebreathing mask with reservoir oxygen delivered
Up to 90%
Bag-mask device with reservoir oxygen delivered
Nearly 100%
Used to administer high concentrations of oxygen to significantly hypoxemic patients who are otherwise breathing adequately
Nonrebreathing mask
When using a nonrebreathing mask, you must ___
Make sure the reservoir bag is full before the mask is placed on the patient
How to adjust the nonrebreathing mask
Adjust the flow rate so that the bag does not fully collapse when the patient inhales, to about 2/3 of the bag volume, or 10 - 15 L/min
Delivers oxygen through two small, tubelike prongs that fit into the patient’s nostrils
Nasal cannula
Typically, the nasal cannula is used in patients with ___
Mild hypoxemia
With the nasal cannula, if you anticipate long transport time, consider the use of ___ to prevent ___
- Humidification
- Causing dryness or irritating the mucous membrane lining the nose
Humidification may be associated with an increased generation of ___
Aerosolized droplets of fluid that may increase the degree to which the patient can transmit disease to other people in the same space
The partial rebreathing mask is similar to a nonrebreathing mask except that ___
There is no one-way valve between the mask and the reservoir
Ideal mask for patients who are experiencing hyperventilation syndrome
Partial rebreathing mask
The partial rebreathing mask is useful if you want to increase the patient’s ___
PaCO2
With a partial rebreathing mask, the patient will rebreathe a ___
Small amount of their exhaled air
Has a number of attachments that enable you to vary the percentage of oxygen being delivered to the patient while a constant flow is maintained from the regulator
Venturi mask
Venturi mask oxygen delivery
24% to 40%
The main advantage of the Venturi mask
The use of its fine adjustment capabilities in the long-term management of physiologically stable patients
When you need to adjust oxygen concentration in an emergency, it is typically done by ___
Adjusting the flow rate or changing the delivery device
If you do not have a tracheostomy mask, you can improvise by ___
Placing a face mask over the stoma
An oxygen humidifier consists of ___
A small single-patient-use bottle of sterile water through which the oxygen leaving the cylinder becomes moisturized before it reaches the patient
A patient who is not breathing needs ___
Artificial ventilation and 100% supplemental oxygen
Fast, shallow breathing moves air primarily in the ___ and does not allow for ___
- Larger airway passages (dead air space)
- Adequate exchange of air and CO2 in the alveoli
Patients with inadequate breathing require ___
Assisted ventilations with some form of positive-pressure ventilation
Two treatment options for a patient in severe respiratory distress or respiratory failure and not breathing adequately
- Assisted ventilation
- CPAP
CPAP
Continuous positive airway pressure
Signs of altered mental status and shallow breathing are indications for ___
Assisted ventilation
Excessive accessory muscle use and fatigue from labored breathing are signs of potential ___
Respiratory failure
Steps to assist a spontaneously breathing patient’s ventilations with a bag-mask device
- Explain the procedure to the patient
- Place the mask over the patient’s nose and mouth
- Squeeze the bag each time the patient breaths, maintaining the same rate as the patient
- After the initial 5 to 10 breaths, slowly adjust the rate and deliver an appropriate tidal volume
- Adjust the rate and tidal volume to maintain an adequate minute volume
Once you determine a patient is not breathing, begin ___ immediately
Artificial ventilation
Methods to provide artificial ventilations
- Mouth-to-mask technique (only in non-work situations when a bag-mask is not available)
- One- or two-person bag-mask device technique
When providing positive-pressure ventilations, this affects ___
Drawing venous blood back to the heart
When positive-pressure ventilation is initiated, more air is needed to ___
Achieve the same oxygenation and ventilatory effects of normal breathing
During positive-pressure ventilation, the increase in airway wall pressure causes the walls of the chest cavity to ___, resulting in ___
- Push out of their normal anatomic shape
- An increase in the overall intrathoracic pressure
The intrathoracic pressure increase affects the ___
Return of venous blood to the heart
Reduced venous return results in ___
Reduced cardiac output
It is imperative that you ___ of artificial ventilations to help prevent the drop in cardiac output
Regulate the rate and volume
The amount of blood ejected by the left ventricle in one minute
Cardiac output
Ventilation rate for apneic adult with a pulse
1 breath every 6 seconds
Ventilation rate for apneic infant or child with a pulse
1 breath every 2 to 3 seconds
Barrier devices don’t provide protection from ___
Diseases transmitted by airborne pathogens or aerosolized droplets such as SARS-CoV2 or TB
Mouth-to-mouth ventilations with or without a barrier device should be provided only in ___
Extreme situations
What is safer than a barrier device for mouth-to-mouth ventilations?
Pocket mask containing a one-way valve with an adequate filter
Mouth-to-mouth ventilations should only be used when ___
The EMT is off-duty, and no bag-mask device is available
Air movement with normal ventilation
Air is sucked into the lungs due to the negative intrathoracic pressure created when the diaphragm contracts
Air movement with positive-pressure ventilation
Air is forced into the lungs through a means of mechanical ventilation
Blood movement with normal ventilation
Normal breathing allows blood to naturally be pulled back to the heart
Blood movement with positive-pressure ventilation
Intrathoracic pressure is increased as air is driven into the lungs, which can reduce blood return to the heart and therefore reduce the amount of blood pumped by the heart
Airway wall pressure with positive-pressure ventilation
More volume is required to have the same effects as normal breathing. As a result, the walls are pushed out of their normal anatomic shape
Esophageal opening pressure with positive-pressure ventilation
Air may be forced into the stomach, especially with aggressive ventilation, causing gastric distention that could result in vomiting and aspiration
Overventilation with positive-pressure ventilation
Too much volume and/or a fast ventilation rate results in increased intrathoracic pressure, gastric distention, and decrease in cardiac output, resulting in hypotension
The bag-mask device provides less ___ than mouth-to-mask ventilation; however, is delivers a higher ___
- Tidal volume
- Oxygen concentration
If you have difficulty ventilation a patient with a bag-mask device, you should ___
Immediately switch to an alternative method, such as the mouth-to-mask technique
Components of an adult bag-mask device
- Disposable self-inflating bag
- No pop-off valve
- Outlet valve that is a true valve for nonrebreathing
- Inline viral filter
- Oxygen reservoir
- One-way, no-jam inlet valve system that provides a maximum of 15 L/min with standard 15/22-mm fittings for face mask and endotracheal tube connection
- Transparent face mask
- Ability to perform under extreme environmental conditions
Total volume of an adult bag-mask
1200 to 1600 mL
Total volume of a pediatric bag-mask
500 to 700 mL
Total volume of an infant bag-mask
150 to 240 mL
The volume of air delivered to the patient is based on one key observation
Chest rise and fall
How much to squeeze the bag in the bag-mask device?
Enough to cause a noticeable rise of the chest, about 600 mL (about 6 to 7 mL/kg) over one second
By delivering just enough tidal volume to see the chest rise, and not ventilating at a rate that is too fast, ___
The risks of gastric distention and cardiac compromise are reduced
With a bag-mask, for a patient with ongoing CPR and an advanced airway in place, use a ventilation rate of ___
1 breath every 6 seconds (10 breaths/min), without pausing chest compressions
When using the bag-mask device during a pandemic or if the patient is highly contagious, ___
A HEPA filter should be placed between the mask and the bag
Inflation of the stomach with air
Gastric distention
Gastric distention most commonly affects ___
Children
Gastric distention is most likely to occur when ___
- Ventilate too forcefully or rapidly with a bag-mask device or pocket mask
- Air way is obstructed as a result of a foreign body or improper head position
Gastric distention can reduce lung volume by ___
Elevating the diaphragm, especially in children and infants
If gastric distention makes it impossible to ventilate the patient and an ALS provider is not available to perform ___, consider ___
- Orogastric tube or nasogastric tube decompression
- Positioning the patient onto their side and applying manual pressure over the upper abdomen (anticipate vomiting and have suction ready)
Manual decompression should be used only as ___
A last resort and is reserved for extreme circumstances
The act of air moving into and out of the lungs during chest compressions
Passive ventilation
Passive ventilation is also called ___
Passive oxygenation or apneic oxygenation
Prior to and during placement of an endotracheal tube (by and ALS provider), consider ___
Applying a nasal cannula and setting the flow rate at 15 L/min to initiate the process of preoxygenation and denitrogenation
Attempts to replace alveolar nitrogen with oxygen
Denitrogenation
Goal of denitrogenation
Increase oxygen reserve in the lungs, minimizing risk of oxygen desaturation during periods of forced apnea during an intubation attempt
Indications that artificial ventilation is adequate
- Visible and equal chest rise and fall
- Ventilations delivered at the appropriate rate
- Heart rate returns to normal range
- Patient’s color improves (pink)
- Oxygen saturation increases
Indications that artificial ventilation is inadequate
- Minimal or no chest rise and fall
- Ventilations are delivered too fast or slow for patient’s age
- Heart rate does not return to normal range
- Patient’s color remains cyanotic, mottled, or deteriorates
- Oxygen saturation does not increase or decreases
When you are performing chest compressions, passive ventilation can be enhanced by ___
Inserting and oropharyngeal airway and providing supplemental oxygen to the patient
You can improve oxygenation during passive ventilation by ___
Applying supplemental oxygen with a nasal cannula or a nonrebreathing mask
A ventilation device attached to a control box that allows the variables of ventilation to be set
Automatic transport ventilator
ATV
Automatic transport ventilator
An EMT must be ___ to use an ATV
Approved and credentialed by the medical director
Most models of ATV have adjustments for ___
Tidal volume and rate
ATV respiratory rate is set to ___
Midpoint or average for the patient’s age
ATV tidal volume is calculated by ___
6 to 7 mL/kg of ideal body weight
The tidal volume of the ATV can be adjusted based on ___
The patient’s chest rise and physiologic response
The ATV is ___ powered
Oxygen
The ability of the alveoli to expand when air is drawn in during inhalation
Compliance
When ventilating a patient, you would recognize poor lung compliance by ___
Noting an increase in resistance when you attempt to ventilate
___trauma can occur in patients being ventilated
Baro
