Egan's Fundamentals of Respiratory Care: Chapter 38 -- Medical Gas Therapy Flashcards

- Primarily affects lungs and central nervous system
- Determining factors include PO2 and exposure time
- Prolonged exposure to high FIO2 can cause infiltrates in lung parenchyma

Occurs in COPD patients with chronic hypercapnia.

Excessive blood O2 levels cause retinal vasoconstriction and necrosis.

- Can occur with FIO2 and above 0.50
- Patients breathing small tidal volumes at greater risk

- Fires in O2 enriched environments continue to occur
- Practitioners in surgery suites and in presence of hyperbaric O2 therapy need to be most careful

1. Low-flow systems.
2. Reservoir systems.
3. High-flow systems.

- Delivers FIO2 of 0.24 to 0.40
- Used with flow rates of 1/4 to 8 L/min
- FIO2 depends on how much room air patient inhales in addition to O2
- Device is usually well-tolerated

- Used at flows of 1/4 to 8 L/min
- Delivers FIO2 of 0.22 to 0.45
- Rarely used in modern health care facilities today
- Has been replaced by nasal cannula

- Surgically placed in trachea through neck by physician
- Uses 40-60% less O2 to achieve same PaO2 by nasal cannula
- Used with flow rates of 1/4 to 4 L/min
- Requires careful maintenance and cleaning
- Complications such as infection are possible

- Designed to conserve oxygen
- Nasal and pendent reservoir
- Can reduce as much as 50-75%
- Humidification usually not necessary

- Higher 02 input
- Mouth-closed breathing
- Low inspiratory flow
- Low tidal volume
- Slow rate of breathing
- Small minute ventilation
- Long inspiratory time
- High I:E ratio

- Lower O2 input
- Mouth-open breathing
- High inspiratory flow
- High tidal volume
- Fast rate of breathing
- Large minute ventilation
- Short inspiratory time
- Low I:E ratio

- Most commonly used reservoir systems
- Three types:
1. Simple mask.
2. Partial re-breathing mask
3. Non re-breathing mask.

- Supply given O2 concentration at flow equaling or exceeding patient's peak inspiratory flo
- Can ensure fixed FIO2
- Most suitable for patients requiring precise FIO2, with higher or variable minute ventilation
- Include air-entrainment or blending systms (Venturi masks or air-entrainment nebulizers)

- Oxygen hood (oxyhood) is generally the bet method for delivering controlled oxygen to infants
- Incubators (isolette) can be used in conjuction with oxyhood
- Regulating cooling and FIO2 can be difficult in an oxygen tent

Provide high FIO2, high relative humidity, and positive pressure

Dose systems conserve by providing flow during inspiration only

Provide 100% FIO2 often during emergencies

- HBO is administered in either multiplace or monoplace chamber
- Multiplace chamber can hold 12 or more people
- Monoplace chamber can hold only 1 patient

1. Air embolism.
2. Carbon monoxide poisoning.

- Improves blood flow to lung
- Reduces shunting
- Improves oxygenation
- Decreases pulmonary vascular resistance
- Low cost alternative drug therapies, including inhaled epoprostenol sodium, are gaining popularity

- Value of helium as therapeutic gas is based solely on its low density
- Can decrease work of breathing for patients with airway obstruction (i.e. asthma, croup, etc.)

- Helium must always be mixed with O2
- Heliox can be prepared at bedside or used from premixed cylinders
- In general, heliox should be delivered to patients via tight-fitting non re-breathing mask with high flow

- Poor vehicle for aerosol transport
- Reduces effectiveness of coughing
- Badly distorts patient's voice
- Hypoxemia can be problem

Used for:
- Hiccups
- Carbon monoxide poisoning
- Preventing complete washout of CO2 during cardiopulmonary bypass
- Available in mixtures of 5%:95% or 7%:93%