Oxygen Devices
I.
Low Flow Oxygen Devices- Any device that does not meet a patient’s
inspiratory demand and varies depending on respiratory rate and VT.
A. Nasal Cannula:
Used for all ages, from neonates to the elderly. Easily applied and managed. Delivers
up to 44-45% of oxygen. Used for shortness of breath, long term oxygen needs, when
a patient is eating or drinking, for COPD patients that require low oxygen
concentrations, also used for home care patients and a wide variety of diseases
requiring oxygen administration at low flows. The nasal cannula is the most widely
used oxygen device and is the cheapest. Nasal cannulas are patient dependent and the
oxygen concentration will vary depending on the patients respirations and tidal
volumes. Oxygen is typically stored in the nasopharynx until the patient inhales.
Approximate O2 Concentrations:
0.5 LPM = 22%
1 LPM = 24%
2 LPM = 28%
3 LPM = 32%
4 LPM = 36%
starting at 4 LPM a bubble humidifier is required to prevent
5 LPM = 40%
irritating the nasal mucosa which can cause nose bleeds or
6 LPM = 44%
drying of mucus.
When applying a nasal cannula to an infant, the cannula is secured to the face by tape.
The total flow applied is typically 1-2 LPM with an attached oxygen blender and
humidifier.
B. Nasal Catheter:
Less commonly used. Long term nasal cannula that bypasses the upper airway. Used
during bronchoscopys and for long term use in children. Soft and smooth open distal
end facilitates non-traumatic insertion, Proximal end is fitted with color coded funnel
shape connector for easy connection to oxygen source. Uses less flow than a nasal
cannula but delivers the same oxygen concentration. Requires a humidifier at any
flow. Hard to insert and may cause gagging and aspiration if inserted to deeply.
Changed every 8 hours!
C. Transtracheal Catheter:
Also less commonly used. Surgically inserted into the trachea by MD. Uses less flow
than a nasal cannula or a nasal catheter. Good for long term oxygen use on patients
that do not tolerate nasal cannulas and need increased mobility. Needs a humidifier at
any flow. Needs to be changed and clean periodically to prevent mucus plugs.
D. Reservoir Cannula:
Uses a reservoir to trap and build up oxygen that the patient inspires. Uses up to 4
LPM of oxygen, and is worn in the same manor as a nasal cannula. There are two
types: pendant and nasal pillow. The pendant cannula hangs down to chest and forms
a pendant reservoir for oxygen. The nasal pillow is a mustache reservoir the sits on
the upper lip. Both types are unattractive for the patient but saves money by using less
flows 0.25 LPM to 4 LPM. Seen mostly during home care.
E. Simple Mask or Oxygen Mask:
Used for patients in need of oxygen in the range of 35% to 50%. The minimum flow
set on the flow meter is 5 to 6 LPM in order to prevent CO2 accumulation in the
mask. The highest flow is 12 LPM. To calculate O2 Concentration take the LPM
times it by 2 and add 20.
5 LPM equals 5 x 2 + 20 = 30%
6 LPM equals 6 x 2 + 20 = 32%
Again this is a estimation since it is a low flow device. This mask is used on children
through adults but not neonates. The mask can be uncomfortable and needs to be
removed to eat. Used for short term or emergency use requiring moderate O2 use
such as CHF, Pulmonary Emboli, Pulmonary Fibrosis, Labor, Surgery, Heart attack,
and a multitude of other diseases. Not for CO2 retainers.
F. Partial rebreathing Mask:
Has a reservoir bag that fills with oxygen but also exhaled CO2. Delivers up to 60%
O2 with flows of 10-15 LPM. The bag should not deflate on inspiration, if it does
INCREASE THE FLOW. Used for the delivery of moderately high FIO2’s and is
given for the same reasons a simple mask is given. Usually seen in emergency rooms.
Not for CO2 retainers. This is a low flow oxygen device, the patient should be
breathing adequately and simply need an increased FIO2.
G.Non-rebreathing Mask:
Looks similar to the partial rebreathing mask except this one has 3 one way valves
that prevents the patient from exhaling CO2 into the reservoir bag. Instead the bag is
filled with 100% O2 that the patient inhales. This device is set at flows of 10-15 LPM
and is similar to the partial rebreathing mask in that the bag should not deflate on
inspiration. This device can deliver 55% to 95% oxygen depending on how many one
way valves are present. This mask is given in all emergencies, for nitrogen washout,
ARDS, heart attack, pulmonary embolism, CHF, pnemothorax, pneumonia, and a
multitude of other diseases in which the patient is spontaneously breathing but
requires high FIO2’s. This is not for CO2 retainers unless it is an emergency
situation.
II.
High Flow Systems- Any device that meets the patients inspiratory demand.
A. Air entraiment mask (Venturi mask or AEM)
An adjustable mask based on Bernoullis principle. Oxygen can be adjusted from 24%
up to 50% with specified flows set on the mask. Lower FIO2’s have more air diluted
into the mask so the orifice or venturi port is wider than higher FIO2’s. This is the
ideal mask for COPD patients since the FIO2 is specific. This mask delivers high
flows that meet a patients inspiratory efforts and is useful in treating patients with
shortness of breath. Patients can be given high flows with low O2 concentrations.
Total flow can be calculated using the correct formula.
B. Large Volume Nebulizer (Air-entrainment nebulizers)
This also uses Bernoullis principle and has an adjustable FIO2. The nebulizer
provides cool mist to patients with stridor or upper airway edema. Also used for
patients with artificial airways in need of humidification. It is also utilized for patients
with thick tenacious secretions. The flow is set between 8 and 15 LPM. The
concentration of O2 is 28% to 100%. The higher the concentration the lower the total
flow due to the closing of the venturi which adds or takes away air dilution. The
nebulizer sometimes requires two flow meters when using higher FIO2 in order to
achieve proper misting.
III Enclosures
A. Oxyhood
Used for neonates and infants that requires oxygen from 21% up to 100%. Flows
must be set at a minimum of 7 LPM to prevent CO2 build up. A hood covers the
infants head without directly attaching to the patient. The hood is comfortable but
difficult to clean. The FIO2 is measured at the bottom near the patients face with an
O2 analyzer due to layering affects of oxygen. The hood amplifies sound, so
minimize noise around the babies sensitive ears. A humidifier is used instead of a
nebulizer due to the noise factor. Used for Nitrogen washout for pneumothorax or as
a weaning tool off nasal CPAP.
B. Isolette
Used for infants that require temperature control. Can give up to 50% FIO2 with
flows set at 8-15 LPM. For infants who need thermal regulation due to neurological
problems or prematurity. The isolette inhibits patient mobility and accessibility. Nasal
cannulas and other oxygen devices can be applied to the patient while in the isolette.
C. Tent
Oxygen tents are used for small children that do not tolerate nasal cannulas or masks.
The tent is also used for the delivery of cool mist for patients with Croup or upper
airway edema. Flow is set at 12-15 LPM, FIO2 of 40-50% can be achieved. The tent
has a vacuum and filter that cleans and circulates the air. Temperature in the tent
should be monitored. The tent often leaks and should be checked routinely.
IV Others
A. Vapotherm
High flow cannula that delivers 100% relative humidity to the patient. The flows are
set between 8-50 LPM for adults and 6-10 LPM for infants.