Oxygen Delivery Systems
q Nasal Cannula and Nasal Catheters
Delivers 24 to 44% oxygen at 1 to 6 L/min
1 = 24
2 = 28
3 = 32
4 = 36
5 = 40
6 = 44
· Nasal Catheters
measured from nose to ear, lubricated and inserted to just above the uvula
**deep insertion can cause air swallowing and gastric distension **must be repositioned every 8 hours to prevent breakdown
· Transtracheal Catheters
Delivers low flow rates (1 to 3 L/min) directly to the trachea through a small incision
Requires less oxygen (lower flows) because the upper airway deadspace is bypassed
may be humidified but often not if run @ less than 5 L/min
there are two types of O2-conserving cannulas
reservoir just below the nose stores ~ 20 mL of O2
allows for lower flows because of increase O2 delivery
pendent stores O2
must exhale through nose
**HFNC - 6-15lpm
· Simple masks
Delivers 35 to 55 % O2 at flows of 5 to 12 L/min
**Must never be used at flows less than 5 L/min to prevent rebreathing of CO2
· Partial Rebreathing Masks
Delivers 35 to 60 % O2 at flow rates of 8 to 15 L/min
**Flow rate must be sufficient to keep bag 1/3 to 1/2 inflated at all times
· Non-rebreathing Mask
Delivers 60 to 90% O2 at flow rates of 8 to 15 L/min (NBRC says 100%)
**Flow rate must be sufficient to keep bag 1/3 to 1/2 inflated at all times
Is equipped with a one-way valve that does not allow exhaled gas into the reservoir
One way valves are located on both expiratory ports of the mask to prevent RA entrainment
High Flow Oxygen Systems
· Methods for setting up high flow oxygen
1) air entrainment mask
2) mechanical aerosol systems
3) Gas Injection Nebulizer- need high flow flowmeters
4) High FiO2
5) Blender and titration system
· Venturi Mask or air-entrainment masks
provide FiO2’s from 24 to 50%
· Aerosol Mask
Delivers 21-100% FiO2 depending on nebulizer setting
Flow rates of 8 to 15 L/min
On 100% the device will probably not meet flow demands.(>60%) (No air entrained so flow = flowmeter setting)
· Face Tent
21% to 40% depending on nebulizer setting
Flow rates of 8 to 15 L/min
Used mainly for patients who can not tolerate a mask
21-100% depending on nebulizer setting
Flow rates of 8 to 15 L/min
Used on intubated or trached patients
· Trach Mask
35-60% O2 depending on nebulizer setting
Flow rates of 10 to 15 L/min
**Adequate flow shown by mist flowing out the exhalation port at all times
· Oxygen Tent
21 -50% at flow rates of 10 to 15 L/min
Used mainly on children with croup or pneumonia
· Important Points
· Head box-
small, clear plastic enclosures over infant’s head or head and upper torso
Head boxes allow for a higher oxygen concentration and more accessibility to patient without disturbing oxygen delivery.
. Best not to entrain room air into head box because of noise and microorganism introduction (Blender)
· air: oxygen entrainment ratios:
BiPAP stands for Bilevel Positive Airway Pressure.
Bilevel means that the pressure varies during each breath cycle.
Inspiration can be triggered by flow or time and is cycled by time or flow.
· IPAP = inspiratory positive airway pressure 8 to 20 cm H2O
· EPAP = expiratory positive airway pressure 2 to 10 cm H2O
The BiPAP aids oxygenation and ventilation in cases of sleep apnea or ventilatory muscle fatigue.
It has also been applied to prevent the more invasive procedures of intubation or tracheostomy.
Low-Flow Humidifiers (unheated)
· Pass-Over Humidifiers
Gas passes over the surface of H20, picking up moisture
· High Flow Humidifiers (heated)
directs gas over a reservoir of heated water.
A more efficient design of the low flow diffusion (bubbler) humidifier.
Besides being heated, the area for gas water interface is increased by use of large diffusion tower. Temp, surface, contact time effect amt
-Bubble through wick
utilize a paper/cloth wick through which the mainstream flow must pass.
-Heat moisture exchangers (HME, artificial nose).
Exhaled heat and moisture are collected and made available to warm and humidity the following inspiration. Change Daily**
Types of Nebulizers
· Jet (Mechanical)
Uses a high pressure gas stream (
--50% of output is in the 0.5-3 micron range
· Babington Nebulizer
Uses the principle of a jet stream of gas being directed through a thin film of continually flowing liquid spread across a rounded surface
To transport patients who require ventilation
Ideal stroke volumes: Adult—800mL avg. Infant—200mL
· Safety devices
-Universal adapter 22-mm OD and a 15-mm ID
-Pressure relief device (25cmH20)
· Self inflating bags
Can be used without gas flow
Usually reusable but disposable are available
Require reservoir to deliver 100% oxygen
· Flow-inflating bags
Depends on a gas source
Must have a tight seal to inflate
Uses a flow-control valve to regulate pressure inflation
· Four standard criteria for initiating mechanical ventilation
acute ventilatory failure
impending ventilatory failure
hypoxemic respiratory failure
Both volume-cycled and pressure-cycled volume delivery modes.
Many older transport ventilators may operate on a time-cycled mode.
A peak inspiratory pressure (PIP) is applied and the pressure difference between the ventilator and the lungs results in inflation until the peak pressure is attained, and passive exhalation follows.
-Pressures are constant - volumes vary
-Inhalation proceeds until a set tidal volume (TV) is delivered and is followed by passive exhalation.
-Since the volume-cycled mode ensures a constant minute ventilation, it is a common choice as an initial ventilatory mode.
-A feature of this mode is that gas is delivered with a constant inspiratory flow pattern, resulting in peak pressures applied to the airways higher than that required for lung distension (plateau pressure).
-Volume delivered is constant - pressures vary
Ti + Te = TCT
TCT = 60/BR
Vt = flow rate x Ti / 60 sec.
flow rate = Vt / Ti
Ti = Vt x 60 sec / flow
· High Frequency Ventilation
Use of supraphysiologic ventilatory rates above 60 rpm
Use of tidal volume smaller than the anatomic dead space
-Types of HFV
High frequency positive pressure ventilation (HFPPV) - refers to the delivery of small tidal volumes through an insufflation catheter or endotracheal tube with circuitry having a minimal compressible volume.
The characteristic rate is 60 - 100 cycles per minute with inspiration taking 20% to 30% of the total cycle time.
VT used are between 3 and 5 ml/kg
High Frequency Jet Ventilation
During High Frequency Jet Ventilation (HFJV), gas is propelled into the lungs at a very high velocity through a jet catheter
Rates of 100-600
Can be used in conjunction with CMV
High Frequency Oscillatory Ventilation
Oscillating device forces small impulses of gas into and out of the airway
Exhalation is said to be active in high-frequency oscillation
Can deliver 1 to 60 Hz.
I Hz equals 60 cycles
5 Hz = ~300 bpm
VT less than VD
· Manipulate Blood Gases with High Frequency:
> to decrease PaCO2:
- decrease frequency with same Ti
- increase Ti with same frequency
>To decrease PaCO2
- dec. frequency with same PIP and Ti
- inc. driving pressure with same frequency and Ti
- increase delta P = increase ventilation
- increase MAP = increased oxygenation
· Oropharyngeal Airway (bite block)
Used on unconscious patients to prevent the tongue from obstruction the airway
Two main types
-Berman is hard plastic with an “I-beam” design
-Guedel is hollow type that has opening in the middle
· Nasopharyngeal Airway (trumpets)
maintains a patent airway by pushing the tongue forward off the posterior portion of the oropharynx
better tolerated by semi-conscious or conscious patients
used to allow nasotracheal suctioning with decreased trauma
· ET Tubes
Indications for ET tubes:
Patent airway (Upper airway obstruction)
Protect the airway
To assist in manual or mechanical ventilation
· Tube size
adult male 8 mm to 9 mm tube
adult female 7 mm to 8 mm tube
Endotracheal tubes (ETT) are sized by either the internal diameter (2.5 to 10 mm) or the external diameter with sizes 32-42 French (Fr).
The must be held with the left hand. (Good for us lefties)
Most adults require a (curved) Macintosh # 3 or 4 blade or a straight Miller #3
· Tracheostomy Tubes
Preferred for long-term
When upper airway obstruction prevents intubation
ET tube is removed only as trach tube is ready to be inserted.
Easier to stabilize, suction and tolerate
Inner Cannulas - Fewer hazards and minimal airway resistance
Obturator - is used for insertion into stoma
Cuff - (if present) is inflated
A Tracheal Button - is a rigid cannula placed stoma after removal of a trach tube. *For Stoma only Pt.
It is generally kept closed during the day to be unobtrusive, and opened at night to eliminate sleep apnea.
· Suctioning removes air as well as secretions from the lungs.
· Hypoxemia can be minimized by hyperoxygenating the patient 1 to 2 minutes
· Usually done with 100% if possible (NRB)
· Patient should be hyperoxygenated between suction attempts
· Suctioning should take less than 15 seconds per pass
Other types of catheters
Yankauer used to suction oropharynx
Coude (directional tip) used to guide catheter into the left mainstem
· Vacuum Systems
Central (wall) vacuum systems connect to a vacuum regulator via a quick connect or DISS connector
**Infants 60-80 **Peds 80-100 **Adults 100-140
Most Chrome molybdenum *2200 psig
· “H” cylinder holds 244 cu ft (6900 L)
· “E” cylinder holds 22 cu ft (622 L)
· (There are 28.3 L in 1 cu ft.)
· Cylinder color codes
oxygen- green or white(international)
nitrogen- black cyclopropane- orange
helium- brown heliox- brown and green
air-yellow, black and white, black and green
carbon dioxide- gray
carbogen- gray and green
nitrous oxide- light blue
· Valves on cylinders allow connection to only one type of gas regulator:
-American Standard Safety System (ASSS) for high pressure connections on large cylinders
Pin Index Safety System (PISS) for high pressure connection on small cylinder
Diameter Index Safety System (DISS) for low pressure (<200psi)
· Cylinder duration:
E cylinder: # of minutes remaining = psig x 0.28
H cylinder: # of minutes remaining= psig x 3.14
· Safety Relief Device
--A frangible disk which breaks to release gas pressure
--A fusible plug that melts to release gas pressure in the event of fire
Before attaching regulator, open cylinder valve slowly for discharge of gas then close. **Place washer on “E”
-Reduce the gas pressure to a workable level (50psi)
--two gauges: cylinder pressure and pressure of the gas
Single stage pressure regulators reduce to 50 PSI in one step and has one pop off
Double stage pressure regulators reduce to a working level in two steps. 150 and then to 50 with two safety relief devices
--Regulators may be preset or adjustable
>Preset is preset at 50 psig
>Adjustable can vary pressure output
>Uncompensated flowmeters will inaccurately indicate flow in the presence of backpressure.
--They do not work when positioned on their side
>Compensated flowmeters accurate in the presence of back pressure.
--Still position dependent
>Bourdon Gauge Flowmeter
--is accurate when laid on it’s side
n Provide medical air through portable or large medical piping systems
n Piston is used for large piping systems.
n Diaphragm is used for portable compressors
n Rotary is used for nebulizers and IPPB
Flow can be adjusted from 1 to 10 L/min but FiO2 is fixed at 40% at high flows
A thermos-like tank (about 40" tall) filled with liquid oxygen.
n A smaller lightweight portable unit can be filled off the reservoir so the patient can take the oxygen with them when they leave home. (HELIOS)
n Liquid oxygen is especially good for active people who need to be out of the home on a frequent basis.
n 50 psi gas source for each oxygen and air
n The blender has pressure regulating valves and mixing controls that allow FiO2s of 21-100% at flows of 2 to 100 L/min
**Audible alarm sounds if inlet pressure decreases (Reed valve)
augmenting lung expansion, **Treat Atelectasis**
delivering aerosol medication
n Properly position patient (High-Fowler’s position)
q Is best strategy for the prevention of atelectasis
q Also used to treat atelectasis
q Should be done hourly for about 10 breaths.
q Intolerated then use alternate (PEP or IPPB)
Percussion is also referred to as cupping, or clapping.
Applies kinetic energy to the chest wall and lung to dislodge secretions
Should be performed over each area for 3 to 5 minutes
Vibration involves the application of a fine tremorous action (manually performed by pressing in the direction that the ribs and soft tissue of the chest move during expiration) over the draining area
q High Frequency Chest Wall Oscillator
nonstretchable vest is worn.
Children as young as 3 years are able to use the vest. A treatment lasts 20-30mins (depending on the size of the chest).
The vest is done sitting upright.
q PEP Therapy
>This pressure allows air to enter behind areas of mucus obstruction and keeps the airways open during exhalation.
>Used for 15-20 minute intervals, 3-4 times a day.
>The patient should be instructed to inspire a larger than normal tidal volume and actively exhale but not forcefully.
>Exhalation is 2-3 times longer than inspiration
>Expiratory pressures range from 10-20 cmH20 at mid-exhalation
>PEP resistance levels are adjustable. 10 to 20 cmH20
q Flutter Valve
Exhaling produces oscillations of pressure and airflow which vibrate the airway walls (loosening mucus)
Positive expiratory pressure averages 10-25 cmH20
Treatment time is about 20 minutes.
Two common heliox mixture are
q 80% He and 20% O2
q 70% he and 30% O2
q The correction factor for the 80:20 mixture is 1.8
q The correction factor for the 70:30 mixture is 1.6
q non-rebreather or ventilated
Uses rotating vane
Measures patient's tidal volume and minute volume. Can also record FVC
Multiple sampling of arterial blood, particularly in the mechanically ventilated patient
v Pulse pressure
>Normally 80-100 mmHg
v Damped pressure tracing
>Occlusion of catheter tip by clot
>Catheter tip resting on wall of vessel
v Clot in transducer or stopcock
>Air bubbles in line
>Abnormally high or low pressure readings
>Improper transducer position (level of heart)
v No pressure reading
>Transducer not open to catheter
The Swan-Ganz catheter is an important aid in monitoring and treating the critically ill patient.
v NBRC term - Flow directed pulmonary artery catheter
v Mixed Venous
It is valuable in assessing cardiac, pulmonary, and fluid status in patients experiencing shock, CHF, pulmonary hypertension, pulmonary edema, and the use of high PEEP levels.
v The Pleur-evac is a three-chambered system
v Approximately 1 to 2 cm of water is put in the water seal chamber (middle)
v Water rises toward the patient side of the chamber during inspiration and returns to the other side on expiration
Can determine the pulse and presence of perfusion as well as SaO2.
v Factors affecting the accuracy of oximeters include:
Intensity of ambient light
Patient and probe motion
The transmitted light intensity
Low perfusion or pulse intensity
Transcutaneous Electrodes measure gas tension through the skin.
Self-contained device that uses a propellant (CFC) to deliver a dose of medication
“Spacers” are available for improved deposition
v Dry Powder Inhalers (DPI)
>disperses dry powdered aerosol
>Requires faster inhalation than MDI
A procedure that involves direct visualization of the patient’s trachea and bronchi.
v Types of bronchoscopes: Rigid and Flexible fiberoptic
- Rigid used on foreign body aspiration
Heat is frequently used to eliminate microorganisms.
v Boiling (100°C) kills within 10 minutes.
v Steam under pressure (Autoclaving) (121°C for 15 min at 15 psi)
v Pasteurization - hot water bath at 63-70ºC for 30 minutes
v Ethylene oxide is the gas most frequently used for sterilization.
v Gluderaldehyde submersion for 10hrs at room temp. At 60 degrees Celsius only needed for 1 hour.