1
Adult
Oxygen Therapy
Self Directed Learning
Package (SDLP)
Document owner: Clinical skills Coordinator & CNS General Medicine & Respiratory
Date created: 10/09/2012
Date of review: 10/09/2013
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Content List
Acknowledgements
Introduction
Learning outcomes
Instructions
Module One: Respiratory Therapy
Module Two: Airway and Breathing
Module Three: Oxygen Delivery Systems
Module Four: High Flow Humidified Oxygen Therapy
Module Five: Monitoring and Titrating Oxygen Therapy
Module Six: Documentation & CDHB Policy
Quiz for modules 1-6
Comments and Feedback
References
Appendix A: Glossary of Terms
Document owner: Clinical skills Coordinator & CNS General Medicine & Respiratory
Date created: 10/09/2012
Date of review: 10/09/2013
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Acknowledgements:
John Hewitt- General Medicine Nurse Specialist. Christchurch Hospital
Christine Beasley – Coordinator Clinical Skills Training Services. Christchurch
Act Health. Early Recognition of Deteriorating Patient (Compass) Australia
Royal Marsden Hospital manual of Clinical Nursing Procedures
British Thoracic Society Emergency Oxygen Guidelines
Australian Resuscitation Council
Review group:
Graeme Webb – Quality Control Coordinator- Child Health. Christchurch
Robyn Cumings – Nurse Coordinator. Christchurch
Sarah Ellery – Clinical Nurse Specialist (Oncology). Christchurch
Wendy Mann – Clinical Tracheotomy Nurse Specialist. Christchurch
Joanna Saunders – Professional Development Nurse Educator. Christchurch
Janette Dallas – Nurse Manager Professional Development Unit. Christchurch
Helen Tregenza – Nurse Educator (Intensive Care Unit) Christchurch
Richard McKinlay - Clinical Manager Physiotherapy. Christchurch
Sarah Fitzgerald – Physiotherapist. Christchurch
Document owner: Clinical skills Coordinator & CNS General Medicine & Respiratory
Date created: 10/09/2012
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Introduction
The administration of supplemental oxygen is an essential element of management
for a wide range of clinical conditions. However oxygen is a drug requiring a
prescription in all but emergency situations. For critically ill patients high
concentration oxygen should be administered immediately and this should then be
recorded after the event in the patient‟s health records (British Thoracic Society,
2008). Failure to administer oxygen correctly and with the right equipment can
result in serious harm to the patient. The safe implementation and patient
monitoring of oxygen is an integral component of the health professional‟s role.
This self learning package covers all aspects of oxygen therapy and is suitable for
Medical Practitioners, Nurses and Midwives, Student Nurses/Midwives (as per
Student Responsibility policy CDHB Volume 12) and Physiotherapists that may be
required to assist with adult patients needing oxygen therapy.
Before commencing this self directed learning package please discuss with your
Educator/Manager which modules would be of most benefit to you in your role,
requirement for updates and any clinical skills sign off required.
Learning Outcomes
To enable health care professionals to be able to:
Identify and discuss the correct use of the different oxygen delivery devices
used through the Canterbury District Health Board
Demonstrate confidence when required to initiate oxygen therapy whilst
awaiting medical support
State and discuss of the importance of titration of oxygen therapy
Locate, discuss and demonstrate the guidelines relating to oxygen prescribing
and correct documentation of oxygen therapy in the CDHB
Instructions
The adult oxygen therapy self directed learning package is designed for the reader
to be able to complete on a modular basis. Modules one - six are compulsory for all
readers. The remaining modules will cover area specific and specialised oxygen
delivery procedures, including the use of high flow nasal oxygen. To determine if
these modules would be appropriate within your clinical care, please discuss with
your Nurse Educator, Clinical Nurse Specialist or equivalent.
Document owner: Clinical skills Coordinator & CNS General Medicine & Respiratory
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Pre-set questions are situated at the end of module six and require completion for
credits/ professional hours to be awarded. You need to attain 100% correct answers
to achieve a pass.
There is a brief overview of the mechanisms of breathing as we recognise that you
will have an understanding of the anatomy and physiology relevant to this self
directed learning package (SDLP). Further reading is recommended, if needed, to
update your knowledge prior to commencement including:
Patient Medication Chart (QM0004)
CDHB Management Guidelines for Common Medical Conditions (Blue Book).
CDHB Early Warning Management Protocol (EWS) (Volume 11)
CDHB Oxygen Therapy Policy: (Volume 12) CDHB Role & Responsibility Policy
Basic Infection Prevention & Control Principles in relation to Fluid &
Medication (Volume 12)
CDHB Patient Identification Policy (Volume 11)
Throughout the SDLP there are markers to bring information to your attention:

Links to further reading, policy and procedure, contacts
Important additional information
Expected time frame to competition
Based on the professional development hours guide modules one – six will take
approximately 1.5 hours to complete.
Educational credits/ professional development hours
Education credits/ 1.5 hours of professional development will be recognised
following the Professional Development hours guide for completion of
modules one – six and submission of question answers.
On completion of the SDLP Education Credits/Professional Development hours
will be accredited to your education record/database by your Nurse Educator,
Clinical Nurse Specialist or equivalent in your work area.
It is your responsibility to ensure your education records are up to date.
Sign off will be completed by your Nurse Educator, Clinical Nurse Specialist or
equivalent within your area of work.
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Module one: Respiratory Therapy
Learning outcomes:
At the completion of this module it is expected that the participant will be
able to:
Discuss the importance of correct oxygen delivery
State the factors that affect adequate oxygen delivery
Introduction:
The administration of supplementary oxygen is an essential element of management
for a wide range of clinical conditions. Oxygen is a drug and for all situations,
excluding emergency events, must be prescribed. Failure to administer oxygen
appropriately can result in serious harm to the patient. The safe implementation and
administration of oxygen therapy with monitoring as per CDHB policy and
procedures, is an integral component of the health professional‟s role. The aim of
supplementary oxygen therapy is to prevent tissue hypoxia and thereby reduce
morbidity and mortality.
Cautions indicated for oxygen therapy
There are no absolute contraindications for oxygen therapy. However supplementary
oxygen should be used with caution in patients (British Thoracic Society [BTC],
2008) who have experienced:
Paraquat poisoning – In New Zealand, Paraquat is widely used in pasture
renovation, clover seed and Lucerne crops for weed removal. The effects of
Paraquat are exacerbated by oxygen and result in congration in the lung
tissue, causing damage to the epithelial cells of the lung by a type of
pulmonary oedema and damage to the lung tissue itself (Robbe & Meggs,
2004).
Acid inhalation – Acid inhalation damages the interstitial tissue and surface
of the lungs and it is thought that high percentages of supplementary oxygen
may release free radicals that exacerbate the process (Nader-Dialal et al.
1998).
Previous cytotoxic agent use - It is hypothesized that Bleomycin has a
synergistic effect which induces pulmonary oxygen toxicity. Oxygen should be
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used with caution for patients who have had recent exposure to Bleomycin.
(Cersosimo, Mathews & Hong, 1985).
Physiology
The respiratory system consists of the lungs for exchange of gases and the ,
respiratory muscles and thorax, which are used as ventilation pumps. Its primary
function is to ensure there are adequate amounts of oxygen delivered to the cells
and to eliminate carbon dioxide, via the blood stream. The failure of this function
results in respiratory failure, as oxygen must be continuously available to all cells of
the body to sustain life.
Oxygen enters the body via the lungs, and is transferred by the blood into the
tissues and then to the cells, here the mitochondrion use the oxygen to produce
energy for metabolism in the form of adenosine triphosphate (ATP).
If normal aerobic respiration is compromised then it will be replaced by anaerobic
respiration. This will see the production of lactic acid. High levels of lactic acid will
result in metabolic acidosis and eventually cell death if not successfully reversed.
There are three components to oxygenation of cells;
Oxygen uptake (process of extracting oxygen fro the environment).
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Oxygen transportation (delivery of oxygen uptake to the cells).
Oxygen utilisation (metabolic need for molecular oxygen by the cells of the
body).
Oxygen uptake
The atmosphere is a composition of several gases. Inspired air at sea level has an
atmospheric pressure of 760mmHg with each gas exerting its own pressure (partial
pressure). Water vapour that mixes with the air on its entry into the upper airway
also exerts partial pressure.
Gas
Oxygen
Carbon Dioxide
Nitrogen
Rare gases
Water vapour
Composition
21%
0.03%
79%
0.003%
Partial Pressure
159mmHg
22.8mmHg
600mmHg
47mmHg
(Adapted from Royal Marsden 2011)
Movement of gases is by diffusion. This involves the movement of gases from a high
partial pressure area to a lower partial pressure area.
Inspired air
Alveolar
Arterial
Capillary
Tissue
Mitochondrial
mmHg (oxygen)
150
103
100
51
20
1-20
Kpa
20
13.7
13.3
6.8
2.7
0.13-1.3
(Royal Marsden 2011)
Diffusion of oxygen commences in the alveoli into the pulmonary capillaries and then
diffuses into the tissues and mitochondria of the cells. Movement of carbon dioxide
occurs from the mitochondria of the cells into the tissue then through the pulmonary
capillaries into the alveoli to be expired.
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The partial pressure of Oxygen in the alveolus is higher than the partial pressure in
the pulmonary capillaries which promotes the transfer of oxygen through the
alveolar membrane into the interstitial spaces and then into the pulmonary
capillaries.
Oxygen transportation
Oxygen is carried in the blood one of two ways dissolved in the plasma or bound to
haemoglobin in red blood cells.
Oxygen dissolved in the plasma makes up only 2-3% of the total oxygen carried as
oxygen is not very soluble. At a partial pressure of 100mmHg there would only be
0.3ml of oxygen per 100ml of plasma, this is measured as PaO2
Oxygen bound to red cells makes up 95-98% of all oxygen carried and is measured
as oxygen saturated (SaO2). Each gram of haemoglobin can carry 0.34ml of oxygen
per 100ml of blood.
Haemoglobin is made up of iron (haem) and protein (globulin) and has four binding
sites which are each able to carry one molecule of oxygen. Saturation occurs when
all four sites have an oxygen molecule attached and so oxygen saturation only gives
an indication of the percentage of sites fully saturated and not partially saturated
sites.
Oxygen supply to the cells can be described as the oxygen delivery chain (Oxygen
delivery = Cardiac Output x Arterial oxygen content). Oxygen delivery therefore
needs firstly good arterial oxygen content consisting of haemoglobin concentration,
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haemoglobin oxygen saturation (SaO2) and partial pressure of oxygen (PaO2) and
secondly good cardiac output
Oxygen Dissociation Curve
The bond between haemoglobin and oxygen can be affected by a number of
physiological factors. This ability of oxygen to bond or be released from the
haemoglobin is described as the oxygen dissociation curve.
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Oxyhaemoglobin curve shift to the right
There is reduced binding of oxygen to haemoglobin forming oxyhaemoglobin and so
oxygen is released to the tissues more easily and saturation will be lower.
Causes of right curve shift include:
Increased body temperature
Increased hydrogen ion content (acidosis) also known as Bohr effect
Increase in carbon dioxide
Increase in 2-3 Diphosphoglycerate (DPG)
Oxyhaemoglobin curve shift to the left
There is an increase in the binding of the oxygen to haemoglobin meaning the
oxygen is released less easily to the tissues causing cellular hypoxia.
Causes of left curve shift include:
Decreased
Decreased
Decreased
Decreased
body temperature
hydrogen ion content (alkalosis)
carbon dioxide
2-3 DPG
Oxygen utilisation
The dissociation curve represents the relationship between carbon dioxide (PaCO2)
and oxygen saturation (SaO2). Oxygen taken up in the lungs is identified by the
upper flat part if the curve. If PaO2 is between 8.0 and 13.3.kPa (60-100mmHg) the
haemoglobin is 90% or more saturated with oxygen. Large changes in PaO2 will lead
to small changes in SaO2 at this stage because of the almost complete saturation of
haemoglobin. Oxygen being released into the tissue is identified by the lower part of
the curve this means there is easy dissociation of oxygen from the haemoglobin for
use in the cells. At this stage small changes in PaO2 cause big changes in SaO2 and
are clinically important.
A patient needs oxygen levels to be maintained at 8kPa (60mmHg), below this level
will cause desaturation at a rapid rate resulting in hypoxia and cell death.
Oxygen consumption
When at rest the oxygen consumption ranges between 200-250ml/minute, with the
average man having a level of 700ml/minute of available oxygen. This then gives an
oxygen reserve of 450-500ml/minute. There are factors that can increase oxygen
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consumption such as fever, sepsis, shivering, restlessness and increased
metabolism. These factors need to be taken into account when measuring arterial
blood gases.
Oxygen delivery
Oxygen is essential for the production of adenosine triphosphate (ATP) by cell
mitochondria and is required as a source of energy for all intracellular functions.
Once oxygen is transferred into the cell a phosphate is added to adenosine
disphosphate (ADP) via a high energy bond forming ATP. This is then stored in the
cell until needed on a temporary basis. When the energy is needed by the cell the
ATP is dephosphorylated back to ADP, releasing energy from the bond.
If there is an inadequate oxygen supply, ATP production falls and as a result cellular
function is depressed through a lack of energy. This in turn can lead to unexpected
deaths or admissions to intensive care units.
Summary:
Oxygen is essential for the adequate production of adenosine triphosphate
(ATP)
If there is inadequate oxygen supply, ATP production falls, and cellular
function is then depressed.
Oxygen delivery = Cardiac Output X Arterial Oxygen Content
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Module two: Airway and Breathing
Learning outcomes:
At the completion of this module it is expected that the participant will be
able to:
Recognise when difficulties with airway or breathing may compromise oxygen
delivery to the tissues.
Discuss why the respiratory rate is such an important marker of the
deteriorating patient.
Introduction
In order for oxygen to reach haemoglobin and be transported around the body to
the tissues, it needs to pass through the upper airway (nose, mouth, trachea) and
lower airways of the lungs (bronchi) to the alveoli. To do this, we need both a
patent airway, and a functioning respiratory nerve and muscle, to move air in and
out of the lungs. Once oxygen is in the alveoli, it diffuses across the thin
alveocapillary membrane, into the blood and attaches to haemoglobin. From here, it
is dependent on pulmonary and then systemic blood flow to move oxygen to the
tissues and cells where it is required.
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Adult airway
Oxygen cannot move into the lower respiratory tract unless the airway is patent.
Causes of airway obstruction can either be functional or mechanical.
Functional airway obstruction can be a result of decreased level of consciousness
causing the relaxation of muscles which allows the tongue to fall back and obstruct
the pharynx.
Mechanical airway obstruction can be caused by the aspiration of a foreign body,
swelling or bleeding in the upper airway (e.g. trauma, allergy and infection).
Mechanical airway obstruction can also result from oedema or spasm of the larynx.
Examination of the airway
Using the “look, listen and feel” (Australian Resuscitation Council, 2011) it is possible
to recognise airway obstruction:
Look: Complete airway obstruction can cause paradoxical chest and
abdominal movements (on inspiration there is outward movement of the
chest but inward movement of the abdomen). There could also be increased
use of accessory muscles of the neck and shoulders with a tracheal tug.
Listen: Complete airway obstruction will result in no breath sounds at the
mouth or nose. In partial or incomplete obstruction attempted inspiration will
be noisy (stridor and inspiratory wheeze) and there will be a reduction in
breath sounds.
Feel: By placing your hand immediately in front of the patient‟s mouth will
allow you to feel if there is any air moving in and out.
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Management of airway obstruction
In the hospital setting many
instances of airway obstruction is
functional, due to decreased
conscious levels. Simple
manoeuvres can be all that is
required to open the airway:
Chin lift
Jaw thrust
Head tilt
Insertion of Oropharyngeal or nasopharyngeal airway (Guedel‟s airway).
Yankauer suction to remove any vomit or secretions, which could be a
contributing factor to the obstruction.
If the patient continues to have a depressed conscious level and is
unable to protect own airway, endotracheal intubation may be required.
Medical support must be called immediately in all patients with an airway
obstruction or if they are unable to maintain own airway.
Medical support must be called in the event of mechanical airway
obstruction as with, swelling, haematoma and infection.
Breathing
Breathing is required to move oxygen in and carbon dioxide out of the lungs and
requires:
The respiratory centre in the brain to be intact.
The nerve pathways from the brain to diaphragm and intercostal muscles to
be intact.
Adequate function of the intercostal and diaphragmatic muscles.
No obstruction in both the large and small airway.
Why respiration rate is important
Respiratory rate can be an important marker to identify either a drop in arterial
saturation or compensation for the presence of a metabolic acidosis. If oxygen
delivery to the tissues is reduced, cells revert to anaerobic metabolism, this
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increases lactate production, resulting in the build up of acid. The accumulation of
lactic acid stimulates an increase in respiratory rate (tachypnoea).
Metabolic acidosis can increase the respiratory rate even though
the arterial oxygen saturation may be normal; this can be a marker of
sepsis or other serious metabolic processes and should not be ignored.
Importance of respiratory rate.
Inadequate oxygen delivery at tissue level
Anaerobic metabolism
Lactate production
Metabolic acidosis
Stimulation of respiratory drive
Increase in respiratory rate
Increase in work of breathing
The decrease in oxygen delivery to the tissues, which results in tachypnoea, can be
due to problems at any point in the oxygen delivery chain.
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Respiratory rate is monitored as an individual parameter of the Early Warning Score
(EWS) Management System which makes up the total EWS.
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Patients may maintain normal saturation whilst increasing their
demand for oxygen and should be assessed as deteriorating
Management
Specific treatment will depend on the cause. Immediate interventions along with
EWS include:
o
o
o
o
o
o
Sit the patient upright as able
Apply oxygen therapy as prescribed
Sputum sample if infection suspected
Chest X-Ray to establish diagnosis
Arterial Blood Gases (DO NOT REMOVE THE OXYGEN)
Physiotherapy
Wheeze/ crackles can be present in other conditions including
anaphylaxis. In this case hypotension is the major concern and the patient
should be prone with legs elevated
The recommended target saturation range for the acutely unwell patient not at risk
of hypercapnic respiratory failure is 94-98% with supplementary oxygen. (BTS
2008). People over the age of 70 years may have oxygen saturation levels below
94% and do not require oxygen therapy if clinically stable.
Summary
Oxygen cannot move into the lower respiratory tract unless the airway is
patent.
Respiratory rate is an important marker in identifying a drop in arterial
saturation and metabolic acidosis.
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Module Three: Oxygen Delivery System
Learning outcomes:
At the completion of this module it is expected that the participant will be
able to:
Identify and discuss the different oxygen delivery devices and what clinical
situation each device is used in.
apply each delivery device correctly to ensure therapeutic administration of
oxygen
change oxygen regulators
The oxygen delivery systems available are classified as fixed and variable
performance devices and are able to deliver a wide range of oxygen concentrations.
Variable performance devices
These do not provide all the gas required for minute ventilation, each breath will
include a proportion of inspired air in addition to the oxygen supplied. The inspired
oxygen volume will depend on a number of variables including the oxygen flow rate
and the patient‟s ventilation pattern. If the patient has a fast or deep ventilation
rate, more air will be included reducing the inspired oxygen concentration. These
devices include nasal prongs, simple facemasks, partial rebreathing and nonrebreather masks.
Nasal prongs/ cannula
The dead space of the nasopharynx is used as a reservoir for oxygen. When the
patient inspires, oxygen and air mix with the reservoir air,
effectively enriching the inspired gas. Oxygen flow rate of
0.5 -4 L/min.
Hudson (standard) facemask
The reservoir volume of oxygen is increased above that
achieved by the nasopharynx. This can give higher oxygen
concentration levels of inspired gas (50-60%). Oxygen flow
rate 5-10 L/min.
This is the initial method of choice in acutely hypoxic
patient‟s i.e. acute asthma, pneumonia, LVF and pulmonary
embolism.
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Non-rebreather facemask
This is a simple face mask with the addition of a reservoir
bag. This can have a one or two way valve over the
exhalation ports (on the side of the mask) which prevent
exhaled gas entering the reservoir bag. This system permits
an inspired oxygen concentration of up to 90%. Oxygen flow
rate of 12-15L/min.
There is a risk of carbon dioxide retention if the flow rate is less
than 5L/min with the adult Hudson mask.
Fixed performance devices
With these devices the inspired oxygen concentration is determined by the oxygen
flow rate and attached diluter as with the venturi mask. The patient‟s rate and depth
of breathing will still alter the amount of inspired oxygen in each breath but they
cannot supply a greater fraction of inspired oxygen (FiO2) than that set by the
diluter. This is especially useful for patients who are at risk of retaining carbon
dioxide if given a high FiO2.
Diluter Setting (Inspired
oxygen)
20-29%
30%
35%
40%
45%
Suggested oxygen flow
rate( Litres/min)
4
5
8
10
13
Please note that depending on manufacturer flow rates may vary
and you should always read the labels
High flow humidified oxygen (via Fisher and Paykel)
Used for long term therapy where drying of the bronchial
secretions needs to be avoided. It is only indicated in special
circumstances but provides accurate fixed FiO2
 Further information on high flow humidified
oxygen can be found in module four of this workbook.
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Portable Oxygen Therapy
Patients being transferred between departments who require oxygen therapy should
be accompanied by a registered nurse if in an unstable condition. It is important to
be confident and competent in the change over of oxygen cylinders should the need
arise. Oxygen cylinders can be requested through the Orderly service and should be
appropriately secured at all times including when in transit.
Oxygen regulators
How to put regulators onto a new oxygen cylinder
Step 1
Break the seal on the valve
Note: If the seal is not in place do
not use the cylinder. Instead put
the cylinder with the empty
cylinders to be returned to BOC
Step 2
Check that the regulator washer is
in place prior to using it
Step 3
Line up the 3 prongs of the
regulator with the oxygen cylinder
holes and then screw on securely –
do not apply high force as this
could damage the valve
Step 4
Turn on the flow gauge first before
turning on the valve to avoid
damaging the flow gauge
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Step 5
Turn on the valve
Step 6
Remove the “full” section of the
oxygen cylinder tag
Summary
It is important to select the correct oxygen delivery system for the right
patient.
Variable performance devices include a percentage of circulating air and
oxygen. Saturation will depend on the patient‟s ventilation pattern.
It is important to be familiar with the portable oxygen therapy system and
regulators.
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Module Four: High Flow Humidified
Oxygen Therapy
Learning Outcomes:
At the completion of this module it is expected that the participant will be
able to:
Describe the mucocilary transport system
Discuss when humidification is used
Identify patients who require humidified oxygen therapy
Introduction:
The airways allow the passage of air from the environment to the terminal bronchi
and alveoli where gaseous exchange can occur. With this exchange the upper
airway consisting of the nose, oral cavity and pharynx have the function of
conditioning inspired air and protecting the lower airways.
Mucocilary transport System
The upper respiratory tract membranes are composed of ciliated pseudostratified
glandular columnar epithelium. The turbinate bones or chonchae divide the nasal
airway into four groove-like air passages, and are responsible for forcing inhaled air
to flow in a steady, regular pattern around the largest possible surface of cilia and
climate-controlling tissue.
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The mucus acts as a” fly trap” to catch particles which are small enough to bypass
the hairs in the nose which act as a filter for inspired air. The Cilia beat in unison to
propel mucus from the nasal cavity and paranasal sinuses toward the nasopharynx
where it can be swallowed or spat out. Mucocilliary transport relies on mucus
production and cilliary function. This function is severely impaired when the airways
dry out.
A rapidly dilating arteriolar circulation to these bones may lead to a sharp increase in
the pressure within in response to acute cooling of the body core - the pain from this
pressure is often referred to as "brain freeze", and is frequently associated with the
rapid consumption of ice cream!
Humidification therapy:
When the upper airway functions are compromised by a pathological process or
when bypassed by an artificial airway (tracheostomy, laryngectomy, or endotracheal
intubation) it is best practice to humidify oxygen.
There is little evidence in the non bypassed patients for the use of humidified
oxygen (BTS, 2008). Despite this there is evidence of patients reporting dryness and
discomfort when having oxygen delivered at a high flow, rates greater than 5L pm.
This discomfort may lead to poor compliance with oxygen therapy which may in turn
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25
compromise patient care. The BTS (2008) present evidence that humidification may
aid physiotherapy and sputum clearance in some patient groups.
Circumstance
High concentration oxygen
(Fi02 >40%)
Conditions affecting
mucocilary transport
Hypothermia
Endotracheal Intubation
New Tracheostomy
Reason for use of heated humidification
Some patients find the effects of prolonged treatment
(>24 hours) with high inspired oxygen concentration
uncomfortable, because of drying of the upper airway.
Patients with severe inflammatory conditions of the
oropharyngeal mucosa may obtain comfort from
humidification therapy even in the absence if high
inspired oxygen concentrations.
Example: Patients with head and neck cancers
undergoing radiation or chemotherapy treatment who
develop Mucositis
In cases of hypothermia heating inspire gas may help
increase core body temperature in some patients if
used in conjunction with other devices.
Humidification of inspired gas during mechanical
ventilation is mandatory
Tracheostomy and Laryngectomy stoma patients
requiring
supplementary
oxygen
must
have
humidification provided.
(CDHB2012)
Summary:
Humidification is not required for the delivery of low flow oxygen or for the
short term use of high flow oxygen
All patients who require invasive ventilation require humidification
All patients who have a tracheostomy or laryngectomy and require oxygen
therapy must have humidification
All patients requiring high flow oxygen therapy over long periods of time:
example oxygen flow > 5lpm, CPAP, BiPAP, Nasal High Flow, may benefit
from humidification to prevent drying of the upper airways
Humidification may also be of benefit to patients with viscous secretions
requiring physiotherapy.
(CDHB
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Module Five: Monitoring and Titrating
Oxygen Therapy
Learning outcomes:
At the completion of this module it is expected that the participant will be
able to:
State and discuss the importance of saturation monitoring.
Explain normal oxygen saturation values.
Demonstrate how to titrate oxygen therapy
Introduction:
If the blood levels of oxygen fall to an extremely low level, even for a small period of
time, tissue hypoxia and cell death will occur. The brain appears to be the most
vulnerable organ during profound hypoxemia. Brain malfunction (confusion,
agitation) is the first symptom of hypoxia and brain injury the most common long
term complication of profound hypoxemia (new confusion/agitation gives a score of
2 on EWS).
All clinical areas who work with acutely unwell inpatients should have access to pulse
oximetry and this combined with the EWS score should be used initially to assess a
patient‟s respiratory function. Oxygen is often initiated outside of the hospital
setting, e.g. Paramedics; in this situation it would be appropriate to assess
respiratory function including pulse oximetry to reduce oxygen therapy.
Supplementary oxygen therapy is required for all acutely hypoxemic patients and
those who are at risk of hypoxemia, e.g. shock and major trauma. Patients who
present with acute breathlessness should not be started on oxygen therapy unless
they are also hypoxemic.
At the bedside assessment of the patient, the clinician is expected to follow the
“ABC” approach, conduct a full set of observations and calculate a „EWS‟. The
oxygen saturations are taken via pulse oximetry readings with a finger or ear probe.
Every clinical area in which oxygen is used must have access to pulse oximetry.
It is important to note that whilst some patients may present with a high EWS score,
may be breathless and have significant hypoxemia, there are groups of patients who
do not present with breathlessness or a high EWS who will also have hypoxemia
(e.g. opiate toxicity).
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Pulse oximetry: usage and limitations.
Pulse oximetry measures haemoglobin oxygen saturation by
measuring light absorption at different wavelengths. Pulse
oximetry is accurate at levels above 88% but is less reliable
at low saturation, e.g. 80%. This Saturation via Pulse
oximetry of Oxygen is called SpO2
Certain situations will make pulse oximetry unreliable, a patient with anaemia may
present with a normal SpO2 because their haemoglobin is well saturated, though
they may be breathless and tachypnoeic because of their low amounts of
haemoglobin equate to an inability to carry enough oxygen to the cells.
Patients with Carbon monoxide poisoning may have a normal SpO2 due to the
carboxyhaemoglobin having a similar light absorption to oxyhaemoglobin. Smokers
may also display a higher SpO2 directly after smoking a cigarette.
More commonly, accuracy is diminished in a patient with poor perfusion, though
more modern oximeters are able to take a reading with low pulse pressures. Site is
important, if you think that an oximeter is not working try it on a better perfused
finger or use an ear lobe attachment.
It is worth noting that pulse oximeters do not measure acidity (pH), CO 2 or Hb so it
vital that Arterial blood gases and a complete blood count are taken where any
clinical disparity is noted.
SpO2 should be used as a fifth vital sign and recorded with every set
of observations alongside the type and amount of oxygen delivery.
Normal oxygen saturation and target ranges.
For adults the accepted range for oxygen saturations is 94-98%. This can gradually
decline with age; however, it is difficult to separate this decline in oxygen
saturations from the effects of disease common with aging. Most experts emphasise
keeping the saturations above 90% for most acutely ill patients, though is there is
no definite degree of hypoxia established which causes cellular damage.
SpO2 target range will be the same as their accepted range, i.e. 94-98%. This
means that oxygen will be given to achieve this specific range. In an emergency
presentation the clinician should try to achieve this range as quickly as possible with
high flow oxygen therapy (via a simple face mask or non-rebreather mask). When
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28
this range is obtained then the oxygen can titrated down to stay within the same
target range.
CO2 retainers
Patients with known COPD or other risk factors, e.g. neuromuscular disease and
chest wall deformities are at risk of hypercapnic (type 2) respiratory failure if
administered prolonged high levels of supplementary oxygen. This group is often
referred to as “CO2 retainers”.
For this group a SpO2 target range of 88-92% is accepted. To obtain this target
range the clinician should use a venturi mask to give a fixed fraction of inspired
oxygen (FiO2) pending arterial blood gas results. This minimises the risk of CO2
retention and aides further clinical decision making regarding oxygen therapy.
Titrating and weaning oxygen therapy.
Every patient who is receiving oxygen therapy should have a stated target range of
oxygen saturations documented in their clinical record. Oxygen is then titrated to
achieve this range.
Patients who are having episodes of low SpO2 should have their Oxygen therapy
increased to achieve their target range. Any increase in prescribed oxygen therapy
requires assessment by their medical team.
Any patient who is requiring a FiO2 of greater than 50% or a flow rate of greater
than 7 Lpm to maintain their target range should be discussed with the ICU outreach
team.
Once a patient is clinically stable then attempts should be made to wean the patient
from oxygen with close attention being paid to their EWS and SpO2. All changes to
oxygen therapy must be documented in the clinical records.
Summary
Target saturation range for an adult is 94-98%
Target saturation range for some one with COPD is 88-92%, this should be
maintained with a fixed performance oxygen delivery system
Any patient with an acute sudden deterioration or who may be at risk of CO2
retention requires an Arterial blood gas measurement.
Increasing oxygen therapy may decrease the effectiveness of the EWS. Any
increase in oxygen therapy requires a medical review.
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29
Module Six: Documentation and CDHB
Policy
Learning outcomes:
At the completion of this module it is expected that the participant will be
able to:
Administration
The administration of supplemental oxygen is an essential element of appropriate
management for a wide range of clinical conditions; however oxygen is a drug and
therefore requires a prescription in all but emergency situations.
Oxygen must be prescribed on the drug administration chart indicating:
Indications
Maximum flow rate/FiO2
Device to be used
Target oxygen saturations
Example of oxygen prescription
Oxygen therapy and medical gases
Date
Device/Delivery
Flow Rate
Target saturation (%)
Signature
Stopped
National Adult Medication Chart
In an emergency situation any qualified nurse/ health professional can commence
oxygen therapy without prescription and pulse oximetry must be available at each
location that oxygen is used.
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Any airway and/or respiratory changes must be documented on the 24 hour care
plan and in the medical notes. Information should include: type of device, litres
/min, saturation levels, EWS and respiration rate.
Management
Tick as appropriate
Oxygen requirements
Airway
Resp
Date:
Night/ Am/Pm
Date:
Date:
Night/Am/Pm Night/Am/Pm
Assistive devices
inhaled medication
Safe swallowing
Tracheostomy
(CDHB 24 hour care plan 2012)
 Canterbury DHB Management Guidelines for Common Medical Conditions (Blue
Book). http://bluebook.streamliners.co.nz
 Oxygen Therapy Policy: CDHB volume 12 Fluid & medication management
manual (2012) http://www.cdhb.govt.nz/cdhbpolicies/documents/vol12/4730oxygen-therapy.pdf
Summary
Oxygen therapy must always be prescribed
All changes to the patients airway and/or respiratory function must be
documented
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31
Quiz - Modules 1-6
The following set questions must be completed to be allocated 1.5 hours
of professional development time.
This is an open workbook and the pass rate is the attainment of 100%
correct answers.
1. What is the aim of administration of supplementary oxygen?
a) Reduce mortality
b) Reduce morbidity
c) Prevent tissue death
d) All of above
2. List the three components that lead to oxygenation of cells
I.
...................................................................................................
II.
………………………………………………………………………………………………
III.
………………………………………………………………………………………………
3. Complete the table below
Gas
Oxygen
?
?
?
Rare gases
Composition
?
79%
0.03 %
Partial pressure
159mmhg
600mmHg
?
47mmHg
?
4. How is oxygen carried in the bloodstream?
a) ……………………………………………………………………………………………………
b) ……………………………………………………………………………………………………
5. Which statement is correct to identify the cause of the oxyhaemoglobin
disassociation curve right shift is?
a) Increased body temperature, increased hydrogen ion content,
increased carbon dioxide, increase in 2-3 DPG
b) Increase in body temperature, decrease in hydrogen ion content,
increase in carbon dioxide, increase in 2-3 DPG
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c) Decrease in body temperature, increase in hydrogen ion content,
increase in carbon dioxide increase in 2-3 DPG
d) Increase in body temperature, increase in hydrogen ion content,
increase in carbon dioxide, decrease in 2-3 DPG
6. Oxygen delivery = ______________ X _________________
7. List the three techniques used to exam the airway
I.
………………………………………………………………………………………………….
II.
………………………………………………………………………………………………….
III.
………………………………………………………………………………………………….
8. In which instances would medical support be requested when dealing with an
obstructed airway?
a) ……………………………………………………………………………………………………
b) .....................................................................................................
9. What is the recommended target saturation for the acutely unwell adult?
a) 95-98%
b) 89-95%
c) 85-90%
d) 94-98%
10. Why is respiratory rate important?
…………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………
11. What device would you use if you wanted to avoid the drying up of bronchial
secretions? …………………………………………………………………………………………….
12. Which classification of delivery device do the following represent?
mask type
Hudson (standard) mask
High flow humidified oxygen
non-rebreather mask
nasal prongs/ cannula
classification
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13. When changing portable oxygen devices what action should you take if the
seal is broken on the new cylinder? ………………………………………………………..
14. Complete the following table relating to the function of the mucocilary
transport system?
Function
The upper airway
Turbinate bones/ Chonchae
Mucus
Cilia
15. List three reasons to use humidified oxygen
…………………………………………………………………………………………………………
………………………………………………………………………………………………………...
…………………………………………………………………………………………………………
16. When would you not require humidified oxygen therapy?
…………………………………………………………………………………………………………….
17. Which is the most vulnerable organ during profound hypoxemia?
…………………………………………………………………………………………………………….
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18. What monitoring is required at all times when administering supplementary
oxygen therapy:
a) Blood pressure and pulse
b) Respiration rate
c) Pulse oximetry
d) Arterial blood gases
19. What other observations need to be recorded when monitoring patients
receiving supplementary oxygen therapy?
………………………………………………………………………………………………………..……
……………………………………………………………………………………………………………
20. What diminishes the accuracy of pulse oximetry?
………………………………………………………………………………………………………..……
……………………………………………………………………………………………………………
21. What does pulse oximetry NOT measure?
………………………………………………………………………………………………………………
…………………………………………………………………………………………………………….
22. What are the risk factors for Co2 retention?
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
23. What is the target saturation rate for a patient retaining CO2?
a) 88-92 %
b) 91-96%
c) 85-90%
d) 82-86%
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24. Select true/ false for each statement.
a) Every patient who is receiving oxygen therapy should have a stated
target range of oxygen saturations documented in their clinical notes.
True / False
b) Patients who are having episodes of low SPO2 can have their oxygen
therapy increased to achieve their target range without assessment
from their medical team
True / False
c) Any patient who is requiring FiO2of greater than 50% or a flow rate
greater than 7 L/min to maintain their target range must be discussed
with the ICU Outreach team
True / False
d) All changes to oxygen therapy must be documented in the clinical
notes
True / False
25. Oxygen is a drug and must be documented including:
a) ………………………………………………………………………………………………..
b) ………………………………………………………………………………………………..
c) ………………………………………………………………………………………………..
26. What details need to be documented on the 24 hr care plan and in the
medical notes to indicate changes in airway and/ respirations?
a) ………………………………………………………………………………………………..
b) ………………………………………………………………………………………………..
c) ………………………………………………………………………………………………..
d) ………………………………………………………………………………………………..
e) ………………………………………………………………………………………………..
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Comments/ feedback
Candidate name:
Area of work:
date of completion:
date of review:
Verified by:
Profession development hours
awarded:
Title:
Reference List
Document owner: Clinical skills Coordinator & CNS General Medicine & Respiratory
Date created: 10/09/2012
Date of review: 10/09/2013
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Act Health. (2012). Early recognition of deteriorating patient (Compass) Australia.
Retrieved August 1, 2012 from http://health.act.gov.au/professionals/generalinformation/compass/deteriorating-patient-compass
Australian Resuscitation Council. (2011). Retrieved August 1, 2012 from
http://www.resus.org.au/
British Thoracic Society Emergency Oxygen Guidelines. (2008). Retrieved August 1,
2012 from http://www.brit-thoracic.org.uk/Guidelines/Emergency-Oxygenuse-in-Adult-Patients.aspx
Canterbury District Health Board. (2012). Oxygen therapy: Fluid & medication
management, Volume 12. Retrieved August 1, 2012 from
http://www.cdhb.govt.nz/cdhbpolicies/documents/vol12/4730-oxygentherapy.pdf
Canterbury District Health Board. (2012). Management for common medical
conditions. Retrieved August 1, 2012 from http://bluebook.streamliners.co.nz
Cersosimo, R.J., Matthews, S.J., & Hong, W.K. (1985). Bleomycin pneumonitis
potentiated by oxygen administration. Drug Intelligence and Clinical
Pharmacology. 1985 Dec; 19(12):921-3.
Lippincott. (2012). Nursing procedures and skills. Retrieved August 1, 2012 from
http://procedures.lww.com
Nader-Djalal, N., Knight, P.R. 3rd., Thusu, K., Davidson, B.A., Holm, B.A., & Johnson
,K.J., et al. (1998). Reactive oxygen species contribute to oxygen-related lung
injury after acid aspiration. Anaesthesia and Analgesia, Jul;87(1), 127-33.
Robbe, W.C., & Meggs, W.J. (2004). Insecticides, herbicides, rodenticides. In:
Tintinalli, J.E., Kelen, G.D., Stapczynski, J.S., Ma, O.J., & Cline, D.M., (Eds.),
Emergency medicine: A comprehensive study guide,6th ed (page 182). New
York: McGraw-Hill.
Royal Marsden. (2012) Royal Marsden hospital manual of clinical nursing procedures.
(8th Edition) Retrieved August 1, 2012 from http://www.rmmonline.co.uk/
Appendix A: Glossary
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ABG
Arterial Blood gas. Shows the pH, oxygen and carbon dioxide content
of the blood.
ATP
Adenosine triphosphate
ADP
Adenosine disphosphate
BiPAP
Bi level positive airway pressure
CO2
Carbon dioxide
CPAP
Continuous positive airway pressure
DPG
Diphosphoglycerate
ERV
Expiratory reserve volume
EWS
Early warning score
FiO2
Fraction of inspired oxygen in a gas mixture
FRC
Functional residual capacity. The volume of air remaining in the lungs
at the end of normal expiration.
Hypercapnia An abnormal increase in the amount of carbon dioxide in the blood.
Hypoxia
Lack of adequate oxygen at cellular level
Hypoxaemia Reduced concentration of oxygen in arterial blood
I:E
Inspiratory/ expiratory
KPa
kilopascal
MIV
Maximum Inspiration volume
MVV
Maximal voluntary ventilation
NIV
None invasive ventilation
PaCO2
Patrial pressure carbon dioxide the artery
PaO2
Partial pressure oxygen in the artery
PEEP
Positive end-expiratory pressure
pH
A measure of the hydrogen ion concentration of a solution and
provides information about acidity or alkalinity of the blood.
PiCO2
Partial inspired carbon dioxide
PiO2
Partial inspired oxygen
RV
Residual volume
SaO2
Arterial oxygen saturation
SpO2
Peripheral oxygen saturation
TLC
Total lung capacity
VA
Alveolar volume – amount of gas which reaches the alveoli per minute
VA= (Vt-VD) x Respiratory rate.
VD
Deadspace volume – the amount of anatomic deadspace
VE
Minute volume – amount of gas expired per breath
VQ
Ventilation/perfusion
Vt
Tidal volume – the amount of gas expired per breath.
WOB
Work of breathing
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