This uploaded file is open for all fields of sphere

1. VARIABLE PERFORMANCE
Mask
Dr Nisar Ahmed Arain
Assistant Professor
Anesthesia/ICU/ER

2. Variable Performance Mask
and Oxygen Delivery System
--An oxygen delivery system/variable
performance mask is a device used to
administer, regulate, and supplement
oxygen
to a subject to increase the arterial
oxygenation.
--In general, the system entrains oxygen
and air
to prepare a fixed concentration
required for
administration.
--Oxygen delivery systems are generally
classified as low-flow or variable
performance devices and high-flow
or fixed-performance devices.

3. INDICATIONS FOR OXYGEN
THERAPY
-Peri and post cardiac or respiratory arrest
-Hypoxia - oxygen saturation levels of <92%
-Acute and chronic hypoxemia PaO2 < 65mmHg,
SaO2 < 92%.
-Signs and symptoms of shock
-Low cardiac output and metabolic acidosis HCO3
<18mmol/l.
-Chronic type two respiratory failure (hypoxia
and hypercapnia).
-Dyspnoea without hypoxemia.
-Post-operatively, dependent on instruction from
surgical team.
-Treatment of pneumothorax
IMPORTANT REQUIREMENTS OF
VARIABLE PERFORMANCE MASK

4. DEFINITIONS
--FiO2 is defined as the percentage or concentration
of
oxygen that a person inhales. The air that we inhale
on
a day to day basis is made up of 21% of oxygen,
78% of
nitrogen and 1% of trace elements such as argon,
carbon dioxide, neon, helium and methane.
--Sometimes, 21% of oxygen may not be enough to
maintain adequate oxygen saturations. In these
situations, supplemental oxygen can be
administered
via various oxygen delivery devices ranging from
nasal
prongs to invasive ventilation.
--This allows the concentration of oxygen to be
increased, potentially increasing the FiO2 to
100%.

5. SpO2
--SpO2 is an estimate of
arterial
oxygen saturation, or
SaO2,
which refers to the amount
of
oxygenated hemoglobin in
the
blood.
--Normal SpO2 95 – 100%

6. PaO2
--PaO2 is the partial pressure of oxygen
dissolved in the blood, expressed in
mmHg.
--If PaO2 is < 80 mmHg, the patient has
arterial hypoxemia.
79 - 70 mmHg =mild hypoxemia.
69 - 60 mmHg =moderate hypoxemia
59 - 50 mmHg =severe hypoxemia
<50 mmHg =extreme hypoxemia

7. LOW FLOW OXYGEN DEVICES
--These provide a fraction of the patient’s minute ventilatory
requirement as pure oxygen.
--The remainder of the ventilatory requirement is filled by
addition
of entrained room air. Flows supplied through these
devices are
low, usually less than 6L/min.
--These are oxygen devices where some room air will be
entrained, and therefore the exact FiO2 cannot be
calculated,
however it can be estimated. How much FiO2 is
delivered to
the patient is dependent on Liter flow set at the
flowmeter,
respiratory rate, and pattern, of the equipment
delivering this
oxygen.
Nasal cannula, simple mask and oxygen conserving

8. NASAL CANNULA
--Low-flow nasal cannulae set to deliver
oxygen at flows between 1-6L/min
lead
to an FiO2 between 0.24 and 0.44
--This Flow of above 6L/min do not
significantly increase FiO2 above
0.44
and these higher flows may result in
drying of mucous membranes and
nose bleed.

9. OXYGEN MASKS
--A simple mask is usually used for
patients
who require a moderate flow rate for a
short period of time.
--It is composed of a plastic mask that fits
snugly over the patient’s mouth and
nose. The mask has holes on each
side
that are used for exhalation and for
air
entrainment if the flow rate is too low.
--Simple mask has the ability to deliver
oxygen
concentrations of 40% to 60% with a
flow
rates from 6 to 10 L/min.
--Because carbon dioxide can build up in
the
mask at low flow rates, do not use a
flow
rate lower than 6 L/min when using this

10. --Oxygen Flow L/min --Approximate (FIO2)
--1
--2
--3
--4
--5
--6
--7
--8
--9
-10
--24%
--28%
--32%
--36%
--40%
--44%
--48%
--52%
--56%
--60%

11. RESERVOIR CANNULAS
--Reservoir cannulas — Reservoir cannulas function
by storing oxygen during exhalation, making that oxygen
available as a bolus upon the onset of the next inhalation.
Reservoir cannulas are particularly useful in patients who
require a flow rate of oxygen 4 L/min or higher.
--These cannulas are available in two configurations:
--A moustache configuration in which the reservoir is
located directly beneath the nose and a pendant
configuration in which oxygen is stored in a reservoir
located on the anterior chest. The reservoir membrane is
pushed forward during exhalation, creating a chamber.
This enables oxygen to be stored during exhalation in the
reservoir. When the patient is ready to inhale, he/she
receives the stored oxygen along with the continuously
flowing supply oxygen, increasing the percent oxygen in
the air that the patient inhales.
--Both reservoir cannulas are simple, reliable,
inexpensive, and disposable. They operate in
response to the patient's nasal airflow.
--Both devices are partial rebreathing systems. As they
return some of the patient's warmed expired air with
elevated moisture, they effectively increase the relative
humidity of the inhaled oxygen.

13. HIGH-FLOW OXYGEN
DEVICES
--These devices meet the inspiratory flow of the
patient, and generate accurate FiO2s so
long
as there is a good seal between the mask
and
the patient's face.
--The flows are such that the patient will not
be
entraining room air that will lower the
FiO2.
--Respiratory rate and tidal volume of the
patient
have no effect on FiO2 delivered.

14. NON REBREATHER MASK

15. --This device is used to deliver high flow rates and
high
concentrations of oxygen. Like the simple mask,
the
nonrebreather mask fits snugly over the patient’s
mouth and nose.
--A nonrebreather mask has ports on each side that
have one-way valves that keep the patient
from breathing in room air to ensure that a
high concentration of oxygen is delivered.
--The mask also has a reservoir bag that is inflated
with
pure oxygen. Between the mask and the bag is
another
one-way valve that allows the patient to breathe in
the
oxygen supplied by the source as well as oxygen
from
the reservoir. This provides the patient with an
oxygen
concentration of nearly 100%.
--A nonrebreather mask can deliver oxygen

16. PARTIAL REBREATHER MASK
--A partial rebreather mask is used for oxygen therapy.
It delivers oxygen gas to the patient at concentrations
of
50 to 70 percent.
--This is basically an NRB with both one-way valves
removed
from the mask. The estimated FiO2 is 60-65%. Flow
should
be set at 6-15 lpm.
--With a partial rebreather mask, when the patient
inhales
they inhale some of the exhaled air, which contains
carbon dioxide. When carbon dioxide enters the
lungs
it stimulates breathing.

17. VENTURI MASK

18. --A Venturi mask is most often used for critically ill patients
who require administration of a specific concentration
of
oxygen. It consists of a mask with holes on each side
that
allow exhaled air to escape. At the base of the mask
are
color-coded entrainment ports that are adjustable to
allow
regulation of the concentration of oxygen
administered.
--A Venturi mask can deliver oxygen concentrations from
24% to 60% with flow rates from 4 to 12 L/min.
Because this device delivers a precise oxygen
concentration and carbon dioxide buildup is
minimal
it is commonly used for patients who have COPD.
Humidification is usually unnecessary with this
device.
--There is entrainment of room air with these devices, but

19. HIGH FLOW NASAL OXYGEN
--High flow nasal oxygen therapy is a form of respiratory support
where oxygen, often in conjunction with compressed air and
humidification, is delivered to a patient at rates of flow higher
than that delivered traditionally in oxygen therapy.
(Traditional
oxygen therapy is up to 16 L/min and high flow oxygen
therapy
is up to 60 L/min.)
--HFNC can generate FiO2 100% and PEEP of up to 7.4 cm H20 at
60 L/min.
--High flow oxygen therapy is usually delivered using a blender
connected to a wall outlet, a humidifier, heated tubing and
nasal cannula.
--It also creates nasopharyngeal dead space washout, thereby
decreasing CO2 rebreathing and provides an oxygen
reservoir.
--It offers low levels of PEEP which may contribute to alveolar
recruitment (decreased dead space), improved compliance
and
decreased work of breathing.

21. HOME OXYGEN DELIVERY SYSTEMS

22. --Oxygen
cylinders
--Oxygen cylinders are the primary source for home
oxygen
portable systems. The advantages of oxygen
cylinders
include the fact that they come in a variety of
sizes, do
not waste oxygen, they can have their duration
increased with the use of a conserving device and
can
provide high liter flows. The disadvantages include
often
cumbersome size, limited duration, need for
frequent
refills and the high storage pressure of the gas
(often up to 2000 psi).
-- Home oxygen
concentrators
--Home oxygen concentrators are compressors that
use
a molecular sieve material to remove the nitrogen
from room air and provide oxygen concentrations
of
85-97% pure oxygen. These concentrators can
provide
liter flows from 0.5l/min to 10l/min. Recent
advances
have allowed concentrators to become more

23. THANK YOU