Transcript Oridion Slide Presentation Oct. 2004

CO2 Physiology
1
What is Carbon Dioxide?
• Capnos comes from the Greek word for
“smoke”
– smoke from the fire of metabolism
– a natural waste product of cellular activity
• CO2 is a compound molecule
– 1 element of carbon and 2 elements of
oxygen
– colorless and heavier than air
– green plants clean up after our exhaled CO2
2
Physiology of CO2
• CO2 produced by cellular metabolism diffuses
across the cell membrane into the circulating
blood.
• The blood transports the CO2 to the lungs.
• Then it diffuses from the blood into the lungs.
• CO2 is eliminated with alveolar ventilation on
exhalation.
3
Physiology of CO2
• Carbon Dioxide is transported in the
blood in three (3) principle forms:
– 5 to 10% as gas & reflected by the PCO2
– 20 to 30% is bound to blood proteins, the
major one being hemoglobin
– 60 to 70% is carried as bicarbonate (HCO3)
4
Physiology of CO2
• About 5-10% of CO2 is eliminate through
exhalation only.
• The rest is recycled in the body through the
circulatory and renal systems.
• The heart and lungs would have to increase
their work 10 times if they were required to
eliminate all the CO2 the body produces!
5
Ventilation &
EtCO2 Monitoring
• Endtidal CO2 (EtCO2) is the CO2
measured at the end of expiration.
• EtCO2 concentration provides a clinical
estimate of the PaCO2, if ventilation and
perfusion are appropriately matched.
• EtCO2 monitoring allows for a breath by
breath assessment of ventilation.
6
Capnography—
The continuous measurement and graphic display
(waveform) of the CO2 concentration in the patient’s
airway during the respiratory cycle.
Normal waveform:
7
Respiratory Cycle
O2
CO2
CO2
O2
Respiratory Cycle
• Oxygenation = oxygen → lungs→ alveoli→ blood
Monitored by a Pulseoximeter
• Metabolism = oxygen is converted to energy +
CO2
Monitored by a Metabolic Computer
• Hymodynamic Parameter
• Monitored by ECG, IPB, NIBP, Temperature
• Ventilation = CO2 → blood→ lungs→ exhalation
Monitored by a Capnograph
9
The relationship – EtCO2 and PaCO2
Normal conditions:
•
•
EtCO2 is between 35 – 45 mmHg
PaCO2 & EtCO2 will be very close
•
EtCO2 is most 2 - 5 mmHg less with normal physiology
Widening of this difference can be caused by:
•
•
•
Incomplete alveolar emptying
Ventilation-perfusion abnormalities
Poor sampling
Capnography monitoring of Critically ill patient may alert
clinicians to underlying conditions
10
PaCO2 vs. EtCO2
PaCO2 – Partial pressure of
CO2 present in arteries
(similar to concentration)
Invasive ABG analysis
11
EtCO2 – concentration of CO2
exhaled in each breath
Non-invasive measurement
at airway
Normal waveform
DD
A-B: Baseline = no CO2 in breath
B-C: Rapid rise in CO2
C-D: Alveolar plateau
D:
End expiration (EtCO2)
D-E: Inhalation
12
Normal waveform - 35-45 mmHg
13
Hypoventilation
14
Hypoventilation with shallow breathing
15
Relationship between EtCO2 and
RR
Breath-to-breath measure of ventilatory status
16
Hyperventilation
17
Some Definitions
• Capnometer
• Capnography
18
Capnometer
A Capnometer
provides only a
numerical
measurement of
carbon dioxide in
mmHg or kPa or
Vol.-%
19
Capnograpy
Capnography
provides the CO2
value and the
waveform of
carbon dioxide
over time
Capnography—
The Ventilation Vital Sign™
•
Earliest sign that something is going wrong
• Breath by breath assessment of ventilation
21
Capnography
An EtCO2 value of e.g. 38 mm/Hg
without a
50
40
30
20
10
0
Time
it´s like a heart rate of e.g. 80 without an
22
CO2 Measurement Technology
General:
• CO2 measurement technology
Infrared absorption
• Technique of airway gas sampling
Main stream vs. side stream vs.
Microstream
23
Sampling Technology
• Mainstream sampling - CO2 analysis
chamber is in-line between the patient airway
and the ventilator circuit
• Sidestream sampling - CO2 analysis
chamber is within the device. The patient’s
expired gas is sucked from the airway and
drawn to that chamber through a sampling
line.
24
Conventional main stream technology
Monitor
Expiration
Inspiration
Fresh gas
25
Conventional
side stream technology
Sample line
(Monitor)
26
Unique solutions for Capnography
= Microstream®
27
Microstream® CO2
•
A combination of a unique CO2
sidestream measurement
technology and;
•
FilterLine (proprietary sampling
lines) - for single patient use
•
Only system providing accurate
EtCO2 readings for non-intubated
patients that receive supplemental
O2 and switch between oral and/or
nasal breathing
28
Microstream® CO2— Major benefits
• Ease of Use
• Reliable Technology
• Flexible for all patient types
• Versatile for all environments
29
Microstream® advantages
Reliable technology
• Superior moisture
handling of liquids,
secretions and humidity
• CO2 specificity – no
cross-sensitivity to
anesthetic gases
• Rugged – no moving
parts in sensor
• Long-term monitoring
30
Microstream® advantages
Flexible for all patient populations –
solution for monitoring Neonates
• 50 ml/min flow rate supports entire
patient population – including
neonates (Competition at 3 – 5
times the flow rate)
• Does not compete for Neonate
tidal volume
• The lower the flow, the less
moisture to be handled
Microstream® advantages
Ease of use
• No expensive sensors to replace
• Yearly calibration – done in 5 minutes
• Warm up time –
45 seconds from
ON until first waveform
and number appears
• One-piece Plug & Play
consumables
32
Microstream® advantages
Light source
Micro sample cell 15 µL
Light source housing
33
1 Eurocent
Microstream® Core Technology
Sensor Housing
I.R Source
Optic Block
(Micro Sample Cell)
I.R Detectors
34
Microstream® advantages
Reliable Technology
• Fast response time
• 1 mm micro bore tubing
reduces delay time
• Crisp waveform –
longitudinal filter maintains
laminar flow
• Build-in water trap –
don't clean and re-use any
FilterLine – it destroys the
inline filter
35
Microstream® advantages
Flexible
• Both intubated and
nonintubated applications
• Alternating mouth and nose
breathing
• Oxygen delivery (low flow O2
solution; solution for high flow
O2 delivery)
• Adult, pediatric, and
neonates
36
Microstream® advantages
Versatile
All clinical environments:
• Critical Care
• Sedation Procedures
• EMS/ED
• Operating Room
37
Unique solutions for Capnography
FilterLine® patient interfaces
38
FilterLine® solutions for all
applications
Intubated
Non-Intubated
Smart Solutions
NIV-Line
Smart CapnoLine /
Smart CapnoLine O2
CapnoLine H
39
FilterLine®
Sets
Smart Solutions for nonintubated patients
“Microstream® technology allows the accurate measurement of
EtCO2 in the absence of an endotracheal tube.”*
• Continuous sampling from both
mouth and nose
• Special oral-piece design optimally
samples from mouth - Increased
surface area provides greater
sampling accuracy in the presence
of low tidal volume
(adult/intermediate size)
*ASA 2001 Jay Brodsky, MD Professor of Anesthesia,
Stanford University Medical Center, CA USA
40
Smart Solutions for nonintubated patients
Smart CapnoLine™ Plus /
Smart CapnoLine™ Plus O2
nasal cannula for CO2 measurement and O2 delivery
• Uni-junction sampling method
ensures optimal waveform and
ultra-fast response time
• Unique O2 delivery method reduces
CO2 sampling dilution (up to 5l/min)
• Solution for high flow O2 delivery
(works effectively under oxygen
delivery mask)
41
Solutions for non-intubated patients
CapnoLine H*™ / CapnoLine H O2
• Enables continuous EtCO2
monitoring in high humidity
environments (i.e. ICU)
• Can be used up to 72 hours
Piece of Nafion
* = Humidity
42
Microstream®—A Unique Solution For
Non-intubated Patients
CO2 sampling / O2 delivery for non-intubated patients (up to 5 L/min.)
Small pin holes deliver
pillow of oxygen around
both nose and mouth
Uni-junction™ of
sampling ports
prevents dilution from
non-breathing source
43
Nasal and Oral
Sampling
Increased surface area
provides greater
sampling accuracy in
the presence of low
tidal volume
FilterLine® Sets - Solutions for intubated
patients
• Easily handles moisture and
secretions without water traps
• Able to measure in any position
• Nafion® tubing allows for longterm monitoring without
moisture build up
• Easily switches to nonintubated monitoring without recalibration of monitor
• Low add. dead space (0,4 cc) to
use on neonates
44
FilterLine® recommendations:
Sedation Areas; GI Lab, Cath Lab, EP Lab
Is the Patient on Oxygen?
45
YES
NO
Smart CapnoLine Plus O2
Smart CapnoLine Plus
FilterLine® information to avoid problems
 Do not try to dry the FilterLine® - this will damage the filter
 Ensure there are no kinks in the sampling line
 Do not cut the oral flange on the Smart CapnoLine
 Do not cover the Nafion®
 Do not instill medications through the airway adapter
 Never pass a suction catheter or stylus through the airway
adapter
 Change the FilterLine® or the Set if a “Blockage” message
appears on the monitor screen or if the readings become
extremely erratic
46
FilterLine® answers for the most FAQ´s:
 Latex free
 Single-patient use
 Not sterile
47
Sedation Procedures
“Monitoring of exhaled carbon dioxide should be
considered for all patients receiving deep sedation and
for patients whose ventilation cannot be directly
observed during moderate sedation.”*
*Practice Guidelines for Sedation and Analgesia by Non-Anesthesiologists,
Developed by the American Society of Anesthesiologists Task Force on Sedation
and Analgesia by Non Anesthesiologists: Anesthesiology 2002; 96:1004
48
Microstream® solutions during
Sedation Procedures
Benefits and Uses
• Assesses  patent airway (airway obstruction)
 protective reflexes
 response to verbal/physical stimuli
• Respiratory changes can immediately be assessed
• Microstream® allows for continuous respiratory
monitoring with no nuisance alarms in procedural
sedation environments where currently there is
minimal usage of monitoring
49
Microstream® solutions during
Sedation Procedures
Applications
• Cardiac Cath. Lab
• GI lab
• Pulmonary lab
• Emergency Department
• Hyperbaric medicine
• Dental Clinics
• Radiology
50
Moderate – procedural sedation
51
Capnography and sedation
How can capnography make a difference in
how you care for the sedated patient?
• What you do will not change
• When you do it will!
Early detection of potential patient compromise
52
Protocol during procedural sedation
Baseline Ventilatory Assessment
• E.g. after 12 hours NPO (nothing by mouth) = EtCO2
• Know the respiratory rate, waveform, and EtCO2 numeric
value before drug administration
Continuous monitoring throughout case and
recovery
•
•
RR, ETCO2 value…changes from baseline (trends)
Changes in the Waveform…Earliest indicator of potential
problems. (size, shape)
Early intervention
53
Changes from baseline
• Change in EtCO2 value > 10 mmHg
• Significant waveform change
Becomes erratic
Flatlines
54
Changes from baseline - action
• Remember the ABC’s (airway, breathing,
circulation)
• Assess the patient
• Follow your normal protocol, which may
include:






55
Ensure open airway
Stimulate patient if necessary
Check the cannula positioning
Stop drug delivery
Inform M.D. / pause procedure if necessary
Administer reversal agents as prescribed
Deep sedation
•
Requires higher vigilance in
ventilatory monitoring
•
•
Maintain patent airway
Potential dead space
ventilation
•
•
Chest moves up and down
Inadequate respiratory effort to clear dead space
56
Assessing for changes from baseline
Hypoventilation with shallow respirations
57
Nursing interventions
• Continue to monitor
• Ask patient to take a deep breath
58
Abnormal waveforms
Absent alveolar plateau indicates
incomplete alveolar emptying or
loss of airway integrity
Possible causes
• Partial airway obstruction caused by:
• Tongue
• Position of head
59
Assessing for changes from baseline
Rebreathing often results from:
• Poor head and neck alignment
• Draping near the airway
• Shallow breathing – not clearing
dead space
60
Assessing for changes from baseline
Dead space ventilation
• Chest movement
• Little – to no air movement in and
out of lungs
61
Abnormal waveforms
Absent alveolar plateau indicates
incomplete alveolar emptying or
loss of airway integrity
Possible causes
• Partial airway obstruction caused by:
– Tongue
– Position of head
62
Nursing interventions
• Assess patient
• Ask patient to take a deep breath
• Adjust patient’s head position, if
necessary
• Adjust cannula position, if
necessary
63
Putting it all together
• The transition from conscious sedation to
unconscious/anesthesia is very subtle and can be
undetected until oxygenation is impaired
• You must be prepared to monitor a patient at a level
deeper than intended
• “Respiratory frequency and adequacy of pulmonary
ventilation are continually monitored”
• Only capnography provides an immediate
notification of a ventilatory event
64