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CAPNOGRAPHYCAPNOGRAPHYpresented by:
Fred Halazon, NREMT-P
Mike Burke, NREMT-P
Cunningham Fire
presented by:
Fred Halazon, NREMT-P
Mike Burke, NREMT-P
Cunningham Fire
What is Capnography?What is Capnography?
Noninvasive, continuous measurement of exhaled carbon dioxide concentration over time
Digital display provides EtCO2 value
Provides a distinct waveform for each respiratory cycle
Noninvasive, continuous measurement of exhaled carbon dioxide concentration over time
Digital display provides EtCO2 value
Provides a distinct waveform for each respiratory cycle
OverviewOverview
History
Anatomy & Physiology
Capnographic waveform
Diagnosing different waveforms
Case studies
History
Anatomy & Physiology
Capnographic waveform
Diagnosing different waveforms
Case studies
RelevanceRelevance
ETT Verification
Cardiac Arrest
Ventilation
Bronchospastic Disease
Early detection of cellular hypoxia
ETT Verification
Cardiac Arrest
Ventilation
Bronchospastic Disease
Early detection of cellular hypoxia
History of capnographyHistory of capnography
Used by anesthesiologists since the 1970s
Standard of care in the OR since 1991
Used by anesthesiologists since the 1970s
Standard of care in the OR since 1991
History of Capnography in EMSHistory of Capnography in EMS
Colormetric- Useful device to confirm ET tube placement in patients not in cardiac arrest
Tube could be in esophagus or that circulation is not bringing CO2 to the lungs
Prone to contamination, leads to false negatives
Colormetric- Useful device to confirm ET tube placement in patients not in cardiac arrest
Tube could be in esophagus or that circulation is not bringing CO2 to the lungs
Prone to contamination, leads to false negatives
History of Capnography in EMSHistory of Capnography in EMS
Pulse oximetry preceded capnography
Pulse oximetry measures oxygenation
Capnography measures ventilation
New technologies now allow use in EMS
Pulse oximetry preceded capnography
Pulse oximetry measures oxygenation
Capnography measures ventilation
New technologies now allow use in EMS
CapnometryCapnometry
Provides only a numerical measurement of carbon dioxide (EtCO2)Provides only a numerical measurement of carbon dioxide (EtCO2)
CapnogramCapnogram
A waveform display of carbon dioxide over timeA waveform display of carbon dioxide over time
Definition of CapnographyDefinition of Capnography
Numerical value of the EtCO2 AND
Waveform of the concentration present in the airway
Respiratory rate detected from the actual airflow
Numerical value of the EtCO2 AND
Waveform of the concentration present in the airway
Respiratory rate detected from the actual airflow
DefinitionsDefinitions
PACO2—Partial pressure of CO2 in the alveoli
PaCO2—Partial pressure of CO2 in arterial blood
PEtCO2—Partial pressure at the end of expiration
PvCO2—Partial pressure of CO2 in mixed venous blood
PCO2—Partial pressure of CO2
PACO2—Partial pressure of CO2 in the alveoli
PaCO2—Partial pressure of CO2 in arterial blood
PEtCO2—Partial pressure at the end of expiration
PvCO2—Partial pressure of CO2 in mixed venous blood
PCO2—Partial pressure of CO2
DefinitionsDefinitions
PaO2—Partial pressure of O2 in arterial blood (hypoxemia)
SPO2—Saturation of arterial blood (POX) percent
SaO2—Percentage of arterial hemoglobin saturated with O2 (POX)
PO2—Partial pressure of O2
PaO2—Partial pressure of O2 in arterial blood (hypoxemia)
SPO2—Saturation of arterial blood (POX) percent
SaO2—Percentage of arterial hemoglobin saturated with O2 (POX)
PO2—Partial pressure of O2
What is Carbon Dioxide?What is Carbon Dioxide?
Capnos comes from the Greek word for “smoke”
Smoke from the Fire of metabolism
Natural waste product of cellular activity
CO2 is a compound molecule
2 elements of oxygen and 1 element of carbon
Colorless and heavier than air
Capnos comes from the Greek word for “smoke”
Smoke from the Fire of metabolism
Natural waste product of cellular activity
CO2 is a compound molecule
2 elements of oxygen and 1 element of carbon
Colorless and heavier than air
Carbon Dioxide TransportCarbon Dioxide Transport
CO2 + H2O H2CO3
Carbonic acid dissociates:
H2CO3 H+ + HCO3
_
CO2 + H2O H2CO3
Carbonic acid dissociates:
H2CO3 H+ + HCO3
_
Gas Transport in BloodGas Transport in Blood
O2 carried in bloodDissolved in blood plasmaBound to hemoglobin with iron
CO2 carried in bloodDissolved in plasma (5-10%)Chemically bound to hemoglobin in (RBC’s) (carbaminohemoglobin) (20-30%)Most carried as bicarbonate ions (HCO3-) (60-70%)
O2 carried in bloodDissolved in blood plasmaBound to hemoglobin with iron
CO2 carried in bloodDissolved in plasma (5-10%)Chemically bound to hemoglobin in (RBC’s) (carbaminohemoglobin) (20-30%)Most carried as bicarbonate ions (HCO3-) (60-70%)
Physiology of CO2Physiology of CO2
End of inspiratory cycle, airways filled with CO2 free gas
CO2 is a product of cellular metabolism
CO2 is continuously diffused across the cell membrane into the circulating blood
End of inspiratory cycle, airways filled with CO2 free gas
CO2 is a product of cellular metabolism
CO2 is continuously diffused across the cell membrane into the circulating blood
Physiology of CO2Physiology of CO2
Transported to the lungs in the blood stream
Diffused across cell membrane into alveoli
Eliminated during exhalation
Transported to the lungs in the blood stream
Diffused across cell membrane into alveoli
Eliminated during exhalation
Oxygen> lungs> alveoli> blood
Muscles + organs
Oxygen + Glucose
O2
CO2
CO2
CO2
O2
cellsenergy
blood
lungs
breath
Physiology of CO2Physiology of CO2
The evolution of CO2 from the alveoli to the mouth during exhalation, and inhalation of CO2 free gases during inspiration gives the characteristic shape to the CO2 curve which is identical in all humans with healthy lungs
The evolution of CO2 from the alveoli to the mouth during exhalation, and inhalation of CO2 free gases during inspiration gives the characteristic shape to the CO2 curve which is identical in all humans with healthy lungs
Capnographic WaveformCapnographic Waveform
A B
C D
EExpirationInspiration Inspiration
Physiology of CO2Physiology of CO2
Alveoli in lower lung is more perfused, but less ventilated
In the more proximal respiratory tract, the CO2 falls gradually to zero at some point
Alveoli in lower lung is more perfused, but less ventilated
In the more proximal respiratory tract, the CO2 falls gradually to zero at some point
0
36
40
44
Physiology of CO2Physiology of CO2
Concentration of CO2 in alveoli is determined by:Concentration of CO2 in alveoli is determined by:
PERFUSION (Q)
VENTILATION (V)
Physiology of CO2Physiology of CO2
Concentration of CO2 in alveoli:
Varies INDIRECTLY with ventilation
Increase Ventilation: Decrease CO2 in Alveoli
Decrease Ventilation: Increase CO2 in Alveoli
Varies DIRECTLY with perfusion
Decrease Perfusion: Decrease CO2 in Alveoli
Increase Perfusion: Increase CO2 in Alveoli
Concentration of CO2 in alveoli:
Varies INDIRECTLY with ventilation
Increase Ventilation: Decrease CO2 in Alveoli
Decrease Ventilation: Increase CO2 in Alveoli
Varies DIRECTLY with perfusion
Decrease Perfusion: Decrease CO2 in Alveoli
Increase Perfusion: Increase CO2 in Alveoli
Oxygenation and VentilationWhat is the difference?
Oxygenation and VentilationWhat is the difference?
Oxygenation: is the transport of O2 via the bloodstream to the cells
Oxygen is required for metabolism
Ventilation: is the movement of air into and out of the lungs
exhaling of CO2 via the respiratory tractCarbon dioxide is a byproduct of metabolism
Oxygenation: is the transport of O2 via the bloodstream to the cells
Oxygen is required for metabolism
Ventilation: is the movement of air into and out of the lungs
exhaling of CO2 via the respiratory tractCarbon dioxide is a byproduct of metabolism
OxygenationOxygenation
Measured by pulse oximetry (SpO2)
Noninvasive measurement
Percentage of oxygen in red blood cells
Changes in ventilation take several minutes to be detected
Affected by motion artifact, poor perfusion, temperature
Measured by pulse oximetry (SpO2)
Noninvasive measurement
Percentage of oxygen in red blood cells
Changes in ventilation take several minutes to be detected
Affected by motion artifact, poor perfusion, temperature
VentilationVentilation
Measured by the end-tidal CO2
Partial pressure (mm Hg) or volume (%) of CO2 in the airway at end of exhalation
Breath-to-breath measurement provides information within seconds
Not affected by motion artifact, distal circulation, temperature
Measured by the end-tidal CO2
Partial pressure (mm Hg) or volume (%) of CO2 in the airway at end of exhalation
Breath-to-breath measurement provides information within seconds
Not affected by motion artifact, distal circulation, temperature
Distinguishing between oxygenation and ventilation
Distinguishing between oxygenation and ventilation
Normal Ventilation/Perfusion RatioNormal Ventilation/Perfusion Ratio
The volume of blood returning to the lungs matches the capacity of the lungs to exchange gases
Ventilation
Cardiac Output
The volume of blood returning to the lungs matches the capacity of the lungs to exchange gases
Ventilation
Cardiac Output
Ventilation-Perfusion (V/Q) Mismatch
Ventilation-Perfusion (V/Q) Mismatch
Phenomenon where either perfusion or ventilation to an area of lung decreases; results in diminished gas exchange, hypoxemia, and hypercapnia
Phenomenon where either perfusion or ventilation to an area of lung decreases; results in diminished gas exchange, hypoxemia, and hypercapnia
If ventilation is held constant, then changes in EtCO2 are
due to changes in cardiac output
Cardiac Output
(L)
EtCO2 (mm Hg)
2 20
3 28
4 32
5 36
BreakBreak
Value of the Capnographic WaveformValue of the Capnographic Waveform
Provides valid EtCO2 value
Visual assessment of patient airway integrity
Verify proper ET tube placement (with pulmonary perfusion)
Waveforms have characteristic shape like an ECG
Provides valid EtCO2 value
Visual assessment of patient airway integrity
Verify proper ET tube placement (with pulmonary perfusion)
Waveforms have characteristic shape like an ECG
Capnographic WaveformCapnographic Waveform
Height shows amount of CO2
Length depicts time
Height shows amount of CO2
Length depicts time
45
0
Phases of CapnogramExpiratory segment
Phases of CapnogramExpiratory segment
Consists of the following three phasesConsists of the following three phases
Phase IPhase I
Phase I- Represents CO2 free gas from airways (Dead Space)Phase I- Represents CO2 free gas from airways (Dead Space)
Phase IPhase I
Beginning of exhalationBeginning of exhalation
A B
I
Phase IIPhase II
Phase II- Consists of rapid upswing (due to mixing of dead space gas with alveolar gas (Ascending Phase)
Phase II- Consists of rapid upswing (due to mixing of dead space gas with alveolar gas (Ascending Phase)
Phase IIPhase II
II
AB
CAscending Phase
Phase IIIPhase III
Phase III- Consists of an alveolar plateau, CO2 rich gas, positive slope, rise in PCO2 (Alveolar Plateau)
Phase III- Consists of an alveolar plateau, CO2 rich gas, positive slope, rise in PCO2 (Alveolar Plateau)
Phase IIIPhase III
A B
C D
I I I
Alveolar Plateau
Slope of Phase IIISlope of Phase III
CO2 is being continuously excreted into the alveoli
Late emptying of alveoli with lower (V/Q) ratios, produces higher PCO2
End-tidal End of the wave of exhalation
CO2 is being continuously excreted into the alveoli
Late emptying of alveoli with lower (V/Q) ratios, produces higher PCO2
End-tidal End of the wave of exhalation
Expiratory segment cont…Expiratory segment cont…
Alpha angle- Angle between phase II and phase III (V/Q status of lung)Alpha angle- Angle between phase II and phase III (V/Q status of lung)
A B
C D
E
Phases of CapnogramInspiratory segment
Phases of CapnogramInspiratory segment
Beta Angle- Angle between phase III and descending limb of inspiratory segmentBeta Angle- Angle between phase III and descending limb of inspiratory segment
A B
C D
E
Inspiratory segmentInspiratory segment
Phase 0- Inspiration, fresh gases inhaled and CO2 falls rapidly to zero (Descending Phase)
Phase 0- Inspiration, fresh gases inhaled and CO2 falls rapidly to zero (Descending Phase)
Phase 0Phase 0
A B
C D
E
0
Descending Phase
Inhalation
End-tidal CO2 (EtCO2)End-tidal CO2 (EtCO2)
Allows monitoring for changes inVentilation—Asthma, COPD, airway edema, FBAO, stroke
Diffusion—Pulmonary edema, alveolar damage, CO poisoning (COHb), smoke inhalation, hydrogen cyanide
Perfusion—shock, pulmonary embolus, cardiac arrest, severe dysrhythmias
Allows monitoring for changes inVentilation—Asthma, COPD, airway edema, FBAO, stroke
Diffusion—Pulmonary edema, alveolar damage, CO poisoning (COHb), smoke inhalation, hydrogen cyanide
Perfusion—shock, pulmonary embolus, cardiac arrest, severe dysrhythmias
Decreased EtCO2Decreased EtCO2
Decreased Metabolism
Analgesia/ sedation
Hypothermia
Circulatory System
Cardiac arrest
Embolism
Sudden hypovolemia or hypotension
Decreased Metabolism
Analgesia/ sedation
Hypothermia
Circulatory System
Cardiac arrest
Embolism
Sudden hypovolemia or hypotension
Respiratory System
Alveolar hyperventilation
Bronchospasm
Mucus plugging
Equipment
Leak in system
Partial obstruction
ETT in hypopharynx
Respiratory System
Alveolar hyperventilation
Bronchospasm
Mucus plugging
Equipment
Leak in system
Partial obstruction
ETT in hypopharynx
Increased EtCO2Increased EtCO2
Increased Metabolism
Pain
Hyperthermia
Malignant hyperthermia
Shivering
Circulatory System
Increased cardiac output with constant ventilation
Increased Metabolism
Pain
Hyperthermia
Malignant hyperthermia
Shivering
Circulatory System
Increased cardiac output with constant ventilation
Respiratory System
Respiratory insufficiency
Respiratory depression
Obstructive lung disease
Equipment
Defective exhalation valve
Exhausted CO2 absorber
Respiratory System
Respiratory insufficiency
Respiratory depression
Obstructive lung disease
Equipment
Defective exhalation valve
Exhausted CO2 absorber
Major Benefits in Pre-HospitalMajor Benefits in Pre-Hospital
Verifying ETT placement and continuous monitoring of position during transport
Cardiac ArrestEffectiveness of cardiac compression
Predictor of survival
Ventilation
Bronchospastic Disease
Verifying ETT placement and continuous monitoring of position during transport
Cardiac ArrestEffectiveness of cardiac compression
Predictor of survival
Ventilation
Bronchospastic Disease
Benefits in HospitalBenefits in Hospital
Verification of ETT placement and continuous monitoring
Cardiac Arrest
Ventilation
Procedural sedation
Verification of ETT placement and continuous monitoring
Cardiac Arrest
Ventilation
Procedural sedation
ETT DisplacementETT Displacement
Most likely occurs when patient is
moved
DislodgedDislodged
DislodgedDislodged
Right Main BronchiRight Main Bronchi
CPRCPR
Force, depth, and rate of chest compressionsForce, depth, and rate of chest compressions
4 5
0
100% mortality if unable to achieve an EtCO2 of 10 mm Hg after 20 minutes
CPRCPR
ROSCROSC
ROSCROSC
4 5
0
ROSC with NaHCO3ROSC with NaHCO3
CPRCPR
Positive pressure ventilation
Increased intrathoracic pressure
Pressure on Vena Cava, decreased preload
Increased RR does not allow for exhalation
Positive pressure ventilation
Increased intrathoracic pressure
Pressure on Vena Cava, decreased preload
Increased RR does not allow for exhalation
CPRCPR
Increased intrathoracic pressure leads to
Decrease in cardiac output, coronary artery perfusion, and CPP
Increased intrathoracic pressure leads to
Decrease in cardiac output, coronary artery perfusion, and CPP
Optimize VentilationOptimize Ventilation
Titrate carbon dioxide levels in patients sensitive to fluctuations
Head Injuries
Stroke
Brain tumors
Brain infections
Titrate carbon dioxide levels in patients sensitive to fluctuations
Head Injuries
Stroke
Brain tumors
Brain infections
Optimize VentilationOptimize Ventilation
Carbon dioxide affects cerebral blood flow (CBF)
Influencing intracranial pressureHypercapnia causes vasodilation
Hyperoxygenate, NOT hyperventilateHyperventilation does not improve oxygenation
Maintain CO2 of 35-40 mm Hg
Carbon dioxide affects cerebral blood flow (CBF)
Influencing intracranial pressureHypercapnia causes vasodilation
Hyperoxygenate, NOT hyperventilateHyperventilation does not improve oxygenation
Maintain CO2 of 35-40 mm Hg
HyperventilationHyperventilation
Hypocapnia < 35 mmHg
Normal range is 35-45 mm Hg (5% vol)
How would hyperventilation change the waveform? (26-30)
Frequency
Duration
Height
Shape
Hypocapnia < 35 mmHg
Normal range is 35-45 mm Hg (5% vol)
How would hyperventilation change the waveform? (26-30)
Frequency
Duration
Height
Shape
HyperventilationHyperventilation
45
0
HypoventilationHypoventilation
Hypercapnia > 45 mmHg
How would hypoventilation change the waveform? (4-12)
Frequency
Duration
Height
Shape
Hypercapnia > 45 mmHg
How would hypoventilation change the waveform? (4-12)
Frequency
Duration
Height
Shape
HypoventilationHypoventilation
45
0
Bronchospasm Bronchospasm
Alveoli unevenly ventilated on inspiration
Asynchronous emptying during expiration
Alters Phase II—“Shark Fin” shaped waveform
Alveoli unevenly ventilated on inspiration
Asynchronous emptying during expiration
Alters Phase II—“Shark Fin” shaped waveform
BronchospasmBronchospasm
45
0
Bronchospasm
BronchospasmBronchospasm
COPDCOPD
AsthmaAsthma
Initial
After therapy
PneumothoraxPneumothorax
Pulmonary EmbolismPulmonary Embolism
Hypercapnia/ RR~?Hypercapnia/ RR~?
15 Sec Triage Tool15 Sec Triage Tool
Rapidly assess pt
Toxins, chemical agents
Spontaneous respirations
Patent airway with adequate ventilation and perfusion
Most acute pts
Seizures
Rapidly assess pt
Toxins, chemical agents
Spontaneous respirations
Patent airway with adequate ventilation and perfusion
Most acute pts
Seizures
15 Sec Triage Tool15 Sec Triage Tool
Terrorism (BNICE)
Absorption skin and respiratory tract
Respiratory depression
Trends
Terrorism (BNICE)
Absorption skin and respiratory tract
Respiratory depression
Trends
Unresponsive patientsUnresponsive patients
6 year old female6 year old female
Status seizure
Found supine in bed with L disconjugate gaze
Unresponsive to stimuli
Vomiting
B/P- 136/66
HR- 136
RR- 40
Skin- warm, dry, acyanotic
Status seizure
Found supine in bed with L disconjugate gaze
Unresponsive to stimuli
Vomiting
B/P- 136/66
HR- 136
RR- 40
Skin- warm, dry, acyanotic
6 year old 6 year old
Tx pt to pram controlling airway
Supplemental O2
Unable to establish IV
Administer 5mg Valium PR
B/P- 108/70
HR- 116
RR- 36
Tx pt to pram controlling airway
Supplemental O2
Unable to establish IV
Administer 5mg Valium PR
B/P- 108/70
HR- 116
RR- 36
6 year old6 year old
Heent- ClrPerrlaChest = rise/fall w/clr BS B/LABD= sntPelvis= stableSmoeX4 w/o angulationBack ClrNo visual signs of Trauma
Heent- ClrPerrlaChest = rise/fall w/clr BS B/LABD= sntPelvis= stableSmoeX4 w/o angulationBack ClrNo visual signs of Trauma
6 year old6 year old
No recent medical hx or illnesses
NKDA
Clonidine for sleep aid at night
Capnographic waveform
No recent medical hx or illnesses
NKDA
Clonidine for sleep aid at night
Capnographic waveform
EtCO2: 50 RR: 36
Decreased Cardiac OutputDecreased Cardiac Output
94 y.o. Female
DNR
Respiratory distress
Skin- ashen, cool, dry
94 y.o. Female
DNR
Respiratory distress
Skin- ashen, cool, dry
HR: 31
EtCO2: 8
RR: 7
CaseCase
35 y.o. male
DK, combative
Possible OD
35 y.o. male
DK, combative
Possible OD
EtCO2: 34RR: 33
DocumentationDocumentation
Continuous waveform allows for legal documentation
Proof of correct tube placement, RR, EtCO2
Effectiveness of treatment in patient care, early detection of deterioration
Continuous waveform allows for legal documentation
Proof of correct tube placement, RR, EtCO2
Effectiveness of treatment in patient care, early detection of deterioration
The era is over when we can justify not knowing whether an ETT is in place or
not.
We may not be able to intubate everybody, but we must always know
when the tube is in place or not.
The era is over when we can justify not knowing whether an ETT is in place or
not.
We may not be able to intubate everybody, but we must always know
when the tube is in place or not.
Break TimeBreak Time
What is up coming and how Capnography will assist
What is up coming and how Capnography will assist
The newest phase in CPR Protocols.
How it will effect our decisions to work a patient or not.
The CPR first protocols.
Therapeutic Hypothermia.
The newest phase in CPR Protocols.
How it will effect our decisions to work a patient or not.
The CPR first protocols.
Therapeutic Hypothermia.
What is Therapeutic Hypothermia
What is Therapeutic Hypothermia
Is an evidence based change in Cardiac Arrest patients
This change effects treatment of the patient with a return to spontaneous pulses.
The studies show good stats that back up this method of treating patients
Is an evidence based change in Cardiac Arrest patients
This change effects treatment of the patient with a return to spontaneous pulses.
The studies show good stats that back up this method of treating patients
The European StudyThe European Study
This study was conducted in Nine hospitals and 5 countries.
The Study was performed completely random.
The patients were accepted into the study based on speed of response to V-fib arrest.
This study was conducted in Nine hospitals and 5 countries.
The Study was performed completely random.
The patients were accepted into the study based on speed of response to V-fib arrest.
The Australian studyThe Australian study
Less involved study.
This study took place in Melbourne and involved four hospitals
This study was done Pseudo random format with patients selected based on an odd or even day.
Less involved study.
This study took place in Melbourne and involved four hospitals
This study was done Pseudo random format with patients selected based on an odd or even day.
CriteriaCriteria
The patient to be accepted into the study had to be a persistent V-fib arrest and still in coma state u/a to hospital.The patient must have Resuscitation efforts performed by trained personnel within 5-15 minutes of collapse.The patient must also have ROSC in under sixty minutes. The patient must also be intubated and ventilated.
The patient to be accepted into the study had to be a persistent V-fib arrest and still in coma state u/a to hospital.The patient must have Resuscitation efforts performed by trained personnel within 5-15 minutes of collapse.The patient must also have ROSC in under sixty minutes. The patient must also be intubated and ventilated.
European Study ProceduresEuropean Study Procedures
The patient was cooled to 32 to 34 degrees Celsius.
This temp was reached in the first four hours of the resuscitation.
Pt was held at this temp for twenty four hours and then passively re-warmed.
The patient was cooled to 32 to 34 degrees Celsius.
This temp was reached in the first four hours of the resuscitation.
Pt was held at this temp for twenty four hours and then passively re-warmed.
Australian Study Australian Study
Pt. Accepted on the same criteria however it was based on if it was an odd or even day.
The pt were cooled to 33 degrees Celsius and kept there for 12 hours and the actively re-warmed after 18 hours.
Pt. Accepted on the same criteria however it was based on if it was an odd or even day.
The pt were cooled to 33 degrees Celsius and kept there for 12 hours and the actively re-warmed after 18 hours.
The Results and they were impressive!
The Results and they were impressive!
In the European Study 75 of 136 patients(55%) had a favorable neurological outcome.
In the normothermic patients the results were still good but not great at 39%
The Australian Study showed a 49% save rate in the hypothermic pt and a 26% in the normothermic pt.
In the European Study 75 of 136 patients(55%) had a favorable neurological outcome.
In the normothermic patients the results were still good but not great at 39%
The Australian Study showed a 49% save rate in the hypothermic pt and a 26% in the normothermic pt.
Why do this work?Why do this work?
The proof is in the pudding for its benefits.
However the actions is slightly more theoretical.
Fist is hypothermia lowers the cerebral metabolic rate for oxygen by 6% for every 1 degree C
Second hypothermia suppresses chemical reactions.
The proof is in the pudding for its benefits.
However the actions is slightly more theoretical.
Fist is hypothermia lowers the cerebral metabolic rate for oxygen by 6% for every 1 degree C
Second hypothermia suppresses chemical reactions.
If this so great why don’t we use it!
If this so great why don’t we use it!
Simple LogisticsThe patient once taken to the hypothermic state must remain there to have benefit. A Rolla coaster approach is not going to work. The equipment to do this efficiently and controlled is expensive but is expected to fall in price as it becomes more widely spread.
Simple LogisticsThe patient once taken to the hypothermic state must remain there to have benefit. A Rolla coaster approach is not going to work. The equipment to do this efficiently and controlled is expensive but is expected to fall in price as it becomes more widely spread.
1. Barton, C. & Wang, E. (1994). Correlation of End-Tidal CO2 Measurements to Arterial PaCO2 in Nonintubated Patients. Annals of Emergency Medicine, 23 (3): 561-562.
2. Bergenholtz, K.F., RN, MSN, CRNP-CS. (2004). Using and understanding Capnography. Microstream capnography solutions. [email protected].
3. Bhavani-Shankar, K., MD, Philip, JH. Defining segments and phases of a time capnogram. Anesthesiology Analg (2000). 91(4): 973-977.
4. Bhavani-Shankar, K., MD. http://capnography.com/
5. Falk, J.L., Rackow, E.C., Weil, M.H. End-tidal carbon dioxide concentration during cardiopulmonary resuscitation. New England Journal of Medicine (1998) 318(10): 607-611.
6. Fowler, Ray, MD, FACEP. www.rayfowler.com
7. Fowler, W.S. Lung Function studies, II. The respiratory deadspace. American Journal of Physiology. (1998) 154: 405-416.
8. Kanowitz, A., MD, FACEP, EMS Director, Arvada, CO. (2004). [Capnography in EMS]. Unpublished raw data.
References
8. Katz SH, Falk JL. Misplaced endotracheal tubes by paramedics in an urban emergency medical services system. Annals of Emergency Medicine (2001) 37(1): 32-37.
9. Medtronic Physio-Control Corporation (2005). http://www.healthcareeducation.org
9. Raff, Hershel, PhD, (2003). Physiology Secrets (2nd ed.) Philadelphia, PA: Hanley & Belfus.
10.Scanlon, V.C. & Sanders, T., (1999). Essentials of Anatomy and Physiology (3rd ed.) Philadelphia, PA: F.A. Davis Co.
11.Thompson, J.E., RRT, FAARC, Jaffe, M.B., PhD. (2005 Jan). Capnography waveforms in the mechanically ventilated patient. Respiratory Care. 50(1): 100-109.
12.Wik L, et al: “Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest.” JAMA. 293(3): 299-304, 2005.
13.Woodruff, D.W., RN, CNS, CCRN, MSN. (2006 Jan/Feb) Deciphering Diagnostics. Nursing made incredibly easy!, 4(1): 4-10.