CPAP (Continuous Positive Airway Pressure) Cardiogenic Pulmonary Edema.
Gold Cross Ambulance Continuous Positive Airway Pressure (CPAP) Airway Endorsement for EMT-Basic...
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Transcript of Gold Cross Ambulance Continuous Positive Airway Pressure (CPAP) Airway Endorsement for EMT-Basic...
Gold Cross Ambulance
Continuous Positive Airway Pressure(CPAP)
Airway Endorsement for EMT-Basic
Sheridan Memorial Hospital
Ruth Wyckoff, M.D.
21 January 2012
Outline1. Definition
2. Goals
3. Physiological effects
4. Delivery systems
5. Applications
6. Contraindications
7. Complications
Definition
• Pressurized method of noninvasive ventilation with or without mechanical assistance.
Goals
• Reduce pre-hospital intubations
• Increase functional residual capacity (FRC)
• Provide a stable airway pressure
• Decrease work of breathing (WOB)
Lung and Aveoli
Functional Residual Capacity (FRC)
• Definition: Volume of gas remaining in lungs after expiration
• CPAP prevents alveolar collapse on expiration
• Greater surface area improves gas exchange
Partial Pressure•The pressure of a gas mixture is equal to the sum of the partial pressures of its constituents.
•This allows oxygen into the blood during inspiration and CO2 out during expiration.
•Example : Air at sea level has a pressure of 1000cm H20.
•Air is 21% oxygen and 79% nitrogen and other gasses.
•partial pressure of oxygen is 1000 X 21% = 210cm H20
So why does oxygen pass into the blood?
Pressure Gradient
Deoxygenated blood has a lower partial pressure of oxygen than alveolar air so oxygen transfers from the air into the blood.
CPAP and Patient Airway Pressure
‘The application of positive airway pressure throughout the whole
respiratory cycle to spontaneously breathing patients.
7.5cm H20 CPAP•Atmospheric pressure can be expressed as 1000cm H2O
•7.5cm H2O CPAP increases the pressure of the alveolar air by approximately 1%.
•This increase in partial pressure ‘forces’ more oxygen into the blood.
•Even this comparatively small change is enough to make a clinical difference as CPAP alters the pressure gradient
ARDS
• CPAP overcomes inspiratory work imposed by auto-peep
• CPAP prevents airway collapse during exhalation
• CPAP improves arterial blood gas values
• CPAP may avoid intubation and mechanical ventilation (Miro 1993)
X-ray ARDS
13
Reducing fluid in the lungs
• CPAP decreases intra-alveolar fluid volume• Facilitates movement of water
• Move from less to more compliant• Improves oxygenation, compliance
Redistribution of extravascular pulmonary
fluid
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Pneumonia
16
Congestive Heart Failure (CHF)
• Definition: Interstitial fluid interferes with gas exchange = pulmonary edema • Increased myocardial workload• Higher O2 demands
Over age of 65 - 10/1000 patientAverage length of stay (LOS) = 6.7 daysThose intubated extend LOSIntubated pts have 4x mortality
Pulmonary Edema
Radiographic evidence
COPD and Asthma
• Both with increased WOB• Hypercapnia• Higher mortality with intubation• Difficulity to wean once intubated
Acute Respiratory Distress Syndrome (ARDS)
• Characteristics• Hypoxemia• Reduced compliance• Large intrapulmonary shunt
• CPAP in early stages may • Correct hypoxemia• Improve compliance• Reduce intrapulmonary shunt• (Schmidt 1975)
Essential Components Of A CPAP System
1. Flow generator
2. CPAP valve
Whisperflow Flow Generators
Caradyne Isobaric CPAP Valve
Patient Connections - Face Mask
The High Flow System In Operation
Air Supply In
Total Flow 60 L/min
Application of CPAP
Application Continued
CPAP System
Clinical Applications of CPAP
Condition Area for TreatmentARDS EmergencyCHF/Pulmonary edema EmergencyAcute Respiratory Failure EmergencyCOPD/Asthma EmergencyAnesthesia Pre OperativeAtelectasis ICU/General WardAlternative to Mechanical Ventilation ICU/General WardWeaning from Mechanical Ventilation ICU/General WardSleep Apnea Home
Contraindications
• Relative• Claustrophobia• Nasal Congestion• Mouth breathing
• Absolute• Cardiac/resp arrest• Hypotension• Need for emergent airway• Pneumothorax• Facial or neurological
injuries, deformities• Upper airway obstruction• High risk of aspiration• Unconscious
Common Complications With CPAP
• Irritation to skin and eyes • Nasal congestion• Dry nose, epistaxis• Sore throat• Barotrauma• Gastric distention• Reduced cardiac output• Hypoventilation
CPAP Training Flow Sheet
2 or more of the following Respiratory Distress Inclusion Criteria
-Retractions of accessory muscles-Brochospasm or Rales on Exam
-Respiratory Rate > 25/min.-O2 Sat. < 92% on high flow O2
Administer CPAP using Max FIO2
-Continue CPAP-Continue COPD/Asthma/Pulmonary Edema Protocol
-Contact Medical Control with a Report
-Contact Medical Control with report-Discontinue CPAP unless advised by Medical Control-Continue Asthma/COPD/Pulmonary Edema Protocols
Stable or Improving Reassess Patient Deteriorating
No Exclusion Criteria Present
-Respiratory/Cardiac Arrest-Pt.unable to follow commands
-Unable tp maintain patent airway independently-Major Trauma
-Suspicion of a Pneumothorax-Vomiting or Active GI Bleed
-Obvious signs/Symptoms of Pulmonary infection
,
Supporting Literature• JAMA December 28, 2005 “Noninvasive Ventilation
in Acute Cardiogenic Edema”, Massip et. al.• Meta-analysis with good to excellent data• 45% reduction in mortality• 60% reduction in need to intubate
• Kosowsky JM, et al. EMS transports for difficulty breathing: is there potential role for CPAP in prehospital setting?. Acad Emerg Med. 2000 Oct; 7(10) 1165.• Strict criteria but demonstrated small number of pts
benefit
Cont’d Literature
Reviews in Cardiovascular Medicine, vol. 3 supl. 4 2002, “Role of Noninvasive Ventilation in the Management of Acutely Decompensated Heart Failure”
“Though BLPAP has theoretical advantages over CPAP, there are questions regarding its safety in a setting of CHF. The Key to success in using NIV to treat severe CHF is proper patient selection, close patient monitoring, proper application of the technology, and objective therapeutic goals. When used appropriately, NIV can be a useful adjunct in the treatment of a subset of patients with acute CHF at risk for endotracheal intubation.”